Overview of NASA Electrified Aircraft Propulsion Research for Large Subsonic Transports

Science.gov (United States)

Jansen, Ralph H.; Bowman, Cheryl; Jankovsky, Amy; Dyson, Rodger; Felder, James L.

2017-01-01

NASA is investing in Electrified Aircraft Propulsion (EAP) research as part of the portfolio to improve the fuel efficiency, emissions, and noise levels in commercial transport aircraft. Turboelectric, partially turboelectric, and hybrid electric propulsion systems are the primary EAP configurations being evaluated for regional jet and larger aircraft. The goal is to show that one or more viable EAP concepts exist for narrow body aircraft and mature tall-pole technologies related to those concepts. A summary of the aircraft system studies, technology development, and facility development is provided. The leading concept for mid-term (2035) introduction of EAP for a single aisle aircraft is a tube and wing, partially turbo electric configuration (STARC-ABL), however other viable configurations exist. Investments are being made to raise the TRL level of light weight, high efficiency motors, generators, and electrical power distribution systems as well as to define the optimal turbine and boundary layer ingestion systems for a mid-term tube and wing configuration. An electric aircraft power system test facility (NEAT) is under construction at NASA Glenn and an electric aircraft control system test facility (HEIST) is under construction at NASA Armstrong. The correct building blocks are in place to have a viable, large plane EAP configuration tested by 2025 leading to entry into service in 2035 if the community chooses to pursue that goal.

Commercial Aircraft Development and the Export Market

Science.gov (United States)

Snodgrass, J.

1972-01-01

The various factors which endanger the future of commercial aircraft development are defined. The factors discussed are: (1) a decline in federally funded research and development programs, (2) a general decline in the economic health of the domestic airlines, (3) the increased cost of development which may be several times the net worth of the company, (4) the development overseas of common market and manufacturing consortia, and (5) foreign manufacturers receiving significant financial support from their national governments. It is stated that unless immediate and innovative solutions to combat these factors are found, the commercial aviation industry will be in serious difficulty.

COMMERCIAL SUPERSONIC TRANSPORT PROGRAM. PHASE II-C REPORT. HIGH STRENGTH STEEL EVALUATION FOR SUPERSONIC AIRCRAFT.

Science.gov (United States)

JET TRANSPORT AIRCRAFT, *AIRFRAMES, SUPERSONIC AIRCRAFT, STEEL , STRUCTURAL PROPERTIES, FRACTURE(MECHANICS), FATIGUE(MECHANICS), STRESS CORROSION...MICROPHOTOGRAPHY, HIGH TEMPERATURE, NICKEL ALLOYS, COBALT ALLOYS, CARBON, BAINITE , COMMERCIAL AIRCRAFT.

Commercial Aircraft Integrated Vehicle Health Management Study

Science.gov (United States)

Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Jones, Sharon Monica; Kurtoglu, Tolga; Leone, Karen M.; Sandifer, Carl E.; Thomas, Megan A.

2010-01-01

Statistical data and literature from academia, industry, and other government agencies were reviewed and analyzed to establish requirements for fixture work in detection, diagnosis, prognosis, and mitigation for IVHM related hardware and software. Around 15 to 20 percent of commercial aircraft accidents between 1988 and 2003 involved inalftfnctions or failures of some aircraft system or component. Engine and landing gear failures/malfunctions dominate both accidents and incidents. The IVI vl Project research technologies were found to map to the Joint Planning and Development Office's National Research and Development Plan (RDP) as well as the Safety Working Group's National Aviation Safety Strategic. Plan (NASSP). Future directions in Aviation Technology as related to IVHlvl were identified by reviewing papers from three conferences across a five year time span. A total of twenty-one trend groups in propulsion, aeronautics and aircraft categories were compiled. Current and ftiture directions of IVHM related technologies were gathered and classified according to eight categories: measurement and inspection, sensors, sensor management, detection, component and subsystem monitoring, diagnosis, prognosis, and mitigation.

Control Design for a Generic Commercial Aircraft Engine

Science.gov (United States)

Csank, Jeffrey; May, Ryan D.

2010-01-01

This paper describes the control algorithms and control design process for a generic commercial aircraft engine simulation of a 40,000 lb thrust class, two spool, high bypass ratio turbofan engine. The aircraft engine is a complex nonlinear system designed to operate over an extreme range of environmental conditions, at temperatures from approximately -60 to 120+ F, and at altitudes from below sea level to 40,000 ft, posing multiple control design constraints. The objective of this paper is to provide the reader an overview of the control design process, design considerations, and justifications as to why the particular architecture and limits have been chosen. The controller architecture contains a gain-scheduled Proportional Integral controller along with logic to protect the aircraft engine from exceeding any limits. Simulation results illustrate that the closed loop system meets the Federal Aviation Administration s thrust response requirements

Hull loss accident model for narrow body commercial aircraft

Directory of Open Access Journals (Sweden)

Somchanok Tiabtiamrat

2010-10-01

Full Text Available Accidents with narrow body aircraft were statistically evaluated covering six families of commercial aircraft includingBoeing B737, Airbus A320, McDonnell Douglas MD80, Tupolev TU134/TU154 and Antonov AN124. A risk indicator for eachflight phase was developed based on motion characteristics, duration time, and the presence of adverse weather conditions.The estimated risk levels based on these risk indicators then developed from the risk indicator. Regression analysis indicatedvery good agreement between the estimated risk level and the accident ratio of hull loss cases per number of delivered aircraft.The effect of time on the hull loss accident ratio per delivered aircraft was assessed for B737, A320 and MD80. Equationsrepresenting the effect of time on hull loss accident ratio per delivered aircraft were proposed for B737, A320, and MD80,while average values of hull loss accident ratio per delivered aircraft were found for TU134, TU154, and AN 124. Accidentprobability equations were then developed for each family of aircraft that the probability of an aircraft in a hull loss accidentcould be estimated for any aircraft family, flight phase, presence of adverse weather factor, hour of day, day of week, monthof year, pilot age, and pilot flight hour experience. A simplified relationship between estimated hull loss accident probabilityand unsafe acts by human was proposed. Numerical investigation of the relationship between unsafe acts by human andfatality ratio suggested that the fatality ratio in hull loss accident was dominated primarily by the flight phase media.

New entrants and overcapacity: lessons from regional aircraft manufacturing

NARCIS (Netherlands)

Steenhuis, H.J.; de Bruijn, E.J.; Heerkens, Johannes M.G.

2010-01-01

The commercial aircraft manufacturing industry has been largely dominated by the advanced economies in North America and Western Europe. During recent decades, several emerging economies have invested heavily in the commercial aircraft industry, notably in regional aircraft manufacturing. This paper

36 CFR 293.6 - Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft...

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Commercial enterprises, roads..., DEPARTMENT OF AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.6 Commercial enterprises, roads, motor vehicles... National Forest Wilderness no commercial enterprises; no temporary or permanent roads; no aircraft landing...

50 CFR 35.5 - Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft...

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Commercial enterprises, roads, motor... Rules § 35.5 Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft... private rights, there shall be no commercial enterprise and no permanent road within a wilderness unit...

REQUIREMENT VERIFICATION AND SYSTEMS ENGINEERING TECHNICAL REVIEW (SETR) ON A COMMERCIAL DERIVATIVE AIRCRAFT (CDA) PROGRAM

Science.gov (United States)

2017-09-01

VERIFICATION AND SYSTEMS ENGINEERING TECHNICAL REVIEW (SETR) ON A COMMERCIAL DERIVATIVE AIRCRAFT (CDA) PROGRAM by Theresa L. Thomas September... ENGINEERING TECHNICAL REVIEW (SETR) ON A COMMERCIAL DERIVATIVE AIRCRAFT (CDA) PROGRAM 5. FUNDING NUMBERS 6. AUTHOR(S) Theresa L. Thomas 7...CODE 13. ABSTRACT (maximum 200 words) The Naval Air Systems Command (NAVAIR) systems engineering technical review (SETR) process does not

Study of advanced fuel system concepts for commercial aircraft and engines

Science.gov (United States)

Versaw, E. F.; Brewer, G. D.; Byers, W. D.; Fogg, H. W.; Hanks, D. E.; Chirivella, J.

1983-01-01

The impact on a commercial transport aircraft of using fuels which have relaxed property limits relative to current commercial jet fuel was assessed. The methodology of the study is outlined, fuel properties are discussed, and the effect of the relaxation of fuel properties analyzed. Advanced fuel system component designs that permit the satisfactory use of fuel with the candidate relaxed properties in the subject aircraft are described. The two fuel properties considered in detail are freezing point and thermal stability. Three candidate fuel system concepts were selected and evaluated in terms of performance, cost, weight, safety, and maintainability. A fuel system that incorporates insulation and electrical heating elements on fuel tank lower surfaces was found to be most cost effective for the long term.

Durability of commercial aircraft and helicopter composite structures

International Nuclear Information System (INIS)

Dexter, H.B.

1982-01-01

The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified

Durability of commercial aircraft and helicopter composite structures

Science.gov (United States)

Dexter, H. B.

1982-01-01

The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified.

Detecting the Use of Intentionally Transmitting Personal Electronic Devices Onboard Commercial Aircraft

Science.gov (United States)

Woods, Randy; Ely, Jay J.; Vahala, Linda

2003-01-01

The need to detect unauthorized usage of intentionally transmitting portable electronic devices (PEDs) onboard commercial aircraft is growing, while still allowing passengers to use selected unintentionally transmitting devices, such as laptop computers and CD players during non-critical stages of flight. The following paper presents an installed system for detecting PEDs over multiple frequency bands. Additionally, the advantages of a fixed verses mobile system are discussed. While data is presented to cover the frequency range of 20 MHz to 6.5 GHz, special attention was given to the Cellular/PCS bands as well as Bluetooth and the FRS radio bands. Measurement data from both the semi-anechoic and reverberation chambers are then analyzed and correlated with data collected onboard a commercial aircraft to determine the dominant mode of coupling inside the passenger cabin of the aircraft versus distance from the source. As a final check of system feasibility, several PEDs transmission signatures were recorded and compared with the expected levels.

Study of advanced fuel system concepts for commercial aircraft

Science.gov (United States)

Coffinberry, G. A.

1985-01-01

An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broadened property fuels. The DC-10-30 wide-body tri-jet aircraft and the CF6-8OX engine were used as a baseline design for the study. Three advanced systems were considered and were specifically aimed at addressing freezing point, thermal stability and lubricity fuel properties. Actual DC-10-30 routes and flight profiles were simulated by computer modeling and resulted in prediction of aircraft and engine fuel system temperatures during a nominal flight and during statistical one-day-per-year cold and hot flights. Emergency conditions were also evaluated. Fuel consumption and weight and power extraction results were obtained. An economic analysis was performed for new aircraft and systems. Advanced system means for fuel tank heating included fuel recirculation loops using engine lube heat and generator heat. Environmental control system bleed air heat was used for tank heating in a water recirculation loop. The results showed that fundamentally all of the three advanced systems are feasible but vary in their degree of compatibility with broadened-property fuel.

Characterization and manufacture of braided composites for large commercial aircraft structures

Science.gov (United States)

Fedro, Mark J.; Willden, Kurtis

1992-01-01

Braided composite materials, one of the advanced material forms which is under investigation in Boeing's ATCAS program, have been recognized as a potential cost-effective material form for fuselage structural elements. Consequently, there is a strong need for more knowledge in the design, manufacture, test, and analysis of textile structural composites. The overall objective of this work is to advance braided composite technology towards applications to a large commercial transport fuselage. This paper summarizes the mechanics of materials and manufacturing demonstration results which have been obtained in order to acquire an understanding of how braided composites can be applied to a commercial fuselage. Textile composites consisting of 1D, 2D triaxial, and 3D braid patterns with thermoplastic and two RTM resin systems were investigated. The structural performance of braided composites was evaluated through an extensive mechanical test program. Analytical methods were also developed and applied to predict the following: internal fiber architectures, stiffnesses, fiber stresses, failure mechanisms, notch effects, and the entire history of failure of the braided composites specimens. The applicability of braided composites to a commercial transport fuselage was further assessed through a manufacturing demonstration. Three foot fuselage circumferential hoop frames were manufactured to demonstrate the feasibility of consistently producing high quality braided/RTM composite primary structures. The manufacturing issues (tooling requirements, processing requirements, and process/quality control) addressed during the demonstration are summarized. The manufacturing demonstration in conjunction with the mechanical test results and developed analytical methods increased the confidence in the ATCAS approach to the design, manufacture, test, and analysis of braided composites.

TEPC measurements in commercial aircraft

International Nuclear Information System (INIS)

Taylor, G. C.; Bentley, R. D.; Horwood, N. A.; Hunter, R.; Iles, R. H.; Jones, J. B. L.; Powell, D.; Thomas, D. J.

2004-01-01

The collaborative project involving the Mullard Space Science Laboratory (MSSL), Virgin Atlantic Airways (VAA), the UK Civil Aviation Authority (CAA) and the UK National Physical Laboratory (NPL) has been performing tissue-equivalent proportional counter measurements of cosmic ray doses in commercial aircraft since January 2000. In that time data have been recorded on over 700 flights, including over 150 flights with Air New Zealand (ANZ). This substantial set of data from the southern hemisphere is an ideal complement to the London-based measurements performed primarily on VAA flights. Although some ANZ data remains to be analysed, dose information from 111 flights has been compared with the CARI and EPCARD computer codes. Overall, the agreement between the measurements and EPCARD was excellent (within 1% for the total ambient dose equivalent), and the difference in the total effective doses predicted by EPCARD and CARI was <5%. (authors)

Nuclear containment structure subjected to commercial and fighter aircraft crash

International Nuclear Information System (INIS)

Sadique, M.R.; Iqbal, M.A.; Bhargava, P.

2013-01-01

Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment

Nuclear containment structure subjected to commercial and fighter aircraft crash

Energy Technology Data Exchange (ETDEWEB)

Sadique, M.R., E-mail: rehan.sadique@gmail.com; Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in; Bhargava, P., E-mail: bhpdpfce@iitr.ernet.in

2013-07-15

Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment.

COMPARISON OF COSMIC RAYS RADIATION DETECTORS ON-BOARD COMMERCIAL JET AIRCRAFT

Czech Academy of Sciences Publication Activity Database

Kubančák, Ján; Ambrožová, Iva; Pachnerová Brabcová, Kateřina; Jakoubek, J.; Kyselová, D.; Ploc, Ondřej; Bemš, J.; Štěpán, Václav; Uchihori, Y.

2015-01-01

Roč. 164, č. 4 (2015), s. 484-488 ISSN 0144-8420 R&D Projects: GA MŠk(CZ) LG13031 Institutional support: RVO:61389005 Keywords : cosmic radiation * commercial jet aircraft * radiation dose Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.894, year: 2015

Emergency Flight Control of a Twin-Jet Commercial Aircraft using Manual Throttle Manipulation

Science.gov (United States)

Cole, Jennifer H.; Cogan, Bruce R.; Fullerton, C. Gordon; Burken, John J.; Venti, Michael W.; Burcham, Frank W.

2007-01-01

The Department of Homeland Security (DHS) created the PCAR (Propulsion-Controlled Aircraft Recovery) project in 2005 to mitigate the ManPADS (man-portable air defense systems) threat to the commercial aircraft fleet with near-term, low-cost proven technology. Such an attack could potentially cause a major FCS (flight control system) malfunction or other critical system failure onboard the aircraft, despite the extreme reliability of current systems. For the situations in which nominal flight controls are lost or degraded, engine thrust may be the only remaining means for emergency flight control [ref 1]. A computer-controlled thrust system, known as propulsion-controlled aircraft (PCA), was developed in the mid 1990s with NASA, McDonnell Douglas and Honeywell. PCA's major accomplishment was a demonstration of an automatic landing capability using only engine thrust [ref 11. Despite these promising results, no production aircraft have been equipped with a PCA system, due primarily to the modifications required for implementation. A minimally invasive option is TOC (throttles-only control), which uses the same control principles as PCA, but requires absolutely no hardware, software or other aircraft modifications. TOC is pure piloting technique, and has historically been utilized several times by flight crews, both military and civilian, in emergency situations stemming from a loss of conventional control. Since the 1990s, engineers at NASA Dryden Flight Research Center (DFRC) have studied TOC, in both simulation and flight, for emergency flight control with test pilots in numerous configurations. In general, it was shown that TOC was effective on certain aircraft for making a survivable landing. DHS sponsored both NASA Dryden Flight Research Center (Edwards, CA) and United Airlines (Denver, Colorado) to conduct a flight and simulation study of the TOC characteristics of a twin-jet commercial transport, and assess the ability of a crew to control an aircraft down to

Fuel cell APU for commercial aircraft

Energy Technology Data Exchange (ETDEWEB)

Daggett, D.L. [Boeing Commercial Airplane, Seattle, WA (United States); Lowery, N. [Princeton Univ., Princeton, NJ (United States); Wittmann, J. [Technische Univ. Muenchen (Germany)

2005-07-01

The Boeing Company has always sought to improve fuel efficiency in commercial aircraft. An opportunity now exists to explore technology that will allow fuel efficiency improvements to be achieved while simultaneously reducing emissions. Replacing the current aircraft gas turbine-powered Auxiliary Power Unit with a hybrid Solid Oxide Fuel Cell is anticipated to greatly improve fuel efficiency, reduce emissions and noise as well as improve airplane performance. However, there are several technology hurdles that need to be overcome. If SOFC technology is to be matured for the betterment of the earth community, the fuel cell industry, aerospace manufacturers and other end users all need to work together to overcome these challenges. Aviation has many of the same needs in fuel cell technology as other sectors, such as reducing cost and improving reliability and fuel efficiency in order to commercialize the technology. However, there are other distinct aerospace needs that will not necessarily be addressed by the industrial sector. These include development of lightweight materials and small-volume fuel cell systems that can reform hydrocarbon fuels. Aviation also has higher levels of safety requirements. Other transportation modes share the same requirement for vibration and shock tolerant fuel cell stacks. Lastly, as fuel cells are anticipated to be operated in flight, they must be capable of operating over a wide range of atmospheric conditions. By itself, the aviation sector does not appear to offer enough of a potential market to justify the investment required by any one manufacturer to develop fuel cells for APU replacements. Therefore, means must be found to modularize components and make SOFC stacks sufficiently similar to industrial units so that manufacturing economy of scales can be brought to bear. Government R and D and industry support are required to advance the technology. Because aerospace fuel cells will be higher performing units, the benefits of

Synthetic Vision System Commercial Aircraft Flight Deck Display Technologies for Unusual Attitude Recovery

Science.gov (United States)

Prinzel, Lawrence J., III; Ellis, Kyle E.; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel

2017-01-01

A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that the lack of external visual references was associated with a flight crew's loss of attitude awareness or energy state awareness in 17 of these events. Therefore, CAST recommended development and implementation of virtual day-Visual Meteorological Condition (VMC) display systems, such as synthetic vision systems, which can promote flight crew attitude awareness similar to a day-VMC environment. This paper describes the results of a high-fidelity, large transport aircraft simulation experiment that evaluated virtual day-VMC displays and a "background attitude indicator" concept as an aid to pilots in recovery from unusual attitudes. Twelve commercial airline pilots performed multiple unusual attitude recoveries and both quantitative and qualitative dependent measures were collected. Experimental results and future research directions under this CAST initiative and the NASA "Technologies for Airplane State Awareness" research project are described.

Comparison of cosmic rays radiation detectors on-board commercial jet aircraft.

Science.gov (United States)

Kubančák, Ján; Ambrožová, Iva; Brabcová, Kateřina Pachnerová; Jakůbek, Jan; Kyselová, Dagmar; Ploc, Ondřej; Bemš, Július; Štěpán, Václav; Uchihori, Yukio

2015-06-01

Aircrew members and passengers are exposed to increased rates of cosmic radiation on-board commercial jet aircraft. The annual effective doses of crew members often exceed limits for public, thus it is recommended to monitor them. In general, the doses are estimated via various computer codes and in some countries also verified by measurements. This paper describes a comparison of three cosmic rays detectors, namely of the (a) HAWK Tissue Equivalent Proportional Counter; (b) Liulin semiconductor energy deposit spectrometer and (c) TIMEPIX silicon semiconductor pixel detector, exposed to radiation fields on-board commercial Czech Airlines company jet aircraft. Measurements were performed during passenger flights from Prague to Madrid, Oslo, Tbilisi, Yekaterinburg and Almaty, and back in July and August 2011. For all flights, energy deposit spectra and absorbed doses are presented. Measured absorbed dose and dose equivalent are compared with the EPCARD code calculations. Finally, the advantages and disadvantages of all detectors are discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Integrated Design of a Long-Haul Commercial Aircraft Optimized for Formation Flying

NARCIS (Netherlands)

Dijkers, H.P.A.; Van Nunen, R.; Bos, D.A.; Gutleb, T.L.M.; Herinckx, L.E.; Radfar, H.; Van Rompuy, E.; Sayin, S.E.; De Wit, J.; Beelaerts van Blokland, W.W.A.

2011-01-01

The airline industry is under continuous pressure to reduce emissions and costs. This paper investigates the feasibility for commercial airlines to use formation flight to reduce emissions and fuel burn. To fly in formation, an aircraft needs to benefit from the wake vortices of the preceding

Automated meteorological data from commercial aircraft via satellite: Present experience and future implications

Science.gov (United States)

Steinberg, R.

1978-01-01

A low-cost communications system to provide meteorological data from commercial aircraft, in neat real-time, on a fully automated basis has been developed. The complete system including the low profile antenna and all installation hardware weighs 34 kg. The prototype system was installed on a B-747 aircraft and provided meteorological data (wind angle and velocity, temperature, altitude and position as a function of time) on a fully automated basis. The results were exceptional. This concept is expected to have important implications for operational meteorology and airline route forecasting.

Fuel containment, lightning protection and damage tolerance in large composite primary aircraft structures

Science.gov (United States)

Griffin, Charles F.; James, Arthur M.

1985-01-01

The damage-tolerance characteristics of high strain-to-failure graphite fibers and toughened resins were evaluated. Test results show that conventional fuel tank sealing techniques are applicable to composite structures. Techniques were developed to prevent fuel leaks due to low-energy impact damage. For wing panels subjected to swept stroke lightning strikes, a surface protection of graphite/aluminum wire fabric and a fastener treatment proved effective in eliminating internal sparking and reducing structural damage. The technology features developed were incorporated and demonstrated in a test panel designed to meet the strength, stiffness, and damage tolerance requirements of a large commercial transport aircraft. The panel test results exceeded design requirements for all test conditions. Wing surfaces constructed with composites offer large weight savings if design allowable strains for compression can be increased from current levels.

Methodology to estimate particulate matter emissions from certified commercial aircraft engines.

Science.gov (United States)

Wayson, Roger L; Fleming, Gregg G; Lovinelli, Ralph

2009-01-01

Today, about one-fourth of U.S. commercial service airports, including 41 of the busiest 50, are either in nonattainment or maintenance areas per the National Ambient Air Quality Standards. U.S. aviation activity is forecasted to triple by 2025, while at the same time, the U.S. Environmental Protection Agency (EPA) is evaluating stricter particulate matter (PM) standards on the basis of documented human health and welfare impacts. Stricter federal standards are expected to impede capacity and limit aviation growth if regulatory mandated emission reductions occur as for other non-aviation sources (i.e., automobiles, power plants, etc.). In addition, strong interest exists as to the role aviation emissions play in air quality and climate change issues. These reasons underpin the need to quantify and understand PM emissions from certified commercial aircraft engines, which has led to the need for a methodology to predict these emissions. Standardized sampling techniques to measure volatile and nonvolatile PM emissions from aircraft engines do not exist. As such, a first-order approximation (FOA) was derived to fill this need based on available information. FOA1.0 only allowed prediction of nonvolatile PM. FOA2.0 was a change to include volatile PM emissions on the basis of the ratio of nonvolatile to volatile emissions. Recent collaborative efforts by industry (manufacturers and airlines), research establishments, and regulators have begun to provide further insight into the estimation of the PM emissions. The resultant PM measurement datasets are being analyzed to refine sampling techniques and progress towards standardized PM measurements. These preliminary measurement datasets also support the continued refinement of the FOA methodology. FOA3.0 disaggregated the prediction techniques to allow for independent prediction of nonvolatile and volatile emissions on a more theoretical basis. The Committee for Aviation Environmental Protection of the International Civil

Impact of Decision Criteria on Federal Aviation Administration Certification of Military Commercial Derivative Aircraft

Science.gov (United States)

2012-03-01

Capt Low was a member of the Sigma Iota Epsilon professional management fraternity. He has performed as an on-equipment and off-equipment...FAA Certification, Military Commercial Derivative Aircraft, Multi-Attribute Decision Making 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

Estimation of nuclear power plant aircraft hazards

International Nuclear Information System (INIS)

Gottlieb, P.

1978-01-01

The standard procedures for estimating aircraft risk to nuclear power plants provide a conservative estimate, which is adequate for most sites, which are not close to airports or heavily traveled air corridors. For those sites which are close to facilities handling large numbers of aircraft movements (airports or corridors), a more precise estimate of aircraft impact frequency can be obtained as a function of aircraft size. In many instances the very large commercial aircraft can be shown to have an acceptably small impact frequency, while the very small general aviation aircraft will not produce sufficiently serious impact to impair the safety-related functions. This paper examines the in between aircraft: primarily twin-engine, used for business, pleasure, and air taxi operations. For this group of aircraft the total impact frequency was found to be approximately once in one million years, the threshold above which further consideration of specific safety-related consequences would be required

Vehicle Design Evaluation Program (VDEP). A computer program for weight sizing, economic, performance and mission analysis of fuel-conservative aircraft, multibodied aircraft and large cargo aircraft using both JP and alternative fuels

Science.gov (United States)

Oman, B. H.

1977-01-01

The NASA Langley Research Center vehicle design evaluation program (VDEP-2) was expanded by (1) incorporating into the program a capability to conduct preliminary design studies on subsonic commercial transport type aircraft using both JP and such alternate fuels as hydrogen and methane;(2) incorporating an aircraft detailed mission and performance analysis capability; and (3) developing and incorporating an external loads analysis capability. The resulting computer program (VDEP-3) provides a preliminary design tool that enables the user to perform integrated sizing, structural analysis, and cost studies on subsonic commercial transport aircraft. Both versions of the VDEP-3 Program which are designated preliminary Analysis VDEP-3 and detailed Analysis VDEP utilize the same vehicle sizing subprogram which includes a detailed mission analysis capability, as well as a geometry and weight analysis for multibodied configurations.

In-service inspection methods for graphite-epoxy structures on commercial transport aircraft

Science.gov (United States)

Phelps, M. L.

1981-01-01

In-service inspection methods for graphite-epoxy composite structures on commercial transport aircraft are determined. Graphite/epoxy structures, service incurred defects, current inspection practices and concerns of the airline and manufacturers, and other related information were determind by survey. Based on this information, applicable inspection nondestructive inspection methods are evaluated and inspection techniques determined. Technology is developed primarily in eddy current inspection.

Automated meteorological data from commercial aircraft via satellite - Present experience and future implications

Science.gov (United States)

Steinberg, R.

1978-01-01

The National Aeronautics and Space Administration has developed a low-cost communications system to provide meteorological data from commercial aircraft, in near real-time, on a fully automated basis. The complete system including the low profile antenna and all installation hardware weighs 34 kg. The prototype system has been installed on a Pan American B-747 aircraft and has been providing meteorological data (wind angle and velocity, temperature, altitude and position as a function of time) on a fully automated basis for the past several months. The results have been exceptional. This concept is expected to have important implications for operational meteorology and airline route forecasting.

Alternate Fuels for Use in Commercial Aircraft

Science.gov (United States)

Daggett, David L.; Hendricks, Robert C.; Walther, Rainer; Corporan, Edwin

2008-01-01

The engine and aircraft Research and Development (R&D) communities have been investigating alternative fueling in near-term, midterm, and far-term aircraft. A drop in jet fuel replacement, consisting of a kerosene (Jet-A) and synthetic fuel blend, will be possible for use in existing and near-term aircraft. Future midterm aircraft may use a biojet and synthetic fuel blend in ultra-efficient airplane designs. Future far-term engines and aircraft in 50-plus years may be specifically designed to use a low- or zero-carbon fuel. Synthetic jet fuels from coal, natural gas, or other hydrocarbon feedstocks are very similar in performance to conventional jet fuel, yet the additional CO2 produced during the manufacturing needs to be permanently sequestered. Biojet fuels need to be developed specifically for jet aircraft without displacing food production. Envisioned as midterm aircraft fuel, if the performance and cost liabilities can be overcome, biofuel blends with synthetic jet or Jet-A fuels have near-term potential in terms of global climatic concerns. Long-term solutions address dramatic emissions reductions through use of alternate aircraft fuels such as liquid hydrogen or liquid methane. Either of these new aircraft fuels will require an enormous change in infrastructure and thus engine and airplane design. Life-cycle environmental questions need to be addressed.

Stability Result For Dynamic Inversion Devised to Control Large Flexible Aircraft

Science.gov (United States)

Gregory, Irene M.

2001-01-01

High performance aircraft of the future will be designed lighter, more maneuverable, and operate over an ever expanding flight envelope. One of the largest differences from the flight control perspective between current and future advanced aircraft is elasticity. Over the last decade, dynamic inversion methodology has gained considerable popularity in application to highly maneuverable fighter aircraft, which were treated as rigid vehicles. This paper is an initial attempt to establish global stability results for dynamic inversion methodology as applied to a large, flexible aircraft. This work builds on a previous result for rigid fighter aircraft and adds a new level of complexity that is the flexible aircraft dynamics, which cannot be ignored even in the most basic flight control. The results arise from observations of the control laws designed for a new generation of the High-Speed Civil Transport aircraft.

Aero-Propulsive Model Design from a Commercial Aircraft in Climb and Cruise Regime using Performance Data =

Science.gov (United States)

Tudor, Magdalena

IATA has estimated, in 2012, at about 2% of global carbon dioxide emissions, the environmental impact of the air transport, as a consequence caused by the rapidly growing of global movement demand of people and goods, and which was effectively taken into account in the development of the aviation industry. The historic achievements of scientific and technical progress in the field of commercial aviation were contributed to this estimate, and even today the research continues to make progress to help to reduce the emissions of greenhouse gases. Advances in commercial aircraft, and its engine design technology had the aim to improve flight performance. These improvements have enhanced the global flight planning of these types of aircrafts. Almost all of these advances rely on generated performance data as reference sources, the most of which are classified as "confidential" by the aircraft manufacturers. There are very few aero-propulsive models conceived for the climb regime in the literature, but none of them was designed without access to an engine database, and/or to performance data in climb and in cruise regimes with direct applicability for flight optimization. In this thesis, aero-propulsive models methodologies are proposed for climb and cruise regimes, using system identification and validation methods, through which airplane performance can be computed and stored in the most compact and easily accessible format for this kind of performance data. The acquiring of performance data in this format makes it possible to optimize flight profiles, used by on-board Flight Management Systems. The aero-propulsive models developed here were investigated on two aircrafts belonging to commercial class, and both of them had offered very good accuracy. One of their advantages is that they can be adapted to any other aircraft of the same class, even if there is no access to their corresponding engine flight data. In addition, these models could save airlines a considerable

Impact of New large Aircraft on Airport Design

Science.gov (United States)

1998-03-01

The object of this project is to assess the impact of the introduction of proposed new large aircraft (NLA) on current airport design standards and administered by the Federal Aviation Administration (FAA). This report identifies several key design a...

Modeling flight attendants' exposure to secondhand smoke in commercial aircraft: historical trends from 1955 to 1989.

Science.gov (United States)

Liu, Ruiling; Dix-Cooper, Linda; Hammond, S Katharine

2015-01-01

Flight attendants were exposed to elevated levels of secondhand smoke (SHS) in commercial aircraft when smoking was allowed on planes. During flight attendants' working years, their occupational SHS exposure was influenced by various factors, including the prevalence of active smokers on planes, fliers' smoking behaviors, airplane flight load factors, and ventilation systems. These factors have likely changed over the past six decades and would affect SHS concentrations in commercial aircraft. However, changes in flight attendants' exposure to SHS have not been examined in the literature. This study estimates the magnitude of the changes and the historic trends of flight attendants' SHS exposure in U.S. domestic commercial aircraft by integrating historical changes of contributing factors. Mass balance models were developed and evaluated to estimate flight attendants' exposure to SHS in passenger cabins, as indicated by two commonly used tracers (airborne nicotine and particulate matter (PM)). Monte Carlo simulations integrating historical trends and distributions of influence factors were used to simulate 10,000 flight attendants' exposure to SHS on commercial flights from 1955 to 1989. These models indicate that annual mean SHS PM concentrations to which flight attendants were exposed in passenger cabins steadily decreased from approximately 265 μg/m(3) in 1955 and 1960 to 93 μg/m(3) by 1989, and airborne nicotine exposure among flight attendants also decreased from 11.1 μg/m(3) in 1955 to 6.5 μg/m(3) in 1989. Using duration of employment as an indicator of flight attendants' cumulative occupational exposure to SHS in epidemiological studies would inaccurately assess their lifetime exposures and thus bias the relationship between the exposure and health effects. This historical trend should be considered in future epidemiological studies.

Insecticide Exposures on Commercial Aircraft: A Literature Review and Screening Level Assessment

Energy Technology Data Exchange (ETDEWEB)

Maddalena, Randy I.; McKone, Thomas E.

2008-10-01

The objective of this project was to provide initial estimates of the relationship between insecticide use on passenger aircraft and exposure levels present in the cabin environment. The work was initially divided into three tasks including 1) a review of insecticide application practices in commercial aircraft, 2) exploratory measurements of insecticide concentrations in treated aircraft and 3) screening level exposure modeling. Task 1 gathered information that is needed to assess the time-concentration history of insecticides in the airline cabin. The literature review focused on application practices, information about the cabin environment and existing measurements of exposure concentrations following treatment. Information from the airlines was not available for estimating insecticide application rates in the U.S. domestic fleet or for understanding how frequently equipment rotate into domestic routes following insecticide treatment. However, the World Health Organization (WHO) recommends several methods for treating aircraft with insecticide. Although there is evidence that these WHO guidelines may not always be followed, and that practices vary by airline, destination, and/or applicator company, the guidelines in combination with information related to other indoor environments provides a plausible basis for estimating insecticide loading rates on aircraft. The review also found that while measurements of exposure concentrations following simulated aerosol applications are available, measurements following residual treatment of aircraft or applications in domestic aircraft are lacking. Task 2 focused on developing an approach to monitor exposure concentrations in aircraft using a combination of active and passive sampling methods. An existing active sampling approach was intended to provide data immediately following treatment while a passive sampler was developed to provide wider coverage of the fleet over longer sampling periods. The passive sampler, based

Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

Science.gov (United States)

Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

2016-04-15

This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. Copyright © 2015 Elsevier B.V. All rights reserved.

Commercial Aircraft Protection

Energy Technology Data Exchange (ETDEWEB)

Ehst, David A. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-10-26

This report summarizes the results of theoretical research performed during 3 years of P371 Project implementation. In results of such research a new scientific conceptual technology of quasi-passive individual infrared protection of heat-generating objects – Spatial Displacement of Thermal Image (SDTI technology) was developed. Theoretical substantiation and description of working processes of civil aircraft individual IR-protection system were conducted. The mathematical models and methodology were presented, there were obtained the analytical dependencies which allow performing theoretical research of the affect of intentionally arranged dynamic field of the artificial thermal interferences with variable contrast onto main parameters of optic-electronic tracking and homing systems.

Deaths and injuries as a result of lightning strikes to aircraft.

Science.gov (United States)

Cherington, M; Mathys, K

1995-07-01

Aircraft are at risk of being struck by lightning or triggering lightning as they fly through clouds. Commercial and private airplanes have been struck, with resultant deaths and injuries to passengers and crew. We were interested in learning how large a problem existed to the American public from lightning strikes to airplanes. We analyzed data from the National Transportation Safety Board (NTSB) on lightning-related accidents in the United States from 1963-89. NTSB recorded 40 lightning-related aircraft accidents. There were 10 commercial airplane accidents reported, 4 of which were associated with 260 fatalities and 28 serious injuries. There were 30 private aircraft accidents that accounted for 30 fatalities and 46 serious injuries. While lightning remains a potential risk to aircraft passengers and crew, modern airplanes are better equipped to lessen the dangers of accidents due to lightning.

Investigation of incidents of terrorism involving commercial aircraft.

Science.gov (United States)

Clark, M A; Wagner, G N; Wright, D G; Ruehle, C J; McDonnell, E W

1989-07-01

Deaths resulting from terrorism involving aircraft have occurred incident to hijackings as well as bombings. Passengers or groups of passengers have been chosen by terrorists as the recipients of violence based on citizenship, religion, and political beliefs. They have usually been segregated from other passengers and subsequently mistreated and/or murdered. Thorough documentation of the injuries of victims is essential to the investigation of such atrocities; a medicolegal autopsy correlated with a scene investigation is of paramount importance. Aircraft bombings can create extremely sensitive political situations and public demands for quick resolution. The autopsy of victims in such circumstances, if properly conducted, can yield invaluable trace evidence leading to the identification of the explosive device. The examination of any surviving victims as well as the aircraft is also critical in reconstructing the event. Deaths occurring as the result of in-flight aircraft bombings can produce injuries by five different mechanisms, viz. blast, shrapnel, decompression, impact with the aircraft, and ground impact.

Integration of structural health monitoring solutions onto commercial aircraft via the Federal Aviation Administration structural health monitoring research program

Science.gov (United States)

Swindell, Paul; Doyle, Jon; Roach, Dennis

2017-02-01

The Federal Aviation Administration (FAA) started a research program in structural health monitoring (SHM) in 2011. The program's goal was to understand the technical gaps of implementing SHM on commercial aircraft and the potential effects on FAA regulations and guidance. The program evolved into a demonstration program consisting of a team from Sandia National Labs Airworthiness Assurance NDI Center (AANC), the Boeing Corporation, Delta Air Lines, Structural Monitoring Systems (SMS), Anodyne Electronics Manufacturing Corp (AEM) and the FAA. This paper will discuss the program from the selection of the inspection problem, the SHM system (Comparative Vacuum Monitoring-CVM) that was selected as the inspection solution and the testing completed to provide sufficient data to gain the first approved use of an SHM system for routine maintenance on commercial US aircraft.

Characterization of the frequency and nature of bleed air contamination events in commercial aircraft.

Science.gov (United States)

Shehadi, M; Jones, B; Hosni, M

2016-06-01

Contamination of the bleed air used to pressurize and ventilate aircraft cabins is of concern due to the potential health and safety hazards for passengers and crew. Databases from the Federal Aviation Administration, NASA, and other sources were examined in detail to determine the frequency of bleed air contamination incidents. The frequency was examined on an aircraft model basis with the intent of identifying aircraft make and models with elevated frequencies of contamination events. The reported results herein may help investigators to focus future studies of bleed air contamination incidents on smaller number of aircrafts. Incident frequency was normalized by the number of aircraft, number of flights, and flight hours for each model to account for the large variations in the number of aircraft of different models. The focus of the study was on aircraft models that are currently in service and are used by major airlines in the United States. Incidents examined in this study include those related to smoke, oil odors, fumes, and any symptom that might be related to exposure to such contamination, reported by crew members, between 2007 and 2012, for US-based carriers for domestic flights and all international flights that either originated or terminated in the US. In addition to the reported frequency of incidents for different aircraft models, the analysis attempted to identify propulsion engines and auxiliary power units associated with aircrafts that had higher frequencies of incidents. While substantial variations were found in frequency of incidents, it was found that the contamination events were widely distributed across nearly all common models of aircraft. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 62: The Influence of Knowledge Diffusion on Aeronautics Innovation: The Research, Development, and Production of Large Commercial Aircraft in France, Germany, and the United Kingdom

Science.gov (United States)

Golich, Vicki L.; Pinelli, Thomas E.

1997-01-01

This paper focuses on how European public policies-individually and collectively - influence the diffusion of knowledge and technology. It begins with an overview of the roles played historically and currently by European governments in the Research, Development and Production (RD&P) of Large Commercial Aircraft (LCA). The analytical framework brings together literature from global political economy, comparative politics, business management, and science and technology policy studies. It distinguishes between the production of knowledge, on the one hand, and the dissemination of knowledge, on the other. France, Germany, and the United Kingdom serve as the analytical cases. The paper concludes with a call for additional research in this area, some tentative lessons learned, and a discussion of the consequences of national strategies and policies for the diffusion of knowledge and technology in an era of globalizaton.

Energy Conversion and Storage Requirements for Hybrid Electric Aircraft

Science.gov (United States)

Misra, Ajay

2016-01-01

Among various options for reducing greenhouse gases in future large commercial aircraft, hybrid electric option holds significant promise. In the hybrid electric aircraft concept, gas turbine engine is used in combination with an energy storage system to drive the fan that propels the aircraft, with gas turbine engine being used for certain segments of the flight cycle and energy storage system being used for other segments. The paper will provide an overview of various energy conversion and storage options for hybrid electric aircraft. Such options may include fuel cells, batteries, super capacitors, multifunctional structures with energy storage capability, thermoelectric, thermionic or a combination of any of these options. The energy conversion and storage requirements for hybrid electric aircraft will be presented. The role of materials in energy conversion and storage systems for hybrid electric aircraft will be discussed.

Passenger thermal comfort and behavior: a field investigation in commercial aircraft cabins.

Science.gov (United States)

Cui, W; Wu, T; Ouyang, Q; Zhu, Y

2017-01-01

Passengers' behavioral adjustments warrant greater attention in thermal comfort research in aircraft cabins. Thus, a field investigation on 10 commercial aircrafts was conducted. Environment measurements were made and a questionnaire survey was performed. In the questionnaire, passengers were asked to evaluate their thermal comfort and record their adjustments regarding the usage of blankets and ventilation nozzles. The results indicate that behavioral adjustments in the cabin and the use of blankets or nozzle adjustments were employed by 2/3 of the passengers. However, the thermal comfort evaluations by these passengers were not as good as the evaluations by passengers who did not perform any adjustments. Possible causes such as differences in metabolic rate, clothing insulation and radiation asymmetry are discussed. The individual difference seems to be the most probable contributor, suggesting possibly that passengers who made adjustments had a narrower acceptance threshold or a higher expectancy regarding the cabin environment. Local thermal comfort was closely related to the adjustments and significantly influenced overall thermal comfort. Frequent flying was associated with lower ratings for the cabin environment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Commercial applications of large-scale Research and Development computer simulation technologies

International Nuclear Information System (INIS)

Kuok Mee Ling; Pascal Chen; Wen Ho Lee

1998-01-01

The potential commercial applications of two large-scale R and D computer simulation technologies are presented. One such technology is based on the numerical solution of the hydrodynamics equations, and is embodied in the two-dimensional Eulerian code EULE2D, which solves the hydrodynamic equations with various models for the equation of state (EOS), constitutive relations and fracture mechanics. EULE2D is an R and D code originally developed to design and analyze conventional munitions for anti-armor penetrations such as shaped charges, explosive formed projectiles, and kinetic energy rods. Simulated results agree very well with actual experiments. A commercial application presented here is the design and simulation of shaped charges for oil and gas well bore perforation. The other R and D simulation technology is based on the numerical solution of Maxwell's partial differential equations of electromagnetics in space and time, and is implemented in the three-dimensional code FDTD-SPICE, which solves Maxwell's equations in the time domain with finite-differences in the three spatial dimensions and calls SPICE for information when nonlinear active devices are involved. The FDTD method has been used in the radar cross-section modeling of military aircrafts and many other electromagnetic phenomena. The coupling of FDTD method with SPICE, a popular circuit and device simulation program, provides a powerful tool for the simulation and design of microwave and millimeter-wave circuits containing nonlinear active semiconductor devices. A commercial application of FDTD-SPICE presented here is the simulation of a two-element active antenna system. The simulation results and the experimental measurements are in excellent agreement. (Author)

19 CFR 122.49b - Electronic manifest requirement for crew members and non-crew members onboard commercial aircraft...

Science.gov (United States)

2010-04-01

...” means air carrier employees and their family members and persons traveling onboard a commercial aircraft...), air carrier employees, their family members, and persons onboard for the safety of the flight are...) Date of birth; (iii) Place of birth (city, state—if applicable, country); (iv) Gender (F = female; M...

78 FR 61388 - TA-W-82,705, the Boeing Company Boeing Commercial Aircraft, (BCA) Including On-Site Leased...

Science.gov (United States)

2013-10-03

... DEPARTMENT OF LABOR Employment and Training Administration TA-W-82,705, the Boeing Company Boeing... Services and Yoh Services Auburn, Washington; TA-W-82,705A, the Boeing Company Boeing Commercial Aircraft...., Triad Systems International, Volt Services and Yoh Services Everett, Washington; TA-W-82,705B, The...

Propulsion controlled aircraft computer

Science.gov (United States)

Cogan, Bruce R. (Inventor)

2010-01-01

A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

THE FUTURE OF PASSENGER AIR TRANSPORT – VERY LARGE AIRCRAFT AND OUT KEY HUMAN FACTORS AFFECTING THE OPERATION AND SAFETY OF PASSENGER AIR TRANSPORT

Directory of Open Access Journals (Sweden)

Petra Skolilova

2017-12-01

Full Text Available The article outlines some human factors affecting the operation and safety of passenger air transport given the massive increase in the use of the VLA. Decrease of the impact of the CO2 world emissions is one of the key goals for the new aircraft design. The main wave is going to reduce the burned fuel. Therefore, the eco-efficiency engines combined with reasonable economic operation of the aircraft are very important from an aviation perspective. The prediction for the year 2030 says that about 90% of people, which will use long-haul flights to fly between big cities. So, the A380 was designed exactly for this time period, with a focus on the right capacity, right operating cost and right fuel burn per seat. There is no aircraft today with better fuel burn combined with eco-efficiency per seat, than the A380. The very large aircrafts (VLAs are the future of the commercial passenger aviation. Operating cost versus safety or CO2 emissions versus increasing automation inside the new generation aircraft. Almost 80% of the world aircraft accidents are caused by human error based on wrong action, reaction or final decision of pilots, the catastrophic failures of aircraft systems, or air traffic control errors are not so frequent. So, we are at the beginning of a new age in passenger aviation and the role of the human factor is more important than ever.

Green energy and large commercial users

International Nuclear Information System (INIS)

Capage, Adam

2000-01-01

The difficulties faced in selling green energy to large commercial users are reviewed in this article. Four steps are identified in helping energy service suppliers (ESP) focus on opportunities for maximising revenue, namely, targeting the best prospects, identifying the right contact person, appealing to the primary contact, and helping contacts to make the sale internally. Companies with environmentally conscious customers and well defined environmental policies and led by those that promote environmental stewardship are recognised as commercial customers most likely to sign a deal for green energy

Commercial Aircraft Airframe Fuel Systems Survey and Analysis.

Science.gov (United States)

1982-07-01

Type of Report end Period Covered Ag Sponsorin ncy Na.e and Address FINAL REPORT U.S. DEPARTMENT OF TRANSPORTATION October, 1980 - June, 1982 FEDERAL...Philadelphia, Pennsylvania Weybridge, Surry England KT130SF Mr. Roy Riseley Mr. William Miles de Havilland Aircraft Cessna Aircraft Company Garratt Blvd. Wallace...Guido F. Pesotti Mr. Frank C. Davis Technical Director Engineering Specialist Empresa Brasileira Aeronautica, S.A. Garrett Turbine Engine Company

Critical joints in large composite primary aircraft structures. Volume 2: Technology demonstration test report

Science.gov (United States)

Bunin, Bruce L.

1985-01-01

A program was conducted to develop the technology for critical structural joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of four large composite multirow bolted joint tests are presented. The tests were conducted to demonstrate the technology for critical joints in highly loaded composite structure and to verify the analytical methods that were developed throughout the program. The test consisted of a wing skin-stringer transition specimen representing a stringer runout and skin splice on the wing lower surface at the side of the fuselage attachment. All tests were static tension tests. The composite material was Toray T-300 fiber with Ciba-Geigy 914 resin in 10 mil tape form. The splice members were metallic, using combinations of aluminum and titanium. Discussions are given of the test article, instrumentation, test setup, test procedures, and test results for each of the four specimens. Some of the analytical predictions are also included.

Predicting capacities of runways serving new large aircraft

Directory of Open Access Journals (Sweden)

K. Gopalakrishnan

2008-03-01

Full Text Available This paper presents a simplified approach for predicting the allowable load repetitions of New Large Aircraft (NLA loading for airfield runways based on Non-Destructive Test (NDT data. Full-scale traffic test results from the Federal Aviation Administration’s National Airport Pavement Test Facility (NAPTF were used to develop the NDT-based evaluation methodology. Four flexible test pavement sections with variable (unbound layer thicknesses were trafficked using six-wheel and four-wheel NLA test gears until the test pavements were deemed failed. Non-destructive tests using a Heavy Weight Deflectometer (HWD were conducted prior to the initiation of traffic testing to measure the pavement surface deflections. In the past, pavement surface deflections have been successfully used as an indicator of airport pavement life. In this study, the HWD surface deflections and the derived Deflection Basin Parameters (DBPs were related to functional performance of NAPTF flexible pavements through simple regression analysis. The results demonstrated the usefulness of NDT data for predicting the performance of airport flexible pavements serving the next generation of aircrafts.

Projected Demand and Potential Impacts to the National Airspace System of Autonomous, Electric, On-Demand Small Aircraft

Science.gov (United States)

Smith, Jeremy C.; Viken, Jeffrey K.; Guerreiro, Nelson M.; Dollyhigh, Samuel M.; Fenbert, James W.; Hartman, Christopher L.; Kwa, Teck-Seng; Moore, Mark D.

2012-01-01

Electric propulsion and autonomy are technology frontiers that offer tremendous potential to achieve low operating costs for small-aircraft. Such technologies enable simple and safe to operate vehicles that could dramatically improve regional transportation accessibility and speed through point-to-point operations. This analysis develops an understanding of the potential traffic volume and National Airspace System (NAS) capacity for small on-demand aircraft operations. Future demand projections use the Transportation Systems Analysis Model (TSAM), a tool suite developed by NASA and the Transportation Laboratory of Virginia Polytechnic Institute. Demand projections from TSAM contain the mode of travel, number of trips and geographic distribution of trips. For this study, the mode of travel can be commercial aircraft, automobile and on-demand aircraft. NASA's Airspace Concept Evaluation System (ACES) is used to assess NAS impact. This simulation takes a schedule that includes all flights: commercial passenger and cargo; conventional General Aviation and on-demand small aircraft, and operates them in the simulated NAS. The results of this analysis projects very large trip numbers for an on-demand air transportation system competitive with automobiles in cost per passenger mile. The significance is this type of air transportation can enhance mobility for communities that currently lack access to commercial air transportation. Another significant finding is that the large numbers of operations can have an impact on the current NAS infrastructure used by commercial airlines and cargo operators, even if on-demand traffic does not use the 28 airports in the Continental U.S. designated as large hubs by the FAA. Some smaller airports will experience greater demand than their current capacity allows and will require upgrading. In addition, in future years as demand grows and vehicle performance improves other non-conventional facilities such as short runways incorporated into

Trends in aircraft engines. Trends in aircraft gas turbines and subsonic engines

Energy Technology Data Exchange (ETDEWEB)

Murashima, Kanji

1988-06-10

While the emphasis of commercial, large aircraft engines is placed on low fuel consumption at high subsonic flight and the turbofan engines with high bypass ratio are dominating, high speed turboprop (ATP) of Mach 0.85 class with low fuel consumption are emerging. UHB with bypass ratio of 15 - 20 are planned with expection for application to intermediate size commercial planes. The pressure ratio is continuously rizing for improved cycle efficiency, reaching 35 - 40 in highest cases. Trends in design technique include: Use of computational aerodynamics and application of two-dimensional structural analysis and the digital simulation of engine characteristics. In the field of large, high bypass turbofan, serious competition is seen between GE and PNA at the thrust level of 5 - 60,000 pounds. Several engines for fighting planes have been approved in the type test and accepted as candidates for next generation of fighting planes including Japan. (15 figs, 36 refs)

The European project CASAM for the protection of commercial airliners in flight

Science.gov (United States)

Vergnolle, Jean-François

2007-10-01

As part of mass transportation systems, commercial aircraft are a potential target for terrorists because they represent one of the best achievements of our society. As a result, an attack would have a large psychological impact on people and economic activity. Several European Commission-funded Research and Technology programs, such as SAFEE and PALMA, are dedicated to technologies and systems that will be implemented onboard aircraft in the near future to increase the security of commercial flights. One of these programs, CASAM, is focusing on a potential solution to reduce aircraft vulnerability against Man Portable Air Defense Systems (MANPADS) during takeoff, ascent and landing. A specific onboard jamming system will be developed, meeting stringent yet competitive requirements that deal with high reliability, low cost and minimal installation constraints. The overall objective of the CASAM Project1 is to design and validate a closed-loop, laser-based DIRCM (Directed IR Countermeasure) module for jamming fired missiles. It will comply with commercial air transportation constraints, including the normal air traffic control rules. For example, the following aspects will be considered: - Environmental friendliness for ground objects and inhabitants close to airports, aircraft safety (maintenance, handling and usage) and high efficiency against the recognized threats; - Upgradability for further and future disseminated threats - Adherence to commercial operation budgets and processes

Durability and damage tolerance of Large Composite Primary Aircraft Structure (LCPAS)

Science.gov (United States)

Mccarty, John E.; Roeseler, William G.

1984-01-01

Analysis and testing addressing the key technology areas of durability and damage tolerance were completed for wing surface panels. The wing of a fuel-efficient, 200-passenger commercial transport airplane for 1990 delivery was sized using graphite-epoxy materials. Coupons of various layups used in the wing sizing were tested in tension, compression, and spectrum fatigue with typical fastener penetrations. The compression strength after barely visible impact damage was determined from coupon and structural element tests. One current material system and one toughened system were evaluated by coupon testing. The results of the coupon and element tests were used to design three distinctly different compression panels meeting the strength, stiffness, and damage-tolerance requirements of the upper wing panels. These three concepts were tested with various amounts of damage ranging from barely visible impact to through-penetration. The results of this program provide the key technology data required to assess the durability and damage-tolerance capability or advanced composites for use in commercial aircraft wing panel structure.

Automatic Flight Control System Design of Level Change Mode for a Large Aircraft

Directory of Open Access Journals (Sweden)

Huajun Gong

2013-02-01

Full Text Available The level change mode is an essential part of large civil aircraft automatic flight control systems. In cruise, with the decrease of the plane's weight caused by fuel consumption and the influence of bad weather, such as thunderstorms, the level change mode is required to solve this problem. This work establishes a nonlinear model of large aircraft, takes level changed from 9500m to 10100m as an example to design control laws for the level change mode in cruise. The classical engineering method is used to design longitudinal and lateral control laws synthetically. The flight qualities are considered in the design process. Simulation results indicate the control laws can meet design requirements and have a good anti-gust performance.

A synergistic glance at the prospects of distributed propulsion technology and the electric aircraft concept for future unmanned air vehicles and commercial/military aviation

Science.gov (United States)

Gohardani, Amir S.

2013-02-01

Distributed propulsion is one of the revolutionary candidates for future aircraft propulsion. In this journal article, the potential role of distributed propulsion technology in future aviation is investigated. Following a historical journey that revisits distributed propulsion technology in unmanned air vehicles and military aircraft, features of this specific technology are highlighted in synergy with an electric aircraft concept and a first-of-a-kind comparison to commercial aircraft employing distributed propulsion arrangements. In light of propulsion-airframe integration and complementary technologies such as boundary layer ingestion, thrust vectoring and circulation control, transpired opportunities and challenges are addressed in addition to a number of identified research directions proposed for future aircraft. The motivation behind enhanced means of communication between engineers, researchers and scientists has stimulated a novel proposed definition for the distributed propulsion technology in aviation and is presented herein.

Large-Scale Flight Phase Identification from ADS-B Data Using Machine Learning Methods

NARCIS (Netherlands)

Sun, J.; Ellerbroek, J.; Hoekstra, J.M.; Lovell, D.; Fricke, H.

2016-01-01

With the increasing availability of ADS-B transponders on commercial aircraft, as well as the rapidly growing deployment of ground stations that provide public access to their data, accessing open aircraft flight data is becoming easier for researchers. Given the large number of operational

Final Rule for Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

Science.gov (United States)

EPA adopted emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft.

31 CFR 560.528 - Aircraft safety.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Aircraft safety. 560.528 Section 560..., Authorizations and Statements of Licensing Policy § 560.528 Aircraft safety. Specific licenses may be issued on a... the safety of civil aviation and safe operation of U.S.-origin commercial passenger aircraft. ...

Commercial Aircraft Pricing: Application of Lessons Learned

Science.gov (United States)

2017-12-01

Given this, and the 45 Sean Broderick , “Boeing Revives Emphasis On Post-Delivery Business...web.stanford.edu/~lanierb/research/Dynamic_Aircraft_RES.pdf. Broderick , Sean. “Boeing Revives Emphasis On Post-Delivery Business.” Inside MRO, MRO

Commercial aircraft composite technology

CERN Document Server

Breuer, Ulf Paul

2016-01-01

This book is based on lectures held at the faculty of mechanical engineering at the Technical University of Kaiserslautern. The focus is on the central theme of societies overall aircraft requirements to specific material requirements and highlights the most important advantages and challenges of carbon fiber reinforced plastics (CFRP) compared to conventional materials. As it is fundamental to decide on the right material at the right place early on the main activities and milestones of the development and certification process and the systematic of defining clear requirements are discussed. The process of material qualification - verifying material requirements is explained in detail. All state-of-the-art composite manufacturing technologies are described, including changes and complemented by examples, and their improvement potential for future applications is discussed. Tangible case studies of high lift and wing structures emphasize the specific advantages and challenges of composite technology. Finally,...

Aircraft, ships, spacecraft, nuclear plants and quality

International Nuclear Information System (INIS)

Patrick, M.G.

1984-05-01

A few quality assurance programs outside the purview of the Nuclear Regulatory Commission were studied to identify features or practices which the NRC could use to enhance its program for assuring quality in the design and construction of nuclear power plants. The programs selected were: the manufacture of large commercial transport aircraft, regulated by the Federal Aviation Administration; US Navy shipbuilding; commercial shipbuilding regulated by the Maritime Administration and the US Coast Guard; Government-owned nuclear plants under the Department of Energy; spacecraft under the National Aeronautics and Space Administration; and the construction of nuclear power plants in Canada, West Germany, France, Japan, Sweden, and the United Kingdom

Measurement of dose equivalent distribution on-board commercial jet aircraft

International Nuclear Information System (INIS)

Kubancak, J.; Ambrozova, I.; Ploc, O.; Pachnerova Brabcova, K.; Stepan, V.; Uchihori, Y.

2014-01-01

The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them [International Commission on Radiation Protection. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21(1-3), (1991)]. According to the Monte Carlo simulations [Battistoni, G., Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the doses to aircrew members taking into consideration the aircraft structures. Adv. Space Res. 36, 1645-1652 (2005) and Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the influence of aircraft shielding on the aircrew exposure through an aircraft mathematical model. Radiat. Prot. Dosim. 108(2), 91-105 (2004)], the ambient dose equivalent rate H*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate H*(10) on-board selected types of aircraft. The authors found that H*(10) values are higher in the front and the back of the cabin and lesser in the middle of the cabin. Moreover, total dosimetry characteristics obtained in this way are in a reasonable agreement with other data, in particular with the above-mentioned simulations. (authors)

Laboratory Validation of Four Black Carbon Measurement Methods for Determination of the Nonvolatile Particulate Matter (nvPM) Mass Emissions from Commercial Aircraft Engines

Science.gov (United States)

Four candidate black carbon (BC) measurement techniques have been identified by the SAE International E-31 Committee for possible use in determining nonvolatile particulate matter (nvPM) mass emissions during commercial aircraft engine certification. These techniques are carbon b...

Development of pressure containment and damage tolerance technology for composite fuselage structures in large transport aircraft

Science.gov (United States)

Smith, P. J.; Thomson, L. W.; Wilson, R. D.

1986-01-01

NASA sponsored composites research and development programs were set in place to develop the critical engineering technologies in large transport aircraft structures. This NASA-Boeing program focused on the critical issues of damage tolerance and pressure containment generic to the fuselage structure of large pressurized aircraft. Skin-stringer and honeycomb sandwich composite fuselage shell designs were evaluated to resolve these issues. Analyses were developed to model the structural response of the fuselage shell designs, and a development test program evaluated the selected design configurations to appropriate load conditions.

Alternate aircraft fuels prospects and operational implications

Science.gov (United States)

Witcofski, R. D.

1977-01-01

The paper discusses NASA studies of the potentials of coal-derived aviation fuels, specifically synthetic aviation kerosene, liquid methane, and liquid hydrogen. Topics include areas of fuel production, air terminal requirements for aircraft fueling (for liquid hydrogen only), and the performance characteristics of aircraft designed to utilize alternate fuels. Energy requirements associated with the production of each of the three selected fuels are determined, and fuel prices are estimated. Subsonic commercial air transports using liquid hydrogen fuel have been analyzed, and their performance and the performance of aircraft which use commercial aviation kerosene are compared. Environmental and safety issues are considered.

Causes and risk factors for fatal accidents in non-commercial twin engine piston general aviation aircraft.

Science.gov (United States)

Boyd, Douglas D

2015-04-01

Accidents in twin-engine aircraft carry a higher risk of fatality compared with single engine aircraft and constitute 9% of all general aviation accidents. The different flight profile (higher airspeed, service ceiling, increased fuel load, and aircraft yaw in engine failure) may make comparable studies on single-engine aircraft accident causes less relevant. The objective of this study was to identify the accident causes for non-commercial operations in twin engine aircraft. A NTSB accident database query for accidents in twin piston engine airplanes of 4-8 seat capacity with a maximum certified weight of 3000-8000lbs. operating under 14CFR Part 91 for the period spanning 2002 and 2012 returned 376 accidents. Accident causes and contributing factors were as per the NTSB final report categories. Total annual flight hour data for the twin engine piston aircraft fleet were obtained from the FAA. Statistical analyses employed Chi Square, Fisher's Exact and logistic regression analysis. Neither the combined fatal/non-fatal accident nor the fatal accident rate declined over the period spanning 2002-2012. Under visual weather conditions, the largest number, n=27, (27%) of fatal accidents was attributed to malfunction with a failure to follow single engine procedures representing the most common contributing factor. In degraded visibility, poor instrument approach procedures resulted in the greatest proportion of fatal crashes. Encountering thunderstorms was the most lethal of all accident causes with all occupants sustaining fatal injuries. At night, a failure to maintain obstacle/terrain clearance was the most common accident cause leading to 36% of fatal crashes. The results of logistic regression showed that operations at night (OR 3.7), off airport landings (OR 14.8) and post-impact fire (OR 7.2) all carried an excess risk of a fatal flight. This study indicates training areas that should receive increased emphasis for twin-engine training/recency. First, increased

Industrial approach to piezoelectric damping of large fighter aircraft components

Science.gov (United States)

Simpson, John; Schweiger, Johannes

1998-06-01

Different concepts to damp structural vibrations of the vertical tail of fighter aircraft are reported. The various requirements for a vertical tail bias an integrated approach for the design. Several active vibrations suppression concepts had been investigated during the preparatory phase of a research program shared by Daimler-Benz Aerospace Military Aircraft (Dasa), Daimler-Benz Forschung (DBF) and Deutsche Forschungsandstalt fuer Luftund Raumfahrt (DLR). Now in the main phase of the programme, four concepts were finally chosen: two concepts with aerodynamic control surfaces and two concepts with piezoelectric components. One piezo concept approach will be described rigorously, the other concepts are briefly addressed. In the Dasa concept, thin surface piezo actuators are set out carefully to flatten the dynamic portion of the combined static and dynamic maximum bending moment loading case directly in the shell structure. The second piezo concept by DLR involves pre-loaded lead zirconate titanate (PZT)-block actuators at host structure fixtures. To this end a research apparatus was designed and built as a full scale simplified fin box with carbon fiber reinformed plastic skins and an aluminium stringer-rib substructure restrained by relevant aircraft fixtures. It constitutes a benchmark 3D-structural impedance. The engineering design incorporates 7kg of PZT surface actuators. The structural system then should be excited to more than 15mm tip displacement amplitude. This prepares the final step to total A/C integration. Typical analysis methods using cyclic thermal analogies adapted to induced load levels are compared. Commercial approaches leading onto basic state space model interpretation wrt. actuator sizing and positioning, structural integrity constraints, FE-validation and testing are described. Both piezoelectric strategies are aimed at straight open-loop performance related to concept weight penalty and input electric power. The required actuators, power

TCV software test and validation tools and technique. [Terminal Configured Vehicle program for commercial transport aircraft operation

Science.gov (United States)

Straeter, T. A.; Williams, J. R.

1976-01-01

The paper describes techniques for testing and validating software for the TCV (Terminal Configured Vehicle) program which is intended to solve problems associated with operating a commercial transport aircraft in the terminal area. The TCV research test bed is a Boeing 737 specially configured with digital computer systems to carry out automatic navigation, guidance, flight controls, and electronic displays research. The techniques developed for time and cost reduction include automatic documentation aids, an automatic software configuration, and an all software generation and validation system.

77 FR 41889 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2012-07-17

... Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA... airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD... identified in this AD, contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support...

The Effect of Modified Control Limits on the Performance of a Generic Commercial Aircraft Engine

Science.gov (United States)

Csank, Jeffrey T.; May, Ryan D.; Gou, Ten-Huei; Litt, Jonathan S.

2012-01-01

This paper studies the effect of modifying the control limits of an aircraft engine to obtain additional performance. In an emergency situation, the ability to operate an engine above its normal operating limits and thereby gain additional performance may aid in the recovery of a distressed aircraft. However, the modification of an engine s limits is complex due to the risk of an engine failure. This paper focuses on the tradeoff between enhanced performance and risk of either incurring a mechanical engine failure or compromising engine operability. The ultimate goal is to increase the engine performance, without a large increase in risk of an engine failure, in order to increase the probability of recovering the distressed aircraft. The control limit modifications proposed are to extend the rotor speeds, temperatures, and pressures to allow more thrust to be produced by the engine, or to increase the rotor accelerations and allow the engine to follow a fast transient. These modifications do result in increased performance; however this study indicates that these modifications also lead to an increased risk of engine failure.

78 FR 60656 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2013-10-02

... Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA... Aircraft Corporation (Sikorsky) Model S-92A helicopters to require modifying the No. 1 engine forward... Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main...

77 FR 23382 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2012-04-19

... Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA... Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD was prompted by the manufacturer's..., contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, Mailstop s581a, 6900...

77 FR 21402 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2012-04-10

... Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA... Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD was prompted by the discovery of tail... identified in this AD, contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support...

Visit to China's ARJ21 Aircraft Manufacturing Facility

National Research Council Canada - National Science Library

Balut, Stephen J; McNicol, David L; Nelson, J. R; Harmon, Bruce R; Holder, Stephen G

2008-01-01

During a December 2007 visit to China to share information about civilian aircraft costs, a delegation from IDA visited the Shanghai Aircraft Manufacturing Facility where the commercial chinese ARJ21...

Technology transfer and catch-up; Lessons from the commercial aircraft industry

NARCIS (Netherlands)

Steenhuis, H.J.; de Bruijn, E.J.; Heerkens, Johannes M.G.

2007-01-01

This paper analyses the technology development and technology transfer strategies in the aircraft manufacturing industry for four industrially developing countries. It is concluded from four case studies that technology catch-up is extremely difficult due to aircraft technology characteristics.

Physical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1-3

Science.gov (United States)

Kinsey, John S.; Dong, Yuanji; Williams, D. Craig; Logan, Russell

2010-06-01

The fine particulate matter (PM) emissions from nine commercial aircraft engine models were determined by plume sampling during the three field campaigns of the Aircraft Particle Emissions Experiment (APEX). Ground-based measurements were made primarily at 30 m behind the engine for PM mass and number concentration, particle size distribution, and total volatile matter using both time-integrated and continuous sampling techniques. The experimental results showed a PM mass emission index (EI) ranging from 10 to 550 mg kg -1 fuel depending on engine type and test parameters as well as a characteristic U-shaped curve of the mass EI with increasing fuel flow for the turbofan engines tested. Also, the Teflon filter sampling indicated that ˜40-80% of the total PM mass on a test-average basis was comprised of volatile matter (sulfur and organics) for most engines sampled. The number EIs, on the other hand, varied from ˜10 15 to 10 17 particles kg -1 fuel with the turbofan engines exhibiting a logarithmic decay with increasing fuel flow. Finally, the particle size distributions of the emissions exhibited a single primary mode that were lognormally distributed with a minor accumulation mode also observed at higher powers for all engines tested. The geometric (number) mean particle diameter ranged from 9.4 to 37 nm and the geometric standard deviation ranged from 1.3 to 2.3 depending on engine type, fuel flow, and test conditions.

Altitude exposures during commercial flight: a reappraisal.

Science.gov (United States)

Hampson, Neil B; Kregenow, David A; Mahoney, Anne M; Kirtland, Steven H; Horan, Kathleen L; Holm, James R; Gerbino, Anthony J

2013-01-01

Hypobaric hypoxia during commercial air travel has the potential to cause or worsen hypoxemia in individuals with pre-existing cardiopulmonary compromise. Knowledge of cabin altitude pressures aboard contemporary flights is essential to counseling patients accurately about flying safety. The objective of the study was to measure peak cabin altitudes during U.S. domestic commercial flights on a variety of aircraft. A handheld mountaineering altimeter was carried by the investigators in the plane cabin during commercial air travel and peak cabin altitude measured. The values were then compared between aircraft models, aircraft classes, and distances flown. The average peak cabin altitude on 207 flights aboard 17 different aircraft was 6341 +/- 1813 ft (1933 m +/- 553 m), significantly higher than when measured in a similar fashion in 1988. Peak cabin altitude was significantly higher for flights longer than 750 mi (7085 +/- 801 ft) compared to shorter flights (5160 +/- 2290 ft/1573 +/- 698 m). Cabin altitude increased linearly with flight distance for flights up to 750 mi in length, but was independent of flight distance for flights exceeding 750 mi. Peak cabin altitude was less than 5000 ft (1524 m) in 70% of flights shorter than 500 mi. Peak cabin altitudes greater than 8000 ft (2438 m) were measured on approximately 10% of the total flights. Peak cabin altitude on commercial aircraft flights has risen over time. Cabin altitude is lower with flights of shorter distance. Physicians should take these factors into account when determining an individual's need for supplemental oxygen during commercial air travel.

Is Model-Based Development a Favorable Approach for Complex and Safety-Critical Computer Systems on Commercial Aircraft?

Science.gov (United States)

Torres-Pomales, Wilfredo

2014-01-01

A system is safety-critical if its failure can endanger human life or cause significant damage to property or the environment. State-of-the-art computer systems on commercial aircraft are highly complex, software-intensive, functionally integrated, and network-centric systems of systems. Ensuring that such systems are safe and comply with existing safety regulations is costly and time-consuming as the level of rigor in the development process, especially the validation and verification activities, is determined by considerations of system complexity and safety criticality. A significant degree of care and deep insight into the operational principles of these systems is required to ensure adequate coverage of all design implications relevant to system safety. Model-based development methodologies, methods, tools, and techniques facilitate collaboration and enable the use of common design artifacts among groups dealing with different aspects of the development of a system. This paper examines the application of model-based development to complex and safety-critical aircraft computer systems. Benefits and detriments are identified and an overall assessment of the approach is given.

New materials for next-generation commercial transports

National Research Council Canada - National Science Library

Committee on New Materials for Advanced Civil Aircraft, Commission on Engineering and Technical Systems, National Research Council

... civil aircraft throughout their service life. The committee investigated the new materials and structural concepts that are likely to be incorporated into next generation commercial aircraft and the factors influencing application decisions...

Depreciation of aircraft

Science.gov (United States)

Warner, Edward P

1922-01-01

There is a widespread, and quite erroneous, impression to the effect that aircraft are essentially fragile and deteriorate with great rapidity when in service, so that the depreciation charges to be allowed on commercial or private operation are necessarily high.

Advanced Air Data Systems for Commercial Aircraft

Science.gov (United States)

2006-01-01

It is possible to get a crude estimate of wind speed and direction while driving a car at night in the rain, with the motion of the raindrop reflections in the headlights providing clues about the wind. The clues are difficult to interpret, though, because of the relative motions of ground, car, air, and raindrops. More subtle interpretation is possible if the rain is replaced by fog, because the tiny droplets would follow the swirling currents of air around an illuminated object, like, for example, a walking pedestrian. Microscopic particles in the air (aerosols) are better for helping make assessments of the wind, and reflective air molecules are best of all, providing the most refined measurements. It takes a bright light to penetrate fog, so it is easy to understand how other factors, like replacing the headlights with the intensity of a searchlight, can be advantageous. This is the basic principle behind a lidar system. While a radar system transmits a pulse of radiofrequency energy and interprets the received reflections, a lidar system works in a similar fashion, substituting a near-optical laser pulse. The technique allows the measurement of relative positions and velocities between the transmitter and the air, which allows measurements of relative wind and of air temperature (because temperature is associated with high-frequency random motions on a molecular level). NASA, as well as the National Oceanic and Atmospheric Administration (NOAA), have interests in this advanced lidar technology, as much of their explorative research requires the ability to measure winds and turbulent regions within the atmosphere. Lidar also shows promise for providing warning of turbulent regions within the National Airspace System to allow commercial aircraft to avoid encounters with turbulence and thereby increase the safety of the traveling public. Both agencies currently employ lidar and optical sensing for a variety of weather-related research projects, such as analyzing

The Aircraft Industry, 2006

National Research Council Canada - National Science Library

Daniel, Keith

2006-01-01

.... and global economic growth. The overall outlook for the industry is positive. Orders for commercial aircraft are up from a boom in air travel that is likely to continue well into the next decade...

The Impact of Rising Temperatures on Aircraft Takeoff Performance

Science.gov (United States)

Coffel, E.; Horton, R. M.; Thompson, T. R.

2017-12-01

Steadily rising mean and extreme temperatures as a result of climate change will likely impact the air transportation system over the coming decades. As air temperatures rise at constant pressure, air density declines, resulting in less lift generation by an aircraft wing at a given airspeed and potentially imposing a weight restriction on departing aircraft. This study presents a general model to project future weight restrictions across a fleet of aircraft with different takeoff weights operating at a variety of airports. We construct performance models for five common commercial aircraft and 19 major airports around the world and use projections of daily temperatures from the CMIP5 model suite under the RCP 4.5 and RCP 8.5 emissions scenarios to calculate required hourly weight restriction. We find that on average, 10-30% of annual flights departing at the time of daily maximum temperature may require some weight restriction below their maximum takeoff weights, with mean restrictions ranging from 0.5 to 4% of total aircraft payload and fuel capacity by mid- to late century. Both mid-sized and large aircraft are affected, and airports with short runways and high tempera- tures, or those at high elevations, will see the largest impacts. Our results suggest that weight restriction may impose a non-trivial cost on airlines and impact aviation operations around the world and that adaptation may be required in aircraft design, airline schedules, and/or runway lengths.

Aircraft Impact Assessment of APR1400 Reactor Containment Building

International Nuclear Information System (INIS)

Moon, Il Hwan; Kim, Do Yeon; Kim, Jae Hee; Kim, Sang Yun

2011-01-01

The implementation of a protection to withstand aircraft impact on safety-related structures and systems is basically based on a probabilistic evaluation for each site, if the licensing body doesn't require a deterministic approach. Existing nuclear power plants in Korea were designed based on the probabilistic approach, and the aircraft impact hazard remained less than a probability of 10 -7 . However, a man-made aircraft impact have been considered as a possible external accident for the nuclear power plant. New plant designs that are to be constructed in the U.S. after July 2009 must consider the effect of impact from a large commercial aircraft according to the requirements of 10 CFR 50.150. Especially, Reactor Containment Building (RCB) housing the safety-related equipment and fuels should be protected safely against aircraft crash without perforation and scabbing failure of external wall. APR1400 RCB is constructed as a prestressed concrete containment vessel (PCCV) which is surrounded by the auxiliary building housing additional safety-related equipment and other systems. In this study, the aircraft impact analyses for the RCB are carried out using Riera forcing function and aircraft model. Considered external wall thickness is 4 ft 6 in. for the cylindrical wall and 4 ft for the dome. Actual strengths of concrete and steel are considered as the material properties. For these analyses, the dynamic increment factor and concrete aging effect are considered in accordance with NEI 07-13(2011)

On the methods and examples of aircraft impact analysis

International Nuclear Information System (INIS)

Arros, J.

2012-01-01

Conclusions: Aircraft impact analysis can be performed today within feasible run times using PCs and available advanced commercial finite element software tools. Adequate element and material model technologies exist. Explicit time integration enables analysis of very large deformation Missile/Target impacts. Meshless/particle based methods may be beneficial for large deformation concrete “punching shear” analysis – potentially solves the “element erosion” problem associated with FE, but are not generally implemented yet in major commercial software. Verification of the complicated modeling technologies continues to be a challenge. Not much work has been done yet on ACI shock loading – redundant and physically separated safety trains key to success. Analysis approach and detail should be “balanced” - commensurate with the significant uncertainties - do not “over-do” details of some parts of the model (e.g., the plane) and the analysis

A Study on External Fire Damage of Structures subjected to Aircraft Impact

International Nuclear Information System (INIS)

Shin, Sang Shup; Hahm, Daegi; Kim, Min Kyu

2015-01-01

A large commercial aircraft consists of various components as fuselage, wings, fuel tank, engine etc. During a collision of the aircraft, the fuel tank with a large amount of jet fuel have a significant effect on the total load of the aircraft as well as causing explosive fire and smoke which affect the safety of the structure and equipment. US Sandia National Laboratories and Finland VTT etc. performed the test and simulation studies to evaluate the dispersion range of the fluid after the crash of liquid filled cylinder missiles. The test condition and results have been referred in this paper. The fluid modeling approach using SPH is applied to evaluate the dispersing range of the fluid, and is compared with the Brown's results. The jet fuel is idealized as particles contained in an aluminum cylinder missile, where those particles can be dispersed to the surrounding area after the missile crashes into a rigid target. The fluid model using the SPH method is briefly verified through comparison with test results, and then the modelling method is applied to a jet fuel model in an aircraft model. The dispersion analysis of jet fuel caused by aircraft impact is performed using an aircraft model for the determination of fire duration and fire affected zone in a nuclear power plant. Finally, the structural integrity of the roof of the structure during a jet fuel fire is evaluated. In this study, the filled jet fuel was modeled by using smooth particle hydrodynamics technique; jet fuel spread area following an aircraft crash was analyzed

A Study on External Fire Damage of Structures subjected to Aircraft Impact

Energy Technology Data Exchange (ETDEWEB)

Shin, Sang Shup [Hanyang University, Seoul (Korea, Republic of); Hahm, Daegi; Kim, Min Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

A large commercial aircraft consists of various components as fuselage, wings, fuel tank, engine etc. During a collision of the aircraft, the fuel tank with a large amount of jet fuel have a significant effect on the total load of the aircraft as well as causing explosive fire and smoke which affect the safety of the structure and equipment. US Sandia National Laboratories and Finland VTT etc. performed the test and simulation studies to evaluate the dispersion range of the fluid after the crash of liquid filled cylinder missiles. The test condition and results have been referred in this paper. The fluid modeling approach using SPH is applied to evaluate the dispersing range of the fluid, and is compared with the Brown's results. The jet fuel is idealized as particles contained in an aluminum cylinder missile, where those particles can be dispersed to the surrounding area after the missile crashes into a rigid target. The fluid model using the SPH method is briefly verified through comparison with test results, and then the modelling method is applied to a jet fuel model in an aircraft model. The dispersion analysis of jet fuel caused by aircraft impact is performed using an aircraft model for the determination of fire duration and fire affected zone in a nuclear power plant. Finally, the structural integrity of the roof of the structure during a jet fuel fire is evaluated. In this study, the filled jet fuel was modeled by using smooth particle hydrodynamics technique; jet fuel spread area following an aircraft crash was analyzed.

Modeling Aircraft Emissions for Regional-scale Air Quality: Adapting a New Global Aircraft Emissions Database for the U.S

Science.gov (United States)

Arunachalam, S.; Baek, B. H.; Vennam, P. L.; Woody, M. C.; Omary, M.; Binkowski, F.; Fleming, G.

2012-12-01

Commercial aircraft emit substantial amounts of pollutants during their complete activity cycle that ranges from landing-and-takeoff (LTO) at airports to cruising in upper elevations of the atmosphere, and affect both air quality and climate. Since these emissions are not uniformly emitted over the earth, and have substantial temporal and spatial variability, it is vital to accurately evaluate and quantify the relative impacts of aviation emissions on ambient air quality. Regional-scale air quality modeling applications do not routinely include these aircraft emissions from all cycles. Federal Aviation Administration (FAA) has developed the Aviation Environmental Design Tool (AEDT), a software system that dynamically models aircraft performance in space and time to calculate fuel burn and emissions from gate-to-gate for all commercial aviation activity from all airports globally. To process in-flight aircraft emissions and to provide a realistic representation of these for treatment in grid-based air quality models, we have developed an interface processor called AEDTproc that accurately distributes full-flight chorded emissions in time and space to create gridded, hourly model-ready emissions input data. Unlike the traditional emissions modeling approach of treating aviation emissions as ground-level sources or processing emissions only from the LTO cycles in regional-scale air quality studies, AEDTproc distributes chorded inventories of aircraft emissions during LTO cycles and cruise activities into a time-variant 3-D gridded structure. We will present results of processed 2006 global emissions from AEDT over a continental U.S. modeling domain to support a national-scale air quality assessment of the incremental impacts of aircraft emissions on surface air quality. This includes about 13.6 million flights within the U.S. out of 31.2 million flights globally. We will focus on assessing spatio-temporal variability of these commercial aircraft emissions, and

Estimation of electromagnetic dosimetric values from non-ionizing radiofrequency fields in an indoor commercial airplane environment.

Science.gov (United States)

Aguirre, Erik; Arpón, Javier; Azpilicueta, Leire; López, Peio; de Miguel, Silvia; Ramos, Victoria; Falcone, Francisco

2014-12-01

In this article, the impact of topology as well as morphology of a complex indoor environment such as a commercial aircraft in the estimation of dosimetric assessment is presented. By means of an in-house developed deterministic 3D ray-launching code, estimation of electric field amplitude as a function of position for the complete volume of a commercial passenger airplane is obtained. Estimation of electromagnetic field exposure in this environment is challenging, due to the complexity and size of the scenario, as well as to the large metallic content, giving rise to strong multipath components. By performing the calculation with a deterministic technique, the complete scenario can be considered with an optimized balance between accuracy and computational cost. The proposed method can aid in the assessment of electromagnetic dosimetry in the future deployment of embarked wireless systems in commercial aircraft.

Commercial Aircraft Trajectory Planning based on Multiphase Mixed-Integer Optimal Control

OpenAIRE

Soler Arnedo, Manuel Fernando

2017-01-01

The main goal of this dissertation is to develop optimal control techniques for aircraft trajectory planning looking at reduction of fuel consumption, emissions and overfly charges in flight plans. The calculation of a flight plan involves the consideration of multiple factors. They can be classified as either continuous or discrete, and include nonlinear aircraft performance, atmospheric conditions, wind conditions, airspace structure, amount of departure fuel, and operational...

Instrumentation on commercial aircraft for monitoring the atmospheric composition on a global scale: the IAGOS system, technical overview of ozone and carbon monoxide measurements

Directory of Open Access Journals (Sweden)

Phillipe Nédélec

2015-06-01

Full Text Available This article presents the In-service Aircraft of a Global Observing System (IAGOS developed for operations on commercial long-range Airbus aircraft (A330/A340 for monitoring the atmospheric composition. IAGOS is the continuation of the former Measurement of OZone and water vapour on Airbus In-service airCraft (MOZAIC programme (1994–2014 with five aircraft operated by European airlines over 20 yr. MOZAIC has provided unique scientific database used worldwide by the scientific community. In continuation of MOZAIC, IAGOS aims to equip a fleet up to 20 aircraft around the world and for operations over decades. IAGOS started in July 2011 with the first instruments installed aboard a Lufthansa A340-300, and a total of six aircraft are already in operation. We present the technical aircraft system concept, with basic instruments for O3, CO, water vapour and clouds; and optional instruments for measuring either NOy, NOx, aerosols or CO2/CH4. In this article, we focus on the O3 and CO instrumentation while other measurements are or will be described in specific papers. O3 and CO are measured by optimised but well-known methods such as UV absorption and IR correlation, respectively. We describe the data processing/validation and the data quality control for O3 and CO. Using the first two overlapping years of MOZAIC/IAGOS, we conclude that IAGOS can be considered as the continuation of MOZAIC with the same data quality of O3 and CO measurements.

77 FR 56581 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2012-09-13

... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Supplemental notice of... airworthiness directive (AD) for the Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopter, which... proposed AD, contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop...

Biomimetic FAA-certifiable, artificial muscle structures for commercial aircraft wings

Science.gov (United States)

Barrett, Ronald M.; Barrett, Cassandra M.

2014-07-01

This paper is centered on a new form of adaptive material which functions much in the same way as skeletal muscle tissue, is structurally modeled on plant actuator cells and capable of rapidly expanding or shrinking by as much as an order of magnitude in prescribed directions. Rapid changes of plant cell shape and sizes are often initiated via ion-transport driven fluid migration and resulting turgor pressure variation. Certain plant cellular structures like those in Mimosa pudica (sensitive plant), Albizia julibrissin (Mimosa tree), or Dionaea muscipula (Venus Flytrap) all exhibit actuation physiology which employs such turgor pressure manipulation. The paper begins with dynamic micrographs of a sectioned basal articulation joint from A. julibrissin. These figures show large cellular dimensional changes as the structure undergoes foliage articulation. By mimicking such structures in aircraft flight control mechanisms, extremely lightweight pneumatic control surface actuators can be designed. This paper shows several fundamental layouts of such surfaces with actuator elements made exclusively from FAA-certifiable materials, summarizes their structural mechanics and shows actuator power and energy densities that are higher than nearly all classes of conventional adaptive materials available today. A sample flap structure is shown to possess the ability to change its shape and structural stiffness as its cell pressures are manipulated, which in turn changes the surface lift-curve slope when exposed to airflows. Because the structural stiffness can be altered, it is also shown that the commanded section lift-curve slope can be similarly controlled between 1.2 and 6.2 rad-1. Several aircraft weight reduction principles are also shown to come into play as the need to concentrate loads to pass through point actuators is eliminated. The paper concludes with a summary of interrelated performance and airframe-level improvements including enhanced gust rejection, load

Biomimetic FAA-certifiable, artificial muscle structures for commercial aircraft wings

International Nuclear Information System (INIS)

Barrett, Ronald M; Barrett, Cassandra M

2014-01-01

This paper is centered on a new form of adaptive material which functions much in the same way as skeletal muscle tissue, is structurally modeled on plant actuator cells and capable of rapidly expanding or shrinking by as much as an order of magnitude in prescribed directions. Rapid changes of plant cell shape and sizes are often initiated via ion-transport driven fluid migration and resulting turgor pressure variation. Certain plant cellular structures like those in Mimosa pudica (sensitive plant), Albizia julibrissin (Mimosa tree), or Dionaea muscipula (Venus Flytrap) all exhibit actuation physiology which employs such turgor pressure manipulation. The paper begins with dynamic micrographs of a sectioned basal articulation joint from A. julibrissin. These figures show large cellular dimensional changes as the structure undergoes foliage articulation. By mimicking such structures in aircraft flight control mechanisms, extremely lightweight pneumatic control surface actuators can be designed. This paper shows several fundamental layouts of such surfaces with actuator elements made exclusively from FAA-certifiable materials, summarizes their structural mechanics and shows actuator power and energy densities that are higher than nearly all classes of conventional adaptive materials available today. A sample flap structure is shown to possess the ability to change its shape and structural stiffness as its cell pressures are manipulated, which in turn changes the surface lift-curve slope when exposed to airflows. Because the structural stiffness can be altered, it is also shown that the commanded section lift-curve slope can be similarly controlled between 1.2 and 6.2 rad −1 . Several aircraft weight reduction principles are also shown to come into play as the need to concentrate loads to pass through point actuators is eliminated. The paper concludes with a summary of interrelated performance and airframe-level improvements including enhanced gust rejection, load

77 FR 68057 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2012-11-15

... Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA... Sikorsky Aircraft Corporation (Sikorsky) Model S-76C helicopters. This AD requires installing an improved... Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street, Stratford, CT...

77 FR 35357 - Atlantic Highly Migratory Species; Commercial Atlantic Region Non-Sandbar Large Coastal Shark...

Science.gov (United States)

2012-06-13

... Highly Migratory Species; Commercial Atlantic Region Non-Sandbar Large Coastal Shark Fishery Opening Date... commercial Atlantic region non-sandbar large coastal shark fishery. This action is necessary to inform... large coastal shark fishery will open on July 15, 2012. FOR FURTHER INFORMATION CONTACT: Karyl Brewster...

Full-Scale Tests of Lightweight Fragment Barriers on Commercial Aircraft

National Research Council Canada - National Science Library

Shockey, Donald

1999-01-01

Because fragments from inflight engine failures can damage critical aircraft components and produce catastrophic consequences, the Federal Aviation Administration is sponsoring research to mitigate...

77 FR 68061 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2012-11-15

... Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA... Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD requires inspecting the tail rotor (T/R... Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street, Stratford, CT...

Instrument Failure, Stress, and Spatial Disorientation Leading to a Fatal Crash With a Large Aircraft.

Science.gov (United States)

Tribukait, Arne; Eiken, Ola

2017-11-01

An aircraft's orientation relative to the ground cannot be perceived via the sense of balance or the somatosensory system. When devoid of external visual references, the pilot must rely on instruments. A sudden unexpected instrument indication is a challenge to the pilot, who might have to question the instrument instead of responding with the controls. In this case report we analyze, from a human-factors perspective, how a limited instrument failure led to a fatal accident. During straight-ahead level flight in darkness, at 33,000 ft, the commander of a civil cargo airplane was suddenly confronted by an erroneous pitch-up indication on his primary flight display. He responded by pushing the control column forward, making a bunt maneuver with reduced/negative Gz during approximately 15 s. The pilots did not communicate rationally or cross-check instruments. Recordings of elevator and aileron positions suggest that the commander made intense efforts to correct for several extreme and erroneous roll and pitch indications. Gz displayed an increasing trend with rapid fluctuations and peaks of approximately 3 G. After 50 s the aircraft entered a turn with decreasing radius and finally hit the ground in an inverted attitude. A precipitate maneuvring response can, even if occurring in a large aircraft at high altitude, result in a seemingly inexorable course of events, ending with a crash. In the present case both pilots were probably incapacitated by acute psychological stress and spatial disorientation. Intense variations in Gz may have impaired the copilot's reading of the functioning primary flight display.Tribukait A, Eiken O. Instrument failure, stress, and spatial disorientation leading to a fatal crash with a large aircraft. Aerosp Med Hum Perform. 2017; 88(11):1043-1048.

Aircraft gas turbines

Energy Technology Data Exchange (ETDEWEB)

Arai, M [Kawasaki Heavy Industries Ltd., Kobe (Japan)

1995-03-01

Recently the international relationship has been playing an important role in the research, development and production of the aircraft gas turbine. The YSX, which is supposed to be the 100-seat class commercial aircraft, has been planned by Japan Aircraft Development (JADC) as an international cooperative project. Recently many western aeroengine companies have offered the collaboration of small turbofan engines which would be installed on YSX to Japanese aeroengine companies (IHI, KHI and MHI). The YSX is powered by 16,000-20,000 1bs thrust class engines. As for medium turbofan engine (V2500), the V 2500 family of 22,000 to 30,000 1bs thrust has been developed since 1983 through international collaboration by seven aeroengine companies in five nations. In this paper, the recent Japan`s activities of the research, development and production with viewing the world-wide movement, are described. 6 figs.

Hearing status among aircraft maintenance personnel in a commercial airline company

Directory of Open Access Journals (Sweden)

Greta Smedje

2011-01-01

Full Text Available The aim was to study subjective and objective hearing loss in a population of aircraft maintenance workers and identify predictors. A total of 327 aircraft maintenance personnel answered a self-administered work environment questionnaire (response rate 76% and underwent audiometric test. The mean values for the hearing threshold at 3, 4, and 6 kHz for the ear with the most hearing loss were compared with a Swedish population database of persons not occupationally exposed to noise. Equivalent noise exposure during a working day was measured. Relationships between subjective and objective hearing loss and possible predictors (age, years of employment, self-reported exposure to solvents, blood pressure, and psycho-social factors were analyzed by multiple logistic regression. At younger ages (<40 years, aircraft maintenance workers had higher hearing thresholds (1-3 dB compared to the reference group, but such a difference was not found in older employees. Relationships were found between age and objective hearing loss, and between exposure to solvents and reported subjective hearing loss. Equivalent noise exposure during working days were 70-91 dB(A with a maximal noise level of 119 dB(A. Aircraft maintenance workers are exposed to equivalent noise levels above the Swedish occupational standard, including some very high peak exposures. Younger employees have a higher age-matched hearing threshold level compared with a reference group. Thus, there is a need for further preventive measures.

RF Coupling into the Fuel Tank of a Large Transport Aircraft from Intentionally Transmitting Peds in the Passenger Cabin

Science.gov (United States)

Nguyen, Truong X.; Dudley, Kenneth L.; Scearce, Stephen A.; Ely, Jay J.; Richardson, Robert E.; Hatfield, Michael O.

2000-01-01

An investigation was performed to study the potential for radio frequency (RF) power radiated from Portable Electronic Devices (PEDs) to create an arcing/sparking event within the fuel tank of a large transport aircraft. This paper describes the experimental methods used for measuring RF coupling to the fuel tank and Fuel Quantity Indication System (FQIS) wiring from PED sources located in the passenger cabin. To allow comparison of voltage/current data obtained in a laboratory chamber FQIS installation to an actual aircraft FQIS installation, aircraft fuel tank RF reverberation characteristics were also measured. Results from the measurements, along with a survey of threats from typical intentional transmitting PEDs are presented. The resulting worst-case power coupled onto fuel tank FQIS wiring is derived. The same approach can be applied to measure RF coupling into various other aircraft systems.

Durability of aircraft composite materials

Science.gov (United States)

Dextern, H. B.

1982-01-01

Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

AutoGNI, the Robot Under the Aircraft Floor: An Automated System for Sampling Giant Aerosol Particles by Impaction in the Free Airstream Outside a Research Aircraft

Science.gov (United States)

Jensen, J. B.; Schwenz, K.; Aquino, J.; Carnes, J.; Webster, C.; Munnerlyn, J.; Wissman, T.; Lugger, T.

2017-12-01

Giant sea-salt aerosol particles, also called Giant Cloud Condensation Nuclei (GCCN), have been proposed as a means of rapidly forming precipitation sized drizzle drops in warm marine clouds (e.g., Jensen and Nugent, 2017). Such rare particles are best sampled from aircraft in air below cloud base, where normal laser optical instruments have too low sample volume to give statistically significant samples of the large particle tail. An automated sampling system (the AutoGNI) has been built to operate from inside a pressurized aircraft. Under the aircraft floor, a pressurized vessel contains 32 custom-built polycarbonate microscope slides. Using robotics with 5 motor drives and 18 positioning switches, the AutoGNI can take slides from their holding cassettes, pass them onto a caddy in an airfoil that extends 200 mm outside the aircraft, where they are exposed in the free airstream, thus avoiding the usual problems with large particle losses in air intakes. Slides are typically exposed for 10-30 s in the marine boundary layer, giving sample volumes of about 100-300 L or more. Subsequently the slides are retracted into the pressure vessel, stored and transported for laboratory microscope image analysis, in order to derive size-distribution histograms. While the aircraft is flying, the AutoGNI system is remotely controlled from a laptop on the ground, using an encrypted commercial satellite connection to the NSF/NCAR GV research aircraft's main server, and onto the AutoGNI microprocessor. The sampling of such GCCN is becoming increasingly important in order to provide complete input data for model calculations of aerosol-cloud interactions and their feedbacks in climate prediction. The AutoGNI has so far been sampling sea-salt GCCN in the Magellan Straight during the 2016 ORCAS project and over the NW Pacific during the 2017 ARISTO project, both from the NSF/NCAR GV research aircraft. Sea-salt particle sizes of 1.4 - 32 μm dry diameter have been observed.

Final Rule for Control of Air Pollution from Aircraft and Aircraft Engines: Emission Standards and Test Procedures

Science.gov (United States)

EPA is amending the existing emission standards for oxides of nitrogen (NOx) for new commercial aircraft engines. These standards are equivalent to the NOx emission standards of the United Nations International Civil Aviation Organization (ICAO).

Resistance ability evaluation of safety-related structures for the simulated aircraft accident

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Jin; Kim, Sung Woon; Choi, Jang Kyu [Daewoo E and C Co., Ltd., Suwon (Korea, Republic of)] (and others)

2003-03-15

Aircraft accidents on nuclear safety-related structures can cause severe damage to the safety of NPP(Nuclear Power Plant)s. To assess the safety of nuclear safety-related structures, the local damage and the dynamic response of global structures should be investigated together. This study have compared several local damage assessment formulas suggested for aircraft as an impactor, and have set the assessment system of local damage for impact-proof design of NPP containment buildings. And the local damage of nuclear safety-related structures in operation in Korea for commercial aircraft as impactor have been estimated. Impact load-time functions of the aircraft crash have been decided to assessment the safety of nuclear safety-related structures against the intentional colliding of commercial aircraft. Boeing 747 and Boeing 767 is selected as target aircraft based on the operation frequencies and weights. Comparison of the fire analysis methods showed that the method considering heat convection and radiation is adequate for the temperature analysis of the aircraft fuel fire. Finally, the study covered the analysis of the major structural drawings and design drawings with which three-dimensional finite element model analysis is expected to be performed.

Identification of Aircraft Hazards

International Nuclear Information System (INIS)

K. Ashley

2006-01-01

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7)

Critical Joints in Large Composite Primary Aircraft Structures. Volume 3: Ancillary Test Results

Science.gov (United States)

Bunin, Bruce L.; Sagui, R. L.

1985-01-01

A program was conducted to develop the technology for critical structural joints for composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. The results of a comprehensive ancillary test program are summarized, consisting of single-bolt composite joint specimens tested in a variety of configurations. These tests were conducted to characterize the strength and load deflection properties that are required for multirow joint analysis. The composite material was Toray 300 fiber and Ciba-Geigy 914 resin, in the form of 0.005 and 0.01 inch thick unidirectional tape. Tests were conducted in single and double shear for loaded and unloaded hole configurations under both tensile and compressive loading. Two different layup patterns were examined. All tests were conducted at room temperature. In addition, the results of NASA Standard Toughness Test (NASA RP 1092) are reported, which were conducted for several material systems.

Photochemical transformation of aircraft exhausts at their transition from the plume to the large scale dispersion in the Northern temperature belt

Energy Technology Data Exchange (ETDEWEB)

Karol, I L; Kiselev, A A [Main Geophysical Observatory, St.Petersburg (Russian Federation)

1998-12-31

The 2-D diurnally varying photochemical model of the Northern temperate zonal tropospheric belt with fixed (off line) temperature and air transport is used for the description of the formation of aircraft exhaust concentration distribution in the North Atlantic commercial flight corridor, based on actual flights in summer and winter. A strong diurnal and seasonal variation of emitted NO{sub x} oxidation rate is revealed and evaluated. (author) 11 refs.

Photochemical transformation of aircraft exhausts at their transition from the plume to the large scale dispersion in the Northern temperature belt

Energy Technology Data Exchange (ETDEWEB)

Karol, I.L.; Kiselev, A.A. [Main Geophysical Observatory, St.Petersburg (Russian Federation)

1997-12-31

The 2-D diurnally varying photochemical model of the Northern temperate zonal tropospheric belt with fixed (off line) temperature and air transport is used for the description of the formation of aircraft exhaust concentration distribution in the North Atlantic commercial flight corridor, based on actual flights in summer and winter. A strong diurnal and seasonal variation of emitted NO{sub x} oxidation rate is revealed and evaluated. (author) 11 refs.

Recent NASA progress in composites. [application to spacecraft and aircraft structures

Science.gov (United States)

Heldenfels, R. R.

1975-01-01

The application of composites in aerospace vehicle structures is reviewed. Research and technology program results and specific applications to space vehicles, aircraft engines, and aircraft and helicopter structures are discussed in detail. Particular emphasis is given to flight service evaluation programs that are or will be accumulating substantial experience with secondary and primary structural components on military and commercial aircraft to increase confidence in their use.

Capacity assessment of concrete containment vessels subjected to aircraft impact

Energy Technology Data Exchange (ETDEWEB)

Andonov, Anton, E-mail: anton.andonov@mottmac.com; Kostov, Marin; Iliev, Alexander

2015-12-15

Highlights: • An approach to assess the containment capacity to aircraft impact via fragility curves is proposed. • Momentum over Area was defined as most suitable reference parameter to describe the aircraft load. • The effect of the impact induced damages on the containment pressure capacity has been studied. • The studied containment shows no reduction of the pressure capacity for the investigated scenarios. • The effectiveness of innovative protective structure against aircraft impact has been evaluated. - Abstract: The paper describes the procedure and the results from the assessment of the vulnerability of a generic pre-stressed containment structure subjected to a large commercial aircraft impact. Impacts of Boeing 737, Boeing 767 and Boeing 747 have been considered. The containment vulnerability is expressed by fragility curves based on the results of a number of nonlinear dynamic analyses. Three reference parameters have been considered as impact intensity measure in the fragility curve definition: peak impact force (PIF), peak impact pressure (PIP) and Momentum over Area (MoA). Conclusions on the most suitable reference parameter as well on the vulnerability of such containment vessels are drawn. The influence of the aircraft impact induced damages on the containment ultimate pressure capacity is also assessed and some preliminary conclusions on this are drawn. The paper also addresses a conceptual design of a protective structure able to decrease the containment vulnerability and provide a preliminary assessment of the applicability of such concept.

Capacity assessment of concrete containment vessels subjected to aircraft impact

International Nuclear Information System (INIS)

Andonov, Anton; Kostov, Marin; Iliev, Alexander

2015-01-01

Highlights: • An approach to assess the containment capacity to aircraft impact via fragility curves is proposed. • Momentum over Area was defined as most suitable reference parameter to describe the aircraft load. • The effect of the impact induced damages on the containment pressure capacity has been studied. • The studied containment shows no reduction of the pressure capacity for the investigated scenarios. • The effectiveness of innovative protective structure against aircraft impact has been evaluated. - Abstract: The paper describes the procedure and the results from the assessment of the vulnerability of a generic pre-stressed containment structure subjected to a large commercial aircraft impact. Impacts of Boeing 737, Boeing 767 and Boeing 747 have been considered. The containment vulnerability is expressed by fragility curves based on the results of a number of nonlinear dynamic analyses. Three reference parameters have been considered as impact intensity measure in the fragility curve definition: peak impact force (PIF), peak impact pressure (PIP) and Momentum over Area (MoA). Conclusions on the most suitable reference parameter as well on the vulnerability of such containment vessels are drawn. The influence of the aircraft impact induced damages on the containment ultimate pressure capacity is also assessed and some preliminary conclusions on this are drawn. The paper also addresses a conceptual design of a protective structure able to decrease the containment vulnerability and provide a preliminary assessment of the applicability of such concept.

Large-scale distribution of tritium in a commercial product

International Nuclear Information System (INIS)

Combs, F.; Doda, R.J.

1979-01-01

Tritium enters the environment from various sources including nuclear reactor operations, weapons testing, natural production, and from the manufacture, use and ultimate disposal of commercial products containing tritium. A recent commercial application of tritium in the United States of America involves the backlighting of liquid crystal displays (LCD) in digital electronic watches. These watches are distributed through normal commercial channels to the general public. One million curies (MCi) of tritium were distributed in 1977 in this product. This is a significant quantity of tritium compared with power reactor-produced tritium (3MCi yearly) or with naturally produced tritium (6MCi yearly). This is the single largest commercial application involving tritium to date. The final disposition of tritium from large quantities of this product, after its useful life, must be estimated by considering the means of disposal and the possibility of dispersal of tritium concurrent with disposal. The most likely method of final disposition of this product will be disposal in solid refuse; this includes burial in land fills and incineration. Burial in land fills will probably contain the tritium for its effective lifetime, whereas incineration will release all the tritium gas (as the oxide) to the atmosphere. The use and disposal of this product will be studied as part of an environmental study that is at present being prepared for the U.S. Nuclear Regulatory Commission. (author)

Subsonic Ultra Green Aircraft Research

Science.gov (United States)

Bradley, Marty K.; Droney, Christopher K.

2011-01-01

This Final Report summarizes the work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team in Phase 1, which includes the time period of October 2008 through March 2010. The team consisted of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech. The team completed the development of a comprehensive future scenario for world-wide commercial aviation, selected baseline and advanced configurations for detailed study, generated technology suites for each configuration, conducted detailed performance analysis, calculated noise and emissions, assessed technology risks, and developed technology roadmaps. Five concepts were evaluated in detail: 2008 baseline, N+3 reference, N+3 high span strut braced wing, N+3 gas turbine battery electric concept, and N+3 hybrid wing body. A wide portfolio of technologies was identified to address the NASA N+3 goals. Significant improvements in air traffic management, aerodynamics, materials and structures, aircraft systems, propulsion, and acoustics are needed. Recommendations for Phase 2 concept and technology projects have been identified.

Analysis of the engine fragment threat and the crush environment for small packages carried on U.S. commercial jet aircraft

International Nuclear Information System (INIS)

Hartman, W.F.; McClure, J.D.; von Riesemann, W.A.

1978-01-01

The results of two separate analyses are reported. The engine fragment analysis determined the probability of a small package being in the path of a fragment from a failure in a gas turbine engine. The calculated values show that, depending on aircraft type, the incidence rate varies by approximately an order of magnitude from a high of about once per 5 million flights to a low of nearly once every 40 million package flights for a flight of five hours' duration. The analysis of the crush environment consisted of an examination of two principal crush modes, i.e., vertical and longitudinal crush. The vertical crush mode was examined by formulating a structural model of the cargo deck beams of the aircraft. The longitudinal crush mode was studied by using dynamic models of the aircraft cargo and the radioactive material package (RAM). The results of the analysis of these crush modes provided the basis for the formulation of a 310 kN/(70,000 lb) crush test to simulate vertical crush. The longitudinal crush analysis indicated that it was possible, under infrequently occurring conditions, to produce extremely large crush forces and hence it was recommended that RAM packages be located in the aft end of aircraft cargo compartments to minimize the effects of longitudinal crush

The Second Joint NASA/FAA/DOD Conference on Aging Aircraft. Pt. 1

Science.gov (United States)

Harris, Charles E. (Editor)

1999-01-01

The purpose of the Conference was to bring together world leaders in aviation safety research, aircraft design and manufacturing, fleet operation and aviation maintenance to disseminate information on current practices and advanced technologies that will assure the continued airworthiness of the aging aircraft in the military and commercial fleets. The Conference included reviews of current industry practices, assessments of future technology requirements, and status of aviation safety research. The Conference provided an opportunity for interactions among the key personnel in the research and technology development community, the original equipment manufacturers, commercial airline operators, military fleet operators, aviation maintenance, and aircraft certification and regulatory authorities. Conference participation was unrestricted and open to the international aviation community.

Proposed Rule and Related Materials for Control of Emissions of Air Pollution From Nonroad Diesel Engines Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures

Science.gov (United States)

EPA is proposing to adopt emission standards and related provisions for aircraft gas turbine engines with rated thrusts greater than 26.7 kilonewtons. These engines are used primarily on commercial passenger and freight aircraft.

Ground impact probability distribution for small unmanned aircraft in ballistic descent

DEFF Research Database (Denmark)

La Cour-Harbo, Anders

2018-01-01

Safety is a key factor in all aviation, and while years of development has made manned aviation relatively safe, the same has yet to happen for unmanned aircraft. However, the rapid development of unmanned aircraft technology means that the range of commercial and scientific applications is growing...

Resin transfer molding for advanced composite primary aircraft structures

Science.gov (United States)

Markus, Alan; Palmer, Ray

1991-01-01

Resin Transfer Molding (RTM) has been identified by Douglas Aircraft Company (DAC) and industry to be one of the promising processes being developed today which can break the cost barrier of implementing composite primary structures into a commercial aircraft production environment. The RTM process developments and scale-up plans Douglas Aircrart will be conducting under the NASA ACT contract are discussed.

Large Field Photogrammetry Techniques in Aircraft and Spacecraft Impact Testing

Science.gov (United States)

Littell, Justin D.

2010-01-01

The Landing and Impact Research Facility (LandIR) at NASA Langley Research Center is a 240 ft. high A-frame structure which is used for full-scale crash testing of aircraft and rotorcraft vehicles. Because the LandIR provides a unique capability to introduce impact velocities in the forward and vertical directions, it is also serving as the facility for landing tests on full-scale and sub-scale Orion spacecraft mass simulators. Recently, a three-dimensional photogrammetry system was acquired to assist with the gathering of vehicle flight data before, throughout and after the impact. This data provides the basis for the post-test analysis and data reduction. Experimental setups for pendulum swing tests on vehicles having both forward and vertical velocities can extend to 50 x 50 x 50 foot cubes, while weather, vehicle geometry, and other constraints make each experimental setup unique to each test. This paper will discuss the specific calibration techniques for large fields of views, camera and lens selection, data processing, as well as best practice techniques learned from using the large field of view photogrammetry on a multitude of crash and landing test scenarios unique to the LandIR.

Fan Noise for a Concept Commercial Supersonic Transport

Science.gov (United States)

Stephens, David

2017-01-01

NASA is currently studying a commercial supersonic transport (CST) aircraft that could carry 35+ passengers at Mach 1.6+ with a 4000+nm range. The aircraft should also meet environmental goals for sonic boom, airport noise and emissions at cruise. With respect to airport noise, considerable effort has been put into predicting the noise due to the jet exhaust. This report describes an internal NASA effort to consider the contribution of fan noise to the overall engine noise of this class of aircraft.

Aircraft Design Software

Science.gov (United States)

1997-01-01

Successful commercialization of the AirCraft SYNThesis (ACSYNT) tool has resulted in the creation of Phoenix Integration, Inc. ACSYNT has been exclusively licensed to the company, an outcome of a seven year, $3 million effort to provide unique software technology to a focused design engineering market. Ames Research Center formulated ACSYNT and in working with the Virginia Polytechnic Institute CAD Laboratory, began to design and code a computer-aided design for ACSYNT. Using a Joint Sponsored Research Agreement, Ames formed an industry-government-university alliance to improve and foster research and development for the software. As a result of the ACSYNT Institute, the software is becoming a predominant tool for aircraft conceptual design. ACSYNT has been successfully applied to high- speed civil transport configuration, subsonic transports, and supersonic fighters.

IDENTIFICATION OF AIRCRAFT HAZARDS

International Nuclear Information System (INIS)

K.L. Ashley

2005-01-01

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7)

Identification of Aircraft Hazards

Energy Technology Data Exchange (ETDEWEB)

K. Ashley

2006-12-08

Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

Achievement report on research and development in the Sunshine Project in fiscal 1976. Comprehensive discussion on hydrogen utilizing subsystems and research on peripheral technologies (Research for aircraft engines); 1976 nendo suiso riyo subsystem no sogoteki kento to shuhen gijutsu ni kansuru kenkyu seika hokokusho. Koku engine ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-05-01

With an objective to utilize hydrogen fuel in aircraft engines, a conceptual design survey was carried out on medium size transport aircraft. Large size long-distance aircraft and SST loaded with a great amount of fuel have the jet fuel (JP) increase take-off weight, affecting largely the selection of wing area and engine thrust. If the hydrogen fuel can be liquefied, large reduction can be achieved and the economic effect can be increased. However, for short-distance transport aircraft, the fuel weight ratio is small, where no large advantage is anticipated even if hydrogen is liquefied. Nevertheless, considering oil depletion in the future, a conceptual design was performed on the YX2688 short-medium distance aircraft being discussed of development. Even the short-medium distance aircraft that can be developed and commercialized as civilian use aircraft has a number of common points with large aircraft development, such as hydrogen fuel using technologies and safety. Although the advantage of using liquefied hydrogen as fuel may of course be smaller in the short-medium distance aircraft than in larger aircraft, the trend of using hydrogen fuel is historical necessity, whose development plans should be moved forward. (NEDO)

V/STOL tilt rotor aircraft study. Volume 2: Preliminary design of research aircraft

Science.gov (United States)

1972-01-01

A preliminary design study was conducted to establish a minimum sized, low cost V/STOL tilt-rotor research aircraft with the capability of performing proof-of-concept flight research investigations applicable to a wide range of useful military and commercial configurations. The analysis and design approach was based on state-of-the-art methods and maximum use of off-the-shelf hardware and systems to reduce development risk, procurement cost and schedules impact. The rotors to be used are of 26 foot diameter and are the same as currently under construction and test as part of NASA Tilt-Rotor Contract NAS2-6505. The aircraft has a design gross weight of 12,000 lbs. The proposed engines to be used are Lycoming T53-L-13B rated at 1550 shaft horsepower which are fully qualified. A flight test investigation is recommended which will determine the capabilities and limitations of the research aircraft.

Environmental Aspects of Aircraft and Airfield Deicing - An Air Force Perspective

Science.gov (United States)

2010-11-01

e l l e n c e COD of Aircraft Deicers ADF Kg O2/Kg compd Ethylene glycol 1.14 T Propylene glycol 1.47 T Isopropyl alcohol 2.11 T Neopentyl glycol ...showed that commercial airports use about 25 million gallons of Aircraft Deicing Fluid (ADF) annually, of which 22.1 M (88%) is Propylene Glycol (PG...S e r v i c e - E x c e l l e n c e AF Aircraft Deicing Overview 70% (107) of bases reported using aircraft deicers Propylene Glycol (PG), AMS 1424

Aircraft Weather Mitigation for the Next Generation Air Transportation System

Science.gov (United States)

Stough, H. Paul, III

2007-01-01

Atmospheric effects on aviation are described by Mahapatra (1999) as including (1) atmospheric phenomena involving air motion - wind shear and turbulence; (2) hydrometeorological phenomena - rain, snow and hail; (3) aircraft icing; (4) low visibility; and (5) atmospheric electrical phenomena. Aircraft Weather Mitigation includes aircraft systems (e.g. airframe, propulsion, avionics, controls) that can be enacted (by a pilot, automation or hybrid systems) to suppress and/or prepare for the effects of encountered or unavoidable weather or to facilitate a crew operational decision-making process relative to weather. Aircraft weather mitigation can be thought of as a continuum (Figure 1) with the need to avoid all adverse weather at one extreme and the ability to safely operate in all weather conditions at the other extreme. Realistic aircraft capabilities fall somewhere between these two extremes. The capabilities of small general aviation aircraft would be expected to fall closer to the "Avoid All Adverse Weather" point, and the capabilities of large commercial jet transports would fall closer to the "Operate in All Weather Conditions" point. The ability to safely operate in adverse weather conditions is dependent upon the pilot s capabilities (training, total experience and recent experience), the airspace in which the operation is taking place (terrain, navigational aids, traffic separation), the capabilities of the airport (approach guidance, runway and taxiway lighting, availability of air traffic control), as well as the capabilities of the airplane. The level of mitigation may vary depending upon the type of adverse weather. For example, a small general aviation airplane may be equipped to operate "in the clouds" without outside visual references, but not be equipped to prevent airframe ice that could be accreted in those clouds.

Emerging nondestructive inspection methods for aging aircraft

Energy Technology Data Exchange (ETDEWEB)

Beattie, A; Dahlke, L; Gieske, J [and others

1994-01-01

This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with a discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.

Inerting Aircraft Fuel Systems Using Exhaust Gases

Science.gov (United States)

Hehemann, David G.

2002-01-01

Our purpose in this proposal was to determine the feasibility of using carbon dioxide, possibly obtained from aircraft exhaust gases as a substance to inert the fuel contained in fuel tanks aboard aircraft. To do this, we decided to look at the effects carbon dioxide has upon commercial Jet-A aircraft fuel. In particular, we looked at the solubility of CO2 in Jet-A fuel, the pumpability of CO2-saturated Jet-A fuel, the flashpoint of Jet-A fuel under various mixtures of air and CO2, the static outgassing of CO2-Saturated Jet-A fuel and the dynamic outgassing of Jet-A fuel during pumping of Jet-A fuel.

A Versatile Simulation Environment of FTC Architectures for Large Transport Aircraft

OpenAIRE

Ossmann, Daniel; Varga, Andreas; Simon, Hecker

2010-01-01

We present a simulation environment with 3-D stereo visualization facilities destined for an easy setup and versatile assessment of fault detection and diagnosis based fault tolerant control systems. This environment has been primarily developed as a technology demonstrator of advanced reconfigurable flight control systems and is based on a realistic six degree of freedom flexible aircraft model. The aircraft control system architecture includes a flexible fault detection and diagnosis syste...

Estimates of the initial vortex separation distance, bo, of commercial aircraft from pulsed lidar data

Science.gov (United States)

2013-01-07

An aircraft in flight generates multiple wake vortices, the largest of which are a result of : the lift on the wings. These vortices rapidly roll up into a counter-rotating vortex pair : behind the aircraft. The initial separation between the centroi...

Aircraft control surface failure detection and isolation using the OSGLR test. [orthogonal series generalized likelihood ratio

Science.gov (United States)

Bonnice, W. F.; Motyka, P.; Wagner, E.; Hall, S. R.

1986-01-01

The performance of the orthogonal series generalized likelihood ratio (OSGLR) test in detecting and isolating commercial aircraft control surface and actuator failures is evaluated. A modification to incorporate age-weighting which significantly reduces the sensitivity of the algorithm to modeling errors is presented. The steady-state implementation of the algorithm based on a single linear model valid for a cruise flight condition is tested using a nonlinear aircraft simulation. A number of off-nominal no-failure flight conditions including maneuvers, nonzero flap deflections, different turbulence levels and steady winds were tested. Based on the no-failure decision functions produced by off-nominal flight conditions, the failure detection and isolation performance at the nominal flight condition was determined. The extension of the algorithm to a wider flight envelope by scheduling on dynamic pressure and flap deflection is examined. Based on this testing, the OSGLR algorithm should be capable of detecting control surface failures that would affect the safe operation of a commercial aircraft. Isolation may be difficult if there are several surfaces which produce similar effects on the aircraft. Extending the algorithm over the entire operating envelope of a commercial aircraft appears feasible.

Analysing the effects of rigid and flexible aircraft dynamics on the ejection of a large store

CSIR Research Space (South Africa)

Jamison, Kevin

2011-09-01

Full Text Available duration ? ERU forces + store weight release causes aircraft ?g-jump? ? Period of ERU force is short enough to excite wing vibration modes ? ERU force/time & front/back force balance important for determining store separation rates from aircraft... ? Constrained motion in other DOF ? Used mass, inertias, CG of aircraft without Katleho ? Used trimmed forces of aircraft with Katleho ? Assumes delay in pilot response to g-jump ? CSIR 2011 Slide 14 Aircraft rigid accelerations Aircraft mass...

Assessment of NDE needs for aging corporate and private aircraft

Science.gov (United States)

Reinhart, Eugene R.

1998-03-01

Considerable attention has been focused on the life extension of ageing military and commercial aircraft by the government and major aircraft fabricators. A vital, but often neglected segment of the aircraft industry is the are of inspecting ageing fleets of corporate and privately-owned aircraft. Many of these aircraft are inspected and maintained by the various FAA-approved repair stations located around the country. Nondestructive inspection (NDI) methods, equipment, and trained inspectors are a key aspect of maintaining these aircraft; however, there are currently several issues that need to be addressed by the private sector NDI community. Personnel training and certification to an accepted standard is critically needed in this industry since experience and capability in NDI can vary considerably between FAA stations and inspectors. Also, the updating of NDI methods are standards is needed. A review of these issues and suggestions for improvement are presented.

Aircraft Anomaly Detection Using Performance Models Trained on Fleet Data

Science.gov (United States)

Gorinevsky, Dimitry; Matthews, Bryan L.; Martin, Rodney

2012-01-01

This paper describes an application of data mining technology called Distributed Fleet Monitoring (DFM) to Flight Operational Quality Assurance (FOQA) data collected from a fleet of commercial aircraft. DFM transforms the data into aircraft performance models, flight-to-flight trends, and individual flight anomalies by fitting a multi-level regression model to the data. The model represents aircraft flight performance and takes into account fixed effects: flight-to-flight and vehicle-to-vehicle variability. The regression parameters include aerodynamic coefficients and other aircraft performance parameters that are usually identified by aircraft manufacturers in flight tests. Using DFM, the multi-terabyte FOQA data set with half-million flights was processed in a few hours. The anomalies found include wrong values of competed variables, (e.g., aircraft weight), sensor failures and baises, failures, biases, and trends in flight actuators. These anomalies were missed by the existing airline monitoring of FOQA data exceedances.

41 CFR 301-70.802 - Must we ensure that travel on Government aircraft is the most cost-effective alternative?

Science.gov (United States)

2010-07-01

...— (i) Travel on a scheduled commercial airline; (ii) Travel on a Federal aircraft; (iii) Travel on a Government aircraft hired as a commercial aviation service (CAS); and (iv) Travel by other available modes of... non-travel related governmental function or for required use travel, using any space available for...

Atmospheric/climatic effects of aircraft emissions

International Nuclear Information System (INIS)

Pueschel, R.F.

1996-01-01

Exhaust emissions from aircraft include oxides of nitrogen (NO x ), water vapor (H 2 O), sulfur dioxide (SO 2 ), carbon dioxide (CO 2 ), carbon monoxide (CO), hydrocarbons (HC) and particles (soot and sulfates). These emissions are small compared to industrial/urban surface emissions. However, because (1) atmospheric residence times of exhaust constituents are longer at altitude, particularly in the stratosphere, than they are in the boundary layer, (2) their background concentrations at altitude are lower than those near the surface, (3) the radiation balance is the more sensitive to atmospheric trace constituents the colder the temperature aloft and (4) inter-hemispheric mixing of aircraft effluents is inhibited, aircraft emissions near and above the tropopause and polewards of 40 degrees latitude can be environmentally critical. That's why atmospheric/climatic effects of aircraft emissions have again received scientific, economic and political scrutiny in the last few years, motivated by growth of subsonic traffic at about 5% per year over the past two decades and the advent of a technologically feasible operation of a supersonic high speed commercial transport (HSCT) fleet

Opportunities for low carbon sustainability in large commercial buildings in China

International Nuclear Information System (INIS)

Jiang Ping; Keith Tovey, N.

2009-01-01

China's building sector consumes one quarter of total energy consumption in the country and plays an important role in long-term ability of the country to achieve sustainable development. This paper discusses a comprehensive approach to achieving low carbon sustainability in large commercial buildings in China incorporating both energy and carbon-reduction strategies. The approach concentrates primarily on three complementary aspects: (a) the introduction of an effective energy management system; (b) the incorporation of relevant advanced energy saving technologies and measures and (c) the promotion of awareness among occupants to make changes in their behaviour towards a more environmental-friendly behaviour. However, reference is also made to the role that renewable energy and offsetting may have in the effective management and environmental performance of buildings. Nine examples of large commercial buildings in Beijing and Shanghai were studied and the average electricity consumption of around 153 kWh/m 2 per annum is about 5 times higher than average electricity use in residential buildings. At the same time the associated green house gas (GHG) emissions are around 158 kg/m 2 per annum.

Offsite radiological consequence analysis for the bounding aircraft crash accident

International Nuclear Information System (INIS)

OBERG, B.D.

2003-01-01

The purpose of this calculation note is to quantitatively analyze a bounding aircraft crash accident for comparison to the DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', Appendix A, Evaluation Guideline of 25 rem. The potential of aircraft impacting a facility was evaluated using the approach given in DOE-STD-3014-96, ''Accident Analysis for Aircraft Crash into Hazardous Facilities''. The following aircraft crash FR-equencies were determined for the Tank Farms in RPP-11736, ''Assessment Of Aircraft Crash FR-equency For The Hanford Site 200 Area Tank Farms'': (1) The total aircraft crash FR-equency is ''extremely unlikely.'' (2) The general aviation crash FR-equency is ''extremely unlikely.'' (3) The helicopter crash FR-equency is ''beyond extremely unlikely.'' (4) For the Hanford Site 200 Areas, other aircraft type, commercial or military, each above ground facility, and any other type of underground facility is ''beyond extremely unlikely.'' As the potential of aircraft crash into the 200 Area tank farms is more FR-equent than ''beyond extremely unlikely,'' consequence analysis of the aircraft crash is required

On the unification of aircraft ultrafine particle emission data

Energy Technology Data Exchange (ETDEWEB)

Kaercher, B.; Busen, R. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Turco, R.P.; Yu Fangqun [California Univ., Los Angeles, CA (United States). Dept. of Atmospheric Sciences; Danilin, M.Y.; Weisenstein, D.K. [Atmospheric and Environmental Research, Inc., Cambridge, MA (United States); Miake-Lye, R.C. [Aerodyne Research, Inc., Billerica, MA (United States)

2000-03-01

To predict the environmental impacts of future commercial aviation, intensive studies have been launched to measure the properties and effects of aircraft emissions. These observations have revealed an extremely wide variance with respect to the number and sizes of the particles produced in the exhaust plumes. Aircraft aerosol ultimately contributes to the population of cloud-forming nuclei, and may lead to significant global radiative and chemical perturbations. In this paper, recent discoveries are coordinated and unified in the form of a physically consistent plume aerosol model that explains most of the observational variance. Using this new approach, it is now practical to carry out reliable global atmospheric simulations of aircraft effects, as demonstrated by a novel assessment of the perturbation of the stratospheric aerosol layer by a supersonic aircraft fleet. (orig.)

A trade-off analysis design tool. Aircraft interior noise-motion/passenger satisfaction model

Science.gov (United States)

Jacobson, I. D.

1977-01-01

A design tool was developed to enhance aircraft passenger satisfaction. The effect of aircraft interior motion and noise on passenger comfort and satisfaction was modelled. Effects of individual aircraft noise sources were accounted for, and the impact of noise on passenger activities and noise levels to safeguard passenger hearing were investigated. The motion noise effect models provide a means for tradeoff analyses between noise and motion variables, and also provide a framework for optimizing noise reduction among noise sources. Data for the models were collected onboard commercial aircraft flights and specially scheduled tests.

Passengers' perception of the safety demonstration on board an aircraft

Science.gov (United States)

Ruenruoy, Ratchada

The cabin safety demonstration on board an aircraft is one of the methods to provide safety information for passengers before aircraft takeoff. However, passengers' enthusiasm toward safety demonstrations is normally low. Therefore, the study of passengers' perception toward safety briefings on board an aircraft is important in increasing the safety awareness for the travelling public on commercial aircraft. A survey was distributed to measure the perceptions of Middle Tennessee State University (MTSU) faculty and staff, Aerospace students, and international students who have traveled in the last year. It was generally found that watching the cabin safety demonstration before aircraft takeoff was believed to be important for passengers. However, the attention to the safety demonstration remained low because the safety briefings were not good enough in terms of clear communication, particularly in the recorded audio demonstration and the live safety demonstration methods of briefing.

The Effects of Commercial Airline Traffic on LSST Observing Efficiency

Science.gov (United States)

Gibson, Rose; Claver, Charles; Stubbs, Christopher

2016-01-01

The Large Synoptic Survey Telescope (LSST) is a ten-year survey that will map the southern sky in six different filters 800 times before the end of its run. In this paper, we explore the primary effect of airline traffic on scheduling the LSST observations in addition to the secondary effect of condensation trails, or contrails, created by the presence of the aircraft. The large national investment being made in LSST implies that small improvments observing efficiency through aircraft and contrail avoidance can result in a significant improvement in the quality of the survey and its science. We have used the Automatic Dependent Surveillance-Broadcast (ADS-B) signals received from commercial aircraft to monitor and record activity over the LSST site. We installed a ADS-B ground station on Cerro Pachón, Chile consiting of a1090Mhz antenna on the Andes Lidar Observatory feeding a RTL2832U software defined radio. We used dump1090 to convert the received ADS-B telementry into Basestation format, where we found that during the busiest time of the night there were only 4 signals being received each minute on average, which will have very small direct effect, if any, on the LSST observing scheduler. As part of future studies we will examin the effects of contrals on LSST observations. Gibson was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experience for Undergraduates Program (AST-1262829).

The Second Joint NASA/FAA/DoD Conference on Aging Aircraft. Part 2

Science.gov (United States)

Harris, Charles E. (Editor)

1999-01-01

The purpose of the Conference was to bring together world leaders in aviation safety research, aircraft design and manufacturing, fleet operation and aviation maintenance to disseminate information on current practices and advanced technologies that will assure the continued airworthiness of the aging aircraft in the military and commercial fleets. The Conference included reviews of current industry practices, assessments of future technology requirements, and status of aviation safety research. The Conference provided an opportunity for interactions among the key personnel in the research and technology development community, the original equipment manufacturers, commercial airline operators, military fleet operators, aviation maintenance, and aircraft certification and regulatory authorities. Conference participation was unrestricted and open to the international aviation community. Appendix B contains the name and addresses of the 623 participants in the Conference.

Aircraft operability methods applied to space launch vehicles

Science.gov (United States)

Young, Douglas

1997-01-01

The commercial space launch market requirement for low vehicle operations costs necessitates the application of methods and technologies developed and proven for complex aircraft systems. The ``building in'' of reliability and maintainability, which is applied extensively in the aircraft industry, has yet to be applied to the maximum extent possible on launch vehicles. Use of vehicle system and structural health monitoring, automated ground systems and diagnostic design methods derived from aircraft applications support the goal of achieving low cost launch vehicle operations. Transforming these operability techniques to space applications where diagnostic effectiveness has significantly different metrics is critical to the success of future launch systems. These concepts will be discussed with reference to broad launch vehicle applicability. Lessons learned and techniques used in the adaptation of these methods will be outlined drawing from recent aircraft programs and implementation on phase 1 of the X-33/RLV technology development program.

Flight Loads Prediction of High Aspect Ratio Wing Aircraft Using Multibody Dynamics

Directory of Open Access Journals (Sweden)

Michele Castellani

2016-01-01

Full Text Available A framework based on multibody dynamics has been developed for the static and dynamic aeroelastic analyses of flexible high aspect ratio wing aircraft subject to structural geometric nonlinearities. Multibody dynamics allows kinematic nonlinearities and nonlinear relationships in the forces definition and is an efficient and promising methodology to model high aspect ratio wings, which are known to be prone to structural nonlinear effects because of the high deflections in flight. The multibody dynamics framework developed employs quasi-steady aerodynamics strip theory and discretizes the wing as a series of rigid bodies interconnected by beam elements, representative of the stiffness distribution, which can undergo arbitrarily large displacements and rotations. The method is applied to a flexible high aspect ratio wing commercial aircraft and both trim and gust response analyses are performed in order to calculate flight loads. These results are then compared to those obtained with the standard linear aeroelastic approach provided by the Finite Element Solver Nastran. Nonlinear effects come into play mainly because of the need of taking into account the large deflections of the wing for flight loads computation and of considering the aerodynamic forces as follower forces.

Perspectives on Highly Adaptive or Morphing Aircraft

Science.gov (United States)

McGowan, Anna-Maria R.; Vicroy, Dan D.; Busan, Ronald C.; Hahn, Andrew S.

2009-01-01

The ability to adapt to different flight conditions has been fundamental to aircraft design since the Wright Brothers first flight. Over a hundred years later, unconventional aircraft adaptability, often called aircraft morphing has become a topic of considerable renewed interest. In the past two decades, this interest has been largely fuelled by advancements in multi-functional or smart materials and structures. However, highly adaptive or morphing aircraft is certainly a cross-discipline challenge that stimulates a wide range of design possibilities. This paper will review some of the history of morphing aircraft including recent research programs and discuss some perspectives on this work.

Flight Dynamics Simulation Modeling and Control of a Large Flexible Tiltrotor Aircraft

Science.gov (United States)

2014-09-01

analyses as it retains a momentum theory type rotor system. Later, CAMRAD, a comprehensive aeromechanics and dynamics model capa- ble of multi-rotor and...isotropic, linearly elastic material. 8. All blades are identical. 9. Euler- Bernoulli beam theory is used, implying plane cross sections remain plane and...aircraft could be improved to achieve a higher fidelity structural response. Currently, flexible wings are modeled as Bernoulli beams. Actual aircraft

Advanced Airborne Defensive Laser for Incorporation on Strike Fighter Aircraft

Science.gov (United States)

2017-09-01

Systems within the Pod The Cyclops pod contains several systems working together to perform the high - level functions. The status of these systems must be...by the aircraft is limited, and Cyclops power requirements are high . commercial off-the-shelf (COTS) Ram Air Turbines are available and are...Supply Subsystem The Cyclops pod must generate its own power due to lack of available power from the aircraft; therefore, the Power supply has high

Discussion on the impact of large commercial airplane to nuclear power plant

International Nuclear Information System (INIS)

Tang Bo

2010-01-01

Briefly introducing the 10CFR50.150, draft guide and technical document of United States which is issued recently by NRC and NEI on impact of large commercial airplane to nuclear power plant, introducing comments from society and public and responses from NRC, and briefly discussing relevant issues. (author)

CFD analysis of aircraft fuel tanks thermal behaviour

Science.gov (United States)

Zilio, C.; Longo, G. A.; Pernigotto, G.; Chiacchio, F.; Borrelli, P.; D'Errico, E.

2017-11-01

This work is carried out within the FP7 European research project TOICA (Thermal Overall Integrated Conception of Aircraft, http://www.toica-fp7.eu/). One of the tasks foreseen for the TOICA project is the analysis of fuel tanks as possible heat sinks for future aircrafts. In particular, in the present paper, commercial regional aircraft is considered as case study and CFD analysis with the commercial code STAR-CCM+ is performed in order to identify the potential capability to use fuel stored in the tanks as a heat sink for waste heat dissipated by other systems. The complex physical phenomena that characterize the heat transfer inside liquid fuel, at the fuel-ullage interface and inside the ullage are outlined. Boundary conditions, including the effect of different ground and flight conditions, are implemented in the numerical simulation approach. The analysis is implemented for a portion of aluminium wing fuel tank, including the leading edge effects. Effect of liquid fuel transfer among different tank compartments and the air flow in the ullage is included. According to Fuel Tank Flammability Assessment Method (FTFAM) proposed by the Federal Aviation Administration, the results are exploited in terms of exponential time constants and fuel temperature difference to the ambient for the different cases investigated.

Acoustical design economic trade off for transport aircraft

Science.gov (United States)

Benito, A.

The effects of ICAO fixed certification limits and local ordinances on acoustic emissions from jets on commercial transport aircraft and costs of operations are explored. The regulations effectively ban some aircraft from operation over populated areas, impose curfews on airports and, in conjunction with local civil aviation rules, levy extra taxes and quotas on noisier equipment. Jet engine manufacturers have attempted to increase the flow laminarity, decrease the exhaust speed and develop acoustic liners for selected duct areas. Retrofits are, however, not usually cost effective due to increased operational costs, e.g., fuel consumption can increase after engine modification because of increased weight. Finally, an attempt is made to assess, monetarily, the costs of noise pollution, wherein fines are levied for noisy aircraft and the money is spent insulating homes from noise.

Active fault-tolerant control strategy of large civil aircraft under elevator failures

Directory of Open Access Journals (Sweden)

Wang Xingjian

2015-12-01

Full Text Available Aircraft longitudinal control is the most important actuation system and its failures would lead to catastrophic accident of aircraft. This paper proposes an active fault-tolerant control (AFTC strategy for civil aircraft with different numbers of faulty elevators. In order to improve the fault-tolerant flight control system performance and effective utilization of the control surface, trimmable horizontal stabilizer (THS is considered to generate the extra pitch moment. A suitable switching mechanism with performance improvement coefficient is proposed to determine when it is worthwhile to utilize THS. Furthermore, AFTC strategy is detailed by using model following technique and the proposed THS switching mechanism. The basic fault-tolerant controller is designed to guarantee longitudinal control system stability and acceptable performance degradation under partial elevators failure. The proposed AFTC is applied to Boeing 747-200 numerical model and simulation results validate the effectiveness of the proposed AFTC approach.

Future aircraft networks and schedules

Science.gov (United States)

Shu, Yan

2011-07-01

Because of the importance of air transportation scheduling, the emergence of small aircraft and the vision of future fuel-efficient aircraft, this thesis has focused on the study of aircraft scheduling and network design involving multiple types of aircraft and flight services. It develops models and solution algorithms for the schedule design problem and analyzes the computational results. First, based on the current development of small aircraft and on-demand flight services, this thesis expands a business model for integrating on-demand flight services with the traditional scheduled flight services. This thesis proposes a three-step approach to the design of aircraft schedules and networks from scratch under the model. In the first step, both a frequency assignment model for scheduled flights that incorporates a passenger path choice model and a frequency assignment model for on-demand flights that incorporates a passenger mode choice model are created. In the second step, a rough fleet assignment model that determines a set of flight legs, each of which is assigned an aircraft type and a rough departure time is constructed. In the third step, a timetable model that determines an exact departure time for each flight leg is developed. Based on the models proposed in the three steps, this thesis creates schedule design instances that involve almost all the major airports and markets in the United States. The instances of the frequency assignment model created in this thesis are large-scale non-convex mixed-integer programming problems, and this dissertation develops an overall network structure and proposes iterative algorithms for solving these instances. The instances of both the rough fleet assignment model and the timetable model created in this thesis are large-scale mixed-integer programming problems, and this dissertation develops subproblem schemes for solving these instances. Based on these solution algorithms, this dissertation also presents

Simulation Packages Expand Aircraft Design Options

Science.gov (United States)

2013-01-01

In 2001, NASA released a new approach to computational fluid dynamics that allows users to perform automated analysis on complex vehicle designs. In 2010, Palo Alto, California-based Desktop Aeronautics acquired a license from Ames Research Center to sell the technology. Today, the product assists organizations in the design of subsonic aircraft, space planes, spacecraft, and high speed commercial jets.

Quantification of crew workload imposed by communications-related tasks in commercial transport aircraft

Science.gov (United States)

Acton, W. H.; Crabtree, M. S.; Simons, J. C.; Gomer, F. E.; Eckel, J. S.

1983-01-01

Information theoretic analysis and subjective paired-comparison and task ranking techniques were employed in order to scale the workload of 20 communications-related tasks frequently performed by the captain and first officer of transport category aircraft. Tasks were drawn from taped conversations between aircraft and air traffic controllers (ATC). Twenty crewmembers performed subjective message comparisons and task rankings on the basis of workload. Information theoretic results indicated a broad range of task difficulty levels, and substantial differences between captain and first officer workload levels. Preliminary subjective data tended to corroborate these results. A hybrid scale reflecting the results of both the analytical and the subjective techniques is currently being developed. The findings will be used to select representative sets of communications for use in high fidelity simulation.

Sensors for in-flight lightning detection on aircraft

NARCIS (Netherlands)

Stelmashuk, V.; Deursen, van A.P.J.; Webster, M.

2008-01-01

Commercial passenger aircraft are on average struck by lightning once a year. The In-flight Lightning Strike Damage Assessment System (ILDAS) project is to develop and validate a prototype of a system capable of in-flight measurement of the current waveform and reconstruction of the path of

Flight service evaluation of Kevlar-49/epoxy composite panels in wide-bodied commercial transport aircraft

Science.gov (United States)

Stone, R. H.

1977-01-01

Kevlar-49 fairing panels, installed as flight service components on three L-1011s, were inspected after three years' service, and found to be performing satisfactorily. There are six Kevlar-49 panels on each aircraft, including sandwich and solid laminate wing-body panels, and 150 C service aft engine fairings. The service history to date indicates that Kevlar-49 epoxy composite materials have satisfactory service characteristics for use in aircraft secondary structure.

Review of Idealized Aircraft Wake Vortex Models

Science.gov (United States)

Ahmad, Nashat N.; Proctor, Fred H.; Duparcmeur, Fanny M. Limon; Jacob, Don

2014-01-01

Properties of three aircraft wake vortex models, Lamb-Oseen, Burnham-Hallock, and Proctor are reviewed. These idealized models are often used to initialize the aircraft wake vortex pair in large eddy simulations and in wake encounter hazard models, as well as to define matched filters for processing lidar observations of aircraft wake vortices. Basic parameters for each vortex model, such as peak tangential velocity and circulation strength as a function of vortex core radius size, are examined. The models are also compared using different vortex characterizations, such as the vorticity magnitude. Results of Euler and large eddy simulations are presented. The application of vortex models in the postprocessing of lidar observations is discussed.

Aircraft Wake Vortex Deformation in Turbulent Atmosphere

OpenAIRE

Hennemann, Ingo; Holzaepfel, Frank

2007-01-01

Large-scale distortion of aircraft wake vortices appears to play a crucial role for aircraft safety during approach and landing. Vortex distortion is investigated based on large eddy simulations of wake vortex evolution in a turbulent atmosphere. A vortex identification method is developed that can be adapted to the vortex scales of interest. Based on the identified vortex center tracks, a statistics of vortex curvature radii is established. This statistics constitutes the basis for understan...

Food-poisoning and commercial air travel.

Science.gov (United States)

McMullan, R; Edwards, P J; Kelly, M J; Millar, B C; Rooney, P J; Moore, J E

2007-09-01

With the introduction of budget airlines and greater competitiveness amongst all airlines, air travel has now become an extremely popular form of travel, presenting its own unique set of risks from food poisoning. Foodborne illness associated with air travel is quite uncommon in the modern era. However, when it occurs, it may have serious implications for passengers and when crew are affected, has the potential to threaten safety. Quality, safe, in-flight catering relies on high standards of food preparation and storage; this applies at the airport kitchens (or at subcontractors' facilities), on the aircraft and in the transportation vehicles which carry the food from the ground source to the aircraft. This is especially challenging in certain countries. Several foodborne outbreaks have been recorded by the airline industry as a result of a number of different failures of these systems. These have provided an opportunity to learn from past mistakes and current practice has, therefore, reached such a standard so as to minimise risk of failures of this kind. This review examines: (i) the origin of food safety in modern commercial aviation; (ii) outbreaks which have occurred previously relating to aviation travel; (iii) the microbiological quality of food and water on board commercial aircraft; and (iv) how Hazard Analysis Critical Control Points may be employed to maintain food safety in aviation travel.

Assessment of the probability of an aircraft accidentally crashing on a nuclear power station

International Nuclear Information System (INIS)

Gravero; Lezer; Lucenet

1975-01-01

The probability of an accidental aircraft crash on a power station not situated near a commercial airport is assessed. Three major points in the general analysis of the problem are developed: analysis of accidents as a function of the phase of the flight and in particular during a flight in transit and examin-ation of aircraft crash conditions to determine the angle of impact on the reactor building for example; determination of the apparent surface of buildings allowing for several parameters: geometry of the building and of the aircraft, geography of the site, relative position of the buildings; assessment of air traffic above the region for the year under consideration distinguishing the weight of the aircraft which implies an investigation of the problem for commercial aviation on the one hand (regular or irregular flights, inter-national or internal) and for general aviation on the other hand. The analysis is determined for the years 1980 - 2000 so that ir will be necessary to extrapolate some of the parameters (development of air traffic, safety of transport, etc). (author)

78 FR 23698 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Science.gov (United States)

2013-04-22

... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Corporation (Sikorsky) Model S-92A helicopters to require modifying the No. 1 engine forward firewall center... Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street...

A methodology to enable rapid evaluation of aviation environmental impacts and aircraft technologies

Science.gov (United States)

Becker, Keith Frederick

Commercial aviation has become an integral part of modern society and enables unprecedented global connectivity by increasing rapid business, cultural, and personal connectivity. In the decades following World War II, passenger travel through commercial aviation quickly grew at a rate of roughly 8% per year globally. The FAA's most recent Terminal Area Forecast predicts growth to continue at a rate of 2.5% domestically, and the market outlooks produced by Airbus and Boeing generally predict growth to continue at a rate of 5% per year globally over the next several decades, which translates into a need for up to 30,000 new aircraft produced by 2025. With such large numbers of new aircraft potentially entering service, any negative consequences of commercial aviation must undergo examination and mitigation by governing bodies so that growth may still be achieved. Options to simultaneously grow while reducing environmental impact include evolution of the commercial fleet through changes in operations, aircraft mix, and technology adoption. Methods to rapidly evaluate fleet environmental metrics are needed to enable decision makers to quickly compare the impact of different scenarios and weigh the impact of multiple policy options. As the fleet evolves, interdependencies may emerge in the form of tradeoffs between improvements in different environmental metrics as new technologies are brought into service. In order to include the impacts of these interdependencies on fleet evolution, physics-based modeling is required at the appropriate level of fidelity. Evaluation of environmental metrics in a physics-based manner can be done at the individual aircraft level, but will then not capture aggregate fleet metrics. Contrastingly, evaluation of environmental metrics at the fleet level is already being done for aircraft in the commercial fleet, but current tools and approaches require enhancement because they currently capture technology implementation through post

Preliminary safety evaluation of an aircraft impact on a near-surface radioactive waste repository

Energy Technology Data Exchange (ETDEWEB)

Lo Frano, R.; Forasassi, G.; Pugliese, G. [Department of Industrial and Civil Engineering (DICI), University of Pisa, Pisa (Italy)

2013-07-01

The aircraft impact accident has become very significant in the design of a nuclear facilities, particularly, after the tragic September 2001 event, that raised the public concern about the potential damaging effects that the impact of a large civilian airplane could bring in safety relevant structures. The aim of this study is therefore to preliminarily evaluate the global response and the structural effects induced by the impact of a military or commercial airplane (actually considered as a 'beyond design basis' event) into a near surface radioactive waste (RWs) disposal facility. The safety evaluation was carried out according to the International safety and design guidelines and in agreement with the stress tests requirements for the security track. To achieve the purpose, a lay out and a scheme of a possible near surface repository, like for example those of the El Cabril one, were taken into account. In order to preliminarily perform a reliable analysis of such a large-scale structure and to determine the structural effects induced by such a types of impulsive loads, a realistic, but still operable, numerical model with suitable materials characteristics was implemented by means of FEM codes. In the carried out structural analyses, the RWs repository was considered a 'robust' target, due to its thicker walls and main constitutive materials (steel and reinforced concrete). In addition to adequately represent the dynamic response of repository under crashing, relevant physical phenomena (i.e. penetration, spalling, etc.) were simulated and analysed. The preliminary assessment of the effects induced by the dynamic/impulsive loads allowed generally to verify the residual strength capability of the repository considered. The obtained preliminary results highlighted a remarkable potential to withstand the impact of military/large commercial aircraft, even in presence of ongoing concrete progressive failure (some penetration and spalling of the

Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

Directory of Open Access Journals (Sweden)

Gino Rinaldi

2012-01-01

Full Text Available Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.

Fuel leak detection on large transport airplanes

OpenAIRE

Behbahani-Pour, M.J.; Radice, G.

2016-01-01

Fuel leakage has the risk of being ignited by external ignition sources, and therefore it is important to detect\\ud any fuel leakage before the departure of the aircraft. Currently, there are no fuel leak detection systems installed\\ud on commercial aircrafts, to detect fuel tank leakage, while only a small number of more recent aircraft, have a fuel\\ud monitoring system, that generates a fuel leak-warning message in cockpit in the case of fuel imbalance between the\\ud tanks. The approach pro...

Investigation of Practical Flight Control Systems for Small Aircraft

NARCIS (Netherlands)

Falkena, W.

2012-01-01

Personal air transportation utilizing small aircraft is a market that is expected to grow significantly in the near future. However, seventy times more accidents occur in this segment as compared with the commercial aviation sector. The majority of these accidents is related to handling and control

Full-Scale Structural and NDI Validation Tests of Bonded Composite Doublers for Commercial Aircraft Applications

Energy Technology Data Exchange (ETDEWEB)

Roach, D.; Walkington, P.

1999-02-01

Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is possible to bond a single Boron-Epoxy composite doubler to the damaged structure. Most of the concerns surrounding composite doubler technology pertain to long-term survivability, especially in the presence of non-optimum installations, and the validation of appropriate inspection procedures. This report focuses on a series of full-scale structural and nondestructive inspection (NDI) tests that were conducted to investigate the performance of Boron-Epoxy composite doublers. Full-scale tests were conducted on fuselage panels cut from retired aircraft. These full-scale tests studied stress reductions, crack mitigation, and load transfer capabilities of composite doublers using simulated flight conditions of cabin pressure and axial stress. Also, structures which modeled key aspects of aircraft structure repairs were subjected to extreme tension, shear and bending loads to examine the composite laminate's resistance to disbond and delamination flaws. Several of the structures were loaded to failure in order to determine doubler design margins. Nondestructive inspections were conducted throughout the test series in order to validate appropriate techniques on actual aircraft structure. The test results showed that a properly designed and installed composite doubler is able to enhance fatigue life, transfer load away from damaged structure, and avoid the introduction of new stress risers (i.e. eliminate global reduction in the fatigue life of the structure). Comparisons with test data obtained prior to the doubler installation revealed that stresses in the parent material can be reduced 30%--60% through the use of the composite doubler. Tests to failure demonstrated that the bondline is able to transfer plastic strains into the doubler and that

Propulsion Study for Small Transport Aircraft Technology (STAT)

Science.gov (United States)

Gill, J. C.; Earle, R. V.; Staton, D. V.; Stolp, P. C.; Huelster, D. S.; Zolezzi, B. A.

1980-01-01

Propulsion requirements were determined for 0.5 and 0.7 Mach aircraft. Sensitivity studies were conducted on both these aircraft to determine parametrically the influence of propulsion characteristics on aircraft size and direct operating cost (DOC). Candidate technology elements and design features were identified and parametric studies conducted to select the STAT advanced engine cycle. Trade off studies were conducted to determine those advanced technologies and design features that would offer a reduction in DOC for operation of the STAT engines. These features were incorporated in the two STAT engines. A benefit assessment was conducted comparing the STAT engines to current technology engines of the same power and to 1985 derivatives of the current technology engines. Research and development programs were recommended as part of an overall technology development plan to ensure that full commercial development of the STAT engines could be initiated in 1988.

Measurements of Long-Lived Trace Gases from Commercial Aircraft Platforms: Development of Instrumentation

Science.gov (United States)

2002-01-01

The upper troposphere (6-12 km altitude) is a poorly understood and highly vulnerable region of the atmosphere. It is important because many trace species, including ozone, have their greatest impact as greenhouse (infrared-absorbing) gases in this region. The addition of relatively small amounts of anthropogenic chemicals, such as nitrogen oxides, can have a dramatic effect on the abundance of ozone. Some of these pollutants are deposited directly, e.g., by aircraft, while others are transported in. The primary goal of this project was to measure several chemical compounds in the upper troposphere that will help us to understand how air is to transported to that part of the atmosphere; that is, does it come down from the stratosphere, does it rise from the surface via convection, and so on. To obtain adequate sampling to accomplish this goal, we proposed to make measurements from revenue aircraft during normal flight operations.

Air Traffic Controller Acceptability of Unmanned Aircraft System Detect-and-Avoid Thresholds

Science.gov (United States)

Mueller, Eric R.; Isaacson, Douglas R.; Stevens, Derek

2016-01-01

A human-in-the-loop experiment was conducted with 15 retired air traffic controllers to investigate two research questions: (a) what procedures are appropriate for the use of unmanned aircraft system (UAS) detect-and-avoid systems, and (b) how long in advance of a predicted close encounter should pilots request or execute a separation maneuver. The controller participants managed a busy Oakland air route traffic control sector with mixed commercial/general aviation and manned/UAS traffic, providing separation services, miles-in-trail restrictions and issuing traffic advisories. Controllers filled out post-scenario and post-simulation questionnaires, and metrics were collected on the acceptability of procedural options and temporal thresholds. The states of aircraft were also recorded when controllers issued traffic advisories. Subjective feedback indicated a strong preference for pilots to request maneuvers to remain well clear from intruder aircraft rather than deviate from their IFR clearance. Controllers also reported that maneuvering at 120 seconds until closest point of approach (CPA) was too early; maneuvers executed with less than 90 seconds until CPA were more acceptable. The magnitudes of the requested maneuvers were frequently judged to be too large, indicating a possible discrepancy between the quantitative UAS well clear standard and the one employed subjectively by manned pilots. The ranges between pairs of aircraft and the times to CPA at which traffic advisories were issued were used to construct empirical probability distributions of those metrics. Given these distributions, we propose that UAS pilots wait until an intruder aircraft is approximately 80 seconds to CPA or 6 nmi away before requesting a maneuver, and maneuver immediately if the intruder is within 60 seconds and 4 nmi. These thresholds should make the use of UAS detect and avoid systems compatible with current airspace procedures and controller expectations.

Deep-UV patterning of commercial grade PMMA for low-cost, large-scale microfluidics

International Nuclear Information System (INIS)

Haiducu, M; Rahbar, M; Foulds, I G; Johnstone, R W; Sameoto, D; Parameswaran, M

2008-01-01

Although PMMA can be exposed using a variety of exposure sources, deep-UV at 254 nm is of interest because it is relatively inexpensive. Additionally, deep-UV sources can be readily scaled to large area exposures. Moreover, this paper will show that depths of over 100µm can be created in commercial grade PMMA using an uncollimated source. These depths are sufficient for creating microfluidic channels. This paper will provide measurements of the dissolution depth of commercial grade PMMA as a function of the exposure dose and etch time, using an IPA:H 2 O developer. Additionally, experiments were run to characterize the dependence of the dissolution rate on temperature and agitation. The patterned substrates were thermally bonded to blank PMMA pieces to enclose the channels and ports were drilled into the reservoirs. The resulting fluidic systems were then tested for leakage. The work herein presents the patterning, development and system behaviour of a complete microfluidics system based on commercial grade PMMA

Cost Analysis for Large Civil Transport Rotorcraft

Science.gov (United States)

Coy, John J.

2006-01-01

This paper presents cost analysis of purchase price and DOC+I (direct operating cost plus interest) that supports NASA s study of three advanced rotorcraft concepts that could enter commercial transport service within 10 to 15 years. The components of DOC+I are maintenance, flight crew, fuel, depreciation, insurance, and finance. The cost analysis aims at VTOL (vertical takeoff and landing) and CTOL (conventional takeoff and landing) aircraft suitable for regional transport service. The resulting spreadsheet-implemented cost models are semi-empirical and based on Department of Transportation and Army data from actual operations of such aircraft. This paper describes a rationale for selecting cost tech factors without which VTOL is more costly than CTOL by a factor of 10 for maintenance cost and a factor of two for purchase price. The three VTOL designs selected for cost comparisons meet the mission requirement to fly 1,200 nautical miles at 350 knots and 30,000 ft carrying 120 passengers. The lowest cost VTOL design is a large civil tilt rotor (LCTR) aircraft. With cost tech factors applied, the LCTR is reasonably competitive with the Boeing 737-700 when operated in economy regional service following the business model of the selected baseline operation, that of Southwest Airlines.

Methanol commercial aviation fuel

International Nuclear Information System (INIS)

Price, R.O.

1992-01-01

Southern California's heavy reliance on petroleum-fueled transportation has resulted in significant air pollution problems within the south Coast Air Basin (Basin) which stem directly from this near total dependence on fossil fuels. To deal with this pressing issue, recently enacted state legislation has proposed mandatory introduction of clean alternative fuels into ground transportation fleets operating within this area. The commercial air transportation sector, however, also exerts a significant impact on regional air quality which may exceed emission gains achieved in the ground transportation sector. This paper addresses the potential, through the implementation of methanol as a commercial aviation fuel, to improve regional air quality within the Basin and the need to flight test and demonstrate methanol as an environmentally preferable fuel in aircraft turbine engines

A Study of the Utilization of Advanced Composites in Fuselage Structures of Commercial Aircraft

Science.gov (United States)

Watts, D. J.; Sumida, P. T.; Bunin, B. L.; Janicki, G. S.; Walker, J. V.; Fox, B. R.

1985-01-01

A study was conducted to define the technology and data needed to support the introduction of advanced composites in the future production of fuselage structure in large transport aircraft. Fuselage structures of six candidate airplanes were evaluated for the baseline component. The MD-100 was selected on the basis of its representation of 1990s fuselage structure, an available data base, its impact on the schedule and cost of the development program, and its availability and suitability for flight service evaluation. Acceptance criteria were defined, technology issues were identified, and a composite fuselage technology development plan, including full-scale tests, was identified. The plan was based on composite materials to be available in the mid to late 1980s. Program resources required to develop composite fuselage technology are estimated at a rough order of magnitude to be 877 man-years exclusive of the bird strike and impact dynamic test components. A conceptual composite fuselage was designed, retaining the basic MD-100 structural arrangement for doors, windows, wing, wheel wells, cockpit enclosure, major bulkheads, etc., resulting in a 32 percent weight savings.

Frequency Analysis of Aircraft hazards for License Application

International Nuclear Information System (INIS)

K. Ashley

2006-01-01

The preclosure safety analysis for the monitored geologic repository at Yucca Mountain must consider the hazard that aircraft may pose to surface structures. Relevant surface structures are located beneath the restricted airspace of the Nevada Test Site (NTS) on the eastern slope of Yucca Mountain, near the North Portal of the Exploratory Studies Facility Tunnel (Figure 1). The North Portal is located several miles from the Nevada Test and Training Range (NTTR), which is used extensively by the U.S. Air Force (USAF) for training and test flights (Figure 1). The NTS airspace, which is controlled by the U.S. Department of Energy (DOE) for NTS activities, is not part of the NTTR. Agreements with the DOE allow USAF aircraft specific use of the airspace above the NTS (Reference 2.1.1 [DIRS 103472], Section 3.1.1 and Appendix A, Section 2.1; and Reference 2.1.2 [DIRS 157987], Sections 1.26 through 1.29). Commercial, military, and general aviation aircraft fly within several miles to the southwest of the repository site in the Beatty Corridor, which is a broad air corridor that runs approximately parallel to U.S. Highway 95 and the Nevada-California border (Figure 2). These aircraft and other aircraft operations are identified and described in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Sections 6 and 8). The purpose of this analysis is to estimate crash frequencies for aircraft hazards identified for detailed analysis in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Section 8). Reference 2.1.3, Section 8, also identifies a potential hazard associated with electronic jamming, which will be addressed in this analysis. This analysis will address only the repository and not the transportation routes to the site. The analysis is intended to provide the basis for: (1) Categorizing event sequences related to aircraft hazards; (2) Identifying design or operational requirements related to aircraft hazards

Frequency Analysis of Aircraft hazards for License Application

Energy Technology Data Exchange (ETDEWEB)

K. Ashley

2006-10-24

The preclosure safety analysis for the monitored geologic repository at Yucca Mountain must consider the hazard that aircraft may pose to surface structures. Relevant surface structures are located beneath the restricted airspace of the Nevada Test Site (NTS) on the eastern slope of Yucca Mountain, near the North Portal of the Exploratory Studies Facility Tunnel (Figure 1). The North Portal is located several miles from the Nevada Test and Training Range (NTTR), which is used extensively by the U.S. Air Force (USAF) for training and test flights (Figure 1). The NTS airspace, which is controlled by the U.S. Department of Energy (DOE) for NTS activities, is not part of the NTTR. Agreements with the DOE allow USAF aircraft specific use of the airspace above the NTS (Reference 2.1.1 [DIRS 103472], Section 3.1.1 and Appendix A, Section 2.1; and Reference 2.1.2 [DIRS 157987], Sections 1.26 through 1.29). Commercial, military, and general aviation aircraft fly within several miles to the southwest of the repository site in the Beatty Corridor, which is a broad air corridor that runs approximately parallel to U.S. Highway 95 and the Nevada-California border (Figure 2). These aircraft and other aircraft operations are identified and described in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Sections 6 and 8). The purpose of this analysis is to estimate crash frequencies for aircraft hazards identified for detailed analysis in ''Identification of Aircraft Hazards'' (Reference 2.1.3, Section 8). Reference 2.1.3, Section 8, also identifies a potential hazard associated with electronic jamming, which will be addressed in this analysis. This analysis will address only the repository and not the transportation routes to the site. The analysis is intended to provide the basis for: (1) Categorizing event sequences related to aircraft hazards; (2) Identifying design or operational requirements related to aircraft hazards.

Aircraft engines. IV

Energy Technology Data Exchange (ETDEWEB)

Ruffles, P C

1989-01-01

Configurational design and thermodynamic performance gain trends are projected into the next 50 years, in view of the growing interest of aircraft manufacturers in both larger and more efficient high-bypass turbofan engines for subsonic flight and variable cycle engines for supersonic flight. Ceramic- and metal-matrix composites are envisioned as the key to achievement of turbine inlet temperatures 300 C higher than the 1400 C which is characteristic of the state-of-the-art, with the requisite high stiffness, strength, and low density. Such fiber-reinforced materials can be readily tailored to furnish greatest strength in a specific direction of loading. Large, low-density engines are critical elements of future 1000-seat aircraft.

A design for KLM Aircraft Services' Planning-rostering indeling chain

NARCIS (Netherlands)

Dekkers, K J.P.

2010-01-01

This report describes a Logistics Management Systems design project that is performed at KLM Aircraft Services (AS). AS is the part of KLM that is responsible for a large portion of the tasks that must be done to an aircraft that has landed and has to be used again. When an aircraft has landed the

Analysis of technology requirements and potential demand for general aviation avionics systems in the 1980's. [technology assessment and technological forecasting of the aircraft industry

Science.gov (United States)

Cohn, D. M.; Kayser, J. H.; Senko, G. M.; Glenn, D. R.

1974-01-01

The trend for the increasing need for aircraft-in-general as a major source of transportation in the United States is presented (military and commercial aircraft are excluded). Social, political, and economic factors that affect the aircraft industry are considered, and cost estimates are given. Aircraft equipment and navigation systems are discussed.

Radiation Safety Issues in High Altitude Commercial Aircraft

Science.gov (United States)

Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.

1995-01-01

The development of a global economy makes the outlook for high speed commercial intercontinental flight feasible, and the development of various configurations operating from 20 to 30 km have been proposed. In addition to the still unresolved issues relating to current commercial operations (12-16 km), the higher dose rates associated with the higher operating altitudes makes il imperative that the uncertainties in the atmospheric radiation environment and the associated health risks be re-examined. Atmospheric radiation associated with the galactic cosmic rays forms a background level which may, under some circumstances, exceed newly recommended allowable exposure limits proposed on the basis of recent evaluations of the A -bomb survivor data (due to increased risk coefficients). These larger risk coefficients, within the context of the methodology for estimating exposure limits, are resulting in exceedingly low estimated allowable exposure limits which may impact even present day flight operations and was the reason for the CEC workshop in Luxembourg (1990). At higher operating altitudes, solar particles events can produce exposures many orders of magnitude above background levels and pose significant health risks to the most sensitive individuals (such as during pregnancy). In this case the appropriate quality factors are undefined, and some evidence exists which indicates that the quality factor for stochastic effects is a substantial underestimate.

No Winglets: What a Drag...Argument for Adding Winglets to Large Air Force Aircraft

Science.gov (United States)

2008-01-01

prices have once again brought improving aircraft aerodynamic efficiencies to the forefront of the energy conservation debate. Displaying how winglets ... winglet . Winglets are small, nearly vertical aerodynamic surfaces mounted on aircraft wingtips. Engineers design them with the same careful attention to...total drag.6 Since winglets , designed as small airfoils, reduce the aerodynamic drag associated with vortices by minimizing the amount of energy used

Molecular bacterial diversity and bioburden of commercial airliner cabin air

Energy Technology Data Exchange (ETDEWEB)

La Duc, M.T.; Stuecker, T.; Venkateswaran, K. [California Inst. of Technology, Pasadena, CA (United States). Jet Propulsion Laboratory, Biotechnology and Planetary Protection Group

2007-11-15

Microorganisms that exist in aircraft air systems are considered to be the primary source of microbial contamination that can lead to illness shortly after flying. More than 600 million passengers board commercial airline flights annually in the United States alone. In this study, culture-independent, biomarker-targeted bacterial enumeration and identification strategies were used to estimate total bacterial burden and diversity within the cabin air of commercial airliners. Air-impingement was used to collect samples of microorganisms from 4 flights on 2 commercial carriers. The total viable microbial population ranged from below detection limits to 4.1 x 10{sup 6} cells/m{sup 3} of air. Microbes were found to gradually accumulate from the time of passenger boarding through mid-flight. A sharp decline in bacterial abundance was then observed. Representatives of the {alpha}, {beta} and {gamma} Proteobacteria, as well as Gram-positive bacteria, were isolated in varying abundance. Airline A had large abundances of Neisseria meningitidis rRNA gene sequences and Streptococcus oralis/mitis sequences. Airline B was dominated by pseudomonas synxantha sequences as well as N. meningitidis and S. oralis/mitis. The cabin air samples housed low bacterial diversity and were typically dominated by a particular subset of bacteria, notably opportunistic pathogenic inhabitants of the human respiratory tract and oral cavity. The microbes were found largely around the ventilation ducts and gasper conduits that supply cabin air. 45 refs., 4 tabs., 3 figs.

Aircraft Fuel Cell Power Systems

Science.gov (United States)

Needham, Robert

2004-01-01

In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results

Airsickness and aircraft motion during short-haul flights.

Science.gov (United States)

Turner, M; Griffin, M J; Holland, I

2000-12-01

There is little quantitative information that can be used to predict the incidence of airsickness from the motions experienced in military or civil aviation. This study examines the relationship between low-frequency aircraft motion and passenger sickness in short-haul turboprop flights within the United Kingdom. A questionnaire survey of 923 fare-paying passengers was conducted on 38 commercial airline flights. Concurrent measurements of aircraft motion were made on all journeys, yielding approximately 30 h of aircraft motion data. Overall, 0.5% of passengers reported vomiting, 8.4% reported nausea (range 0% to 34.8%) and 16.2% reported illness (range 0% to 47.8%) during flight. Positive correlations were found between the percentage of passengers who experienced nausea or felt ill and the magnitude of low-frequency lateral and vertical motion, although neither motion uniquely predicted airsickness. The incidence of motion sickness also varied with passenger age, gender, food consumption and activity during air travel. No differences in sickness were found between passengers located in different seating sections of the aircraft, or as a function of moderate levels of alcohol consumption. The passenger responses suggest that a useful prediction of airsickness can be obtained from magnitudes of low frequency aircraft motion. However, some variations in airsickness may also be explained by individual differences between passengers and their psychological perception of flying.

Suicide and Murder-Suicide Involving Aircraft.

Science.gov (United States)

Kenedi, Christopher; Friedman, Susan Hatters; Watson, Dougal; Preitner, Claude

2016-04-01

This is a systematic review of suicide and homicide-suicide events involving aircraft. In aeromedical literature and in the media, these very different events are both described as pilot suicide, but in psychiatry they are considered separate events with distinct risk factors. Medical databases, internet search engines, and aviation safety databases were searched in a systematic way to obtain relevant cases. Relevant articles were searched for additional references. There were 65 cases of pilot suicide and 6 cases of passengers who jumped from aircraft found. There were also 18 cases of homicide-suicide found involving 732 deaths. Pilots perpetrated 13 homicide-suicide events. Compared to non-aviation samples, a large percentage of pilot suicides in this study were homicide-suicides (17%). Homicide-suicide events occur extremely rarely. However, their impact in terms of the proportion of deaths is significant when compared to deaths from accidents. There is evidence of clustering where pilot suicides occur after by media reports of suicide or homicide-suicide. Five of six homicide-suicide events by pilots of commercial airliners occurred after they were left alone in the cockpit. This, along with a sixth incident in which active intervention by a Japan Air crew saved 147 lives, suggests that having two flight members in the cockpit is potentially protective. No single factor was associated with the risk for suicide or homicide-suicide. Factors associated with both events included legal and financial crises, occupational conflict, mental illness, and relationship stressors. Drugs and/or alcohol played a role in almost half of suicides, but not in homicide-suicides.

Conceptual design study of 1985 commercial tilt rotor transports. Volume 3. STOL design summary. Final report

Energy Technology Data Exchange (ETDEWEB)

Sambell, K.W.

1976-04-01

A conceptual design study is presented of 1,985 commercial tilt rotor STOL transports for a NASA 200 n. mi. (370 km) STOL Mission. A 100-passenger STOL Variant (Bell D313) of the Phase I VTOL Tilt Rotor Aircraft is defined. Aircraft characteristics are given; with the aircraft redesigned to meet 2,000-foot (610 m) field criteria, with emphasis on low fuel consumption and low direct operating cost. The 100-passenger STOL Tilt Rotor Aircraft was analyzed for performance, weights, economics, handling qualities, noise footprint and aeroelastic stability. (GRA)

Bayesian Software Health Management for Aircraft Guidance, Navigation, and Control

Science.gov (United States)

Schumann, Johann; Mbaya, Timmy; Menghoel, Ole

2011-01-01

Modern aircraft, both piloted fly-by-wire commercial aircraft as well as UAVs, more and more depend on highly complex safety critical software systems with many sensors and computer-controlled actuators. Despite careful design and V&V of the software, severe incidents have happened due to malfunctioning software. In this paper, we discuss the use of Bayesian networks (BNs) to monitor the health of the on-board software and sensor system, and to perform advanced on-board diagnostic reasoning. We will focus on the approach to develop reliable and robust health models for the combined software and sensor systems.

77 FR 39648 - Atlantic Highly Migratory Species; Commercial Gulf of Mexico Non-Sandbar Large Coastal Shark Fishery

Science.gov (United States)

2012-07-05

... Large Coastal Shark Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... commercial fishery for non-sandbar large coastal sharks (LCS) in the Gulf of Mexico region. This action is.... SUPPLEMENTARY INFORMATION: The Atlantic shark fisheries are managed under the 2006 Consolidated Atlantic Highly...

Exploitation of commercial remote sensing images: reality ignored?

Science.gov (United States)

Allen, Paul C.

1999-12-01

The remote sensing market is on the verge of being awash in commercial high-resolution images. Market estimates are based on the growing numbers of planned commercial remote sensing electro-optical, radar, and hyperspectral satellites and aircraft. EarthWatch, Space Imaging, SPOT, and RDL among others are all working towards launch and service of one to five meter panchromatic or radar-imaging satellites. Additionally, new advances in digital air surveillance and reconnaissance systems, both manned and unmanned, are also expected to expand the geospatial customer base. Regardless of platform, image type, or location, each system promises images with some combination of increased resolution, greater spectral coverage, reduced turn-around time (request-to- delivery), and/or reduced image cost. For the most part, however, market estimates for these new sources focus on the raw digital images (from collection to the ground station) while ignoring the requirements for a processing and exploitation infrastructure comprised of exploitation tools, exploitation training, library systems, and image management systems. From this it would appear the commercial imaging community has failed to learn the hard lessons of national government experience choosing instead to ignore reality and replicate the bias of collection over processing and exploitation. While this trend may be not impact the small quantity users that exist today it will certainly adversely affect the mid- to large-sized users of the future.

Studying impact damage on carbon-fiber reinforced aircraft composite panels with sonicir

International Nuclear Information System (INIS)

Han Xiaoyan; Zhang Ding; He Qi; Song Yuyang; Lubowicki, Anthony; Zhao Xinyue; Newaz, Golam.; Favro, Lawrence D.; Thomas, Robert L.

2011-01-01

Composites are becoming more important materials in commercial aircraft structures such as the fuselage and wings with the new B787 Dreamliner from Boeing which has the target to utilize 50% by weight of composite materials. Carbon-fiber reinforced composites are the material of choice in aircraft structures. This is due to their light weight and high strength (high strength-to-weight ratio), high specific stiffness, tailorability of properties, design flexibility etc. Especially, by reducing the aircraft's body weight by using such lighter structures, the cost of fuel can be greatly reduced with the high jet fuel price for commercial airlines. However, these composites are prone to impact damage and the damage may occur without any observable sign on the surface, yet resulting in delaminations and disbonds that may occur well within the layers. We are studying the impact problem with carbon-fiber reinforced composite panels and developing SonicIR for this application as a fast and wide-area NDE technology. In this paper, we present our results in studying composite structures including carbon-fiber reinforced composite materials, and preliminary quantitative studies on delamination type defect depth identification in the panels.

Aging Military Aircraft Landscape : A Case for End-of-Life Fleet Optimization

NARCIS (Netherlands)

Newcamp, J.M.; Verhagen, W.J.C.; Curran, Ricky

2016-01-01

Military aircraft fleets are continuing to age despite increased structural integrity concerns and rising maintenance costs. Aircraft are not being replaced or retired in large numbers but are instead having their lives extended beyond their original design service lives. Because aging aircraft cost

NASA's Zero-g aircraft operations

Science.gov (United States)

Williams, R. K.

1988-01-01

NASA's Zero-g aircraft, operated by the Johnson Space Center, provides the unique weightless or zero-g environment of space flight for hardware development and test and astronaut training purposes. The program, which began in 1959, uses a slightly modified Boeing KC-135A aircraft, flying a parabolic trajectory, to produce weightless periods of 20 to 25 seconds. The program has supported the Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz and Shuttle programs as well as a number of unmanned space operations. Typical experiments for flight in the aircraft have included materials processing experiments, welding, fluid manipulation, cryogenics, propellant tankage, satellite deployment dynamics, planetary sciences research, crew training with weightless indoctrination, space suits, tethers, etc., and medical studies including vestibular research. The facility is available to microgravity research organizations on a cost-reimbursable basis, providing a large, hands-on test area for diagnostic and support equipment for the Principal Investigators and providing an iterative-type design approach to microgravity experiment development. The facility allows concepts to be proven and baseline experimentation to be accomplished relatively inexpensively prior to committing to the large expense of a space flight.

A Software Toolkit to Accelerate Emission Predictions for Turboelectric/Hybrid Electric Aircraft Propulsion, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Electric propulsion represents an attractive path for reducing overall emissions. For larger commercial aircrafts operating in the mega-watt range, power...

Flight Extraction and Phase Identification for Large Automatic Dependent Surveillance–Broadcast Datasets

NARCIS (Netherlands)

Sun, J.; Ellerbroek, J.; Hoekstra, J.M.

2017-01-01

AUTOMATIC dependent surveillance–broadcast (ADS-B) [1,2] is widely implemented in modern commercial aircraft and will become mandatory equipment in 2020. Flight state information such as position, velocity, and vertical rate are broadcast by tens of thousands of aircraft around the world constantly

Design of the crashworthy structure of an urban aircraft

Directory of Open Access Journals (Sweden)

Shang Bairong

2017-01-01

Full Text Available With the development of general aviation, the urban aircraft is around the corner. The urban aircraft with composite is considered as an ultralight vehicle and the crashworthiness is of vital importance for such an ultralight aircraft. Composites are being widely and increasingly used in the aerospace industry because of their advantages that include the high specific strength and stiffness over traditional metallic materials. Besides, composites have the potential for absorbing the energy in a crash event. The crashworthiness of the cockpit section is analyzed in this paper and some modifications in the subfloor have been made to improve the survivability of the pilot. Advances in commercial softwares have enabled engineers to simulate crash events. The three-dimensional structure model is established by use of CATIA software and the crash process is simulated by MSC/DYTRAN. By comparing the crashworthiness of composite structures, reliable basis is provided for the design of a safe and sound structure.

A Collection of Nonlinear Aircraft Simulations in MATLAB

Science.gov (United States)

Garza, Frederico R.; Morelli, Eugene A.

2003-01-01

Nonlinear six degree-of-freedom simulations for a variety of aircraft were created using MATLAB. Data for aircraft geometry, aerodynamic characteristics, mass / inertia properties, and engine characteristics were obtained from open literature publications documenting wind tunnel experiments and flight tests. Each nonlinear simulation was implemented within a common framework in MATLAB, and includes an interface with another commercially-available program to read pilot inputs and produce a three-dimensional (3-D) display of the simulated airplane motion. Aircraft simulations include the General Dynamics F-16 Fighting Falcon, Convair F-106B Delta Dart, Grumman F-14 Tomcat, McDonnell Douglas F-4 Phantom, NASA Langley Free-Flying Aircraft for Sub-scale Experimental Research (FASER), NASA HL-20 Lifting Body, NASA / DARPA X-31 Enhanced Fighter Maneuverability Demonstrator, and the Vought A-7 Corsair II. All nonlinear simulations and 3-D displays run in real time in response to pilot inputs, using contemporary desktop personal computer hardware. The simulations can also be run in batch mode. Each nonlinear simulation includes the full nonlinear dynamics of the bare airframe, with a scaled direct connection from pilot inputs to control surface deflections to provide adequate pilot control. Since all the nonlinear simulations are implemented entirely in MATLAB, user-defined control laws can be added in a straightforward fashion, and the simulations are portable across various computing platforms. Routines for trim, linearization, and numerical integration are included. The general nonlinear simulation framework and the specifics for each particular aircraft are documented.

Assessment of critical infrastructure for impact of large commercial aircraft

International Nuclear Information System (INIS)

Iliev, Alexander; Kostov, Marin; Andonov, Anton

2014-01-01

The erection process is simple; often used civil engineering structures. The structure can be manufactured apart from the site and can be assembled on site within short time.The relatively light steel construction (compared to reinforced concrete)could be erected on existing building surrounding the containment, thus reducing the necessary height compared to free standing massive concrete structures. In many cases it has to be constructed on only one or two sides on the containment, as the containment building is usually not accessible. The costs of such a structure compared to free standing reinforced concrete are lower.

Large eddy simulation of air pollution produced by aircraft engine emissions inside the airport

Energy Technology Data Exchange (ETDEWEB)

Synylo, Kateryna [National Aviation University (Ukraine)], email: synylo@nau.edu.ua

2011-07-01

With the increase of air traffic movement, air pollution from airport emissions has become an important concern. In the past, various research has been undertaken on the impact of aircraft engines on the upper troposphere and lower stratosphere, however the impact that emissions have on airports themselves is not taken into account by the most frequently used monitoring software programs. The aim of this paper is to present the use of a CFD simulation to determine the dynamic and fluid mechanics characteristics of aircraft emissions near the ground. The CFD simulation was carried out using Fluent 6.3 software and the effects of counter-rotating vortices and wind conditions on fulfilled gases jet. It was found that numerical simulation is able to resolve difficult equations and provide realistic results. This study demonstrated that the use of CFD computation could be used to improve local air quality modeling and assessment of the impact of aircraft emissions at airports.

AIRFORCE. Aircraft emissions and radiative forcing from emissions

Energy Technology Data Exchange (ETDEWEB)

Meijer, E.W.; Kelder, H.; Velthoven, P.F.J. van; Wauben, W.M.F. [Royal Netherlands Meteorological Inst., De Bilt (Netherlands); Beck, J.P.; Velders, G.J.M. [National Inst. of Public Health and the Environment, Bilthoven (Netherlands); Lelieveld, J.; Scheeren, B.A. [Institute of Marine and Atmospheric Research Utrecht (Netherlands)

1997-12-31

The Dutch AIRFORCE project focuses on the effects of subsonic aircraft emissions on the chemical composition of the atmosphere and subsequent radiative forcing. It includes measurements in the tropopause region and the modelling of exhaust plumes and large-scale effects. An aircraft exhaust plume model has been developed to study plume processes. The results of the plume model are used in the global transport chemistry model CTMK to determine large-scale effects of plume processes. Due to the efficient conversion of NO{sub x} into HNO{sub 3} inside aircraft exhaust plumes, a decrease of about 25% of the O{sub 3} perturbation was found in the NAFC at 200 hPa in July. Measurements of hydrocarbons revealed a dominant role of the anthropogenic continental emissions of light hydrocarbons in the tropopause region. (author) 20 refs.

AIRFORCE. Aircraft emissions and radiative forcing from emissions

Energy Technology Data Exchange (ETDEWEB)

Meijer, E W; Kelder, H; Velthoven, P F.J. van; Wauben, W M.F. [Royal Netherlands Meteorological Inst., De Bilt (Netherlands); Beck, J P; Velders, G J.M. [National Inst. of Public Health and the Environment, Bilthoven (Netherlands); Lelieveld, J; Scheeren, B A [Institute of Marine and Atmospheric Research Utrecht (Netherlands)

1998-12-31

The Dutch AIRFORCE project focuses on the effects of subsonic aircraft emissions on the chemical composition of the atmosphere and subsequent radiative forcing. It includes measurements in the tropopause region and the modelling of exhaust plumes and large-scale effects. An aircraft exhaust plume model has been developed to study plume processes. The results of the plume model are used in the global transport chemistry model CTMK to determine large-scale effects of plume processes. Due to the efficient conversion of NO{sub x} into HNO{sub 3} inside aircraft exhaust plumes, a decrease of about 25% of the O{sub 3} perturbation was found in the NAFC at 200 hPa in July. Measurements of hydrocarbons revealed a dominant role of the anthropogenic continental emissions of light hydrocarbons in the tropopause region. (author) 20 refs.

Subsonic Ultra Green Aircraft Research Phase II: N+4 Advanced Concept Development

Science.gov (United States)

Bradley, Marty K.; Droney, Christopher K.

2012-01-01

This final report documents the work of the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team on Task 1 of the Phase II effort. The team consisted of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, and Georgia Tech. Using a quantitative workshop process, the following technologies, appropriate to aircraft operational in the N+4 2040 timeframe, were identified: Liquefied Natural Gas (LNG), Hydrogen, fuel cell hybrids, battery electric hybrids, Low Energy Nuclear (LENR), boundary layer ingestion propulsion (BLI), unducted fans and advanced propellers, and combinations. Technology development plans were developed.

An artificial intelligence-based structural health monitoring system for aging aircraft

Science.gov (United States)

Grady, Joseph E.; Tang, Stanley S.; Chen, K. L.

1993-01-01

To reduce operating expenses, airlines are now using the existing fleets of commercial aircraft well beyond their originally anticipated service lives. The repair and maintenance of these 'aging aircraft' has therefore become a critical safety issue, both to the airlines and the Federal Aviation Administration. This paper presents the results of an innovative research program to develop a structural monitoring system that will be used to evaluate the integrity of in-service aerospace structural components. Currently in the final phase of its development, this monitoring system will indicate when repair or maintenance of a damaged structural component is necessary.

Analysis of Small Aircraft as a Transportation System

Science.gov (United States)

Dollyhigh, Samuel M.; Yackovetsky, Robert E. (Technical Monitor)

2002-01-01

An analysis was conducted to examine the market viability of small aircraft as a transportation mode in competition with automobile and scheduled commercial air travel by estimating the pool of users that would potentially switch to on-demand air travel due to cost/time savings. The basis for the analysis model was the Integrated Air Transportation System Evaluation Tool (IATSET) which was developed under contract to NASA by the Logistics Management Institute. IATSET is a macroeconomic model that predicts at a National level the mode choice between automobile, scheduled air, and on-demand air travel based on the value of a travelers time and monetary cost of the trip. A number of modifications are detailed to the original IATSET to better model the changing small aircraft environment. The potential trip market was modeled for the Eclipse 500 operated as a corporate jet and as an air taxi for the business travel market. The Cirrus 20R and a $80K single engine piston aircraft (based on automobile manufacturing technology) are evaluated in the pleasure and personal business travel market.

Automatic non-destructive system for quality assurance of welded elements in the aircraft industry

Science.gov (United States)

Chady, Tomasz; Waszczuk, Paweł; Szydłowski, Michał; Szwagiel, Mariusz

2018-04-01

Flaws that might be a result of the welding process have to be detected, in order to assure high quality thus reliability of elements exploited in aircraft industry. Currently the inspection stage is conducted manually by a qualified workforce. There are no commercially available systems that could support or replace humans in the flaw detection process. In this paper authors present a novel non-destructive system developed for quality assurance purposes of welded elements utilized in the aircraft industry.

The application of surface science in the solution of aircraft materials problems

International Nuclear Information System (INIS)

Arnott, D.R.

1999-01-01

Full text: There is now a tendency for both commercial and military aircraft to be maintained and operated for several decades. Indeed some of our front-line defence aircraft have programme withdrawal lives approaching half a century. This places significant demands on the materials used in engines and airframes. The properties and performance of the materials can degrade with time leading to an increase in the importance of repair and maintenance technologies. As most materials problems start at a surface or an interface, it is not surprising that surface sensitive tools are used to resolve many degradation problems. In some cases, the resolution of problems can lead to life-enhancing improvements for the aircraft. This paper will examine some of the practical issues in the use of surface analytical tools for the examination and resolution of practical aircraft problems. Illustrations will be drawn from the application of surface analysis in the areas of corrosion, fracture and adhesive bonding. Copyright (1999) Australian X-ray Analytical Association Inc

Structural design for aircraft impact loading

International Nuclear Information System (INIS)

Schmidt, R.; Heckhausen, H.; Chen, C.; Rieck, P.J.; Lemons, G.W.

1977-01-01

The distribution of military aircraft and proximity to commercial air routes requires the analysis of aircraft impact effect on nuclear power plant facilities in Europe. The typical approach on recent projects has been the hardening of safety-related buildings and/or protection of redundant safety-related equipment through separation. The 'hardened-building' approach has led to the consideration of severe shock and vibration caused by the aircraft impact and development of corresponding floor response spectra for component design. Conservatively calculated loads resulting from these are in some cases quite severe. The reactor auxiliary system building (Soft Shell Hardcore design) allows a more defensive alternate in the form of a partially softened design. In this approach the equipment layout is arranged such that equipment performing either safety functions or having the potential for significant release of radioactivity (upon destruction) is located in the central area of the plant and is enclosed in thick concrete walls for shielding and protection purposes. The non-safety class equipment is arranged in the area peripheral to the hardened central area and enclosed in thin concrete walls. Since the kinetic energy of the impacting aircraft is absorbed by the collapsed thin walls and ceilings, the vibrational effect on the safety class equipment is drastically reduced. In order to achieve the objective of absorbing high kinetic energy and yet reduce the shock and vibration effects, the softened exterior walls require low resistance and high ductility. This investigation determines the feasibility of two 0.5 m thick walls of the Soft Shell with the simplest possible mathematical model. (Auth.)

Potential for Fuel Tank Fire and Hydrodynamic Ram from Uncontained Aircraft Engine Debris

Science.gov (United States)

1997-01-01

This report addresses the potential consequences of the impact and penetration of fuel tanks by debris from uncontained engine failures on commercial jet aircraft. The report presents a brief review of accident data and of the pertinent technical lit...

Compton imaging tomography for nondestructive evaluation of large multilayer aircraft components and structures

Science.gov (United States)

Romanov, Volodymyr; Grubsky, Victor; Zahiri, Feraidoon

2017-02-01

We present a novel NDT/NDE tool for non-contact, single-sided 3D inspection of aerospace components, based on Compton Imaging Tomography (CIT) technique, which is applicable to large, non-uniform, and/or multilayer structures made of composites or lightweight metals. CIT is based on the registration of Compton-scattered X-rays, and permits the reconstruction of the full 3D (tomographic) image of the inspected objects. Unlike conventional computerized tomography (CT), CIT requires only single-sided access to objects, and therefore can be applied to large structures without their disassembly. The developed tool provides accurate detection, identification, and precise 3D localizations and measurements of any possible internal and surface defects (corrosions, cracks, voids, delaminations, porosity, and inclusions), and also disbonds, core and skin defects, and intrusion of foreign fluids (e.g., fresh and salt water, oil) inside of honeycomb sandwich structures. The NDE capabilities of the system were successfully demonstrated on various aerospace structure samples provided by several major aerospace companies. Such a CIT-based tool can detect and localize individual internal defects with dimensions about 1-2 mm3, and honeycomb disbond defects less than 6 mm by 6 mm area with the variations in the thickness of the adhesive by 100 m. Current maximum scanning speed of aircraft/spacecraft structures is about 5-8 min/ft2 (50-80 min/m2).

Rapid evaluation of buildings and infrastructure to accidental and deliberate aircraft impact

International Nuclear Information System (INIS)

Tennant, D.; Levine, H.; Mould, J.; Vaughan, D.

2014-01-01

Recent events involving the impact of large transport aircraft such as the Boeing 767 and 757 into the World Trade Center Towers and the Pentagon have revealed the vulnerability of such structures to terrorist attack. Incidents involving smaller general aviation aircraft have shown the damage that this class of plane can do beyond a protected perimeter. These incidents have elicited inquiries with regard to the effects of impacts of these aircraft types into other critical facilities including aboveground and below ground storage facilities, nuclear power plants, damns and other military and civilian installations. A significant capability to evaluate these threats has been developed during the past 10 years. Small medium and large aircraft have been impacted into buried and aboveground reinforced concrete and light steel frame storage facilities. Both explicit aircraft models and Riera functions (a simplified aircraft impact loading function) have been used to generate an extensive data base. The effects of engines impacting have been studied separately as penetrators. Illustrated in this paper is validation of computational tools for impacts into structures and the initial development of a generalized evaluation tool for rapid evaluation of threats and consequence of aircraft impact into protected facilities

Rapid evaluation of buildings and infrastructure to accidental and deliberate aircraft impact

Energy Technology Data Exchange (ETDEWEB)

Tennant, D., E-mail: tennant@wai.com [Weidlinger Associates, Inc., 6301 Indian School Road NE, Suite 501, Albuquerque, NM 87122 (United States); Levine, H., E-mail: levine@ca.wai.com [Weidlinger Associates, Inc., 399 W. El Camino Real, Suite 200, Mountain View, CA 94040 (United States); Mould, J.; Vaughan, D. [Weidlinger Associates, Inc., 399 W. El Camino Real, Suite 200, Mountain View, CA 94040 (United States)

2014-04-01

Recent events involving the impact of large transport aircraft such as the Boeing 767 and 757 into the World Trade Center Towers and the Pentagon have revealed the vulnerability of such structures to terrorist attack. Incidents involving smaller general aviation aircraft have shown the damage that this class of plane can do beyond a protected perimeter. These incidents have elicited inquiries with regard to the effects of impacts of these aircraft types into other critical facilities including aboveground and below ground storage facilities, nuclear power plants, damns and other military and civilian installations. A significant capability to evaluate these threats has been developed during the past 10 years. Small medium and large aircraft have been impacted into buried and aboveground reinforced concrete and light steel frame storage facilities. Both explicit aircraft models and Riera functions (a simplified aircraft impact loading function) have been used to generate an extensive data base. The effects of engines impacting have been studied separately as penetrators. Illustrated in this paper is validation of computational tools for impacts into structures and the initial development of a generalized evaluation tool for rapid evaluation of threats and consequence of aircraft impact into protected facilities.

An under-aisle air distribution system facilitating humidification of commercial aircraft cabins

Energy Technology Data Exchange (ETDEWEB)

Zhang, Tengfei; Yin, Shi; Wang, Shugang [School of Civil and Hydraulic Engineering, Dalian University of Technology (DUT), 2 Linggong Road, Dalian 116024 (China)

2010-04-15

Air environment in aircraft cabins has long been criticized especially for the dryness of the air within. Low moisture content in cabins is known to be responsible for headache, tiredness and many other non-specific symptoms. In addition, current widely used air distribution systems on airplanes dilute internally generated pollutants by promoting air mixing and thus impose risks of infectious airborne disease transmission. To boost air humidity level while simultaneously restricting air mixing, this investigation uses a validated computational fluid dynamics (CFD) program to design a new under-aisle air distribution system for wide-body aircraft cabins. The new system supplies fully outside, dry air at low momentum through a narrow channel passage along both side cabin walls to middle height of the cabin just beneath the stowage bins, while simultaneously humidified air is supplied through both perforated under aisles. By comparing with the current mixing air distribution system in terms of distribution of relative humidity, CO{sub 2} concentration, velocity, temperature and draught risk, the new system is found being able to improve the relative humidity from the existent 10% to the new level of 20% and lessen the inhaled CO{sub 2} concentration by 30%, without causing moisture condensation on cabin interior and inducing draught risks for passengers. The water consumption rate in air humidification is only around 0.05 kg/h per person, which should be affordable by airliners. (author)

Evaluation of a Hydrogen Fuel Cell Powered Blended-Wing-Body Aircraft Concept for Reduced Noise and Emissions

Science.gov (United States)

Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.

2004-01-01

This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.

Development of A Hydraulic Drive for a novel Diesel-Hydraulic system for Large commercial Vehicles

DEFF Research Database (Denmark)

Stecki, J. S.; Conrad, Finn; Matheson, P.

2002-01-01

The objectives and results of the research project Hybrid Diesel-Hydraulic System for Large commercial vehicles, e.g. urban freight delivery, buses or garbage trucks. The paper presents and discusses the research and development of the system, modelling approach and results from preliminary...... performance tests on a 10 ton vehicle....

Magnesium Diboride Superconducting Coils for Electric Propulsion Systems for Large Aircraft, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The recent development of magnesium diboride superconducting wires makes possible the potential to have much lighter weight superconducting coils for heavy aircraft...

Aircraft accident analysis for emergency planning and safety analysis

International Nuclear Information System (INIS)

Nicolosi, S.L.; Jordan, H.; Foti, D.; Mancuso, J.

1996-01-01

Potential aircraft accidents involving facilities at the Rocky Flats Environmental Technology Site (Site) are evaluated to assess their safety significance. This study addresses the probability and facility penetrability of aircraft accidents at the Site. The types of aircraft (large, small, etc.) that may credibly impact the Site determine the types of facilities that may be breached. The methodology used in this analysis follows elements of the draft Department of Energy Standard ''Accident Analysis for Aircraft Crash into Hazardous Facilities'' (July 1995). Key elements used are: the four-factor frequency equation for aircraft accidents; the distance criteria for consideration of airports, airways, and jet routes; the consideration of different types of aircraft; and the Modified National Defense Research Committee (NDRC) formula for projectile penetration, perforation, and minimum resistant thickness. The potential aircraft accident frequency for each type of aircraft applicable to the Site is estimated using a four-factor formula described in the draft Standard. The accident frequency is the product of the annual number of operations, probability of an accident, probability density function, and area. The annual number of operations is developed from site-specific and state-wide data

Fuel-Conservation Guidance System for Powered-Lift Aircraft

Science.gov (United States)

Erzberger, Heinz; McLean, John D.

1981-01-01

A technique is described for the design of fuel-conservative guidance systems and is applied to a system that was flight tested on board NASA's sugmentor wing jet STOL research aircraft. An important operational feature of the system is its ability to rapidly synthesize fuel-efficient trajectories for a large set of initial aircraft positions, altitudes, and headings. This feature allows the aircraft to be flown efficiently under conditions of changing winds and air traffic control vectors. Rapid synthesis of fuel-efficient trajectories is accomplished in the airborne computer by fast-time trajectory integration using a simplified dynamic performance model of the aircraft. This technique also ensures optimum flap deployment and, for powered-lift STOL aircraft, optimum transition to low-speed flight. Also included in the design is accurate prediction of touchdown time for use in four-dimensional guidance applications. Flight test results have demonstrated that the automatically synthesized trajectories produce significant fuel savings relative to manually flown conventional approaches.

Damage evaluation of 500 MWe Indian Pressurized Heavy Water Reactor nuclear containment for aircraft impact

Energy Technology Data Exchange (ETDEWEB)

Kukreja, Mukesh [Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)]. E-mail: mrkukreja@yahoo.com

2005-08-01

Safety assessment of Indian nuclear containments has been carried out for aircraft impact. The loading time history for Boeing and Airbus categories of aircrafts is generated based on the principle of momentum transfer of crushable aircrafts. The case studies include the analysis of BWR Mark III containment as a benchmark problem and analyses of Pressurised Heavy Water Reactor containment (inner and outer containment) for impulsive loading due to aircraft impact. Initially, the load is applied on outer containment wall model and subsequently the load is transferred to inner containment after the local perforation of the outer containment wall is noticed in the transient simulation. The analysis methodology evolved in the present work would be useful for studying the behavior of double containment walls and multi barrier structural configurations for aircraft impact with higher energies. The present analysis illustrates that with the provision of double containments for Indian nuclear power plants, adequate reserve strength is available for the case of an extremely low probability event of missile impact generated due to the commercial aircrafts operated in India.

Damage evaluation of 500 MWe Indian Pressurized Heavy Water Reactor nuclear containment for aircraft impact

International Nuclear Information System (INIS)

Kukreja, Mukesh

2005-01-01

Safety assessment of Indian nuclear containments has been carried out for aircraft impact. The loading time history for Boeing and Airbus categories of aircrafts is generated based on the principle of momentum transfer of crushable aircrafts. The case studies include the analysis of BWR Mark III containment as a benchmark problem and analyses of Pressurised Heavy Water Reactor containment (inner and outer containment) for impulsive loading due to aircraft impact. Initially, the load is applied on outer containment wall model and subsequently the load is transferred to inner containment after the local perforation of the outer containment wall is noticed in the transient simulation. The analysis methodology evolved in the present work would be useful for studying the behavior of double containment walls and multi barrier structural configurations for aircraft impact with higher energies. The present analysis illustrates that with the provision of double containments for Indian nuclear power plants, adequate reserve strength is available for the case of an extremely low probability event of missile impact generated due to the commercial aircrafts operated in India

Utilization of sonar technology and microcontroller towards reducing aviation hazards during ground handling of aircraft

Science.gov (United States)

Khanam, Mosammat Samia; Biswas, Debasish; Rashid, Mohsina; Salam, Md Abdus

2017-12-01

Safety is one of the most important factors in the field of aviation. Though, modern aircraft are equipped with many instruments/devices to enhance the flight safety but it is seen that accidents/incidents are never reduced to zero. Analysis of the statistical summary of Commercial Jet Airplane accidents highlights that fatal accidents that occurred worldwide from 2006 through 2015 is 11% during taxing, loading/unloading, parking and towing. Human, handling the aircrafts is one of the most important links in aircraft maintenance and hence play a significant role in aviation safety. Effort has been made in this paper to obviate human error in aviation and outline an affordable system that monitors the uneven surface &obstacles for safe "towing in" and "towing out" of an aircraft by the ground crew. The system revolves around implementation of sonar technology by microcontroller. Ultrasonic sensors can be installed on aircraft wings and tail section to identify the uneven surface &obstacles ahead and provide early warning to the maintenance ground crews.

Building Toward an Unmanned Aircraft System Training Strategy

Science.gov (United States)

2014-01-01

and fly at altitudes higher than commercial airlines do. They file instrument flight rules flight plans. However, BAMS-D and Triton do not...incorporate sense-and-avoid technology, and conflicts can exist with visual flight rules aircraft in the airspace. Airspace issues exist at some Navy training...MODS, Washington, DC, February 2011, p. 1 of 10. 164 Peter La Franchi , “Directory: Unmanned Air Vehicles,” Flight International, June 21st, 2005, p. 56

An Improved Wake Vortex Tracking Algorithm for Multiple Aircraft

Science.gov (United States)

Switzer, George F.; Proctor, Fred H.; Ahmad, Nashat N.; LimonDuparcmeur, Fanny M.

2010-01-01

The accurate tracking of vortex evolution from Large Eddy Simulation (LES) data is a complex and computationally intensive problem. The vortex tracking requires the analysis of very large three-dimensional and time-varying datasets. The complexity of the problem is further compounded by the fact that these vortices are embedded in a background turbulence field, and they may interact with the ground surface. Another level of complication can arise, if vortices from multiple aircrafts are simulated. This paper presents a new technique for post-processing LES data to obtain wake vortex tracks and wake intensities. The new approach isolates vortices by defining "regions of interest" (ROI) around each vortex and has the ability to identify vortex pairs from multiple aircraft. The paper describes the new methodology for tracking wake vortices and presents application of the technique for single and multiple aircraft.

Large scale commercial fabrication of high quality graphene-based assays for biomolecule detection

Science.gov (United States)

Lerner, Mitchell; Gao, Yingning; Goldsmith, Brett; Barron, Francie

Large numbers of high quality graphene transistors with mobility approximately 5000 cm2 / V * s were fabricated by chemical vapor deposition and packaged into ceramic carriers with an open cavity design. The ceramic carrier is compatible with standard electronics assembly, enabling the readout of graphene properties on the benchtop without large, expensive probing systems. After chemical functionalization, these sensors demonstrate sensitivity in the pM range and selectivity to many classes of biomolecules as a three terminal liquid-gated field effect transistor. High precision measurements of protein kinetics captured using this technology, commercially known as AGILE R100, are comparable and can exceed the capabilities of state-of-the-art biomolecule characterization tools. Recently published in Sensors and Actuators B

The Use of In-service Passenger Aircraft for Measuring Atmospheric Composition on a Global Scale : the European Research Infrastructure IAGOS

Science.gov (United States)

Blot, R.; Nedelec, P.; Petetin, H.; Thouret, V.; Cohen, Y.

2017-12-01

The In-Service Aircraft for a Global Observing System (IAGOS; http://www.iagos.org) is an European Research Infrastructure that provides cost-effective global atmospheric composition measurements at high resolution using commercial passenger aircraft. It is the continuation of the MOZAIC (1994-2014) and the CARIBIC (since 1997) programs that has provided a unique scientific database using 6 aircraft operated by European airlines over two decades. Thanks to growing interests of several international Airlines to contribute to the academic climate research, the IAGOS aircraft fleet (started in 2011), with the IAGOS-CORE basic instrumentation, has expanded to 9 Airbus A340/A330 aircraft up to now. Here, we present this IAGOS-CORE instrumentation that continuously sample carbon monoxide, ozone, water vapor and cloud droplets. We focus on carbon monoxide and ozone measurements which are performed by optimized, but well known, methods such as UV absorption and IR correlation. We describe the data processing/validation and the data quality control. With already more than 20 and 15 years of continuous ozone and carbon monoxide measurements, respectively, the IAGOS/MOZAIC data are particularly suitable for climatologies and trends. Also, since commercial aircraft are daily operated, the near-real time IAGOS-CORE data are also used to observe pollution plumes and to validate air-quality models as well as satellite products.

Toward the bi-modal camber morphing of large aircraft wing flaps: the CleanSky experience

Science.gov (United States)

Pecora, R.; Amoroso, F.; Magnifico, M.

2016-04-01

The Green Regional Aircraft (GRA), one of the six CleanSky platforms, represents the largest European effort toward the greening of next generation air transportation through the implementation of advanced aircraft technologies. In this framework researches were carried out to develop an innovative wing flap enabling airfoil morphing according to two different modes depending on aircraft flight condition and flap setting: - Camber morphing mode. Morphing of the flap camber to enhance high-lift performances during take-off and landing (flap deployed); - Tab-like morphing mode. Upwards and downwards deflection of the flap tip during cruise (flap stowed) for load control at high speed and consequent optimization of aerodynamic efficiency. A true-scale flap segment of a reference aircraft (EASA CS25 category) was selected as investigation domain for the new architecture in order to duly face the challenges posed by real wing installation issues especially with reference to the tapered geometrical layout and 3D aerodynamic loads distributions. The investigation domain covered the flap region spanning 3.6 m from the wing kink and resulted characterized by a taper ratio equal to 0.75 with a root chord of 1.2 m. High TRL solutions for the adaptive structure, actuation and control system were duly analyzed and integrated while assuring overall device compliance with industrial standards and applicable airworthiness requirements.

Application of AI methods to aircraft guidance and control

Science.gov (United States)

Hueschen, Richard M.; Mcmanus, John W.

1988-01-01

A research program for integrating artificial intelligence (AI) techniques with tools and methods used for aircraft flight control system design, development, and implementation is discussed. The application of the AI methods for the development and implementation of the logic software which operates with the control mode panel (CMP) of an aircraft is presented. The CMP is the pilot control panel for the automatic flight control system of a commercial-type research aircraft of Langley Research Center's Advanced Transport Operating Systems (ATOPS) program. A mouse-driven color-display emulation of the CMP, which was developed with AI methods and used to test the AI software logic implementation, is discussed. The operation of the CMP was enhanced with the addition of a display which was quickly developed with AI methods. The display advises the pilot of conditions not satisfied when a mode does not arm or engage. The implementation of the CMP software logic has shown that the time required to develop, implement, and modify software systems can be significantly reduced with the use of the AI methods.

Efficient Multidisciplinary Analysis Approach for Conceptual Design of Aircraft with Large Shape Change

Science.gov (United States)

Chwalowski, Pawel; Samareh, Jamshid A.; Horta, Lucas G.; Piatak, David J.; McGowan, Anna-Maria R.

2009-01-01

The conceptual and preliminary design processes for aircraft with large shape changes are generally difficult and time-consuming, and the processes are often customized for a specific shape change concept to streamline the vehicle design effort. Accordingly, several existing reports show excellent results of assessing a particular shape change concept or perturbations of a concept. The goal of the current effort was to develop a multidisciplinary analysis tool and process that would enable an aircraft designer to assess several very different morphing concepts early in the design phase and yet obtain second-order performance results so that design decisions can be made with better confidence. The approach uses an efficient parametric model formulation that allows automatic model generation for systems undergoing radical shape changes as a function of aerodynamic parameters, geometry parameters, and shape change parameters. In contrast to other more self-contained approaches, the approach utilizes off-the-shelf analysis modules to reduce development time and to make it accessible to many users. Because the analysis is loosely coupled, discipline modules like a multibody code can be easily swapped for other modules with similar capabilities. One of the advantages of this loosely coupled system is the ability to use the medium- to high-fidelity tools early in the design stages when the information can significantly influence and improve overall vehicle design. Data transfer among the analysis modules are based on an accurate and automated general purpose data transfer tool. In general, setup time for the integrated system presented in this paper is 2-4 days for simple shape change concepts and 1-2 weeks for more mechanically complicated concepts. Some of the key elements briefly described in the paper include parametric model development, aerodynamic database generation, multibody analysis, and the required software modules as well as examples for a telescoping wing

A Whitham-Theory Sonic-Boom Analysis of the TU-144 Aircraft at a Mach Number of 2.2

Science.gov (United States)

Mack, Robert J.

1999-01-01

Officially, the Tu-144 was the first supersonic-cruise, passenger-carrying aircraft to enter commercial service. Design, construction, and testing were carried out by the Soviet Union, flight certification was by the Soviet Union, and the only regular passenger flights were scheduled and flown across the territory of the Soviet Union. Although it was not introduced to international passenger service, there were many significant engineering accomplishments achieved in the design, production, and flight of this aircraft. Development of the aircraft began with a prototype stage. Systematic testing and redesign led to a production aircraft in discrete stages that measurably improved the performance of the aircraft from the starting concept to final aircraft certification. It flew in competition with the English-French Concorde for a short time, but was withdrawn from national commercial service due to a lack of interest by airlines outside the Soviet Union. NASA became interested in the Tu- 144 aircraft when it was offered for use as a flying "testbed" in the study of operating characteristics of a supersonic-cruise commercial airplane. Since it had been in supersonic-cruise service, the Tu- 144 had operational characteris'tics similar to those anticipated in the conceptual aircraft designs being studied by the United States aircraft companies. In addition to the other operational tests being conducted on the Tu-144 aircraft, it was proposed that two sets of sonic-boom pressure signature measurements be made. The first set would be made on the ground, using techniques and devices similar to those in reference I and many other subsequent studies. A second set would be made in the air with an instrumented aircraft flying close under the Tu-144 in supersonic flight. Such in-flight measurements would require pressure gages that were capable of accurately recording the flow-field overpressures generated by the Tu- 144 at relatively close distances under the vehicle

Radon investigations - Soil and commercial projects

International Nuclear Information System (INIS)

Goodwin, R.W.

1987-01-01

The liability issues of radon exposure have prompted potential purchasers of vacant land for commercial/industrial development, and commercial landlords, renting large commercial buildings, to determine the radon gas levels at such sites. This paper deals with both pre-construction sites subject to freezing conditions and to large commercial structures. A correlation of radon gas levels within a commercial building and a sister pre-construction site confirms the validity of using activated charcoal canisters as a cost effective means to combating radon in large structures

14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

An Integrated Approach to Aircraft Modelling and Flight Control Law Design

NARCIS (Netherlands)

Looye, G.H.N.

2008-01-01

The design of flight control laws (FCLs) for automatic and manual (augmented) control of aircraft is a complicated task. FCLs have to fulfil large amounts of performance criteria and must work reliably in all flight conditions, for all aircraft configurations, and in adverse weather conditions.

Fluid-structure interaction by the mixed SPH-FE method with application to aircraft ditching

Directory of Open Access Journals (Sweden)

P Groenenboom

2016-10-01

Full Text Available This paper deals with numerical simulation of fluid-structure interaction as it occurs during aircraft ditching – an emergency condition where an aircraft is forced to land on water. The work is motivated by the requirement for aircraft manufactures to analyze ditching as part of the aircraft certification process requested by airworthiness authorities. The strong interaction of highly non-linear fluid flow phenomena and structural responses requires a coupled solution of this transient problem. Therefore, an approach coupling Smoothed Particle Hydrodynamics and the Finite Element method within the commercial, explicit software Virtual Performance Solutions has been pursued. In this paper, several innovative features are presented, which allow for accurate and efficient solution. Finally, exemplary numerical results are successfully compared to experimental data from a unique test campaign of guided ditching tests at quasi-full scale impact conditions. It may be concluded that through the application of state-of-the-art numerical techniques it has become possible to simulate the coupled fluidstructure interaction as occurring during ditching. Therefore, aircraft manufacturers may significantly benefit from numerical analysis for design and certification purposes.

Empirical analysis of the effect of descent flight path angle on primary gaseous emissions of commercial aircraft.

Science.gov (United States)

Turgut, Enis T; Usanmaz, Oznur; Rosen, Marc A

2018-05-01

In this study, the effects of descent flight path angle (between 1.25° and 4.25°) on aircraft gaseous emissions (carbon monoxide, total hydrocarbons and nitrogen oxides) are explored using actual flight data from aircraft flight data recording system and emissions indices from the International Civil Aviation Organization. All emissions parameters are corrected to flight conditions using Boeing Fuel Flow Method2, where the ambient air pressure, temperature and humidity data are obtained from long-term radiosonde data measured close to the arrival airport. The main findings highlight that the higher the flight path angle, the higher the emission indices of CO and HC, whereas the lower the emissions index of NO x and fuel consumption. Furthermore, during a descent, a heavier aircraft tends to emit less CO and HC, and more NO x . For a five-tonne aircraft mass increase, the average change in emissions indices are found to be -4.1% and -5.7% (CO), -5.4% and -8.2% (HC), and +1.1% and +1.6% (NO x ) for high and low flight path angle groups, respectively. The average emissions indices for CO, HC and NO x during descent are calculated to be 24.5, 1.7 and 5.6 g/kg of fuel, whereas the average emissions for descending from 32,000 ft (9.7 km) and 24,000 ft (7.3 km) are calculated to be 7-8 kg (CO), ∼0.5 kg (HC) and ∼3 kg (NO x ). Copyright © 2018 Elsevier Ltd. All rights reserved.

Flight service evaluation of Kevlar-49 epoxy composite panels in wide-bodies commercial transport aircraft

Science.gov (United States)

Stone, R. H.

1983-01-01

Kevlar-49 fairing panels, installed as flight service components on three L-1011s, were inspected after 9 years of service. There are six Kevlar-49 panels on each aircraft: a left hand and right hand set of a wing body sandwich fairing; a solid laminate under wing fillet panel; and a 422 K (300 F) service aft engine fairing. The fairings have accumulated a total of 70,000 hours, with one ship set having over 24,000 hours service. The Kevlar-49 components were found to be performing satisfactorily in service with no major problems, or any condition requiring corrective action. The only defects noted were minor impact damage, a few minor disbonds and a minor degree of fastener hole fraying and elongation. These are for the most part comparable to damage noted on fiberglass fairings. The service history to date indicates that Kevlar-49 epoxy composite materials have satisfactory service characteristics for use in aircraft secondary structure.

Study of aircraft electrical power systems

Science.gov (United States)

1972-01-01

The formulation of a philosophy for devising a reliable, efficient, lightweight, and cost effective electrical power system for advanced, large transport aircraft in the 1980 to 1985 time period is discussed. The determination and recommendation for improvements in subsystems and components are also considered. All aspects of the aircraft electrical power system including generation, conversion, distribution, and utilization equipment were considered. Significant research and technology problem areas associated with the development of future power systems are identified. The design categories involved are: (1) safety-reliability, (2) power type, voltage, frequency, quality, and efficiency, (3) power control, and (4) selection of utilization equipment.

Preliminary Design of Aerial Spraying System for Microlight Aircraft

Science.gov (United States)

Omar, Zamri; Idris, Nurfazliawati; Rahim, M. Zulafif

2017-10-01

Undoubtedly agricultural is an important sector because it provides essential nutrients for human, and consequently is among the biggest sector for economic growth worldwide. It is crucial to ensure crops production is protected from any plant diseases and pests. Thus aerial spraying system on crops is developed to facilitate farmers to for crops pests control and it is very effective spraying method especially for large and hilly crop areas. However, the use of large aircraft for aerial spaying has a relatively high operational cost. Therefore, microlight aircraft is proposed to be used for crops aerial spraying works for several good reasons. In this paper, a preliminary design of aerial spraying system for microlight aircraft is proposed. Engineering design methodology is adopted in the development of the aerial sprayer and steps involved design are discussed thoroughly. A preliminary design for the microlight to be attached with an aerial spraying system is proposed.

47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

Science.gov (United States)

2010-10-01

... board aircraft. Air-ground systems operating in these frequency bands are referred to in this part as... systems. 22.857 Section 22.857 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground...

Materials for fire resistant passenger seats in aircraft

Science.gov (United States)

Tesoro, G.; Moussa, A.

1980-01-01

The paper considers the selection of cushioning foam and upholstery fabric materials for aircraft passenger seats. Polyurethane, polychloroprene, polyimide, and polyphosphazene are the foam materials considered; and a variety of commercial and developmental fabrics (including wool, cotton, synthetics, and blends) are examined. Viable approaches to the design of fire-resistant seat assemblies are indicated. Results of an experimental laboratory study of fabrics and fabric/foam assemblies exposed to external point-source radiative heat flux are discussed.

A manpower scheduling heuristic for aircraft maintenance application

Science.gov (United States)

Sze, San-Nah; Sze, Jeeu-Fong; Chiew, Kang-Leng

2012-09-01

This research studies a manpower scheduling for aircraft maintenance, focusing on in-flight food loading operation. A group of loading teams with flexible shifts is required to deliver and upload packaged meals from the ground kitchen to aircrafts in multiple trips. All aircrafts must be served within predefined time windows. The scheduling process takes into account of various constraints such as meal break allocation, multi-trip traveling and food exposure time limit. Considering the aircrafts movement and predefined maximum working hours for each loading team, the main objective of this study is to form an efficient roster by assigning a minimum number of loading teams to the aircrafts. We proposed an insertion based heuristic to generate the solutions in a short period of time for large instances. This proposed algorithm is implemented in various stages for constructing trips due to the presence of numerous constraints. The robustness and efficiency of the algorithm is demonstrated in computational results. The results show that the insertion heuristic more efficiently outperforms the company's current practice.

Nitrogen oxides and ozone in the tropopause region of the Northern Hemisphere: Measurements from commercial aircraft in 1995/1996 and 1997

Science.gov (United States)

Brunner, Dominik; Staehelin, Johannes; Jeker, Dominique; Wernli, Heini; Schumann, Ulrich

2001-11-01

Measurements of nitrogen oxides (NO and NO2) and ozone (O3) were performed from a Swissair B-747 passenger aircraft in two extended time periods (May 1995 to May 1996, August to November 1997) in the framework of the Swiss NOXAR and the European POLINAT 2 project. The measurements were obtained on a total of 623 flights between Europe and destinations in the United States and the Far East. NO2 measurements were obtained only after December 1995 and were less precise than the NO measurements. Therefore daytime NO2 values were derived from measured NO and O3 concentrations assuming photostationary equilibrium. The completed NOx data set (measured NO, measured NO2 during night, and calculated NO2 during day) includes a complete annual cycle and is the most extensive and representative data set currently available for the upper troposphere (UT) and the lower stratosphere (LS) covering a significant proportion of the northern hemisphere between 15°N and 65°N. NOx concentrations in midlatitudes (30°-60°N) showed a marked seasonal variation both in the UT and the LS with a maximum in summer (median/mean values of 159/264 pptv in UT, 199/237 pptv in LS) and a minimum in winter (51/99 pptv in UT, 67/91 pptv in LS). Mean NOx concentrations were generally much higher than the respective median values, in particular in the UT, which reflects the important contribution from comparatively few very high concentrations observed in large-scale convection/lightning and small-scale aircraft plumes. Seasonal mean NOx concentrations in the UT were up to 3-4 times higher over continental regions than over the North Atlantic during summer. Lightning production of NO and convective vertical transport from the polluted boundary layer thus appear to have dominated the upper tropospheric NOx budget over these continental regions, particularly during summer. Ozone concentrations at aircraft cruising levels typically varied by an order of magnitude due to the strong vertical gradient in

Multi-objective optimization of aircraft design for emission and cost reductions

Directory of Open Access Journals (Sweden)

Wang Yu

2014-02-01

Full Text Available Pollutant gases emitted from the civil jet are doing more and more harm to the environment with the rapid development of the global commercial aviation transport. Low environmental impact has become a new requirement for aircraft design. In this paper, estimation method for emission in aircraft conceptual design stage is improved based on the International Civil Aviation Organization (ICAO aircraft engine emissions databank and the polynomial curve fitting methods. The greenhouse gas emission (CO2 equivalent per seat per kilometer is proposed to measure the emissions. An approximate sensitive analysis and a multi-objective optimization of aircraft design for tradeoff between greenhouse effect and direct operating cost (DOC are performed with five geometry variables of wing configuration and two flight operational parameters. The results indicate that reducing the cruise altitude and Mach number may result in a decrease of the greenhouse effect but an increase of DOC. And the two flight operational parameters have more effects on the emissions than the wing configuration. The Pareto-optimal front shows that a decrease of 29.8% in DOC is attained at the expense of an increase of 10.8% in greenhouse gases.

Hand held lasers, a hazard to aircraft: How do we address this?

Science.gov (United States)

Barat, K.

2015-10-01

The availability of hand held lasers, commonly termed "laser pointers" is easy and wide spread, through commercial web sites and brick & mortar stores. The output of these hand held devices ranges from 1-5 milliWatts (mW) the legal laser pointer output limit, to 5000mW (5Watts). This is thousand times the maximum limit for pointers. Sadly the abuse of these devices is also wide spread. Over the last few years over 3000 aircraft are exposed to laser hits per year. While these aircraft exposures are of no danger to the aircraft frame but they can cause pilot distractions with the potential to cause a serve accident. The presentation will discuss the problem review visual effects, the regulatory response and how educators need to be aware of the problem and can take steps to educate students in the hope of having an effect.

N+3 Aircraft Concept Designs and Trade Studies. Volume 1

Science.gov (United States)

Greitzer, E. M.; Bonnefoy, P. A.; DelaRosaBlanco, E.; Dorbian, C. S.; Drela, M.; Hall, D. K.; Hansman, R. J.; Hileman, J. I.; Liebeck, R. H.; Levegren, J.;

Management of cosmic radiation exposure for aircraft crew in Japan

International Nuclear Information System (INIS)

Yasuda, H.; Sato, T.; Yonehara, H.; Kosako, T.; Fujitaka, K.; Sasaki, Y.

2011-01-01

The International Commission on Radiological Protection has recommended that cosmic radiation exposure of crew in commercial jet aircraft be considered as occupational exposure. In Japan, the Radiation Council of the government has established a guideline that requests domestic airlines to voluntarily keep the effective dose of cosmic radiation for aircraft crew below 5 mSv y -1 . The guideline also gives some advice and policies regarding the method of cosmic radiation dosimetry, the necessity of explanation and education about this issue, a way to view and record dose data, and the necessity of medical examination for crew. The National Inst. of Radiological Sciences helps the airlines to follow the guideline, particularly for the determination of aviation route doses by numerical simulation. The calculation is performed using an original, easy-to-use program package called 'JISCARD EX' coupled with a PHITS-based analytical model and a GEANT4-based particle tracing code. The new radiation weighting factors recommended in 2007 are employed for effective dose determination. The annual individual doses of aircraft crew were estimated using this program. (authors)

Aircraft noise in the region of the Bucharest-Otopeni Airport. [noise pollution in airport environment

Science.gov (United States)

Costescu, M.; Gherghel, C.; Curtoglu, A.

1974-01-01

Aircraft noise, especially in the region adjoining airports, constitutes a problem that will be aggravated in the near future because of increasing aircraft traffic and the appearance of new types of large tonnage aircraft with continuously increasing powers and speeds. Criteria for the evaluation of aircraft noise are reported and some results of studies carried out in the region of Bucharest-Otopeni Airport are detailed.

Application of image based measurement techniques for the investigation of aeroengine performance on a commercial aircraft in ground operation

OpenAIRE

Schröder, Andreas; Geisler, Reinhard; Schanz, Daniel; Agocs, Janos; Pallek, Dieter; Schroll, Michael; Klinner, Joachim; Beversdorff, Manfred; Voges, Melanie; Willert, Christian

2014-01-01

The investigation of the flow and sound field upstream and downstream of a full scale aeroengine is aimed at providing important reference data required for reliable modeling and prediction. In this regard a wide variety of contactless and non-invasive laser optical and acoustic measurement techniques have matured in recent years to allow their application on full scale aircraft. Within a measurement campaign involving an Airbus A320 DLR research aircraft inside a sound-attenuating hangar at ...

A Study of Transparent Plastics for use on Aircraft, Special Report

Science.gov (United States)

Axilrod, Benjamin M.; Kline, Gordon M.

1937-01-01

Various transparent organic plastics, including both commercially available and experimental materials, have been examined to determine their suitability for use as flexible windshields on aircraft, The properties which have been studied include light transmission, haziness, distortion, resistance to weathering, scratch and indentation hardness, impact strength, dimensional stability, resistance to water and various cleaning fluids, bursting strength at normal and low temperatures, and flammability.

AIRTV: Broadband Direct to Aircraft

Science.gov (United States)

Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.

2002-01-01

Airlines have been continuously upgrading their wide-body, long-haul aircraft with IFE (in-flight entertainment) systems that can support from 12 to 24 channels of video entertainment as well as provide the infrastructure to enable in-seat delivery of email and internet services. This is a direct consequence of increased passenger demands for improved in-flight services along with the expectations that broadband delivery systems capable of providing live entertainment (news, sports, financial information, etc.) and high speed data delivery will soon be available. The recent events of Sept. 11 have slowed the airline's upgrade of their IFE systems, but have also highlighted the compelling need for broadband aeronautical delivery systems to include operational and safety information. Despite the impact of these events, it is estimated that by 2005 more than 3000 long haul aircraft (servicing approximately 1 billion passengers annually) will be fully equipped with modern IFE systems. Current aircraft data delivery systems, which use either Inmarsat or NATS, are lacking in bandwidth and consequently are unsuitable to satisfy passenger demands for broadband email/internet services or the airlines' burgeoning data requirements. Present live video delivery services are limited to regional coverage and are not readily expandable to global or multiregional service. Faced with a compelling market demand for high data transport to aircraft, AirTV has been developing a broadband delivery system that will meet both passengers' and airlines' needs. AirTV is a global content delivery system designed to provide a range of video programming and data services to commercial airlines. When AirTV is operational in 2004, it will provide a broadband connection directly to the aircraft, delivering live video entertainment, internet/email service and essential operational and safety data. The system has been designed to provide seamless global service to all airline routes except for those

FAULT DIAGNOSIS OF AN AIRCRAFT CONTROL SURFACES WITH AN AUTOMATED CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

Blessing D. Ogunvoul

2017-01-01

Full Text Available This article is devoted to studying of fault diagnosis of an aircraft control surfaces using fault models to identify specific causes. Such failures as jamming, vibration, extreme run out and performance decrease are covered.It is proved that in case of an actuator failure or flight control structural damage, the aircraft performance decreases significantly. Commercial aircraft frequently appear in the areas of military conflicts and terrorist activity, where the risk of shooting attack is high, for example in Syria, Iraq, South Sudan etc. Accordingly, it is necessary to create and assess the fault model to identify the flight control failures.The research results demonstrate that the adequate fault model is the first step towards the managing the challenges of loss of aircraft controllability. This model is also an element of adaptive failure-resistant management model.The research considers the relationship between the parameters of an i th state of a control surface and its angular rate, also parameters classification associated with specific control surfaces in order to avoid conflict/inconsistency in the determination of a faulty control surface and its condition.The results of the method obtained in this article can be used in the design of an aircraft automated control system for timely identification of fault/failure of a specific control surface, that would contribute to an effective role aimed at increasing the survivability of an aircraft and increasing the acceptable level of safety due to loss of control.

Statistical summary of commercial jet aircraft accidents : worldwide operations, 1959-2009

Science.gov (United States)

2010-07-01

The accident statistics presented in this summary are confined to worldwide commercial jet airplanes that are heavier than 60,000 pounds maximum gross weight. Within that set of airplanes, there are two groups excluded: : 1) Airplanes manufactured in...

Selling safety: the use of celebrities in improving awareness of safety in commercial aviation.

Science.gov (United States)

Molesworth, Brett R C; Seneviratne, Dimuth; Burgess, Marion

2016-07-01

The aim of this study was to investigate the influential power of a celebrity to convey key safety messages in commercial aviation using a pre-flight safety briefing video. In addition, the present research sought to examine the effectiveness of subtitles in aiding the recall of these important messages as well as how in-cabin aircraft noise affects recall of this information. A total of 101 participants were randomly divided into four groups (no noise without subtitles, no noise with subtitles, noise without subtitles and noise with subtitles) and following exposure to a pre-recorded pre-flight safety briefing video were tested for recall of key safety messages within that video. Participants who recognised and recalled the name of the celebrity in the safety briefing video recalled significantly more of the messages than participants who did not recognise the celebrity. Subtitles were also found to be effective, however, only in the presence of representative in-cabin aircraft noise. Practitioner Summary: Passenger attention to pre-flight safety briefings on commercial aircraft is poor. Utilising the celebrity status of a famous person may overcome this problem. Results suggest that celebrities do increase the recall of safety-related information.

Applications of advanced transport aircraft in developing countries

Science.gov (United States)

Gobetz, F. W.; Assarabowski, R. J.; Leshane, A. A.

1978-01-01

Four representative market scenarios were studied to evaluate the relative performance of air-and surface-based transportation systems in meeting the needs of two developing contries, Brazil and Indonesia, which were selected for detailed case studies. The market scenarios were: remote mining, low-density transport, tropical forestry, and large cargo aircraft serving processing centers in resource-rich, remote areas. The long-term potential of various aircraft types, together with fleet requirements and necessary technology advances, is determined for each application.

NASA's Pursuit of Low-Noise Propulsion for Low-Boom Commercial Supersonic Vehicles

Science.gov (United States)

Bridges, James; Brown, Clifford A.; Seidel, Jonathan A.

2018-01-01

Since 2006, when the Fundamental Aeronautics Program was instituted within NASA's Aeronautics Mission Directorate, there has been a Project looking at the technical barriers to commercial supersonic flight. Among the barriers is the noise produced by aircraft during landing and takeoff. Over the years that followed, research was carried out at NASA aeronautics research centers, often in collaboration with academia and industry, addressing the problem. In 2013, a high-level milestone was established, described as a Technical Challenge, with the objective of demonstrating the feasibility of a low-boom supersonic airliner that could meet current airport noise regulations. The Technical Challenge was formally called "Low Noise Propulsion for Low Boom Aircraft", and was completed in late 2016. This paper reports the technical findings from this Technical Challenge, reaching back almost 10 years to review the technologies and tools that were developed along the way. It also discusses the final aircraft configuration and propulsion systems required for a supersonic civilian aircraft to meet noise regulations using the technologies available today. Finally, the paper documents the model-scale tests that validated the acoustic performance of the study aircraft.

Information note about the protection of nuclear facilities against aircraft crashes; Note d'information sur la protection des installations nucleaires contre les chutes d'avions

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The protection of nuclear facilities against external risks (earthquakes, floods, fires etc..) is an aspect of safety taken into consideration by the French authority of nuclear safety (ASN). Concerning the aircraft crashes, the fundamental safety rules make three categories of aircraft: the small civil aircraft (weight < 5.7 t), the military aircraft, and the commercial aircraft (w > 5.7 t). Nuclear facilities are designed to resist against crashes of aircraft from the first category only, because the probability of the accidental crash of a big aircraft are extremely low. This document comprises an information note about the protection of nuclear facilities against aircraft crashes, a dossier about the safety of nuclear facilities with respect to external risks in general (natural disasters and aircraft crashes), and an article about the protection of nuclear power plants against aircraft crashes (design, safety measures, regulation, surveillance, experience feedback). (J.S.)

Sulfuric Acid and Soot Particles in Aircraft Exhaust

Science.gov (United States)

Pueschel, Rudolf F.; Verma, S.; Ferry, G. V.; Goodman, J.; Strawa, A. W.; Gore, Warren J. Y. (Technical Monitor)

1997-01-01

Aircraft have become the fastest, fairly convenient and, in most cases of long-distance travel, most economical mode of travel. This is reflected in the increase of commercial air traffic at a rate of 6% per year since 1978. Future annual growth rates of passenger miles of 4% for domestic and 6% for international routes are projected. A still larger annual increase of 8.5% is expected for the Asia/Pacific region. To meet that growth, Boeing predicts the addition of 15,900 new aircraft to the world's fleets, valued at more than $1.1 trillion, within the next 20 years. The largest concern of environmental consequences of aircraft emissions deals with ozone (O3), because: (1) the O3 layer protects the blaspheme from short-ultraviolet radiation that can cause damage to human, animal and plant life, and possibly affect agricultural production and the marine food chain; (2) O3 is important for the production of the hydroxyl radical (OH) which, in turn, is responsible for the destruction of other greenhouse gases, e.g., methane (CH4) and for the removal of other pollutants, and (3) O3 is a greenhouse gas. Additional information is contained in the original extended abstract.

Flight assessment of a large supersonic drone aircraft for research use

Science.gov (United States)

Eckstrom, C. V.; Peele, E. L.

1974-01-01

An assessment is made of the capabilities of the BQM-34E supersonic drone aircraft as a test bed research vehicle. This assessment is made based on a flight conducted for the purpose of obtaining flight test measurements of wing loads at various maneuver flight conditions. Flight plan preparation, flight simulation, and conduct of the flight test are discussed along with a presentation of the test data obtained and an evaluation of how closely the flight test followed the test plan.

Aircraft Detection from VHR Images Based on Circle-Frequency Filter and Multilevel Features

Directory of Open Access Journals (Sweden)

Feng Gao

2013-01-01

Full Text Available Aircraft automatic detection from very high-resolution (VHR images plays an important role in a wide variety of applications. This paper proposes a novel detector for aircraft detection from very high-resolution (VHR remote sensing images. To accurately distinguish aircrafts from background, a circle-frequency filter (CF-filter is used to extract the candidate locations of aircrafts from a large size image. A multi-level feature model is then employed to represent both local appearance and spatial layout of aircrafts by means of Robust Hue Descriptor and Histogram of Oriented Gradients. The experimental results demonstrate the superior performance of the proposed method.

41 CFR 301-70.801 - When may we authorize travel on Government aircraft?

Science.gov (United States)

2010-07-01

... travel on Government aircraft only as follows: (a) For official travel when— (1) No scheduled commercial... in accordance with §§ 301-10.262(a) and 301-70.803(a). (c) For space available travel when— (1) The... to travel space available under 10 U.S.C. 4744 and regulations implementing that statute. ...

Operation of commercially-based microcomputer technology in a space radiation environment

Science.gov (United States)

Yelverton, J. N.

This paper focuses on detection and recovery techniques that should enable the reliable operation of commercially-based microprocessor technology in the harsh radiation environment of space and at high altitudes. This approach is especially significant in light of the current shift in emphasis (due to cost) from space hardened Class-S parts qualification to a more direct use of commercial parts. The method should offset some of the concern that the newer high density state-of-the-art RISC and CISC microprocessors can be used in future space applications. Also, commercial aviation, should benefit, since radiation induced transients are a new issue arising from the increased quantities of microcomputers used in aircraft avionics.

Subsonic Ultra Green Aircraft Research. Phase II - Volume I; Truss Braced Wing Design Exploration

Science.gov (United States)

Bradley, Marty K.; Droney, Christopher K.; Allen, Timothy J.

2015-01-01

This report summarizes the Truss Braced Wing (TBW) work accomplished by the Boeing Subsonic Ultra Green Aircraft Research (SUGAR) team, consisting of Boeing Research and Technology, Boeing Commercial Airplanes, General Electric, Georgia Tech, Virginia Tech, NextGen Aeronautics, and Microcraft. A multi-disciplinary optimization (MDO) environment defined the geometry that was further refined for the updated SUGAR High TBW configuration. Airfoil shapes were tested in the NASA TCT facility, and an aeroelastic model was tested in the NASA TDT facility. Flutter suppression was successfully demonstrated using control laws derived from test system ID data and analysis models. Aeroelastic impacts for the TBW design are manageable and smaller than assumed in Phase I. Flutter analysis of TBW designs need to include pre-load and large displacement non-linear effects to obtain a reasonable match to test data. With the updated performance and sizing, fuel burn and energy use is reduced by 54% compared to the SUGAR Free current technology Baseline (Goal 60%). Use of the unducted fan version of the engine reduces fuel burn and energy by 56% compared to the Baseline. Technology development roadmaps were updated, and an airport compatibility analysis established feasibility of a folding wing aircraft at existing airports.

Recent developments in advanced aircraft aluminium alloys

International Nuclear Information System (INIS)

Dursun, Tolga; Soutis, Costas

2014-01-01

Highlights: • To compete with composites, performance of aluminium alloys should be increased. • Al–Li alloys have higher strength, fracture and fatigue/corrosion resistance. • Improvements of aerospace Al alloys are due to optimised solute content and ratios. • In selecting new materials, there should be no reduction in the level of safety. • The use of hybrid materials could provide additional opportunities for Al alloys. - Abstract: Aluminium alloys have been the primary material for the structural parts of aircraft for more than 80 years because of their well known performance, well established design methods, manufacturing and reliable inspection techniques. Nearly for a decade composites have started to be used more widely in large commercial jet airliners for the fuselage, wing as well as other structural components in place of aluminium alloys due their high specific properties, reduced weight, fatigue performance and corrosion resistance. Although the increased use of composite materials reduced the role of aluminium up to some extent, high strength aluminium alloys remain important in airframe construction. Aluminium is a relatively low cost, light weight metal that can be heat treated and loaded to relatively high level of stresses, and it is one of the most easily produced of the high performance materials, which results in lower manufacturing and maintenance costs. There have been important recent advances in aluminium aircraft alloys that can effectively compete with modern composite materials. This study covers latest developments in enhanced mechanical properties of aluminium alloys, and high performance joining techniques. The mechanical properties on newly developed 2000, 7000 series aluminium alloys and new generation Al–Li alloys are compared with the traditional aluminium alloys. The advantages and disadvantages of the joining methods, laser beam welding and friction stir welding, are also discussed

Turboelectric Distributed Propulsion in a Hybrid Wing Body Aircraft

Science.gov (United States)

Felder, James L.; Brown, Gerald V.; DaeKim, Hyun; Chu, Julio

2011-01-01

The performance of the N3-X, a 300 passenger hybrid wing body (HWB) aircraft with turboelectric distributed propulsion (TeDP), has been analyzed to see if it can meet the 70% fuel burn reduction goal of the NASA Subsonic Fixed Wing project for N+3 generation aircraft. The TeDP system utilizes superconducting electric generators, motors and transmission lines to allow the power producing and thrust producing portions of the system to be widely separated. It also allows a small number of large turboshaft engines to drive any number of propulsors. On the N3-X these new degrees of freedom were used to (1) place two large turboshaft engines driving generators in freestream conditions to maximize thermal efficiency and (2) to embed a broad continuous array of 15 motor driven propulsors on the upper surface of the aircraft near the trailing edge. That location maximizes the amount of the boundary layer ingested and thus maximizes propulsive efficiency. The Boeing B777-200LR flying 7500 nm (13890 km) with a cruise speed of Mach 0.84 and an 118100 lb payload was selected as the reference aircraft and mission for this study. In order to distinguish between improvements due to technology and aircraft configuration changes from those due to the propulsion configuration changes, an intermediate configuration was included in this study. In this configuration a pylon mounted, ultra high bypass (UHB) geared turbofan engine with identical propulsion technology was integrated into the same hybrid wing body airframe. That aircraft achieved a 52% reduction in mission fuel burn relative to the reference aircraft. The N3-X was able to achieve a reduction of 70% and 72% (depending on the cooling system) relative to the reference aircraft. The additional 18% - 20% reduction in the mission fuel burn can therefore be attributed to the additional degrees of freedom in the propulsion system configuration afforded by the TeDP system that eliminates nacelle and pylon drag, maximizes boundary

Indexing, screening, coding and cataloging of earth resources aircraft mission data

Science.gov (United States)

1977-01-01

Tasks completed are as follows: (1) preparation of large Area Crop Inventory experiment for data base entry;(2) preparation of Earth Observations Aircraft Flight summary reports for publication; (3) updating of the aircraft mission index coverage map and Ames aircraft flight map; (4) Prepared of Earth Observation Helicopter Flight reports for publication; and (5) indexing of LANDSAT imagery. (6) formulation of phase 3 biowindows 1, 2, 3, and 4 listings by country, footprint, and acqusition dates; (7) preparation of flight summary reports; and (8) preparation of an Alaska state index coverage map.

Oil spill remote sensing sensors and aircraft

International Nuclear Information System (INIS)

Fingas, M.; Fruhwirth, M.; Gamble, L.

1992-01-01

The most common form of remote sensing as applied to oil spills is aerial remote sensing. The technology of aerial remote sensing, mainly from aircraft, is reviewed along with aircraft-mounted remote sensors and aircraft modifications. The characteristics, advantages, and limitations of optical techniques, infrared and ultraviolet sensors, fluorosensors, microwave and radar sensors, and slick thickness sensors are discussed. Special attention is paid to remote sensing of oil under difficult circumstances, such as oil in water or oil on ice. An infrared camera is the first sensor recommended for oil spill work, as it is the cheapest and most applicable device, and is the only type of equipment that can be bought off-the-shelf. The second sensor recommended is an ultraviolet and visible-spectrum device. The laser fluorosensor offers the only potential for discriminating between oiled and un-oiled weeds or shoreline, and for positively identifying oil pollution on ice and in a variety of other situations. However, such an instrument is large and expensive. Radar, although low in priority for purchase, offers the only potential for large-area searches and foul-weather remote sensing. Most other sensors are experimental or do not offer good potential for oil detection or mapping. 48 refs., 8 tabs

Flight service evaluation of Kevlar-49 epoxy composite panels in wide-bodied commercial transport aircraft

Science.gov (United States)

Stone, R. H.

1984-01-01

Kevlar-49 fairing panels, installed as flight service components on three L-1011s, were inspected after 10 years of service. There are six Kevlar-49 panels on each aircraft: a left-hand and right-hand set of a wing-body sandwich fairing; a solid laminate under-wing fillet panel; and a 422 K (300 F) service aft engine fairing. The three L-1011s include one each in service with Eastern, Air Canada, and TWA. The fairings have accumulated a total of 79,568 hours, with one ship set having nearly 28,000 hours service. The inspections were conducted at the airlines' major maintenance bases with the participation of Lockheed Engineering. The Kevlar-49 components were found to be performing satisfactorily in service with no major problems, or any condition requiring corrective action. The only defects noted were minor impact damage, a few minor disbonds and a minor degree of fastener hole fraying and elongation. These are for the most part comparable to damage noted on fiberglass fairings. The service history obtained in this program indicates that Kevlar-49 epoxy composite materials have satisfactory service characteristics for use in aircraft secondary structure.

Space Station Workshop: Commercial Missions and User Requirements

Science.gov (United States)

1988-01-01

The topics of discussion addressed during a three day workshop on commercial application in space are presented. Approximately half of the program was directed towards an overview and orientation to the Space Station Project; the technical attributes of space; and present and future potential commercial opportunities. The remaining time was spent addressing technological issues presented by previously-formed industry working groups, who attempted to identify the technology needs, problems or issues faced and/or anticipated by the following industries: extraction (mining, agriculture, petroleum, fishing, etc.); fabrication (manufacturing, automotive, aircraft, chemical, pharmaceutical and electronics); and services (communications, transportation and retail robotics). After the industry groups presented their technology issues, the workshop divided into smaller discussion groups composed of: space experts from NASA; academia; industry experts in the appropriate disciplines; and other workshop participants. The needs identified by the industry working groups, space station technical requirements, proposed commercial ventures and other issues related to space commercialization were discussed. The material summarized and reported are the consensus from the discussion groups.

Advanced composite structural concepts and material technologies for primary aircraft structures

Science.gov (United States)

Jackson, Anthony

1991-01-01

Structural weight savings using advanced composites have been demonstrated for many years. Most military aircraft today use these materials extensively and Europe has taken the lead in their use in commercial aircraft primary structures. A major inhibiter to the use of advanced composites in the United States is cost. Material costs are high and will remain high relative to aluminum. The key therefore lies in the significant reduction in fabrication and assembly costs. The largest cost in most structures today is assembly. As part of the NASA Advanced Composite Technology Program, Lockheed Aeronautical Systems Company has a contract to explore and develop advanced structural and manufacturing concepts using advanced composites for transport aircraft. Wing and fuselage concepts and related trade studies are discussed. These concepts are intended to lower cost and weight through the use of innovative material forms, processes, structural configurations and minimization of parts. The approach to the trade studies and the downselect to the primary wing and fuselage concepts is detailed. The expectations for the development of these concepts is reviewed.

Large eddy simulation of soot evolution in an aircraft combustor

Science.gov (United States)

Mueller, Michael E.; Pitsch, Heinz

2013-11-01

An integrated kinetics-based Large Eddy Simulation (LES) approach for soot evolution in turbulent reacting flows is applied to the simulation of a Pratt & Whitney aircraft gas turbine combustor, and the results are analyzed to provide insights into the complex interactions of the hydrodynamics, mixing, chemistry, and soot. The integrated approach includes detailed models for soot, combustion, and the unresolved interactions between soot, chemistry, and turbulence. The soot model is based on the Hybrid Method of Moments and detailed descriptions of soot aggregates and the various physical and chemical processes governing their evolution. The detailed kinetics of jet fuel oxidation and soot precursor formation is described with the Radiation Flamelet/Progress Variable model, which has been modified to account for the removal of soot precursors from the gas-phase. The unclosed filtered quantities in the soot and combustion models, such as source terms, are closed with a novel presumed subfilter PDF approach that accounts for the high subfilter spatial intermittency of soot. For the combustor simulation, the integrated approach is combined with a Lagrangian parcel method for the liquid spray and state-of-the-art unstructured LES technology for complex geometries. Two overall fuel-to-air ratios are simulated to evaluate the ability of the model to make not only absolute predictions but also quantitative predictions of trends. The Pratt & Whitney combustor is a Rich-Quench-Lean combustor in which combustion first occurs in a fuel-rich primary zone characterized by a large recirculation zone. Dilution air is then added downstream of the recirculation zone, and combustion continues in a fuel-lean secondary zone. The simulations show that large quantities of soot are formed in the fuel-rich recirculation zone, and, furthermore, the overall fuel-to-air ratio dictates both the dominant soot growth process and the location of maximum soot volume fraction. At the higher fuel

Volcanic Ash -Aircraft Encounter Damages: in Volcanological Point of View

Science.gov (United States)

Aydar, Erkan; Aladaǧ, Çaǧdaş Hakan; Menteş, Turhan

2017-04-01

The jet era or age began at 1930 and 40's in aviation sector, with the production of first jet engine for the aircrafts. Since 1950's, the commercial aviation with regular flights were established. Civil aviation and air-transport drastically increased due to intensive demand, and declared at least 10 fold since 1970 by IATA report. Parallelly to technological and economical developpement, the commercial jets became more comfortable, secure and rapid, bringing the world smaller, the countries closer. On the other hand, according to Global Volcanism Program Catalogues of Smithsonian Institute, about 1,500 volcanoes have erupted in the Holocene, 550 of them have had historical eruptions and considered as active. Besides an average of 55-60 volcanoes erupt each year, and about 8-10 of these eruptions produce ash clouds that reach aircraft flight altitudes (Salinas and Watt, 2004). Volcanic ash can be expected to be in air routes at altitudes greater than 9 km (30,000 ft) for roughly 20 days per year worldwide (Miller &Casadeval, 2000). A precious compilation of incidents due to encounters of aircrafts with volcanic ash clouds covering the years between 1953 and 2009 was used in this work (Guffanti et al., 2010-USGS Report) with an additional information on Eyfjallajökull-2010 eruption. According to this compilation,129 incidents happened within the concerned time interval. The damages, in general, fall in second and third class of Severity index, indicating the damages are limited on airframe of the planes, or some abrasions in jet engine, windblast etc.. We focused on fourth class of severity index involving the damages on jet engine of aircraft (engine fail) due to ingestion of volcanic ash and investigate eruption style and caused damage relationships. During the eruptive sequences of Mts Saint Helen (USA), Galunggung (Indonesia, 2 incidents), Redoubt (USA), Pinatubo (Philipinnes), Unzen (Japan), Manam (Papua New Guinea), Soufriere Hills (Lesser Antilles), Chaiten

Preliminary Study on Effect of Aviation Fuel in the Safety Evaluation of Nuclear Power Plant Crashed by Aircraft

International Nuclear Information System (INIS)

Jin, Byeong Moo; Jeon, Se Jin; Lee, Yun Seok; Kim, Young Jin

2011-01-01

As the safety assessments of nuclear power plants for the hypothetical large civil aircraft crash should be made mandatory, studies on large aircraft-nuclear power plant impact analyses and assessments are actively in progress. The large civil aircraft are being operated with a large amount of fuel and the fuel can be assumed to contribute to the impact loads at the impact. The fuel, i.e., the internal liquid can be considered as added masses classically in the evaluation of the impact load. According to the recent experimental research, it has been shown that the impact load of high speed impacting body with internal liquid is much higher than that of the mass-equivalent impacting body. In this study, the impact loads according to the existence of the internal liquid are computed by numerical methods and the safety assessment of nuclear power plant crashed by large civil aircraft are performed as an application

'Oorja' in India: Assessing a large-scale commercial distribution of advanced biomass stoves to households.

Science.gov (United States)

Thurber, Mark C; Phadke, Himani; Nagavarapu, Sriniketh; Shrimali, Gireesh; Zerriffi, Hisham

2014-04-01

Replacing traditional stoves with advanced alternatives that burn more cleanly has the potential to ameliorate major health problems associated with indoor air pollution in developing countries. With a few exceptions, large government and charitable programs to distribute advanced stoves have not had the desired impact. Commercially-based distributions that seek cost recovery and even profits might plausibly do better, both because they encourage distributors to supply and promote products that people want and because they are based around properly-incentivized supply chains that could more be scalable, sustainable, and replicable. The sale in India of over 400,000 "Oorja" stoves to households from 2006 onwards represents the largest commercially-based distribution of a gasification-type advanced biomass stove. BP's Emerging Consumer Markets (ECM) division and then successor company First Energy sold this stove and the pelletized biomass fuel on which it operates. We assess the success of this effort and the role its commercial aspect played in outcomes using a survey of 998 households in areas of Maharashtra and Karnataka where the stove was sold as well as detailed interviews with BP and First Energy staff. Statistical models based on this data indicate that Oorja purchase rates were significantly influenced by the intensity of Oorja marketing in a region as well as by pre-existing stove mix among households. The highest rate of adoption came from LPG-using households for which Oorja's pelletized biomass fuel reduced costs. Smoke- and health-related messages from Oorja marketing did not significantly influence the purchase decision, although they did appear to affect household perceptions about smoke. By the time of our survey, only 9% of households that purchased Oorja were still using the stove, the result in large part of difficulties First Energy encountered in developing a viable supply chain around low-cost procurement of "agricultural waste" to make

Information note about the protection of nuclear facilities against aircraft crashes; Note d'information sur la protection des installations nucleaires contre les chutes d'avions

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The protection of nuclear facilities against external risks (earthquakes, floods, fires etc..) is an aspect of safety taken into consideration by the French authority of nuclear safety (ASN). Concerning the aircraft crashes, the fundamental safety rules make three categories of aircraft: the small civil aircraft (weight < 5.7 t), the military aircraft, and the commercial aircraft (w > 5.7 t). Nuclear facilities are designed to resist against crashes of aircraft from the first category only, because the probability of the accidental crash of a big aircraft are extremely low. This document comprises an information note about the protection of nuclear facilities against aircraft crashes, a dossier about the safety of nuclear facilities with respect to external risks in general (natural disasters and aircraft crashes), and an article about the protection of nuclear power plants against aircraft crashes (design, safety measures, regulation, surveillance, experience feedback). (J.S.)

Large Aircraft Robotic Paint Stripping (LARPS) system and the high pressure water process

Science.gov (United States)

See, David W.; Hofacker, Scott A.; Stone, M. Anthony; Harbaugh, Darcy

1993-03-01

The aircraft maintenance industry is beset by new Environmental Protection Agency (EPA) guidelines on air emissions, Occupational Safety and Health Administration (OSHA) standards, dwindling labor markets, Federal Aviation Administration (FAA) safety guidelines, and increased operating costs. In light of these factors, the USAF's Wright Laboratory Manufacturing Technology Directorate and the Aircraft Division of the Oklahoma City Air Logistics Center initiated a MANTECH/REPTECH effort to automate an alternate paint removal method and eliminate the current manual methylene chloride chemical stripping methods. This paper presents some of the background and history of the LARPS program, describes the LARPS system, documents the projected operational flow, quantifies some of the projected system benefits and describes the High Pressure Water Stripping Process. Certification of an alternative paint removal method to replace the current chemical process is being performed in two phases: Process Optimization and Process Validation. This paper also presents the results of the Process Optimization for metal substrates. Data on the coating removal rate, residual stresses, surface roughness, preliminary process envelopes, and technical plans for process Validation Testing will be discussed.

Flight test guidelines for homebuilt and experimental aircraft

CSIR Research Space (South Africa)

White, WJ

2013-04-01

Full Text Available experience totalling approximately 7,000 flying hours on forty-five different variants of military aircraft, nearly all in the flight-test environment. He holds a Commercial Pilot’s Licence with a Class I test pilot rating. During his twenty-eight years... of military flight-testing, he was involved in the fixed wing fighter programmes and weapons development testing and amongst others, he was the project test pilot on the Cheetah C, the Mirage IIIRZ/Atar 09K50 engine integration and the Mirage F1 fitted...

An Integrated Knowledge Based Engineering Mechatronics Modeling Approach to Support the Design of Unstable and Unmanned Aircraft

NARCIS (Netherlands)

Tian, F.N.

2015-01-01

The commercial transport aircraft industry is currently developing new “more electric aircraft” (MEA) designs in which various conventional mechanical, hydraulic and pneumatic power systems are replaced with electrically-based power systems. Their objective is to improve the overall flight

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground Based Computation and Control Systems and Human Health and Safety

Science.gov (United States)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).

Developing Large-Scale Bayesian Networks by Composition: Fault Diagnosis of Electrical Power Systems in Aircraft and Spacecraft

Science.gov (United States)

Mengshoel, Ole Jakob; Poll, Scott; Kurtoglu, Tolga

2009-01-01

In this paper, we investigate the use of Bayesian networks to construct large-scale diagnostic systems. In particular, we consider the development of large-scale Bayesian networks by composition. This compositional approach reflects how (often redundant) subsystems are architected to form systems such as electrical power systems. We develop high-level specifications, Bayesian networks, clique trees, and arithmetic circuits representing 24 different electrical power systems. The largest among these 24 Bayesian networks contains over 1,000 random variables. Another BN represents the real-world electrical power system ADAPT, which is representative of electrical power systems deployed in aerospace vehicles. In addition to demonstrating the scalability of the compositional approach, we briefly report on experimental results from the diagnostic competition DXC, where the ProADAPT team, using techniques discussed here, obtained the highest scores in both Tier 1 (among 9 international competitors) and Tier 2 (among 6 international competitors) of the industrial track. While we consider diagnosis of power systems specifically, we believe this work is relevant to other system health management problems, in particular in dependable systems such as aircraft and spacecraft. (See CASI ID 20100021910 for supplemental data disk.)

Small transport aircraft technology

Science.gov (United States)

Williams, L. J.

1983-01-01

Information on commuter airline trends and aircraft developments is provided to upgrade the preliminary findings of a NASA-formed small transport aircraft technology (STAT) team, established to determine whether the agency's research and development programs could help commuter aircraft manufacturers solve technical problems related to passenger acceptance and use of 19- to 50-passenger aircraft. The results and conclusions of the full set of completed STAT studies are presented. These studies were performed by five airplane manufacturers, five engine manufacturers, and two propeller manufacturers. Those portions of NASA's overall aeronautics research and development programs which are applicable to commuter aircraft design are summarized. Areas of technology that might beneficially be expanded or initiated to aid the US commuter aircraft manufacturers in the evolution of improved aircraft for the market are suggested.

Low-Cost Composite Materials and Structures for Aircraft Applications

Science.gov (United States)

Deo, Ravi B.; Starnes, James H., Jr.; Holzwarth, Richard C.

2003-01-01

A survey of current applications of composite materials and structures in military, transport and General Aviation aircraft is presented to assess the maturity of composites technology, and the payoffs realized. The results of the survey show that performance requirements and the potential to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are the main reasons for the selection of composite materials for current aircraft applications. Initial acquisition costs of composite airframe components are affected by high material costs and complex certification tests which appear to discourage the widespread use of composite materials for aircraft applications. Material suppliers have performed very well to date in developing resin matrix and fiber systems for improved mechanical, durability and damage tolerance performance. The next challenge for material suppliers is to reduce material costs and to develop materials that are suitable for simplified and inexpensive manufacturing processes. The focus of airframe manufacturers should be on the development of structural designs that reduce assembly costs by the use of large-scale integration of airframe components with unitized structures and manufacturing processes that minimize excessive manual labor.

Copycats in Pilot Aircraft-Assisted Suicides after the Germanwings Incident

Directory of Open Access Journals (Sweden)

Tanja Laukkala

2018-03-01

Full Text Available Aircraft-assisted pilot suicide is a rare but serious phenomenon. The aim of this study was to evaluate changes in pilot aircraft-assisted suicide risks, i.e., a copycat effect, in the U.S. and Germany after the Germanwings 2015 incident in the French Alps. Aircraft-assisted pilot suicides were searched in the U.S. National Transportation Safety Board (NTSB accident investigation database and in the German Bundestelle für Flugunfalluntersuchung (BFU Reports of Investigation database five years before and two years after the deliberate crash of the Germanwings flight into the French Alps in 2015. The relative risk (RR of the aircraft-assisted pilot suicides was calculated. Two years after the incident, three out of 454 (0.66% fatal incidents were aircraft-assisted suicides compared with six out of 1292 (0.46% in the prior five years in the NTSB database. There were no aircraft-assisted pilot suicides in the German database during the two years after or five years prior to the Germanwings crash. The relative aircraft-assisted pilot suicide risk for the U.S. was 1.4 (95% CI 0.3–4.2 which was not statistically significant. Six of the pilots who died by suicide had told someone of their suicidal intentions. We consider changes in the rate to be within a normal variation. Responsible media coverage of aircraft incidents is important due to the large amount of publicity that these events attract.

Copycats in Pilot Aircraft-Assisted Suicides after the Germanwings Incident

Science.gov (United States)

Vuorio, Alpo; Bor, Robert; Budowle, Bruce; Navathe, Pooshan; Pukkala, Eero; Sajantila, Antti

2018-01-01

Aircraft-assisted pilot suicide is a rare but serious phenomenon. The aim of this study was to evaluate changes in pilot aircraft-assisted suicide risks, i.e., a copycat effect, in the U.S. and Germany after the Germanwings 2015 incident in the French Alps. Aircraft-assisted pilot suicides were searched in the U.S. National Transportation Safety Board (NTSB) accident investigation database and in the German Bundestelle für Flugunfalluntersuchung (BFU) Reports of Investigation database five years before and two years after the deliberate crash of the Germanwings flight into the French Alps in 2015. The relative risk (RR) of the aircraft-assisted pilot suicides was calculated. Two years after the incident, three out of 454 (0.66%) fatal incidents were aircraft-assisted suicides compared with six out of 1292 (0.46%) in the prior five years in the NTSB database. There were no aircraft-assisted pilot suicides in the German database during the two years after or five years prior to the Germanwings crash. The relative aircraft-assisted pilot suicide risk for the U.S. was 1.4 (95% CI 0.3–4.2) which was not statistically significant. Six of the pilots who died by suicide had told someone of their suicidal intentions. We consider changes in the rate to be within a normal variation. Responsible media coverage of aircraft incidents is important due to the large amount of publicity that these events attract. PMID:29534475

Development of Textile Reinforced Composites for Aircraft Structures

Science.gov (United States)

Dexter, H. Benson

1998-01-01

NASA has been a leader in development of composite materials for aircraft applications during the past 25 years. In the early 1980's NASA and others conducted research to improve damage tolerance of composite structures through the use of toughened resins but these resins were not cost-effective. The aircraft industry wanted affordable, robust structures that could withstand the rigors of flight service with minimal damage. The cost and damage tolerance barriers of conventional laminated composites led NASA to focus on new concepts in composites which would incorporate the automated manufacturing methods of the textiles industry and which would incorporate through-the-thickness reinforcements. The NASA Advanced Composites Technology (ACT) Program provided the resources to extensively investigate the application of textile processes to next generation aircraft wing and fuselage structures. This paper discusses advanced textile material forms that have been developed, innovative machine concepts and key technology advancements required for future application of textile reinforced composites in commercial transport aircraft. Multiaxial warp knitting, triaxial braiding and through-the-thickness stitching are the three textile processes that have surfaced as the most promising for further development. Textile reinforced composite structural elements that have been developed in the NASA ACT Program are discussed. Included are braided fuselage frames and window-belt reinforcements, woven/stitched lower fuselage side panels, stitched multiaxial warp knit wing skins, and braided wing stiffeners. In addition, low-cost processing concepts such as resin transfer molding (RTM), resin film infusion (RFI), and vacuum-assisted resin transfer molding (VARTM) are discussed. Process modeling concepts to predict resin flow and cure in textile preforms are also discussed.

X-36 Tailless Fighter Agility Research Aircraft in flight

Science.gov (United States)

1997-01-01

The lack of a vertical tail on the X-36 technology demonstrator is evident as the remotely piloted aircraft flies a low-altitude research flight above Rogers Dry Lake at Edwards Air Force Base in the California desert on October 30, 1997. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three

Conceptual Design of a Small Hybrid Unmanned Aircraft System

Directory of Open Access Journals (Sweden)

Umberto Papa

2017-01-01

Full Text Available UAS (Unmanned Aircraft System technologies are today extremely required in various fields of interest, from military to civil (search and rescue, environmental surveillance and monitoring, and entertainment. Besides safety and legislative issues, the main obstacle to civilian applications of UAS systems is the short time of flight (endurance, which depends on the equipped power system (battery pack and the flight mission (low/high speed or altitude. Long flight duration is fundamental, especially with tasks that require hovering capability (e.g., river flow monitoring, earthquakes, devastated areas, city traffic monitoring, and archeological sites inspection. This work presents the conceptual design of a Hybrid Unmanned Aircraft System (HUAS, merging a commercial off-the-shelf quadrotor and a balloon in order to obtain a good compromise between endurance and weight. The mathematical models for weights estimation and balloon static performance analysis are presented, together with experimental results in different testing scenarios and complex environments, which show 50% improvement of the flight duration.

Large-scale commercial applications of the in situ vitrification remediation technology

International Nuclear Information System (INIS)

Campbell, B.E.; Hansen, J.E.; McElroy, J.L.; Thompson, L.E.; Timmerman, C.L.

1994-01-01

The first large-scale commercial application of the innovative In Situ Vitrification (ISV) remediation technology was completed at the Parsons Chemical/ETM Enterprises Superfund site in Michigan State midyear 1994. This project involved treating 4,800 tons of pesticide and mercury-contaminated soil. The project also involved performance of the USEPA SITE Program demonstration test for the ISV technology. The Parsons project involved consolidation and staging of contaminated soil from widespread locations on and nearby the site. This paper presents a brief description of the ISV technology along with case-study type information on these two sites and the performance of the ISV technology on them. The paper also reviews other remediation projects where ISV has been identified as the/a preferred remedy, and where ISV is currently planned for use. These sites include soils contaminated with pesticides, dioxin, PCP, paint wastes, and a variety of heavy metals. This review of additional sites also includes a description of a planned radioactive mixed waste remediation project in Australia that contains large amounts of plutonium, uranium, lead, beryllium, and metallic and other debris buried in limestone and dolomitic soil burial pits. Initial test work has been completed on this application, and preparations are now underway for pilot testing in Australia. This project will demonstrate the applicability of the ISV technology to the challenging application of buried mixed wastes

Finite Element Analysis of Composite Aircraft Fuselage Frame

Science.gov (United States)

Dandekar, Aditya Milind

Composites have been introduced in aircraft industries, for their stronger, stiffer, and lighter properties than their metal-alloys counterparts. The general purpose of an aircraft is to transport commercial or military payload. Aircraft frames primarily maintains the shape of fuselage and prevent instability of the structure. Fuselage is similar as wing in construction which consist of longitudinal elements (longerons and stringers), transverse elements (frames and bulkheads) and its external skin. The fuselage is subjected to forces such as the wing reactions, landing gear reaction, empennage reaction, inertia forces subjected due to size and weight, internal pressure forces due to high altitude. Frames also ensure fail-safe design against skin crack propagation due to hoops stress. Ideal fuselage frames cross section is often circular ring shape with a frame cap of Z section. They are mainly made up of light alloy commonly used is aluminium alloys such as Al-2024, Al-7010, Al-7050, Al-7175. Aluminium alloys have good strength to density ratios in compression and bending of thin plate. A high strength to weight ratio of composite materials can result in a lighter aircraft structure or better safety factor. This research focuses on analysis of fuselage frame under dynamic load condition with change in material. Composites like carbon fibre reinforced plastics [CFRP] and glass fibre reinforced plastics [GFRP] are compared with traditional aluminium alloy Al-7075. The frame is subjected to impact test by dropping it at a velocity of 30 ft. / secs from a height of 86 inch from its centre of gravity. These parameters are considered in event of failure of landing gear, and an aircraft is subject to belly landing or gear-up landing. The shear flow is calculated due to impact force which acts in radial direction. The frame is analysed under static structural and explicit dynamic load conditions. Geometry is created in ANSYS Design Modeler. Analysis setup is created using

Tunable diode laser in-situ CH4 measurements aboard the CARIBIC passenger aircraft: instrument performance assessment

Science.gov (United States)

Dyroff, C.; Zahn, A.; Sanati, S.; Christner, E.; Rauthe-Schöch, A.; Schuck, T. J.

2014-03-01

A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyser (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne operation. It was characterised in the laboratory with respect to instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation, a calibration strategy is described that utilises CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppb for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppb. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately determined and the uncertainty is estimated to be 12.4 ppb. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppb at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.

Structural evaluation of spent nuclear fuel storage facilities under aircraft crash impact (2). Horizontal impact test onto reduced scale metal cask due to aircraft engine missile

International Nuclear Information System (INIS)

Namba, Kosuke; Shirai, Koji; Saegusa, Toshiari

2009-01-01

In this study, to confirm the sealing performance of a metal cask subjected to impact force due to possible commercial aircraft crash against a spent fuel storage facility, the horizontal impact test was carried out. In the test, an aircraft engine missile with a speed of 57.3 m/s attacked the reduced scale metal cask containing helium gas, which stands vertically. Then the leak rate and sliding displacement of the lid were measured. The leak rate increased rapidly and reached to 4.0 x 10 -6 Pa·m 3 /sec. After that, the leak rate decreased slowly and converged to 1.0x10 -6 Pa·m 3 /sec after 20 hours from the impact test. The leak rate of a full scale cask was evaluated using that of reduced scale cask obtained by the test. Then the leak rate of the full scale cask was 3.5x10 -5 Pa·m 3 /sec. This result showed that the sealing performance of the full scale metal cask would not be affected immediately by the horizontal impact of the aircraft engine with a speed of 57.3 m/s. (author)

Enhanced vision flight deck technology for commercial aircraft low-visibility surface operations

Science.gov (United States)

Arthur, Jarvis J.; Norman, R. M.; Kramer, Lynda J.; Prinzel, Lawerence J.; Ellis, Kyle K.; Harrison, Stephanie J.; Comstock, J. R.

2013-05-01

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) airfield during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and minification effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

Graphene-Based Ultra-Light Batteries for Aircraft

Science.gov (United States)

Calle, Carlos I.; Kaner, Richard B.

2014-01-01

Develop a graphene-based ultracapacitor prototype that is flexible, thin, lightweight, durable, low cost, and safe and that will demonstrate the feasibility for use in aircraft center dot These graphene-based devices store charge on graphene sheets and take advantage of the large accessible surface area of graphene (2,600 m2/g) to increase the electrical energy that can be stored. center dot The proposed devices should have the electrical storage capacity of thin-film-ion batteries but with much shorter charge/discharge cycle times as well as longer lives center dot The proposed devices will be carbon-based and so will not have the same issues with flammability or toxicity as the standard lithium-based storage cells There are two main established methods for the storage and delivery of electrical energy: center dot Batteries - Store energy with electrochemical reactions - High energy densities - Slow charge/discharge cycles - Used in applications requiring large amounts of energy ? aircraft center dot Electrochemical capacitors - Store energy in electrochemical double layers - Fast charge/discharge cycles - Low energy densities - Used in electronics devices - Large capacitors are used in truck engine cranking

Occupational Contact Dermatitis in the Canadian Aircraft Industry.

Science.gov (United States)

Loranger, Camille; Moreau, Linda; Sasseville, Denis

Aircraft building exposes workers to irritant and sensitizing products. The aim of this article was to study occupational dermatoses among aircraft workers over 25 years. The files of aerospace workers referred between 1990 and 2015 were extracted from the database of the McGill University Health Centre contact dermatitis clinic. These were subdivided according to demographics, type of work, patch testing results, and final diagnosis. Of 305 workers, 58% were 40 years or younger; one third were women. Onset of dermatitis varied from 2 months to 25 years, but 120 cases (39%) occurred during the first 3 years. Fifty-one percent of the cases involved assemblers, and 27% were composite material technicians, which were overrepresented as they constitute 10% of the workforce. Of the 305 workers, 152 suffered from allergic contact dermatitis, and 96 had irritant contact dermatitis. Of those with allergic contact dermatitis, 124 reacted to epoxy-based workplace products, but only 48 had positive patch tests to commercially available epoxy allergens. More than 60% of the cases of epoxy allergy would have been missed without testing with workplace products.

Predicting visibility of aircraft.

Directory of Open Access Journals (Sweden)

Andrew Watson

Full Text Available Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO. In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration.

Impact of aircraft systems within aircraft operation: A MEA trajectory optimisation study

OpenAIRE

Seresinhe, R.

2014-01-01

Air transport has been a key component of the socio-economic globalisation. The ever increasing demand for air travel and air transport is a testament to the success of the aircraft. But this growing demand presents many challenges. One of which is the environmental impact due to aviation. The scope of the environmental impact of aircraft can be discussed from many viewpoints. This research focuses on the environmental impact due to aircraft operation. Aircraft operation causes...

ERAST: Scientific Applications and Technology Commercialization

Science.gov (United States)

Hunley, John D. (Compiler); Kellogg, Yvonne (Compiler)

2000-01-01

This is a conference publication for an event designed to inform potential contractors and appropriate personnel in various scientific disciplines that the ERAST (Environmental Research Aircraft and Sensor Technology) vehicles have reached a certain level of maturity and are available to perform a variety of missions ranging from data gathering to telecommunications. There are multiple applications of the technology and a great many potential commercial and governmental markets. As high altitude platforms, the ERAST vehicles can gather data at higher resolution than satellites and can do so continuously, whereas satellites pass over a particular area only once each orbit. Formal addresses are given by Rich Christiansen, (Director of Programs, NASA Aerospace Technology Ent.), Larry Roeder, (Senior Policy Advisor, U.S. Dept. of State), and Dr. Marianne McCarthy, (DFRC Education Dept.). The Commercialization Workshop is chaired by Dale Tietz (President, New Vista International) and the Science Workshop is chaired by Steve Wegener, (Deputy Manager of NASA ERAST, NASA Ames Research Center.

Economic modeling of fault tolerant flight control systems in commercial applications

Science.gov (United States)

Finelli, G. B.

1982-01-01

This paper describes the current development of a comprehensive model which will supply the assessment and analysis capability to investigate the economic viability of Fault Tolerant Flight Control Systems (FTFCS) for commercial aircraft of the 1990's and beyond. An introduction to the unique attributes of fault tolerance and how they will influence aircraft operations and consequent airline costs and benefits is presented. Specific modeling issues and elements necessary for accurate assessment of all costs affected by ownership and operation of FTFCS are delineated. Trade-off factors are presented, aimed at exposing economically optimal realizations of system implementations, resource allocation, and operating policies. A trade-off example is furnished to graphically display some of the analysis capabilities of the comprehensive simulation model now being developed.

Influences of nuclear containment radius on the aircraft impact force based on the Riera function

Energy Technology Data Exchange (ETDEWEB)

Zhang, T.; Wu, H., E-mail: abrahamhao@126.com; Fang, Q.; Gong, Z.M.

2015-11-15

Highlights: • A fine aircraft model of A320 was built and verified by available limited prototype impacting tests. • The influences of aircraft longitudinal crushing strength on the impact process were analyzed. • The influences of NPP containment radius on the impact force were numerically studied. • The Riera function was modified by considering the radius effect of NPP containment. - Abstract: The aircraft impact force directly influences the local failure and global response of the nuclear power plant (NPP) containment, while the existing theoretical models and the field tests were almost based on the flat target. In order to analyze the radius effect of the circular sectional containment on the impact force, a fine FE model of the commercial aircraft A320 was established and validated by the available limited full-scale F-4 Phantom impact experiment. In order to determine the force to crush the A320 FE model, the influences of aircraft longitudinal crushing strength on the impact process were analyzed based on the Riera function. Considering the containment decaying effect to aircraft impact velocity, the impact impulse was theoretically calculated, while the influences of the losses of mass and energy were not included. The numerical simulations of A320 aircrafts impacting on simplified NPP containments with different radii were conducted, which could well reproduce the airframe crushing and debris scattering. By comparison of the simulated impact impulses and the calculation values by the Riera function, the coefficients corresponding to different containment radii are derived and a fitting formula is obtained. Finally, an improved Riera function dependent on the dimensionless ratio of nuclear containment radius and aircraft wingspan is proposed.

Aircraft to aircraft intercomparison during SEMAPHORE

Science.gov (United States)

Lambert, Dominique; Durand, Pierre

1998-10-01

During the Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale (SEMAPHORE) experiment, performed in the Azores region in 1993, two French research aircraft were simultaneously used for in situ measurements in the atmospheric boundary layer. We present the results obtained from one intercomparison flight between the two aircraft. The mean parameters generally agree well, although the temperature has to be slightly shifted in order to be in agreement for the two aircraft. A detailed comparison of the turbulence parameters revealed no bias. The agreement is good for variances and is satisfactory for fluxes and skewness. A thorough study of the errors involved in flux computation revealed that the greatest accuracy is obtained for latent heat flux. Errors in sensible heat flux are considerably greater, and the worst results are obtained for momentum flux. The latter parameter, however, is more accurate than expected from previous parameterizations.

Statistical aspects of carbon fiber risk assessment modeling. [fire accidents involving aircraft

Science.gov (United States)

Gross, D.; Miller, D. R.; Soland, R. M.

1980-01-01

The probabilistic and statistical aspects of the carbon fiber risk assessment modeling of fire accidents involving commercial aircraft are examined. Three major sources of uncertainty in the modeling effort are identified. These are: (1) imprecise knowledge in establishing the model; (2) parameter estimation; and (3)Monte Carlo sampling error. All three sources of uncertainty are treated and statistical procedures are utilized and/or developed to control them wherever possible.

Engineering assessment of in situ sulfate production onboard aircraft at high altitude

Science.gov (United States)

Smith, J.; Dykema, J. A.; Keith, D.

2016-12-01

Stratospheric injection of scattering aerosols has been proposed as a way to reduce global temperature increases by decreasing net atmospheric radiative forcing. Several methods have been suggested as a means of implementing solar geoengineering, and high altitude aircraft have been identified as an accessible means delivering sulfate aerosols to the lower and mid-stratosphere. This research initiative analyzes the design features of an onboard open cycle chemical plant capable of in situ sulfur to sulfate conversion, and compares the required mass to that of transporting pre-fabricated gaseous or liquid sulfate aerosol precursors. Scaling from aero-derivative gas turbine engines, commercial catalytic converters, and existing aerospace materials indicate that aircraft equipped with such a system could provide a substantial mass benefit compared to direct transport of compound sulfate products.

Enhanced Vision Flight Deck Technology for Commercial Aircraft Low-Visibility Surface Operations

Science.gov (United States)

Arthur, Jarvis J., III; Norman, R. Michael; Kramer, Lynda J.; Prinzel, Lawrence J., III; Ellis, Kyle K. E.; Harrison, Stephanie J.; Comstock, J. Ray

2013-01-01

NASA Langley Research Center and the FAA collaborated in an effort to evaluate the effect of Enhanced Vision (EV) technology display in a commercial flight deck during low visibility surface operations. Surface operations were simulated at the Memphis, TN (FAA identifier: KMEM) air field during nighttime with 500 Runway Visual Range (RVR) in a high-fidelity, full-motion simulator. Ten commercial airline flight crews evaluated the efficacy of various EV display locations and parallax and mini cation effects. The research paper discusses qualitative and quantitative results of the simulation experiment, including the effect of EV display placement on visual attention, as measured by the use of non-obtrusive oculometry and pilot mental workload. The results demonstrated the potential of EV technology to enhance situation awareness which is dependent on the ease of access and location of the displays. Implications and future directions are discussed.

‘Oorja’ in India: Assessing a large-scale commercial distribution of advanced biomass stoves to households

Science.gov (United States)

Thurber, Mark C.; Phadke, Himani; Nagavarapu, Sriniketh; Shrimali, Gireesh; Zerriffi, Hisham

2015-01-01

Replacing traditional stoves with advanced alternatives that burn more cleanly has the potential to ameliorate major health problems associated with indoor air pollution in developing countries. With a few exceptions, large government and charitable programs to distribute advanced stoves have not had the desired impact. Commercially-based distributions that seek cost recovery and even profits might plausibly do better, both because they encourage distributors to supply and promote products that people want and because they are based around properly-incentivized supply chains that could more be scalable, sustainable, and replicable. The sale in India of over 400,000 “Oorja” stoves to households from 2006 onwards represents the largest commercially-based distribution of a gasification-type advanced biomass stove. BP's Emerging Consumer Markets (ECM) division and then successor company First Energy sold this stove and the pelletized biomass fuel on which it operates. We assess the success of this effort and the role its commercial aspect played in outcomes using a survey of 998 households in areas of Maharashtra and Karnataka where the stove was sold as well as detailed interviews with BP and First Energy staff. Statistical models based on this data indicate that Oorja purchase rates were significantly influenced by the intensity of Oorja marketing in a region as well as by pre-existing stove mix among households. The highest rate of adoption came from LPG-using households for which Oorja's pelletized biomass fuel reduced costs. Smoke- and health-related messages from Oorja marketing did not significantly influence the purchase decision, although they did appear to affect household perceptions about smoke. By the time of our survey, only 9% of households that purchased Oorja were still using the stove, the result in large part of difficulties First Energy encountered in developing a viable supply chain around low-cost procurement of “agricultural waste” to

Deep Production Well for Geothermal Direct-Use Heating of A Large Commercial Greenhouse, Radium Springs, Rio Grande Rift, New Mexico; FINAL

International Nuclear Information System (INIS)

James C. Witcher

2002-01-01

Expansion of a large commercial geothermally-heated greenhouse is underway and requires additional geothermal fluid production. This report discusses the results of a cost-shared U.S. Department of Energy (DOE) and A.R. Masson, Inc. drilling project designed to construct a highly productive geothermal production well for expansion of the large commercial greenhouse at Radium Springs. The well should eliminate the potential for future thermal breakthrough from existing injection wells and the inducement of inflow from shallow cold water aquifers by geothermal production drawdown in the shallow reservoir. An 800 feet deep production well, Masson 36, was drilled on a US Bureau of Land Management (BLM) Geothermal Lease NM-3479 at Radium Springs adjacent to the A. R. Masson Radium Springs Farm commercial greenhouse 15 miles north of Las Cruces in Dona Ana County, New Mexico just west of Interstate 25 near the east bank of the Rio Grande. The area is in the Rio Grande rift, a tectonically-active region with high heat flow, and is one of the major geothermal provinces in the western United State

Mathematical Modeling of the Braking System of Wheeled Mainline Aircraft

Directory of Open Access Journals (Sweden)

I. S. Shumilov

2016-01-01

Full Text Available The braking system of the landing gear wheels of a mainline aircraft has to meet mandatory requirements laid out in the Aviation Regulations AP-25 (Para 25.735. «Brakes and brake systems". These requirements are essential when creating the landing gear wheel brake control system (WBCS and are used as main initial data in its mathematical modeling. The WBCS is one of the most important systems to ensure the safe completion of the flight. It is a complex of devices, i.e. units (hydraulic, electrical, and mechanical, connected through piping, wiring, mechanical constraints. This complex should allow optimizing the braking process when a large number of parameters change. The most important of them are the following: runway friction coefficient (RFC, lifting force, weight and of the aircraft, etc. The main structural elements involved in braking the aircraft are: aircraft wheels with pneumatics (air tires and brake discs, WBCS, and cooling system of gear wheels when braking.To consider the aircraft deceleration on the landing run is of essence at the stage of design, development, and improvement of brakes and braking systems. Based on analysis of equation of the aircraft motion and energy balance can be determined energy loading and its basic design parameters, braking distances and braking time.As practice and analysis of energy loading show, they (brake + wheel absorb the aircraftpossessed kinetic energy at the start of braking as much as 60-70%, 70-80%, and 80-90%, respectively, under normal increased, and emergency operating conditions. The paper presents a procedure for the rapid calculation of energy loading of the brake wheel.Currently, the mainline aircrafts use mainly electrohydraulic brake systems in which there are the main, backup, and emergency-parking brake systems. All channels are equipped with automatic anti-skid systems. Their presence in the emergency (the third reserve channel significantly improves the reliability and safety of

A Large Hemi-Anechoic Enclosure for Community-Compatible Aeroacoustic Testing of Aircraft Propulsion Systems

Science.gov (United States)

Cooper, Beth A.

1993-01-01

A large hemi-anechoic (absorptive walls and acoustically hard floor) noise control enclosure has been erected around a complex of test stands at the NASA Lewis Research Center in Cleveland, Ohio. This new state-of-the-art Aeroacoustic Propulsion Laboratory (APL) provides an all-weather, semisecure test environment while limiting noise to acceptable levels in surrounding residential neighborhoods. The 39.6 m (130 ft) diameter geodesic dome structure houses the new Nozzle Aeroacoustic Test Rig (NATR), an ejector-powered M = 0.3 free jet facility for acoustic testing of supersonic aircraft exhaust nozzles and turbomachinery. A multi-axis, force-measuring Powered Lift Facility (PLF) stand for testing of Short Takeoff Vertical Landing (STOVL) vehicles is also located within the dome. The design of the Aeroacoustic Propulsion Laboratory efficiently accomodates the research functions of two separate test rigs, one of which (NATR) requires a specialized environment for taking acoustic measurements. Absorptive fiberglass wedge treatment on the interior surface of the dome provides a hemi-anechoic interior environment for obtaining the accurate acoustic measurements required to meet research program goals. The APL is the first known geodesic dome structure to incorporate transmission-loss properties as well as interior absorption into a free-standing, community-compatible, hemi-anechoic test facility.

Automated analysis of aircraft configurations for safe separation enabled by quantitative grading of results; presentation

CSIR Research Space (South Africa)

Jamison, Kevin

2012-09-01

Full Text Available perturbations of: • store mass and physical properties • ejector rack performance • aircraft release flight conditions • stations on aircraft • neighbouring stores – MIL-HDBK 1763: 271.4 – Results in a very large analysis matrix! From: Tutty, M...

Commercialization plan laser-based decoating systems

International Nuclear Information System (INIS)

Freiwald, J.; Freiwald, D.A.

1998-01-01

F2 Associates Inc. (F2) is a small, high-technology firm focused on developing and commercializing environmentally friendly laser ablation systems for industrial-rate removal of surface coatings from metals, concrete, and delicate substrates such as composites. F2 has a contract with the US Department of Energy Federal Energy Technology Center (FETC) to develop and test a laser-based technology for removing contaminated paint and other contaminants from concrete and metal surfaces. Task 4.1 in Phase 2 of the Statement of Work for this DOE contract requires that F2 ''document its plans for commercializing and marketing the stationary laser ablation system. This document shall include a discussion of prospects for commercial customers and partners and may require periodic update to reflect changing strategy. This document shall be submitted to the DOE for review.'' This report is being prepared and submitted in fulfillment of that requirement. This report describes the laser-based technology for cleaning and coatings removal, the types of laser-based systems that have been developed by F2 based on this technology, and the various markets that are emerging for this technology. F2's commercialization and marketing plans are described, including how F2's organization is structured to meet the needs of technology commercialization, F2's strategy and marketing approach, and the necessary steps to receive certification for removing paint from aircraft and DOE certification for D and D applications. The future use of the equipment built for the DOE contract is also discussed

X-36 Tailless Fighter Agility Research Aircraft arrival at Dryden

Science.gov (United States)

1996-01-01

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft in it's hangar at NASA Dryden Flight Research Center, Edwards, California, following its arrival on July 2, 1996. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X-36 prototype weighed approximately 1,250 pounds. It was 19 feet long and three feet high with a wingspan of

NASA Electric Aircraft Test Bed (NEAT) Development Plan - Design, Fabrication, Installation

Science.gov (United States)

Dyson, Rodger W.

2016-01-01

As large airline companies compete to reduce emissions, fuel, noise, and maintenance costs, it is expected that more of their aircraft systems will shift from using turbofan propulsion, pneumatic bleed power, and hydraulic actuation, to instead using electrical motor propulsion, generator power, and electrical actuation. This requires new flight-weight and flight-efficient powertrain components, fault tolerant power management, and electromagnetic interference mitigation technologies. Moreover, initial studies indicate some combination of ambient and cryogenic thermal management and relatively high bus voltages when compared to state of practice will be required to achieve a net system benefit. Developing all these powertrain technologies within a realistic aircraft architectural geometry and under realistic operational conditions requires a unique electric aircraft testbed. This report will summarize existing testbed capabilities located in the U.S. and details the development of a unique complementary testbed that industry and government can utilize to further mature electric aircraft technologies.

The Low-Noise Potential of Distributed Propulsion on a Catamaran Aircraft

Science.gov (United States)

Posey, Joe W.; Tinetti, A. F.; Dunn, M. H.

2006-01-01

The noise shielding potential of an inboard-wing catamaran aircraft when coupled with distributed propulsion is examined. Here, only low-frequency jet noise from mid-wing-mounted engines is considered. Because low frequencies are the most difficult to shield, these calculations put a lower bound on the potential shielding benefit. In this proof-of-concept study, simple physical models are used to describe the 3-D scattering of jet noise by conceptualized catamaran aircraft. The Fast Scattering Code is used to predict noise levels on and about the aircraft. Shielding results are presented for several catamaran type geometries and simple noise source configurations representative of distributed propulsion radiation. Computational analyses are presented that demonstrate the shielding benefits of distributed propulsion and of increasing the width of the inboard wing. Also, sample calculations using the FSC are presented that demonstrate additional noise reduction on the aircraft fuselage by the use of acoustic liners on the inboard wing trailing edge. A full conceptual aircraft design would have to be analyzed over a complete mission to more accurately quantify community noise levels and aircraft performance, but the present shielding calculations show that a large acoustic benefit could be achieved by combining distributed propulsion and liner technology with a twin-fuselage planform.

Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

Science.gov (United States)

Hanser, F. A.; Sellers, B.; Briehl, D. C.

1978-01-01

An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

Aircraft Route Recovery Based on An Improved GRASP Method

Directory of Open Access Journals (Sweden)

Yang He

2017-01-01

Full Text Available Aircrafts maintenance, temporary airport closures are common factors that disrupt normal flight schedule. The aircraft route recovery aims to recover original schedules by some strategies, including flights swaps, and cancellations, which is a NP-hard problem. This paper proposes an improved heuristic procedure based on Greedy Random Adaptive Search Procedure (GRASP to solve this problem. The effectiveness and high global optimization capability of the heuristic is illustrated through experiments based on large-scale problems. Compared to the original one, it is shown that the improved procedure can find feasible flight recovered schedules with lower cost in a short time.

Monte Carlo Calculation of the Radiation Field at Aircraft Altitudes

Energy Technology Data Exchange (ETDEWEB)

Roesler, Stefan

2001-08-24

Energy spectra of secondary cosmic rays are calculated for aircraft altitudes and a discrete set of solar modulation parameters and rigidity cutoff values covering all possible conditions. The calculations are based on the Monte Carlo code FLUKA and on the most recent information on the interstellar cosmic ray flux including a detailed model of solar modulation. Results are compared to a large variety of experimental data obtained on ground and aboard of aircrafts and balloons, such as neutron, proton, and muon spectra and yields of charged particles. Furthermore, particle fluence is converted into ambient dose equivalent and effective dose and the dependence of these quantities on height above sea level, solar modulation, and geographic location is studied. Finally, calculated dose equivalent is compared to results of comprehensive measurements performed aboard of aircrafts.

Reducing Conservatism in Aircraft Engine Response Using Conditionally Active Min-Max Limit Regulators

Science.gov (United States)

May, Ryan D.; Garg, Sanjay

2012-01-01

Current aircraft engine control logic uses a Min-Max control selection structure to prevent the engine from exceeding any safety or operational limits during transients due to throttle commands. This structure is inherently conservative and produces transient responses that are slower than necessary. In order to utilize the existing safety margins more effectively, a modification to this architecture is proposed, referred to as a Conditionally Active (CA) limit regulator. This concept uses the existing Min-Max architecture with the modification that limit regulators are active only when the operating point is close to a particular limit. This paper explores the use of CA limit regulators using a publicly available commercial aircraft engine simulation. The improvement in thrust response while maintaining all necessary safety limits is demonstrated in a number of cases.

COMPARATIVE ANALYSIS OF TRANSPORT AIRCRAFT, BACKROUND FOR SHORT/ MEDIUM COURIER TRANSPORT AIRCRAFT PROCUREMENT

Directory of Open Access Journals (Sweden)

Matei POPA

2010-03-01

Full Text Available In accordance with Air Force requirements, the comparative analysis of short/medium transport aircraft comes to sustain procurement decision of short/medium transport aircraft. This paper presents, in short, the principles and the results of the comparative analysis for short/medium military transport aircraft.

Aircraft Icing Handbook. Volume 1

Science.gov (United States)

1991-03-01

Maryland - . . . Kohiman Aviation, Lawrence , Kansas Ohio State University, Columbus, Ohio .I --- t-r 1-- - -t I.Q,,- t ../e . Pratt and Whitney...lower; about six percent at -22 ’F (-30 *C). 1.2.3 Variations with Season The summer or warm season months create large warm air masses which can...on Aircraft Surfaces," NASA TM 87184, May 1986. 2-54 Hausman , R.J. and Turnock, S.R., "Investigation of Surface Water Behavior During Glaze Ice

SOLAR AIRCRAFT DESIGN

OpenAIRE

RAHMATI, Sadegh; GHASED, Amir

2015-01-01

Abstract. Generally domain Aircraft uses conventional fuel. These fuel having limited life, high cost and pollutant. Also nowadays price of petrol and other fuels are going to be higher, because of scarcity of those fuels. So there is great demand of use of non-exhaustible unlimited source of energy like solar energy. Solar aircraft is one of the ways to utilize solar energy. Solar aircraft uses solar panel to collect the solar radiation for immediate use but it also store the remaining part ...

Aircraft family design using enhanced collaborative optimization

Science.gov (United States)

Roth, Brian Douglas

Significant progress has been made toward the development of multidisciplinary design optimization (MDO) methods that are well-suited to practical large-scale design problems. However, opportunities exist for further progress. This thesis describes the development of enhanced collaborative optimization (ECO), a new decomposition-based MDO method. To support the development effort, the thesis offers a detailed comparison of two existing MDO methods: collaborative optimization (CO) and analytical target cascading (ATC). This aids in clarifying their function and capabilities, and it provides inspiration for the development of ECO. The ECO method offers several significant contributions. First, it enhances communication between disciplinary design teams while retaining the low-order coupling between them. Second, it provides disciplinary design teams with more authority over the design process. Third, it resolves several troubling computational inefficiencies that are associated with CO. As a result, ECO provides significant computational savings (relative to CO) for the test cases and practical design problems described in this thesis. New aircraft development projects seldom focus on a single set of mission requirements. Rather, a family of aircraft is designed, with each family member tailored to a different set of requirements. This thesis illustrates the application of decomposition-based MDO methods to aircraft family design. This represents a new application area, since MDO methods have traditionally been applied to multidisciplinary problems. ECO offers aircraft family design the same benefits that it affords to multidisciplinary design problems. Namely, it simplifies analysis integration, it provides a means to manage problem complexity, and it enables concurrent design of all family members. In support of aircraft family design, this thesis introduces a new wing structural model with sufficient fidelity to capture the tradeoffs associated with component

Documentation of Atmospheric Conditions During Observed Rising Aircraft Wakes

Science.gov (United States)

Zak, J. Allen; Rodgers, William G., Jr.

1997-01-01

Flight tests were conducted in the fall of 1995 off the coast of Wallops Island, Virginia in order to determine characteristics of wake vortices at flight altitudes. A NASA Wallops Flight Facility C130 aircraft equipped with smoke generators produced visible wakes at altitudes ranging from 775 to 2225 m in a variety of atmospheric conditions, orientations (head wind, cross wind), and airspeeds. Meteorological and aircraft parameters were collected continuously from a Langley Research Center OV-10A aircraft as it flew alongside and through the wake vortices at varying distances behind the C130. Meteorological data were also obtained from special balloon observations made at Wallops. Differential GPS capabilities were on each aircraft from which accurate altitude profiles were obtained. Vortices were observed to rise at distances beyond a mile behind the C130. The maximum altitude was 150 m above the C130 in a near neutral atmosphere with significant turbulence. This occurred from large vertical oscillations in the wakes. There were several cases when vortices did not descend after a very short initial period and remained near generation altitude in a variety of moderately stable atmospheres and wind shears.

Commercial and Institutional Waste

DEFF Research Database (Denmark)

Christensen, Thomas Højlund; Fruergaard, Thilde

2011-01-01

Commercial and institutional waste is primarily from retail (stores), hotels, restaurants, health care (except health risk waste), banks, insurance companies, education, retirement homes, public services and transport. Within some of these sectors, e.g. retail and restaurants, large variations...... are found in terms of which products and services are offered. Available data on unit generation rates and material composition as well as determining factors are discussed in this chapter. The characterizing of commercial and institutional waste is faced with the problem that often only a part of the waste...... is handled in the municipal waste system, where information is easily accessible. An important part of commercial and institutional waste is packaging waste, and enterprises with large quantities of clean paper, cardboard and plastic waste may have their own facilities for baling and storing their waste...

A Lightweight Loudspeaker for Aircraft Communications and Active Noise Control

Science.gov (United States)

Warnaka, Glenn E.; Kleinle, Mark; Tsangaris, Parry; Oslac, Michael J.; Moskow, Harry J.

1992-01-01

A series of new, lightweight loudspeakers for use on commercial aircraft has been developed. The loudspeakers use NdFeB magnets and aluminum alloy frames to reduce the weight. The NdFeB magnet is virtually encapsulated by steel in the new speaker designs. Active noise reduction using internal loudspeakers was demonstrated to be effective in 1983. A weight, space, and cost efficient method for creating the active sound attenuating fields is to use the existing cabin loudspeakers for both communication and sound attenuation. This will require some additional loudspeaker design considerations.

Calculation of odour emissions from aircraft engines at Copenhagen Airport

Energy Technology Data Exchange (ETDEWEB)

Winther, Morten; Kousgaard, Uffe [National Environmental Research Institute, Frederiksborgvej 399, 4000 Roskilde (Denmark); Oxboel, Arne [FORCE Technology, Park Alle 345, 2605 Broendby (Denmark)

2006-07-31

In a new approach the odour emissions from aircraft engines at Copenhagen Airport are calculated using actual fuel flow and emission measurements (one main engine and one APU: Auxiliary Power Unit), odour panel results, engine specific data and aircraft operational data for seven busy days. The calculation principle assumes a linear relation between odour and HC emissions. Using a digitalisation of the aircraft movements in the airport area, the results are depicted on grid maps, clearly reflecting aircraft operational statistics as single flights or total activity during a whole day. The results clearly reflect the short-term temporal fluctuations of the emissions of odour (and exhaust gases). Aircraft operating at low engine thrust (taxiing, queuing and landing) have a total odour emission share of almost 98%, whereas the shares for the take off/climb out phases (2%) and APU usage (0.5%) are only marginal. In most hours of the day, the largest odour emissions occur, when the total amount of fuel burned during idle is high. However, significantly higher HC emissions for one specific engine cause considerable amounts of odour emissions during limited time periods. The experimentally derived odour emission factor of 57 OU/mg HC is within the range of 23 and 110 OU/mg HC used in other airport odour studies. The distribution of odour emission results between aircraft operational phases also correspond very well with the results for these other studies. The present study uses measurement data for a representative engine. However, the uncertainties become large when the experimental data is used to estimate the odour emissions for all aircraft engines. More experimental data is needed to increase inventory accuracy, and in terms of completeness it is recommended to make odour emission estimates also for engine start and the fuelling of aircraft at Copenhagen Airport in the future. (author)

Calculation of odour emissions from aircraft engines at Copenhagen Airport.

Science.gov (United States)

Winther, Morten; Kousgaard, Uffe; Oxbøl, Arne

2006-07-31

In a new approach the odour emissions from aircraft engines at Copenhagen Airport are calculated using actual fuel flow and emission measurements (one main engine and one APU: Auxiliary Power Unit), odour panel results, engine specific data and aircraft operational data for seven busy days. The calculation principle assumes a linear relation between odour and HC emissions. Using a digitalisation of the aircraft movements in the airport area, the results are depicted on grid maps, clearly reflecting aircraft operational statistics as single flights or total activity during a whole day. The results clearly reflect the short-term temporal fluctuations of the emissions of odour (and exhaust gases). Aircraft operating at low engine thrust (taxiing, queuing and landing) have a total odour emission share of almost 98%, whereas the shares for the take off/climb out phases (2%) and APU usage (0.5%) are only marginal. In most hours of the day, the largest odour emissions occur, when the total amount of fuel burned during idle is high. However, significantly higher HC emissions for one specific engine cause considerable amounts of odour emissions during limited time periods. The experimentally derived odour emission factor of 57 OU/mg HC is within the range of 23 and 110 OU/mg HC used in other airport odour studies. The distribution of odour emission results between aircraft operational phases also correspond very well with the results for these other studies. The present study uses measurement data for a representative engine. However, the uncertainties become large when the experimental data is used to estimate the odour emissions for all aircraft engines. More experimental data is needed to increase inventory accuracy, and in terms of completeness it is recommended to make odour emission estimates also for engine start and the fuelling of aircraft at Copenhagen Airport in the future.

Aircraft operations management manual

Science.gov (United States)

1992-01-01

The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.

Development of an Unmanned Aircraft Systems Program: ACUASI

Science.gov (United States)

Webley, P. W.; Cahill, C. F.; Rogers, M.; Hatfield, M. C.

2017-12-01

The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) has developed a comprehensive program that incorporates pilots, flight/mission planners, geoscientists, university undergraduate and graduate students, and engineers together as one. We lead and support unmanned aircraft system (UAS) missions for geoscience research, emergency response, humanitarian needs, engineering design, and policy development. We are the University of Alaska's UAS research program, lead the Federal Aviation Administration (FAA) Pan-Pacific UAS Test Range Complex (PPUTRC) with Hawaii, Oregon, and Mississippi and in 2015 became a core member of the FAA Center of Excellence for UAS Research, managed by Mississippi State University. ACUASI's suite of aircraft include small hand-launched/vertical take-off and landing assets for short-term rapid deployment to large fixed-wing gas powered systems that provide multiple hours of flight time. We have extensive experience in Arctic and sub-Arctic environments and will present on how we have used our aircraft and payloads in numerous missions that include beyond visual line of sight flights, mapping the river ice-hazard in Alaska during spring break-up, and providing UAS-based observations for local Alaskans to navigate through the changing ice shelf of Northern Alaska. Several sensor developments of interest in the near future include building payloads for thermal infrared mapping at high spatial resolutions, combining forward and nadir looking cameras on the same UAS aircraft for topographic mapping, and using neutral density and narrow band filters to map very high temperature thermally active hazards, such as forest fires and volcanic eruptions. The ACUASI team working together provide us the experience, tools, capabilities, and personnel to build and maintain a world class research center for unmanned aircraft systems as well as support both real-time operations and geoscience research.

Future-proofing an aircraft self-protection IR signature database

CSIR Research Space (South Africa)

Alayeda, M

2012-09-01

Full Text Available Aircraft self-protection against heat seeking missile threats is an extremely important topic worldwide, recently even more so with the instability in the Middle East region due to, for example, the large number of man-portable air defense systems...

Conceptual design of high speed supersonic aircraft: A brief review on SR-71 (Blackbird) aircraft

Science.gov (United States)

Xue, Hui; Khawaja, H.; Moatamedi, M.

2014-12-01

The paper presents the conceptual design of high-speed supersonic aircraft. The study focuses on SR-71 (Blackbird) aircraft. The input to the conceptual design is a mission profile. Mission profile is a flight profile of the aircraft defined by the customer. This paper gives the SR-71 aircraft mission profile specified by US air force. Mission profile helps in defining the attributes the aircraft such as wing profile, vertical tail configuration, propulsion system, etc. Wing profile and vertical tail configurations have direct impact on lift, drag, stability, performance and maneuverability of the aircraft. A propulsion system directly influences the performance of the aircraft. By combining the wing profile and the propulsion system, two important parameters, known as wing loading and thrust to weight ratio can be calculated. In this work, conceptual design procedure given by D. P. Raymer (AIAA Educational Series) is applied to calculate wing loading and thrust to weight ratio. The calculated values are compared against the actual values of the SR-71 aircraft. Results indicates that the values are in agreement with the trend of developments in aviation.

A modular approach to large-scale design optimization of aerospace systems

Science.gov (United States)

Hwang, John T.

Gradient-based optimization and the adjoint method form a synergistic combination that enables the efficient solution of large-scale optimization problems. Though the gradient-based approach struggles with non-smooth or multi-modal problems, the capability to efficiently optimize up to tens of thousands of design variables provides a valuable design tool for exploring complex tradeoffs and finding unintuitive designs. However, the widespread adoption of gradient-based optimization is limited by the implementation challenges for computing derivatives efficiently and accurately, particularly in multidisciplinary and shape design problems. This thesis addresses these difficulties in two ways. First, to deal with the heterogeneity and integration challenges of multidisciplinary problems, this thesis presents a computational modeling framework that solves multidisciplinary systems and computes their derivatives in a semi-automated fashion. This framework is built upon a new mathematical formulation developed in this thesis that expresses any computational model as a system of algebraic equations and unifies all methods for computing derivatives using a single equation. The framework is applied to two engineering problems: the optimization of a nanosatellite with 7 disciplines and over 25,000 design variables; and simultaneous allocation and mission optimization for commercial aircraft involving 330 design variables, 12 of which are integer variables handled using the branch-and-bound method. In both cases, the framework makes large-scale optimization possible by reducing the implementation effort and code complexity. The second half of this thesis presents a differentiable parametrization of aircraft geometries and structures for high-fidelity shape optimization. Existing geometry parametrizations are not differentiable, or they are limited in the types of shape changes they allow. This is addressed by a novel parametrization that smoothly interpolates aircraft

A paleo-aerodynamic exploration of the evolution of nature's flyers, man's aircraft, and the needs and options for future technology innovations

Science.gov (United States)

Kulfan, Brenda M.

2009-03-01

Insights and observations of fascinating aspects of birds, bugs and flying seeds, of inspired aerodynamic concepts, and visions of past, present and future aircraft developments are presented. The evolution of nature's flyers, will be compared with the corresponding evolution of commercial aircraft. We will explore similarities between nature's creations and man's inventions. Many critical areas requiring future significant technology based solutions remain. With the advent of UAVs and MAVs, the gap between "possible" and "actual" is again very large. Allometric scaling procedures will be used to explore size implications on limitations and performance capabilities of nature's creations. Biologically related technology development concepts including: bionics, biomimicry, neo-bionic, pseudo-mimicry, cybernetic and non-bionic approaches will be discussed and illustrated with numerous examples. Technology development strategies will be discussed along with the pros and cons for each. Future technology developments should include a synergistic coupling of "discovery driven", "product led" and "technology acceleration" strategies. The objective of this presentation is to inspire the creative nature existing within all of us. This is a summary all text version of the complete report with the same title that report includes approximately 80 figures, photos and charts and much more information.

Assessing effects of military aircraft noise on residential property values near airbases

Science.gov (United States)

Fidell, Sanford; Tabachnick, Barbara; Silvati, Laura; Cook, Brenda

The question, 'Does military aircraft noise exposure affect residential property values in the vicinity of Air Force bases?', can be asked and answered with varying degrees of generality and tolerable errors of inference. Definitive answers are difficult to develop because the question itself may not be meaningful in some circumstances: property values are affected by many factors other than aircraft noise which can fluctuate greatly in different areas and during different time periods; credible attribution of causality for changes in property values uniquely to aircraft noise requires many costly study design measures; and prior findings suggest that if a relationship exists, it is not a large or especially strong one. Thus, evidence of a simple geographic association between aircraft noise exposure and residential property values does not provide a conclusive answer to the question. In an effort to develop more compelling evidence, the US Air Force is planning to compare historical records of sale prices of properties in areas of differential aircraft noise exposure during specific time periods with predictions of sale prices derived from a validated statistical model of residential property values.

Aircraft Configuration and Flight Crew Compliance with Procedures While Conducting Flight Deck Based Interval Management (FIM) Operations

Science.gov (United States)

Shay, Rick; Swieringa, Kurt A.; Baxley, Brian T.

2012-01-01

Flight deck based Interval Management (FIM) applications using ADS-B are being developed to improve both the safety and capacity of the National Airspace System (NAS). FIM is expected to improve the safety and efficiency of the NAS by giving pilots the technology and procedures to precisely achieve an interval behind the preceding aircraft by a specific point. Concurrently but independently, Optimized Profile Descents (OPD) are being developed to help reduce fuel consumption and noise, however, the range of speeds available when flying an OPD results in a decrease in the delivery precision of aircraft to the runway. This requires the addition of a spacing buffer between aircraft, reducing system throughput. FIM addresses this problem by providing pilots with speed guidance to achieve a precise interval behind another aircraft, even while flying optimized descents. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) human-in-the-loop experiment employed 24 commercial pilots to explore the use of FIM equipment to conduct spacing operations behind two aircraft arriving to parallel runways, while flying an OPD during high-density operations. This paper describes the impact of variations in pilot operations; in particular configuring the aircraft, their compliance with FIM operating procedures, and their response to changes of the FIM speed. An example of the displayed FIM speeds used incorrectly by a pilot is also discussed. Finally, this paper examines the relationship between achieving airline operational goals for individual aircraft and the need for ATC to deliver aircraft to the runway with greater precision. The results show that aircraft can fly an OPD and conduct FIM operations to dependent parallel runways, enabling operational goals to be achieved efficiently while maintaining system throughput.

Solar thermal aircraft

Science.gov (United States)

Bennett, Charles L.

2007-09-18

A solar thermal powered aircraft powered by heat energy from the sun. A heat engine, such as a Stirling engine, is carried by the aircraft body for producing power for a propulsion mechanism, such as a propeller. The heat engine has a thermal battery in thermal contact with it so that heat is supplied from the thermal battery. A solar concentrator, such as reflective parabolic trough, is movably connected to an optically transparent section of the aircraft body for receiving and concentrating solar energy from within the aircraft. Concentrated solar energy is collected by a heat collection and transport conduit, and heat transported to the thermal battery. A solar tracker includes a heliostat for determining optimal alignment with the sun, and a drive motor actuating the solar concentrator into optimal alignment with the sun based on a determination by the heliostat.

Can pilots still fly? Role distribution and hybrid interaction in advanced automated aircraft

OpenAIRE

Weyer, Johannes

2015-01-01

Recent accidents of commercial airplanes have raised the question once more whether pilots can rely on automation in order to fly advanced aircraft safely. Although the issue of human-machine interaction in aviation has been investigated frequently, profound knowledge about pilots’ perceptions and attitudes is fragmentary and partly out-dated. The paper at hand presents the results of a pilot survey, which has been guided by a collaborative perspective of human-automation decision-making. It ...

Study of V/STOL aircraft implementation. Volume 1: Summary

Science.gov (United States)

Portenier, W. J.; Webb, H. M.

1973-01-01

A high density short haul air market which by 1980 is large enough to support the introduction of an independent short haul air transportation system is discussed. This system will complement the existing air transportation system and will provide relief of noise and congestion problems at conventional airports. The study has found that new aircraft, exploiting V/STOL and quiet engine technology, can be available for implementing these new services, and they can operate from existing reliever and general aviation airports. The study has also found that the major funding requirements for implementing new short haul services could be borne by private capital, and that the government funding requirement would be minimal and/or recovered through the airline ticket tax. In addition, a suitable new short haul aircraft would have a market potential for $3.5 billion in foreign sales. The long lead times needed for aircraft and engine technology development will require timely actions by federal agencies.

Investigation of display issues relevant to the presentation of aircraft fault information

Science.gov (United States)

Allen, Donald M.

1989-01-01

This research, performed as a part of NASA Langley's Faultfinder project, investigated display implementation issues related to the introduction of real time fault diagnostic systems into next generation commercial aircraft. Three major issues were investigated: visual display styles for presenting fault related information to the crew, the form the output from the expert system should take, and methods for filtering fault related information for presentation to the crew. Twenty-four flight familiar male volunteers participated as subjects. Five subjects were NASA test pilots, six were Commercial Airline Pilots, seven were Air Force Lear Jet pilots, and six were NASA personnel familiar with flight (non-pilots). Subjects were presented with aircraft subsystem information on a CRT screen. They were required to identify the subsystems presented in a display and to remember the state (normal or abnormal) of subsystem parameter information contained in the display. The results of the study indicated that in the simpler experimental test cases (i.e., those involving single subsystem failures and composite hypothesis displays) subjects' performance did not differ across the different display formats. However, for the more complex cases (i.e., those involving multiple subsystem faults and multiple hypotheses displays), subjects' performance was superior in the text- and picture-based display formats compared to the symbol-based format. In addition, the findings suggest that a layered approached to information display is appropriate.

Long Range Aircraft Trajectory Prediction

OpenAIRE

Magister, Tone

2009-01-01

The subject of the paper is the improvement of the aircraft future trajectory prediction accuracy for long-range airborne separation assurance. The strategic planning of safe aircraft flights and effective conflict avoidance tactics demand timely and accurate conflict detection based upon future four–dimensional airborne traffic situation prediction which is as accurate as each aircraft flight trajectory prediction. The improved kinematics model of aircraft relative flight considering flight ...

Comparison of PM emissions from a commercial jet engine burning conventional, biomass, and Fischer-Tropsch fuels.

Science.gov (United States)

Lobo, Prem; Hagen, Donald E; Whitefield, Philip D

2011-12-15

Rising fuel costs, an increasing desire to enhance security of energy supply, and potential environmental benefits have driven research into alternative renewable fuels for commercial aviation applications. This paper reports the results of the first measurements of particulate matter (PM) emissions from a CFM56-7B commercial jet engine burning conventional and alternative biomass- and, Fischer-Tropsch (F-T)-based fuels. PM emissions reductions are observed with all fuels and blends when compared to the emissions from a reference conventional fuel, Jet A1, and are attributed to fuel properties associated with the fuels and blends studied. Although the alternative fuel candidates studied in this campaign offer the potential for large PM emissions reductions, with the exception of the 50% blend of F-T fuel, they do not meet current standards for aviation fuel and thus cannot be considered as certified replacement fuels. Over the ICAO Landing Takeoff Cycle, which is intended to simulate aircraft engine operations that affect local air quality, the overall PM number-based emissions for the 50% blend of F-T fuel were reduced by 34 ± 7%, and the mass-based emissions were reduced by 39 ± 7%.

A numerical model for bird strike on sidewall structure of an aircraft nose

Directory of Open Access Journals (Sweden)

Liu Jun

2014-06-01

Full Text Available In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH and finite element (FE method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the bird-strike tests and a numerical model is established using a commercial software PAM-CRASH. The bird model shows no signs of instability and correctly modeled the break-up of the bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH–FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of bird strike.

Adapting existing training standards for unmanned aircraft: finding ways to train staff for unmanned aircraft operations

CSIR Research Space (South Africa)

Burger, CR

2011-09-01

Full Text Available - unmanned aircraft; pilot training. I. INTRODUCTION Unmanned aircraft offer flexibility not found in manned aircraft. They can be made smaller and cheaper to operate. They offer payload advantages relative to small manned aircraft. They can also perform... certificate to non-state users. To facilitate useful operations by UAs, future operations must be subject to no more than routine notification (e.g. an ATC flight plan), just like manned aircraft already are. Before such operations can be established, some...

Airline view of LH2 as a fuel for commercial aircraft

Energy Technology Data Exchange (ETDEWEB)

Wilkinson, K.G.

1983-01-01

Fuel for air transport is a particularly important matter, because it is an energy-intensive form of transport. Price and energy density are therefore correspondingly critical. Airlines views tend to be short term because there is no future if they do not survive tomorrow. Thus, although petroleum supply and price has been unstable since 1973, airlines' primary concern has been with economizing the use of fuel and specifying more fuel economic equipment for the future, rather than serious pursuit of more radical solutions. LH2 gives promise of being a serious candidate for the longer term, but there is not yet convincing proof that cheaper seat mile costs could be produced in today's circumstances. The situation could be changed by the realization of laminar flow by surface cooling at subsonic speeds. There is a strong case for a modest programme of carefully aimed research on an international basis to fill the most important gaps in our knowledge on the design of LH2 fueled aircraft. Future crises in energy supplies may well raise questions of transport fuel strategy which will heed this background for wise decision-making. Particular significance attaches to the place of nuclear power in world energy policy since this dominates the question of LH2 availability and price. 2 references, 2 figures.

19 CFR 122.49c - Master crew member list and master non-crew member list requirement for commercial aircraft...

Science.gov (United States)

2010-04-01

..., DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members Onboard... sections, must electronically transmit to Customs and Border Protection (CBP), by means of an electronic...

Development of Stitched Composite Structure for Advanced Aircraft

Science.gov (United States)

Jegley, Dawn; Przekop, Adam; Rouse, Marshall; Lovejoy, Andrew; Velicki, Alex; Linton, Kim; Wu, Hsi-Yung; Baraja, Jaime; Thrash, Patrick; Hoffman, Krishna

2015-01-01

structures where weight and through-the-thickness strength are design considerations. An overview of the development of PRSEUS technology for commercial transport aircraft is the subject of this paper.

Human Factors Aspects of Aircraft Accidents

Science.gov (United States)

1982-10-01

invaatiaaamanta traa important« : chainaa da grand entratian avion, revision daa motaura at banca d’aaaala, reviaion daa Equipements nEceaaitant daa...defectueux. Sur le plan des accidents d’apparells militaires, qui sort quelque peu de ma specia- lite, les renseignements disponibles dans la presse ...Undoubtedly, a compelling reason for staying with the aircraft was to try to regain pitch attitude control in view of a large audience of press and

Flight service evaluation of kevlar-49 epoxy composite panels in wide-bodied commercial transport aircraft: Flight service report

Science.gov (United States)

Stone, R. H.

1981-01-01

Kevlar-49 fairing panels, installed as flight service components on three L-1011s, were inspected after 7 years service. There are six Kevlar-49 panels on each aircraft: a left hand and right hand set of a wing-body sandwich fairing; a slid laminate under-wing fillet panel; and a 422 K service aft engine fairing. The three L-1011s include one each in service with Eastern, Air Canada, and TWA. The fairings have accumulated a total of 52,500 hours, with one ship set having 17.700 hours service. The inspections were conducted at the airlines' major maintenance bases with the participation of Lockheed Engineering. The Kevlar-49 components were found to be performing satisfactorily in service with no major problems or any condition requiring corrective action. The only defects noted were minor impact damage and a minor degree of fastener hole fraying and elongation. These are for the most part comparable to damage noted on fiberglass fairings. The service history to date indicates that Kevlar-49 epoxy composite materials have satisfactory service characteristics for use in aircraft secondary structure.

40 CFR 87.6 - Aircraft safety.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Aircraft safety. 87.6 Section 87.6... POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES General Provisions § 87.6 Aircraft safety. The provisions of... met within the specified time without creating a safety hazard. ...

Planned Improvements for the WB-57F Aircraft

Science.gov (United States)

Baccus, S.; Roberts, A.; Ross, M.

2003-12-01

NASA WB-57F aircraft have supported the atmospheric science community for over 30 years. Recent attention has focused on the chemistry and dynamics of the UTLS region of the atmosphere and several NASA sponsored field campaigns (ACCENT, CRYSTAL-FACE) have made critical use of the WB-57F's unique ability to carry large (3 ton) payloads during extended cruise at all altitudes from the lower troposphere to the lower stratosphere (20 km ceiling). In addition, the WB-57F's robust structure permits a large number and variety of instruments to be carried at inlet-favorable locations on the aircraft. In order to further improve the WB-57F's performance and unique utility to the atmospheric research and spacecraft validation communities, NASA is planning several upgrades to the WB-57F including state-of-the-art avionics and autopilot, landing gear replacement, maximum gross weight increase, engine replacement, and ultrapod installation. We will review the present WB-57F performance, plans for upcoming science campaigns, and plans for increased WB-57F payload, range, endurance, and ceiling resulting from the upgrades.

Large Scale Monte Carlo Simulation of Neutrino Interactions Using the Open Science Grid and Commercial Clouds

International Nuclear Information System (INIS)

Norman, A.; Boyd, J.; Davies, G.; Flumerfelt, E.; Herner, K.; Mayer, N.; Mhashilhar, P.; Tamsett, M.; Timm, S.

2015-01-01

Modern long baseline neutrino experiments like the NOvA experiment at Fermilab, require large scale, compute intensive simulations of their neutrino beam fluxes and backgrounds induced by cosmic rays. The amount of simulation required to keep the systematic uncertainties in the simulation from dominating the final physics results is often 10x to 100x that of the actual detector exposure. For the first physics results from NOvA this has meant the simulation of more than 2 billion cosmic ray events in the far detector and more than 200 million NuMI beam spill simulations. Performing these high statistics levels of simulation have been made possible for NOvA through the use of the Open Science Grid and through large scale runs on commercial clouds like Amazon EC2. We details the challenges in performing large scale simulation in these environments and how the computing infrastructure for the NOvA experiment has been adapted to seamlessly support the running of different simulation and data processing tasks on these resources. (paper)

Titanium fasteners. [for aircraft industry

Science.gov (United States)

Phillips, J. L.

1972-01-01

Titanium fasteners are used in large quantities throughout the aircraft industry. Most of this usage is in aluminum structure; where titanium structure exists, titanium fasteners are logically used as well. Titanium fasteners offer potential weight savings to the designer at a cost of approximately $30 per pound of weight saved. Proper and least cost usage must take into consideration type of fastener per application, galvanic couples and installation characteristics of protective coatings, cosmetic appearance, paint adhesion, installation forces and methods available and fatigue performance required.

Evaluation of Mobile Phone Interference With Aircraft GPS Navigation Systems

Science.gov (United States)

Pace, Scott; Oria, A. J.; Guckian, Paul; Nguyen, Truong X.

2004-01-01

This report compiles and analyzes tests that were conducted to measure cell phone spurious emissions in the Global Positioning System (GPS) radio frequency band that could affect the navigation system of an aircraft. The cell phone in question had, as reported to the FAA (Federal Aviation Administration), caused interference to several GPS receivers on-board a small single engine aircraft despite being compliant with data filed at the time with the FCC by the manufacturer. NASA (National Aeronautics and Space Administration) and industry tests show that while there is an emission in the 1575 MHz GPS band due to a specific combination of amplifier output impedance and load impedance that induces instability in the power amplifier, these spurious emissions (i.e., not the intentional transmit signal) are similar to those measured on non-intentionally transmitting devices such as, for example, laptop computers. Additional testing on a wide sample of different commercial cell phones did not result in any emission in the 1575 MHz GPS Band above the noise floor of the measurement receiver.

Electrical short circuit and current overload tests on aircraft wiring

Science.gov (United States)

Cahill, Patricia

1995-01-01

The findings of electrical short circuit and current overload tests performed on commercial aircraft wiring are presented. A series of bench-scale tests were conducted to evaluate circuit breaker response to overcurrent and to determine if the wire showed any visible signs of thermal degradation due to overcurrent. Three types of wire used in commercial aircraft were evaluated: MIL-W-22759/34 (150 C rated), MIL-W-81381/12 (200 C rated), and BMS 1360 (260 C rated). A second series of tests evaluated circuit breaker response to short circuits and ticking faults. These tests were also meant to determine if the three test wires behaved differently under these conditions and if a short circuit or ticking fault could start a fire. It is concluded that circuit breakers provided reliable overcurrent protection. Circuit breakers may not protect wire from ticking faults but can protect wire from direct shorts. These tests indicated that the appearance of a wire subjected to a current that totally degrades the insulation looks identical to a wire subjected to a fire; however the 'fire exposed' conductor was more brittle than the conductor degraded by overcurrent. Preliminary testing indicates that direct short circuits are not likely to start a fire. Preliminary testing indicated that direct short circuits do not erode insulation and conductor to the extent that ticking faults did. Circuit breakers may not safeguard against the ignition of flammable materials by ticking faults. The flammability of materials near ticking faults is far more important than the rating of the wire insulation material.

Review of Design Aspects and Challenges of Efficient and Quiet Amphibious Aircraft

Science.gov (United States)

D, Rhea P. Liem Ph.

2018-04-01

Apart from the commercial and military aviation sectors, the general aviation (GA) sector is expected to experience a rapid growth, especially in Asia. The increasing economic activities in the region would demand for more efficient and convenient transportation, which would open door to more GA services. This development would require sufficient infrastructure supports, including airports. However, insufficient land area has often imposed limitations in airport development. As such, some areas (e.g., remote islands) are not easily accessible by air. One implication is that travels can only be done via land or water, which might prolong the travel time. This applies to business travels, with the significant increase in business and economic activities, which in turns demands for more efficient and faster mobility. In other cases, this involves some rural areas where the infrastructures are not very well-developed, and where the geographical terrains are too challenging to build a pad for vertical takeoff and landing (VTOL) air vehicles. Under such circumstances, it would be imperative to enable air travels to carry critical logistics such as medical supplies, food, and even sick patients. In this regard, we propose to develop a low-payload, low-altitude amphibious aircraft, which can takeoff and land on both water and land. Aircraft design process is a complex procedure and multidisciplinary in nature, and for amphibious aircraft design we need to consider the two takeoff and landing modes, which imposes further challenges to the design. In this paper we present two preliminary design projects, for two-seater and ten-seater aircraft. To design an efficient and quiet amphibious aircraft, we conduct some experiments on noise shielding mechanisms to reduce the propeller noise. The challenges and resulting designs are briefly discussed in this paper. Amphibious aircraft development will be very relevant to Indonesia, which is the world’s largest archipelago with

Examining the Relationship Between Passenger Airline Aircraft Maintenance Outsourcing and Aircraft Safety

Science.gov (United States)

Monaghan, Kari L.

The problem addressed was the concern for aircraft safety rates as they relate to the rate of maintenance outsourcing. Data gathered from 14 passenger airlines: AirTran, Alaska, America West, American, Continental, Delta, Frontier, Hawaiian, JetBlue, Midwest, Northwest, Southwest, United, and USAir covered the years 1996 through 2008. A quantitative correlational design, utilizing Pearson's correlation coefficient, and the coefficient of determination were used in the present study to measure the correlation between variables. Elements of passenger airline aircraft maintenance outsourcing and aircraft accidents, incidents, and pilot deviations within domestic passenger airline operations were analyzed, examined, and evaluated. Rates of maintenance outsourcing were analyzed to determine the association with accident, incident, and pilot deviation rates. Maintenance outsourcing rates used in the evaluation were the yearly dollar expenditure of passenger airlines for aircraft maintenance outsourcing as they relate to the total airline aircraft maintenance expenditures. Aircraft accident, incident, and pilot deviation rates used in the evaluation were the yearly number of accidents, incidents, and pilot deviations per miles flown. The Pearson r-values were calculated to measure the linear relationship strength between the variables. There were no statistically significant correlation findings for accidents, r(174)=0.065, p=0.393, and incidents, r(174)=0.020, p=0.793. However, there was a statistically significant correlation for pilot deviation rates, r(174)=0.204, p=0.007 thus indicating a statistically significant correlation between maintenance outsourcing rates and pilot deviation rates. The calculated R square value of 0.042 represents the variance that can be accounted for in aircraft pilot deviation rates by examining the variance in aircraft maintenance outsourcing rates; accordingly, 95.8% of the variance is unexplained. Suggestions for future research include

Structural analysis of a metal spent-fuel storage cask in an aircraft crash for risk assessment

International Nuclear Information System (INIS)

Almomani, Belal; Lee, Sanghoon; Kang, Hyun Gook

2016-01-01

Highlights: • Several engine-applied loads with different locations of impact on the storage cask body were implemented. • Cask structural responses due to the influence of engine impact loadings were analyzed. • Leakage path areas from lid closure openings were numerically calculated. • Release fractions that depend on the generated seal opening areas and fuel damage ratios were estimated. - Abstract: Evaluations of the impact resistance of a dry storage cask under mechanical impact loadings resulting from a large commercial aircraft crash have become an important issue for designers and evaluators, in order to promote interim dry storage activities and to evaluate design safety margins. This study presents a method to evaluate the structural integrity of a generic metal cask subjected to various mechanical loading conditions, which represent aircraft engine impacts, on different locations of the cask body. Thirty representative impact conditions are analyzed to provide a comprehensive evaluation of cask damage response. The applied engine impact load–time functions were carefully re-derived by utilizing CRIEPI’s proposed curve through Riera’s approach for six impact velocities, and applied to five locations on a freestanding cask: lateral impacts on the lower half, center of gravity, and upper half of the cask body, corner impact on the lid closure, and vertical impact on the center of the lid closure. A nonlinear dynamic finite element analysis is performed to evaluate the dynamic response of the cask lid closure system and to calculate the lid gaps. The release fractions from the cask to the environment for each impact condition are preliminarily estimated by referring to a proposed methodology from literature. It is believed that this paper presents a systematic process to connect the mechanical analysis of a cask response at the moment of aircraft engine impact with its radiological consequence analysis.

Structural analysis of a metal spent-fuel storage cask in an aircraft crash for risk assessment

Energy Technology Data Exchange (ETDEWEB)

Almomani, Belal, E-mail: balmomani@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Sanghoon, E-mail: shlee1222@kmu.ac.kr [Department of Mechanical and Automotive Engineering, Keimyung University, Dalgubeol-daero 1095, Dalseo-gu, Daegu (Korea, Republic of); Kang, Hyun Gook, E-mail: hyungook@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2016-11-15

Highlights: • Several engine-applied loads with different locations of impact on the storage cask body were implemented. • Cask structural responses due to the influence of engine impact loadings were analyzed. • Leakage path areas from lid closure openings were numerically calculated. • Release fractions that depend on the generated seal opening areas and fuel damage ratios were estimated. - Abstract: Evaluations of the impact resistance of a dry storage cask under mechanical impact loadings resulting from a large commercial aircraft crash have become an important issue for designers and evaluators, in order to promote interim dry storage activities and to evaluate design safety margins. This study presents a method to evaluate the structural integrity of a generic metal cask subjected to various mechanical loading conditions, which represent aircraft engine impacts, on different locations of the cask body. Thirty representative impact conditions are analyzed to provide a comprehensive evaluation of cask damage response. The applied engine impact load–time functions were carefully re-derived by utilizing CRIEPI’s proposed curve through Riera’s approach for six impact velocities, and applied to five locations on a freestanding cask: lateral impacts on the lower half, center of gravity, and upper half of the cask body, corner impact on the lid closure, and vertical impact on the center of the lid closure. A nonlinear dynamic finite element analysis is performed to evaluate the dynamic response of the cask lid closure system and to calculate the lid gaps. The release fractions from the cask to the environment for each impact condition are preliminarily estimated by referring to a proposed methodology from literature. It is believed that this paper presents a systematic process to connect the mechanical analysis of a cask response at the moment of aircraft engine impact with its radiological consequence analysis.

SUSTAINABLE GROWTH OF THE COMMERCIAL AVIATION INDUSTRY IN MALAYSIA USING A SYSTEM DYNAMICS APPROACH

Directory of Open Access Journals (Sweden)

B. S. TAN

2015-09-01

Full Text Available The environmental impact of the commercial aviation industry for an emerging economy like Malaysia is under-studied. The focus on the subject has thus far concentrated either on non geographical performance of the aviation industry or technical performance of aircrafts and that leaves the sustainability of the commercial aviation industry for an economy, or more specifically, an emerging economy least understood. Hence, this paper aims to investigate the sustainability of the growth of the commercial aviation industry in Malaysia and its impact upon the environment using a system dynamics approach. VENSIM is employed to model the commercial aviation industry in Malaysia as a dynamic system to evaluate the CO2 emitted from each component within the industry in order to forecast its overall CO2 emission. Results from the analysis show that sustainable growth can be affected by adopting short and long term strategies identified in this study.

Greenhouse gas measurements from aircraft during CARVE

Science.gov (United States)

Chang, R. Y.; Miller, C. E.; Dinardo, S. J.; Karion, A.; Sweeney, C.; Daube, B.; Pittman, J. V.; Miller, J. B.; Budney, J. W.; Gottlieb, E. W.; Santoni, G. W.; Kort, E. A.; Wofsy, S. C.

2012-12-01

Permafrost in the Arctic contain large carbon pools that are currently non-labile. As the polar regions warm, these carbon reserves can be released into the atmosphere and impact the greenhouse gas budget. In order to predict future climate scenarios, we need to understand the emissions of these greenhouse gases under varying environmental conditions. This study presents aircraft measurements made as a part of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) which flew over Alaska from May to September 2012 and captured seasonal and spatial variations. Results from in situ cavity ring down spectroscopy measurements of CO2, CH4 and CO will be discussed and compared with aircraft measurements made during the summer of 1988 as a part of the Arctic Boundary Layer Expedition as well as relevant measurements from the HIAPER Pole-to-Pole Observations experiments (2009-2011).

Determination of aircraft noise variability using an acoustic camera

NARCIS (Netherlands)

Merino Martinez, R.; Snellen, M.; Simons, D.G.

2016-01-01

Nowadays, aircraft noise is one of the major problems to be dealt with by the aerospace industry and especially suffered by the residents living in the vicinities of airports. The enforcement of noise control environmental laws around airports is hindered due to the large variability observed in the

System for indicating fuel-efficient aircraft altitude

Science.gov (United States)

Gary, B. L. (Inventor)

1984-01-01

A method and apparatus are provided for indicating the altitude at which an aircraft should fly so the W/d ratio (weight of the aircraft divided by the density of air) more closely approaches the optimum W/d for the aircraft. A passive microwave radiometer on the aircraft is directed at different angles with respect to the horizon to determine the air temperature, and therefore the density of the air, at different altitudes. The weight of the aircraft is known. The altitude of the aircraft is changed to fly the aircraft at an altitude at which is W/d ratio more closely approaches the optimum W/d ratio for that aircraft.

Aurora Flight Sciences' Perseus B Remotely Piloted Aircraft in Flight

Science.gov (United States)

1998-01-01

from a mobile flight control station on the ground. A Global Positioning System (GPS) unit provides navigation data for continuous and precise location during flight. The ground control station features dual independent consoles for aircraft control and systems monitoring. A flight termination system, required for all remotely piloted aircraft being flown in military-restricted airspace, includes a parachute system deployed on command plus a C-Band radar beacon and a Mode-C transponder to aid in location. Dryden has provided hanger and office space for the Perseus B aircraft and for the flight test development team when on site for flight or ground testing. NASA's ERAST project is developing aeronautical technologies for a new generation of remotely piloted and autonomous aircraft for a variety of upper-atmospheric science missions and commercial applications. Dryden is the lead center in NASA for ERAST management and operations. Perseus B is approximately 25 feet long, has a wingspan of 71.5 feet, and stands 12 feet high. Perseus B is powered by a Rotax 914, four-cylinder piston engine mounted in the mid-fuselage area and integrated with an Aurora-designed three-stage turbocharger, connected to a lightweight two-blade propeller.

Jet stream winds - Comparisons of analyses with independent aircraft data over Southwest Asia

Science.gov (United States)

Tenenbaum, J.

1991-01-01

Cruise-level wind data from commercial aircraft are obtained, and these data are compared with operational jet stream analyses over southwest Asia, an area of limited conventional data. Results from an ensemble of 11 cases during January 1989 and individual cases during December 1988-March 1989 are presented. The key results are: (1) European Centre for Medium-Range Weather Forecasts (ECMWF), National Meteorological Center, and United Kingdom Meteorological Office analyses of the subtropical jet in southwest Asia are 11 percent, 17 percent, and 17 percent weaker, respectively, than aircraft observations; (2) analyzed poleward shears range up to 1 f (0.00007/s) compared with up to 3 f (0.00021/s) in the aircraft observations where f is the local Coriolis parameters; (3) the ECMWF errors are largest at the base of the jet; (4) the mean ECMWF core location is latitudinally correct but has an rms latitude variance of 1.5 deg; (5) isolated erroneous radiosondes produce unmeteorological structures in the analyzed subtropical jet stream; and (6) the increased utilization of automated aircraft reports is likely to produce a spurious secular increase in the apparent strength of the jets. The magnitude and spatial extent of the errors seen are near limits of current GCM resolution (100 km) but should be resolvable. The results imply that studies of GCM systematic jet stream wind errors in weather and climate forecasts must be interpreted with caution in this region.

Quelling Cabin Noise in Turboprop Aircraft via Active Control

Science.gov (United States)

Kincaid, Rex K.; Laba, Keith E.; Padula, Sharon L.

1997-01-01

Cabin noise in turboprop aircraft causes passenger discomfort, airframe fatigue, and employee scheduling constraints due to OSHA standards for exposure to high levels of noise. The noise levels in the cabins of turboprop aircraft are typically 10 to 30 decibels louder than commercial jet noise levels. However. unlike jet noise the turboprop noise spectrum is dominated by a few low frequency tones. Active structural acoustic control is a method in which the control inputs (used to reduce interior noise) are applied directly to a vibrating structural acoustic system. The control concept modeled in this work is the application of in-plane force inputs to piezoceramic patches bonded to the wall of a vibrating cylinder. The goal is to determine the force inputs and locations for the piezoceramic actuators so that: (1) the interior noise is effectively damped; (2) the level of vibration of the cylinder shell is not increased; and (3) the power requirements needed to drive the actuators are not excessive. Computational experiments for data taken from a computer generated model and from a laboratory test article at NASA Langley Research Center are provided.

Fuel containment and damage tolerance for large composite primary aircraft structures. Phase 1: Testing

Science.gov (United States)

Sandifer, J. P.

1983-01-01

Technical problems associated with fuel containment and damage tolerance of composite material wings for transport aircraft were identified. The major tasks are the following: (1) the preliminary design of damage tolerant wing surface using composite materials; (2) the evaluation of fuel sealing and lightning protection methods for a composite material wing; and (3) an experimental investigation of the damage tolerant characteristics of toughened resin graphite/epoxy materials. The test results, the test techniques, and the test data are presented.

Inhalation toxicology. I., Design of a small-animal test system, II. Determination of the relative toxic hazards of 75 aircraft cabin materials.

Science.gov (United States)

1977-01-01

In an effort to further the cause of increased safety for those who ride in commercial aircraft, this paper presents a detailed description of the genesis of a small-scale, laboratory test system that utilizes small animals to evaluate the relative t...

Aircraft Control Using Engine Thrust: A History of Learning TOC Real-Time

Science.gov (United States)

Cole, Jennifer H.; Batteas, Frank; Fullerton, Gordon

2006-01-01

A history of learning the operation of Throttles Only Control (TOC) to control an aircraft in real time using engine thrust is shown. The topics include: 1) Past TOC Accidents/Incidents; 2) 1972: DC-10 American Airlines; 3) May 1974: USAF B-52H; 4) April 1975: USAF C-5A; 5) April 1975: USAF C-5A; 6) 1981: USAF B-52G; 7) August 1985: JAL 123 B-747; 8) JAL 123 Survivor Story; 9) JAL 123 Investigation Findings; 10) July 1989: UAL 232 DC-10; 11) UAL 232 DC-10; 12) Eastwind 517 B-737; 13) November 2003: DHL A-300; 14) Historically, TOC has saved lives; 15) Automated Throttles-Only Control; 16) PCA Project; 17) Propulsion-Controlled Aircraft; 18) MD-11 PCA System and Flight Test Envelope; 19) MD-11 Simulation, PCA ILS-Soupled Landing Dispersion; 20) Throttles-Only Pitch and Roll Control Power; 21) PCA in Commercial Fleet; 22) Fall 2005: PCAR Project; 23) PCAR Background - TOC; and 24) PCAR Background - TOC.

Cosmic radiation dose in the aircraft

International Nuclear Information System (INIS)

Vukovic, B.; Radolic, V.; Varga, M.; Planinic, J.; Vekic, B.

2006-01-01

When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A 320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb - Paris - Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 μSv/h and the TLD dosimeter registered the total dose of 75 μSv or the average dose rate of 2.7 μSv/h; the neutron dosimeter gave the dose rate of 2.4 μSv/h. In the same month, February 2005, a traveling to the Japan (24 hours-flight: Zagreb - Frankfurt - Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h; the neutron dosimeter gave the dose rate of 2.5 μSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude the neutron component curried about 50% of the total dose, that was near other known data. (author)

Water Vapor Sensors Go Sky-High to Assure Aircraft Safety

Science.gov (United States)

2006-01-01

JPL used a special tunable diode laser, which NASA scientists could tune to different wavelengths, like a radio being tuned to different frequencies, to accurately target specific molecules and detect small traces of gas. This tunable diode laser was designed to emit near-infrared light at wavelengths absorbed by the gas or gases being detected. The light energy being absorbed by the target gas is related to the molecules present. This is usually measured in parts per million or parts per billion. Multiple measurements are made every second, making the system quick to respond to variations in the target gas. NASA scientists developed this technology as part of the 1999 Mars Polar Lander mission to explore the possibility of life-giving elements on Mars. NASA has since used the tunable diode laser-based gas sensor on aircraft and on balloons to successfully study weather and climate, global warming, emissions from aircraft, and numerous other areas where chemical gas analysis is needed. SpectraSensors, Inc., was formed in 1999 as a spinoff company of JPL, to commercialize tunable diode laser-based analyzers for industrial gas-sensing applications (Spinoff 2000). Now, the San Dimas, California-based firm has come back to the market with a new product featuring the NASA-developed instrument for atmospheric monitoring. This instrument is now helping aircraft avoid hazardous weather conditions and enabling the National Weather Service to provide more accurate weather forecasts.

Fettered aircraft for using wind energy

Energy Technology Data Exchange (ETDEWEB)

Hoeppner, H.; Horvath, E.; Ulrich, S.

1980-08-28

The invention concerns an aircraft tethered by cables, whose balloon-shaped central body produces static and aerodynamic upthrust and which carries turbines, which are used to convert wind energy and to drive the aircraft. The purpose of the invention is to provide an aircraft, which will keep wind energy plant at the optimum height. A new type of aircraft is used to solve the problem, which, according to the invention, combines static upthrust, the production of aerodynamic upthrust, wind energy conversion, energy transport and forward drive in a technically integrated aircraft. If the use of windpower is interrupted, then if necessary the drive together with a remote control system provides controlled free flight of the aircraft. One variant of the object of the invention consists of a central, balloon-shaped body for upthrust, in which there are wind turbines driving electrical generators. According to the invention the motors required to start the wind turbines are of such dimensions that they will drive the turbines in free flight of the aircraft and thus provide forward drive of the aircraft. A power generating unit, consisting of an internal combustion engine and the starter motors switched over to generator operation is used to provide house service supplies for control and regulation of the aircraft.

Large strain variable stiffness composites for shear deformations with applications to morphing aircraft skins

Science.gov (United States)

McKnight, G. P.; Henry, C. P.

2008-03-01

Morphing or reconfigurable structures potentially allow for previously unattainable vehicle performance by permitting several optimized structures to be achieved using a single platform. The key to enabling this technology in applications such as aircraft wings, nozzles, and control surfaces, are new engineered materials which can achieve the necessary deformations but limit losses in parasitic actuation mass and structural efficiency (stiffness/weight). These materials should exhibit precise control of deformation properties and provide high stiffness when exercised through large deformations. In this work, we build upon previous efforts in segmented reinforcement variable stiffness composites employing shape memory polymers to create prototype hybrid composite materials that combine the benefits of cellular materials with those of discontinuous reinforcement composites. These composites help overcome two key challenges for shearing wing skins: the resistance to out of plane buckling from actuation induced shear deformation, and resistance to membrane deflections resulting from distributed aerodynamic pressure loading. We designed, fabricated, and tested composite materials intended for shear deformation and address out of plane deflections in variable area wing skins. Our designs are based on the kinematic engineering of reinforcement platelets such that desired microstructural kinematics is achieved through prescribed boundary conditions. We achieve this kinematic control by etching sheets of metallic reinforcement into regular patterns of platelets and connecting ligaments. This kinematic engineering allows optimization of materials properties for a known deformation pathway. We use mechanical analysis and full field photogrammetry to relate local scale kinematics and strains to global deformations for both axial tension loading and shear loading with a pinned-diamond type fixture. The Poisson ratio of the kinematically engineered composite is ~3x higher than

Conceptual design of hybrid-electric transport aircraft

Science.gov (United States)

Pornet, C.; Isikveren, A. T.

2015-11-01

The European Flightpath 2050 and corresponding Strategic Research and Innovation Agenda (SRIA) as well as the NASA Environmentally Responsible Aviation N+ series have elaborated aggressive emissions and external noise reduction targets according to chronological waypoints. In order to deliver ultra-low or even zero in-flight emissions levels, there exists an increasing amount of international research and development emphasis on electrification of the propulsion and power systems of aircraft. Since the late 1990s, a series of experimental and a host of burgeouning commercial activities for fixed-wing aviation have focused on glider, ultra-light and light-sport airplane, and this is proving to serve as a cornerstone for more ambitious transport aircraft design and integration technical approaches. The introduction of hybrid-electric technology has dramatically expanded the design space and the full-potential of these technologies will be drawn through synergetic, tightly-coupled morphological and systems integration emphasizing propulsion - as exemplified by the potential afforded by distributed propulsion solutions. With the aim of expanding upon the current repository of knowledge associated with hybrid-electric propulsion systems a quad-fan arranged narrow-body transport aircraft equipped with two advanced Geared-Turbofans (GTF) and two Electrical Fans (EF) in an under-wing podded installation is presented in this technical article. The assessment and implications of an increasing Degree-of-Hybridization for Useful Power (HP,USE) on the overall sizing, performance as well as flight technique optimization of fuel-battery hybrid-electric aircraft is addressed herein. The integrated performance of the concept was analyzed in terms of potential block fuel burn reduction and change in vehicular efficiency in comparison to a suitably projected conventional aircraft employing GTF-only propulsion targeting year 2035. Results showed that by increasing HP,USE, significant

A Study of Bird Ingestions Into Large High Bypass Ratio Turbine Aircraft Engines.

Science.gov (United States)

1984-09-01

average weights based on ".S _ _ _ L TABLE 2.3 CUMULATIVE DISTRIBUTION OF INCESTION EVENTS FOR REVISED IST and 2ND YEAR Year I Year 2 month £,ant Cue. It...7Q iMIM I MLLS*NIcE r2 UN MU.SA=Yc RSZU54 VIGURI 5-5. IM 31211-524 SWGIM/ ,UVC MOM W 3- ’u bi~ mum riom - * 1-5)5 Us1 CrMN-2 ugh Dowus Turbofan Knein... son time. The following codes refer to entries in Appendix E. AIRCRAFT (AC) WEATHER (WX) 1 - )C8 IFR - Instruent Flight Rules 2 - OClO VFR - Visual

A Review of Current and Prospective Factors for Classification of Civil Unmanned Aircraft Systems

Science.gov (United States)

Hayhurst, Kelly J.; Maddalon, Jeffrey M.; Morris, A. Terry; Neogi, Natasha; Verstynen, Harry A.

2014-01-01

While progress is being made on integrating unmanned aircraft systems (UAS) into our national airspace on a broad scale, much work remains to establish appropriate certification standards and operational procedures, particularly with respect to routine commercial operations. This paper summarizes research to examine the extent to which today's civil aircraft taxonomy applies to UAS, and, if needed, how that taxonomy could be amended to better cover different UAS designs and operations. Factors that shape the current taxonomy, as defined in the Federal Aviation Regulations, were assessed for applicability to UAS, potential incompatibilities were identified, and additional factors were proposed that might be useful for an updated aircraft taxonomy intended to cover UAS. The results suggest the possibility of constructing new groups in the taxonomy for UAS under a restricted category that share common airworthiness standards. Establishing distinct groups for UAS and associated standards that enable low risk operations for compensation or hire could be a timely step toward full integration. Such a step would allow the civil aviation industry and regulators to gain valuable experience with UAS while carefully controlling access and potential harm to the aviation system as a whole.

Videopanorama Frame Rate Requirements Derived from Visual Discrimination of Deceleration During Simulated Aircraft Landing

Science.gov (United States)

Furnstenau, Norbert; Ellis, Stephen R.

2015-01-01

In order to determine the required visual frame rate (FR) for minimizing prediction errors with out-the-window video displays at remote/virtual airport towers, thirteen active air traffic controllers viewed high dynamic fidelity simulations of landing aircraft and decided whether aircraft would stop as if to be able to make a turnoff or whether a runway excursion would be expected. The viewing conditions and simulation dynamics replicated visual rates and environments of transport aircraft landing at small commercial airports. The required frame rate was estimated using Bayes inference on prediction errors by linear FRextrapolation of event probabilities conditional on predictions (stop, no-stop). Furthermore estimates were obtained from exponential model fits to the parametric and non-parametric perceptual discriminabilities d' and A (average area under ROC-curves) as dependent on FR. Decision errors are biased towards preference of overshoot and appear due to illusionary increase in speed at low frames rates. Both Bayes and A - extrapolations yield a framerate requirement of 35 game scores the model based d'(FR)-extrapolation exhibits the best agreement and indicates even higher FRmin > 40 Hz for minimizing decision errors. Definitive recommendations require further experiments with FR > 30 Hz.

Aircraft Capability Management

Science.gov (United States)

Mumaw, Randy; Feary, Mike

2018-01-01

This presentation presents an overview of work performed at NASA Ames Research Center in 2017. The work concerns the analysis of current aircraft system management displays, and the initial development of an interface for providing information about aircraft system status. The new interface proposes a shift away from current aircraft system alerting interfaces that report the status of physical components, and towards displaying the implications of degradations on mission capability. The proposed interface describes these component failures in terms of operational consequences of aircraft system degradations. The research activity was an effort to examine the utility of different representations of complex systems and operating environments to support real-time decision making of off-nominal situations. A specific focus was to develop representations that provide better integrated information to allow pilots to more easily reason about the operational consequences of the off-nominal situations. The work is also seen as a pathway to autonomy, as information is integrated and understood in a form that automated responses could be developed for the off-nominal situations in the future.

Assessment of the environmental impact of the FAA proposed rule making affecting the conditions of transport of radioactive materials on aircraft

International Nuclear Information System (INIS)

Hall, R.J.; Hendrickson, P.L.; King, J.C.; McSweeney, T.I.; Shipler, D.B.; Brown, C.L.; Davis, D.K.; Watson, E.C.

1975-01-01

Amendments to Federal Aviation Administration (FAA) regulations relating to the transporting of radioactive materials on commercial aircraft are presented. Potential effects of the proposed changes are examined in the environmental impact statement, which is presented in the 10 sections and 5 appendices of this document. (JGB)

Combining control input with flight path data to evaluate pilot performance in transport aircraft.

Science.gov (United States)

Ebbatson, Matt; Harris, Don; Huddlestone, John; Sears, Rodney

2008-11-01

When deriving an objective assessment of piloting performance from flight data records, it is common to employ metrics which purely evaluate errors in flight path parameters. The adequacy of pilot performance is evaluated from the flight path of the aircraft. However, in large jet transport aircraft these measures may be insensitive and require supplementing with frequency-based measures of control input parameters. Flight path and control input data were collected from pilots undertaking a jet transport aircraft conversion course during a series of symmetric and asymmetric approaches in a flight simulator. The flight path data were analyzed for deviations around the optimum flight path while flying an instrument landing approach. Manipulation of the flight controls was subject to analysis using a series of power spectral density measures. The flight path metrics showed no significant differences in performance between the symmetric and asymmetric approaches. However, control input frequency domain measures revealed that the pilots employed highly different control strategies in the pitch and yaw axes. The results demonstrate that to evaluate pilot performance fully in large aircraft, it is necessary to employ performance metrics targeted at both the outer control loop (flight path) and the inner control loop (flight control) parameters in parallel, evaluating both the product and process of a pilot's performance.

Essentials of aircraft armaments

CERN Document Server

Kaushik, Mrinal

2017-01-01

This book aims to provide a complete exposure about armaments from their design to launch from the combat aircraft. The book details modern ammunition and their tactical roles in warfare. The proposed book discusses aerodynamics, propulsion, structural as well as navigation, control, and guidance of aircraft armament. It also introduces the various types of ammunition developed by different countries and their changing trends. The book imparts knowledge in the field of design, and development of aircraft armaments to aerospace engineers and covers the role of the United Nations in peacekeeping and disarmament. The book will be very useful to researchers, students, and professionals working in design and manufacturing of aircraft armaments. The book will also serve air force and naval aspirants, and those interested in working on defence research and developments organizations. .

Schweizer RU-38A Twin-Condor: covert surveillance aircraft

Science.gov (United States)

O'Toole, Michael J.; Schweizer, Paul H.

1997-11-01

The world order has changed and with it, governments are now faced with waging a new type of `ware.' Regional instability, drug trafficking, environmental issues, international terrorism, and illegal immigration are examples of escalating problems that cross international boundaries and threaten the security of nations. The first and most important element in coping with these illegal activities is the ability to detect and monitor events in a timely and secure fashion. Conventional means of gathering intelligence such as large airborne collection systems and satellites lack the flexibility, dwell times, and cost effectiveness to meet many of today's needs. There is a growing requirement for airborne platforms that can covertly perform surveillance missions during either day or night and in a cost effective manner. To meet this need, Schweizer Aircraft has recently developed the RU-38A twin-engine surveillance aircraft. This paper discusses the evolution and principle design concepts of this aircraft and how its unique performance enables the RU-38A to achieve new levels of surveillance capability.

Applying Best Practices to Military Commercial-Derivative Aircraft Engine Sustainment: Assessment of Using Parts Manufacturer Approval (PMA) Parts and Designated Engineering Representative (DER) Repairs

Science.gov (United States)

2016-01-01

savings through greater use of non-OEM alternate parts and services 5 According to Broderick (2013), the FAA developed regulations governing PMA parts...when operators of surplus military aircraft wanted to keep them operat- ing safely and the OEMs were no longer making new parts ( Broderick , 2013...of the world’s aircraft and engines will be leased by the year 2020 (Sean Broderick , 2014). Categorization of Risks of Greater Use of PMA Parts and

Fire-retardant decorative inks for aircraft interiors

Science.gov (United States)

Kourtides, D. A.; Nir, Z.; Mikroyannidis, J. A.

1985-01-01

Commercial and experimental fire retardants were screened as potential fire retardants for acrylic printing inks used on aircraft interior sandwich panels. The fire retardants are selected according to their physical properties and their thermostabilities. A criterion for selecting a more stable fire retardant is established. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are used to determine thermostabilities. Results show that the fire retardant formulations are more thermally stable than the acrylic ink control. It is determined that an ink formulation containing a brominated phenol and carboxy-terminated butadiene acrylonitrile which has been modified with a brominated polymeric additive (BPA), yields the highest limiting oxygen index (LOI) of all the compounds tested. All of the fire-retardant formulations have a higher oxygen index than the baseline acrylic ink.

Molecular descriptor data explain market prices of a large commercial chemical compound library

Science.gov (United States)

Polanski, Jaroslaw; Kucia, Urszula; Duszkiewicz, Roksana; Kurczyk, Agata; Magdziarz, Tomasz; Gasteiger, Johann

2016-06-01

The relationship between the structure and a property of a chemical compound is an essential concept in chemistry guiding, for example, drug design. Actually, however, we need economic considerations to fully understand the fate of drugs on the market. We are performing here for the first time the exploration of quantitative structure-economy relationships (QSER) for a large dataset of a commercial building block library of over 2.2 million chemicals. This investigation provided molecular statistics that shows that on average what we are paying for is the quantity of matter. On the other side, the influence of synthetic availability scores is also revealed. Finally, we are buying substances by looking at the molecular graphs or molecular formulas. Thus, those molecules that have a higher number of atoms look more attractive and are, on average, also more expensive. Our study shows how data binning could be used as an informative method when analyzing big data in chemistry.

Drag Reduction Devices for Aircraft (Latest Citations from the Aerospace Database)

Science.gov (United States)

1996-01-01

The bibliography contains citations concerning the modeling, application, testing, and development of drag reduction devices for aircraft. Slots, flaps, fences, large-eddy breakup (LEBU) devices, vortex generators and turbines, Helmholtz resonators, and winglets are among the devices discussed. Contour shaping to ensure laminar flow, control boundary layer transition, or minimize turbulence is also covered. Applications include the wings, nacelles, fuselage, empennage, and externals of aircraft designed for high-lift, subsonic, or supersonic operation. The design, testing, and development of directional grooves, commonly called riblets, are covered in a separate bibliography.(Contains 50-250 citations and includes a subject term index and title list.)

Evaluation of low-cost commercial-off-the-shelf autopilot systems for SUAS operations

Science.gov (United States)

Brown, Calvin Thomas

With this increase in unmanned aircraft system (UAS) operations, there is a need for a structured process to evaluate different commercially available systems, particularly autopilots. The Remotely Operated Aircraft Management, Interpretation, and Navigation from Ground or ROAMING scale was developed to meet this need. This scale is a modification of the widely accepted Handling Qualities Rating scale developed by George Cooper and Robert Harper Jr. The Cooper-Harper scale allows pilots to rate a vehicle's performance in completing some task. Similarly, the ROAMING scale allows UAS operators to evaluate the management and observability of UAS in completing some task. The standardized evaluative process consists of cost, size, weight, and power (SWAP) analysis, ease of implementation through procedural description of setup, ROAMING scale rating, a slightly modified NASA TLX rating, and comparison of manual operation to autonomous operation of the task. This standard for evaluation of autopilots and their software will lead to better understanding of the workload placed on UAS operators and indicate where improvements to design and operational procedures can be made. An assortment of low-cost commercial-off-the-shelf (COTS) autopilots were selected for use in the development of the evaluation and results of these tests demonstrate the commonalities and differences in these systems.

Concurrent airline fleet allocation and aircraft design with profit modeling for multiple airlines

Science.gov (United States)

Govindaraju, Parithi

A "System of Systems" (SoS) approach is particularly beneficial in analyzing complex large scale systems comprised of numerous independent systems -- each capable of independent operations in their own right -- that when brought in conjunction offer capabilities and performance beyond the constituents of the individual systems. The variable resource allocation problem is a type of SoS problem, which includes the allocation of "yet-to-be-designed" systems in addition to existing resources and systems. The methodology presented here expands upon earlier work that demonstrated a decomposition approach that sought to simultaneously design a new aircraft and allocate this new aircraft along with existing aircraft in an effort to meet passenger demand at minimum fleet level operating cost for a single airline. The result of this describes important characteristics of the new aircraft. The ticket price model developed and implemented here enables analysis of the system using profit maximization studies instead of cost minimization. A multiobjective problem formulation has been implemented to determine characteristics of a new aircraft that maximizes the profit of multiple airlines to recognize the fact that aircraft manufacturers sell their aircraft to multiple customers and seldom design aircraft customized to a single airline's operations. The route network characteristics of two simple airlines serve as the example problem for the initial studies. The resulting problem formulation is a mixed-integer nonlinear programming problem, which is typically difficult to solve. A sequential decomposition strategy is applied as a solution methodology by segregating the allocation (integer programming) and aircraft design (non-linear programming) subspaces. After solving a simple problem considering two airlines, the decomposition approach is then applied to two larger airline route networks representing actual airline operations in the year 2005. The decomposition strategy serves

In-flight monitoring of particle deposition in the environmental control systems of commercial airliners in China

Science.gov (United States)

Cao, Qing; Xu, Qiuyu; Liu, Wei; Lin, Chao-Hsin; Wei, Daniel; Baughcum, Steven; Norris, Sharon; Chen, Qingyan

2017-04-01

Severe air pollution and low on-time performance of commercial flights in China could increase particle deposition in the environmental control systems (ECSs) of commercial airliners. The particles deposited in the ECSs could negatively affect the performance of the airplanes. In addition, particles that penetrate into the aircraft cabin could adversely impact the health of passengers and crew members. This investigation conducted simultaneous measurements of particle mass concentration and size distribution inside and outside the cabin during 64 commercial flights of Boeing 737 and Airbus 320 aircraft departing from or arriving at Tianjin Airport in China. The results showed that the PM2.5 mass concentration deposition in the ECSs of these airplanes ranged from 50% to 90%, which was much higher than that measured in an airplane with a ground air-conditioning unit. The average deposition rates of particles with diameters of 0.5-1 μm, 1-2 μm, 2-5 μm, 5-10 μm, and >10 μm were 89 ± 8%, 85 ± 13%, 80 ± 13%, 73 ± 15%, and 80 ± 14%, respectively. The in-flight measurement results indicated that the particle concentration in the breathing zone was higher than that in the air-supply zone, which implies a significant contribution by particles in the interior of the cabin. Such particles come from human emissions or particle resuspension from interior surfaces.

The design space exploration and preliminary testing of a new class of tailsitting quadrotor aircraft

Science.gov (United States)

Bodlak, Eric

Within the last decade, multi-rotor aircraft have become the most prevalent form of unmanned aerial vehicle (UAV), with applications in the military, commercial, and civilian sectors. This is due primarily to advances in electronics that allow small-scale aircraft systems to be produced and controlled in an affordable manner. Such systems are maneuvered by precisely varying the thrust and torque of individual rotors to produce flight control forces, thereby eliminating much of the mechanical complexity inherent in conventional helicopter configurations. Although many UAV missions exploit the ability to hover in place, many also require the ability to quickly and efficiently dash from point to point. Rotorcraft, in general, are limited in this capacity, since rotor thrust must also be used to produce lift. Transitional aircraft represent an alternative that blends the vertical take-off and landing (VTOL) capabilities of rotorcraft with the forward flight performance of fixed-wing aircraft, but they often rely on cumbersome mechanisms, such as additional or rotating powerplants. UAVs, however, have no need to maintain cockpit orientation. Consequently, a tailsitting quadcopter concept was devised by Dr. Ron Barrett to combine quadcopter hovering performance with the high-speed flight of fixed-wing craft. This paper lays out the arguments for such an aircraft--the XQ-139 --and examines the performance of XQ-139 variants with installed power values ranging from 100 W to 10,000 kW. Battery-electric, rotary engine, turboprop, and hybrid propulsive options are considered, and the merits of each discussed. Additionally, an XQ-139 prototype was designed and constructed, and stationary test was used to compare the aircraft's installed efficiency with that of a typical quadcopter. The prototype was found to be approximately 5% more efficient in hover mode than the quadcopter to which it was compared.

A Reasoned Action Model of Male Client Involvement in Commercial Sex Work in Kibera, A Large Informal Settlement in Nairobi, Kenya.

Science.gov (United States)

Roth, Eric Abella; Ngugi, Elizabeth; Benoit, Cecilia; Jansson, Mikael; Hallgrimsdottir, Helga

2014-01-01

Male clients of female sex workers (FSWs) are epidemiologically important because they can form bridge groups linking high- and low-risk subpopulations. However, because male clients are hard to locate, they are not frequently studied. Recent research emphasizes searching for high-risk behavior groups in locales where new sexual partnerships form and the threat of HIV transmission is high. Sub-Saharan Africa public drinking venues satisfy these criteria. Accordingly, this study developed and implemented a rapid assessment methodology to survey men in bars throughout the large informal settlement of Kibera, Nairobi, Kenya, with the goal of delineating cultural and economic rationales associated with male participation in commercial sex. The study sample consisted of 220 male patrons of 110 bars located throughout Kibera's 11 communities. Logistic regression analysis incorporating a modified Reasoned Action Model indicated that a social norm condoning commercial sex among male peers and the cultural belief that men should practice sex before marriage support commercial sex involvement. Conversely, lacking money to drink and/or pay for sexual services were barriers to male commercial sex involvement. Results are interpreted in light of possible harm reduction programs focusing on FSWs' male clients.

41 CFR 102-33.95 - What is the process for budgeting to acquire commercial aviation services (CAS)?

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is the process for budgeting to acquire commercial aviation services (CAS)? 102-33.95 Section 102-33.95 Public Contracts and... Parts The Process for Budgeting to Acquire Government Aircraft § 102-33.95 What is the process for...

Cascade Convolutional Neural Network Based on Transfer-Learning for Aircraft Detection on High-Resolution Remote Sensing Images

Directory of Open Access Journals (Sweden)

Bin Pan

2017-01-01

Full Text Available Aircraft detection from high-resolution remote sensing images is important for civil and military applications. Recently, detection methods based on deep learning have rapidly advanced. However, they require numerous samples to train the detection model and cannot be directly used to efficiently handle large-area remote sensing images. A weakly supervised learning method (WSLM can detect a target with few samples. However, it cannot extract an adequate number of features, and the detection accuracy requires improvement. We propose a cascade convolutional neural network (CCNN framework based on transfer-learning and geometric feature constraints (GFC for aircraft detection. It achieves high accuracy and efficient detection with relatively few samples. A high-accuracy detection model is first obtained using transfer-learning to fine-tune pretrained models with few samples. Then, a GFC region proposal filtering method improves detection efficiency. The CCNN framework completes the aircraft detection for large-area remote sensing images. The framework first-level network is an image classifier, which filters the entire image, excluding most areas with no aircraft. The second-level network is an object detector, which rapidly detects aircraft from the first-level network output. Compared with WSLM, detection accuracy increased by 3.66%, false detection decreased by 64%, and missed detection decreased by 23.1%.

Commercial Diplomats as corporate entrepreneurs: an institutional perspective

NARCIS (Netherlands)

Visser, R.; Ruel, Hubertus Johannes Maria; Ruel, H.J.M.

2012-01-01

This chapter presents a study on the work of commercial diplomats as international business promoters at foreign posts. Research has largely overlooked the actual roles and activities of commercial diplomats in explaining the effectiveness of commercial diplomacy and international business support.

Descriptive Study of an Outbreak of Avian Urolithiasis in a Large Commercial Egg Complex in Algeria

Directory of Open Access Journals (Sweden)

Hicham SID

2011-03-01

Full Text Available Avian urolithiasis is one of the major causes of mortality in poultry. However, in Algeria this condition has never been described. An outbreak of avian urolithiasis was observed on a large commercial egg complex in the department of Chlef (West of Algeria. The clinical features of this condition are to be described. Mortality associated to urolithiasis started at the onset of egg production, estimated to 0.7 % per week. Urolithiasis induced an egg drop estimated to 12%. Dead and live layers were both necropsied and examined for kidney lesions. Most of the birds examined presented enlarged ureters, renal atrophy and visceral gout deposition.

Large Disparities in Receipt of Glaucoma Care between Enrollees in Medicaid and Those with Commercial Health Insurance.

Science.gov (United States)

Elam, Angela R; Andrews, Chris; Musch, David C; Lee, Paul P; Stein, Joshua D

2017-10-01

To determine whether the type of health insurance a patient possesses and a patient's race/ethnicity affect receipt of common tests to monitor open-angle glaucoma (OAG). Retrospective longitudinal cohort study. A total of 21 766 persons aged ≥40 years with newly diagnosed OAG between 2007 and 2011 enrolled in Medicaid or a large United States managed care network. We determined the proportion of patients with newly diagnosed OAG who underwent visual field (VF) testing, fundus photography (FP), other ocular imaging (OOI), or none of these tests within the first 15 months after initial OAG diagnosis. Multivariable logistic regression was used to assess the extent by which health insurance type and race/ethnicity affected the odds of undergoing glaucoma testing. Odds ratios (OR) of undergoing VF testing, FP, OOI, or none of these tests in the 15 months after initial OAG diagnosis with 95% confidence intervals (CI). A total of 18 372 persons with commercial health insurance and 3394 Medicaid recipients met the study inclusion criteria. The proportions of persons with commercial health insurance with newly diagnosed OAG who underwent VF, FP, and OOI were 63%, 22%, and 54%, respectively, whereas the proportions were 35%, 19%, and 30%, respectively, for Medicaid recipients. Compared with those with commercial health insurance, Medicaid recipients were 234% more likely to not receive any glaucoma testing in the 15 months after initial diagnosis (OR = 3.34; 95% CI, 3.07-3.63). After adjustment for confounders, whites with OAG enrolled in Medicaid had 198% higher odds of receiving no glaucoma testing compared with whites possessing commercial health insurance (OR = 2.98; 95% CI, 2.66-3.33). Blacks with Medicaid insurance demonstrated 291% higher odds (OR = 3.91; 95% CI, 3.40-4.49) of not receiving any glaucoma testing compared with blacks with commercial health insurance. Irrespective of race/ethnicity, Medicaid recipients with OAG are receiving substantially less

Hydrant refueling system as an optimisation of aircraft refuelling

Directory of Open Access Journals (Sweden)

Martin HROMÁDKA

2015-09-01

Full Text Available At large international airports, aircraft can be refuelled either by fuel trucks or using dedicated underground pipeline systems. The latter, hydrant refuelling, is considered to be an optimal fuelling method as it increases safety, shortens the aircraft turnaround time and cuts the overall costs. However, at smaller airports, implementation of this system can lead to high investment costs. Thus, the paper discusses the airport size from which this system may be efficient to implement. Various definitions of term “airport size” are assessed. Based on data collection, the hydrant system model is created within the paper. As a result, methodology for assessing the suitability of hydrant system implementation is set. This methodology can be used at every airport using three simple inputs.

Aircraft versus spacecraft for remote monitoring of water quality in U.S. coastal zones

Science.gov (United States)

Darnell, W. L.

1977-01-01

To provide guidance for conducting future water monitoring missions over U.S. coasts, aircraft and spacecraft approaches were defined and quantitatively compared. Sensors, aircraft and spacecraft were selected from current or developmental types for the hardware concepts and monitoring was assumed to begin in 1981-1983. Comparative data are presented on capabilities and costs to monitor both recognized pollution sites and broad shelf areas. For these mission requirements, a large fleet of light aircraft provided better coverage and at lower costs generally than one spacecraft, assuming a single, multi-spectral sensor on each platform. This result could change, however, should additional useful sensors with low cost penalties be found for the spacecraft.

Mortality among a cohort of U.S. commercial airline cockpit crew.

Science.gov (United States)

Yong, Lee C; Pinkerton, Lynne E; Yiin, James H; Anderson, Jeri L; Deddens, James A

2014-08-01

We evaluated mortality among 5,964 former U.S. commercial cockpit crew (pilots and flight engineers). The outcomes of a priori interest were non-chronic lymphocytic leukemia, central nervous system (CNS) cancer (including brain), and malignant melanoma. Vital status was ascertained through 2008. Life table and Cox regression analyses were conducted. Cumulative exposure to cosmic radiation was estimated from work history data. Compared to the U.S. general population, mortality from all causes, all cancer, and cardiovascular diseases was decreased, but mortality from aircraft accidents was highly elevated. Mortality was elevated for malignant melanoma but not for non-chronic lymphocytic leukemia. CNS cancer mortality increased with an increase in cumulative radiation dose. Cockpit crew had a low all-cause, all-cancer, and cardiovascular disease mortality but elevated aircraft accident mortality. Further studies are needed to clarify the risk of CNS and other radiation-associated cancers in relation to cosmic radiation and other workplace exposures. © 2014 Wiley Periodicals, Inc.

Hydrogen Storage for Aircraft Applications Overview

Science.gov (United States)

Colozza, Anthony J.; Kohout, Lisa (Technical Monitor)

2002-01-01

Advances in fuel cell technology have brought about their consideration as sources of power for aircraft. This power can be utilized to run aircraft systems or even provide propulsion power. One of the key obstacles to utilizing fuel cells on aircraft is the storage of hydrogen. An overview of the potential methods of hydrogen storage was compiled. This overview identifies various methods of hydrogen storage and points out their advantages and disadvantages relative to aircraft applications. Minimizing weight and volume are the key aspects to storing hydrogen within an aircraft. An analysis was performed to show how changes in certain parameters of a given storage system affect its mass and volume.

Managing systems faults on the commercial flight deck: Analysis of pilots' organization and prioritization of fault management information

Science.gov (United States)

Rogers, William H.

1993-01-01

In rare instances, flight crews of commercial aircraft must manage complex systems faults in addition to all their normal flight tasks. Pilot errors in fault management have been attributed, at least in part, to an incomplete or inaccurate awareness of the fault situation. The current study is part of a program aimed at assuring that the types of information potentially available from an intelligent fault management aiding concept developed at NASA Langley called 'Faultfinde' (see Abbott, Schutte, Palmer, and Ricks, 1987) are an asset rather than a liability: additional information should improve pilot performance and aircraft safety, but it should not confuse, distract, overload, mislead, or generally exacerbate already difficult circumstances.

PROVING THE CAPABILITY FOR LARGE SCALE REGIONAL LAND-COVER DATA PRODUCTION BY SELF-FUNDED COMMERCIAL OPERATORS

Directory of Open Access Journals (Sweden)

M. W. Thompson

2017-11-01

Full Text Available For service providers developing commercial value-added data content based on remote sensing technologies, the focus is to typically create commercially appropriate geospatial information which has downstream business value. The primary aim being to link locational intelligence with business intelligence in order to better make informed decisions. From a geospatial perspective this locational information must be relevant, informative, and most importantly current; with the ability to maintain the information timeously into the future for change detection purposes. Aligned with this, GeoTerraImage has successfully embarked on the production of land-cover/land-use content over southern Africa. The ability for a private company to successfully implement and complete such an exercise has been the capability to leverage the combined advantages of cutting edge data processing technologies and methodologies, with emphasis on processing repeatability and speed, and the use of a wide range of readily available imagery. These production workflows utilise a wide range of integrated procedures including machine learning algorithms, innovative use of non-specialists for sourcing of reference data, and conventional pixel and object-based image classification routines, and experienced/expert landscape interpretation. This multi-faceted approach to data produce development demonstrates the capability for SMME level commercial entities such as GeoTerraImage to generate industry applicable large data content, in this case, wide area coverage land-cover and land-use data across the sub-continent. Within this development, the emphasis has been placed on the key land-use information, such as mining, human settlements, and agriculture, given the importance of this geo-spatial land-use information in business and socio-economic applications and decision making.

Aircraft Carrier Exposure Testing of Aircraft Materials

National Research Council Canada - National Science Library

Lee, Eui

2004-01-01

.... Test and control specimens were affixed on exposure racks and installed on aircraft carriers to compare adhesive bonding primers for aluminum and to determine the static property behavior of various...

Population census of a large common tern colony with a small unmanned aircraft.

Directory of Open Access Journals (Sweden)

Dominique Chabot

Full Text Available Small unmanned aircraft systems (UAS may be useful for conducting high-precision, low-disturbance waterbird surveys, but limited data exist on their effectiveness. We evaluated the capacity of a small UAS to census a large (>6,000 nests coastal Common tern (Sterna hirundo colony of which ground surveys are particularly disruptive and time-consuming. We compared aerial photographic tern counts to ground nest counts in 45 plots (5-m radius throughout the colony at three intervals over a nine-day period in order to identify sources of variation and establish a coefficient to estimate nest numbers from UAS surveys. We also compared a full colony ground count to full counts from two UAS surveys conducted the following day. Finally, we compared colony disturbance levels over the course of UAS flights to matched control periods. Linear regressions between aerial and ground counts in plots had very strong correlations in all three comparison periods (R2 = 0.972-0.989, P < 0.001 and regression coefficients ranged from 0.928-0.977 terns/nest. Full colony aerial counts were 93.6% and 94.0%, respectively, of the ground count. Varying visibility of terns with ground cover, weather conditions and image quality, and changing nest attendance rates throughout incubation were likely sources of variation in aerial detection rates. Optimally timed UAS surveys of Common tern colonies following our method should yield population estimates in the 93-96% range of ground counts. Although the terns were initially disturbed by the UAS flying overhead, they rapidly habituated to it. Overall, we found no evidence of sustained disturbance to the colony by the UAS. We encourage colonial waterbird researchers and managers to consider taking advantage of this burgeoning technology.

Evaluation of Large Grained UO{sub 2} Pellet's Manufacturability in a Commercial Plant and Development of its Technology

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung Jae; Lee, J. N.; Lee, S. J. [Korea Nuclear Fuel Co. Ltd., Daejeon (Korea, Republic of)] (and others)

2007-02-15

To apply the various methods for grain growth of the fuel pellet to the commercial manufacturing process, which have been developed through the 'Advanced Fuel Pellet Development Program' in KAERI, it is necessary to conduct the performance test on the mass product line of UO{sub 2} pellets. For this purpose there are two main areas to be evaluated: The first area is the manufacturability of the lab-developed methods on large volume equipment (kg-batch) and commercial manufacturing scale. As a second part the material characteristics should satisfy the specification requirements for the UO{sub 2} pellet design. Above all, the applicability tests for the 'Seed' and 'Micro-doping' technology respectively were performed in the KNFC UO{sub 2} pellet commercial product line. These tests focused on the manufacturability on mass production and acceptable properties of the developed samples on demands of UO{sub 2} pellet design criteria. The tests showed very positive results. Judging from all the test results, the Al micro-doping method is likely to be the best way to enhance the grain size of UO{sub 2} pellet in the KNFC commercial product line without installation of any additional equipment. Through a series of additional reproducibility tests and process optimization, the micro-doping technology will be good applied for X-gen fuel pellet in the near future.

Modeling and control for a blended wing body aircraft a case study

CERN Document Server

Schirrer, Alexander

2015-01-01

This book demonstrates the potential of the blended wing body (BWB) concept for significant improvement in both fuel efficiency and noise reduction and addresses the considerable challenges raised for control engineers because of characteristics like open-loop instability, large flexible structure, and slow control surfaces. This text describes state-of-the-art and novel modeling and control design approaches for the BWB aircraft under consideration. The expert contributors demonstrate how exceptional robust control performance can be achieved despite such stringent design constraints as guaranteed handling qualities, reduced vibration, and the minimization of the aircraft’s structural loads during maneuvers and caused by turbulence. As a result, this innovative approach allows the building of even lighter aircraft structures, and thus results in considerable efficiency improvements per passenger kilometer. The treatment of this large, complex, parameter-dependent industrial control problem highlights relev...

14 CFR 49.11 - FAA Aircraft Registry.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false FAA Aircraft Registry. 49.11 Section 49.11... AIRCRAFT TITLES AND SECURITY DOCUMENTS General § 49.11 FAA Aircraft Registry. To be eligible for recording, a conveyance must be mailed to the FAA Aircraft Registry, Department of Transportation, Post Office...

Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, and Human Health and Safety

Science.gov (United States)

Atwell, William; Koontz, Steve; Normand, Eugene

2012-01-01

Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems. The effects of primary cosmic ray particles and secondary particle showers produced by nuclear reactions with the atmosphere, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth s surface, especially if the net target area of the sensitive electronic system components is large. Finally, accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO). In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as human health and the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in ground-based atmospheric flight, and space flight environments. Ground test methods applied to microelectronic components and systems are used in combinations with radiation transport and reaction codes to predict the performance of microelectronic systems in their operating environments. Similar radiation transport

Annoyance by aircraft noise and fear of overflying aircraft in relation to attitudes toward the environment and community

Science.gov (United States)

Loeb, M.; Moran, S. V.

1977-01-01

It has been suggested that expressions of annoyance attributable to aircraft noise may reflect in part fear of aircraft overflights and possible crashes. If this is true, then residents of areas where crashes have occurred should express more annoyance. To test this hypothesis, 50 residents of an Albany, New York area where an aircraft crash producing fatalities recently occurred and 50 residents of a comparable nearby area without such a history, were asked to respond to a 'Quality of Life Questionnaire.' Among the items were some designed to test annoyance by noise and fear of aircraft overflights. It was predicted that those in the crash area would express more fear and would more often identify aircraft as a noise source. These hypotheses were sustained. A near-replication was carried out in Louisville, Kentucky; results were much the same. Analyses indicated that for the crash-area groups, there was associating of aircraft fear and noise annoyance responses; this was true to an apparently lesser extent for non-crash groups. The greater annoyance of crash groups by aircraft community noise apparently does not carry over to situations in which aircraft noise is assessed in the laboratory.

The Aircraft Morphing Program

Science.gov (United States)

Wlezien, R. W.; Horner, G. C.; McGowan, A. R.; Padula, S. L.; Scott, M. A.; Silcox, R. J.; Simpson, J. O.

1998-01-01

In the last decade smart technologies have become enablers that cut across traditional boundaries in materials science and engineering. Here we define smart to mean embedded actuation, sensing, and control logic in a tightly coupled feedback loop. While multiple successes have been achieved in the laboratory, we have yet to see the general applicability of smart devices to real aircraft systems. The NASA Aircraft Morphing program is an attempt to couple research across a wide range of disciplines to integrate smart technologies into high payoff aircraft applications. The program bridges research in seven individual disciplines and combines the effort into activities in three primary program thrusts. System studies are used to assess the highest- payoff program objectives, and specific research activities are defined to address the technologies required for development of smart aircraft systems. In this paper we address the overall program goals and programmatic structure, and discuss the challenges associated with bringing the technologies to fruition.

Smart aircraft fastener evaluation (SAFE) system: a condition-based corrosion detection system for aging aircraft

Science.gov (United States)

Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.

1996-05-01

The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.

75 FR 41986 - Certification of Aircraft and Airmen for the Operation of Light-Sport Aircraft; Modifications to...

Science.gov (United States)

2010-07-20

...- Sport Aircraft; Modifications to Rules for Sport Pilots and Flight Instructors With a Sport Pilot Rating... rule; OMB approval of information collection. SUMMARY: This document announces the Office of Management... rule, ``Certification of Aircraft and Airmen for the Operation of Light-Sport Aircraft; Modifications...

A Fiber-Optic Aircraft Lightning Current Measurement Sensor

Science.gov (United States)

Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George N.

2013-01-01

A fiber-optic current sensor based on the Faraday Effect is developed for aircraft installations. It can measure total lightning current amplitudes and waveforms, including continuing current. Additional benefits include being small, lightweight, non-conducting, safe from electromagnetic interference, and free of hysteresis and saturation. The Faraday Effect causes light polarization to rotate in presence of magnetic field in the direction of light propagation. Measuring the total induced light polarization change yields the total current enclosed. The system operates at 1310nm laser wavelength and can measure approximately 300 A - 300 kA, a 60 dB range. A reflective polarimetric scheme is used, where the light polarization change is measured after a round-trip propagation through the fiber. A two-detector setup measures the two orthogonal polarizations for noise subtraction and improved dynamic range. The current response curve is non-linear and requires a simple spline-fit correction. Effects of high current were achieved in laboratory using combinations of multiple fiber and wire loops. Good result comparisons against reference sensors were achieved up to 300 kA. Accurate measurements on a simulated aircraft fuselage and an internal structure illustrate capabilities that maybe difficult with traditional sensors. Also tested at a commercial lightning test facility from 20 kA to 200 kA, accuracy within 3-10% was achieved even with non-optimum setups.

Phenomena of Foamed Concrete under Rolling of Aircraft Wheels

Science.gov (United States)

Jiang, Chun-shui; Yao, Hong-yu; Xiao, Xian-bo; Kong, Xiang-jun; Shi, Ya-jie

2014-04-01

Engineered Material Arresting System (EMAS) is an effective technique to reduce hazards associated with aircraft overrunning runway. In order to ascertain phenomena of the foamed concrete used for EMAS under rolling of aircraft wheel, a specially designed experimental setup was built which employed Boeing 737 aircraft wheels bearing actual vertical loads to roll through the foamed concrete. A number of experiments were conducted upon this setup. It is discovered that the wheel rolls the concrete in a pure rolling manner and crushes the concrete downwards, instead of crushing it forward, as long as the concrete is not higher than the wheel axle. The concrete is compressed into powder in-situ by the wheel and then is brought to bottom of the wheel. The powder under the wheel is loose and thus is not able to sustain wheel braking. It is also found that after being rolled by the wheel the concrete exhibits either of two states, i.e. either 'crushed through' whole thickness of the concrete or 'crushed halfway', depending on combination of strength of the concrete, thickness of the concrete, vertical load the wheel carries, tire dimension and tire pressure. A new EMAS design concept is developed that if an EMAS design results in the 'crushed through' state for the main gears while the 'crushed halfway' state for the nose gear, the arresting bed would be optimal to accommodate the large difference in strength between the nose gear and the main gear of an aircraft.

Aircraft Cabin Environmental Quality Sensors

Energy Technology Data Exchange (ETDEWEB)

Gundel, Lara; Kirchstetter, Thomas; Spears, Michael; Sullivan, Douglas

2010-05-06

The Indoor Environment Department at Lawrence Berkeley National Laboratory (LBNL) teamed with seven universities to participate in a Federal Aviation Administration (FAA) Center of Excellence (COE) for research on environmental quality in aircraft. This report describes research performed at LBNL on selecting and evaluating sensors for monitoring environmental quality in aircraft cabins, as part of Project 7 of the FAA's COE for Airliner Cabin Environmental Research (ACER)1 effort. This part of Project 7 links to the ozone, pesticide, and incident projects for data collection and monitoring and is a component of a broader research effort on sensors by ACER. Results from UCB and LBNL's concurrent research on ozone (ACER Project 1) are found in Weschler et al., 2007; Bhangar et al. 2008; Coleman et al., 2008 and Strom-Tejsen et al., 2008. LBNL's research on pesticides (ACER Project 2) in airliner cabins is described in Maddalena and McKone (2008). This report focused on the sensors needed for normal contaminants and conditions in aircraft. The results are intended to complement and coordinate with results from other ACER members who concentrated primarily on (a) sensors for chemical and biological pollutants that might be released intentionally in aircraft; (b) integration of sensor systems; and (c) optimal location of sensors within aircraft. The parameters and sensors were selected primarily to satisfy routine monitoring needs for contaminants and conditions that commonly occur in aircraft. However, such sensor systems can also be incorporated into research programs on environmental quality in aircraft cabins.

Impact analysis of composite aircraft structures

Science.gov (United States)

Pifko, Allan B.; Kushner, Alan S.

1993-01-01

The impact analysis of composite aircraft structures is discussed. Topics discussed include: background remarks on aircraft crashworthiness; comments on modeling strategies for crashworthiness simulation; initial study of simulation of progressive failure of an aircraft component constructed of composite material; and research direction in composite characterization for impact analysis.

[Micron]ADS-B Detect and Avoid Flight Tests on Phantom 4 Unmanned Aircraft System

Science.gov (United States)

Arteaga, Ricardo; Dandachy, Mike; Truong, Hong; Aruljothi, Arun; Vedantam, Mihir; Epperson, Kraettli; McCartney, Reed

2018-01-01

Researchers at the National Aeronautics and Space Administration Armstrong Flight Research Center in Edwards, California and Vigilant Aerospace Systems collaborated for the flight-test demonstration of an Automatic Dependent Surveillance-Broadcast based collision avoidance technology on a small unmanned aircraft system equipped with the uAvionix Automatic Dependent Surveillance-Broadcast transponder. The purpose of the testing was to demonstrate that National Aeronautics and Space Administration / Vigilant software and algorithms, commercialized as the FlightHorizon UAS"TM", are compatible with uAvionix hardware systems and the DJI Phantom 4 small unmanned aircraft system. The testing and demonstrations were necessary for both parties to further develop and certify the technology in three key areas: flights beyond visual line of sight, collision avoidance, and autonomous operations. The National Aeronautics and Space Administration and Vigilant Aerospace Systems have developed and successfully flight-tested an Automatic Dependent Surveillance-Broadcast Detect and Avoid system on the Phantom 4 small unmanned aircraft system. The Automatic Dependent Surveillance-Broadcast Detect and Avoid system architecture is especially suited for small unmanned aircraft systems because it integrates: 1) miniaturized Automatic Dependent Surveillance-Broadcast hardware; 2) radio data-link communications; 3) software algorithms for real-time Automatic Dependent Surveillance-Broadcast data integration, conflict detection, and alerting; and 4) a synthetic vision display using a fully-integrated National Aeronautics and Space Administration geobrowser for three dimensional graphical representations for ownship and air traffic situational awareness. The flight-test objectives were to evaluate the performance of Automatic Dependent Surveillance-Broadcast Detect and Avoid collision avoidance technology as installed on two small unmanned aircraft systems. In December 2016, four flight tests

Skylon: An Example of Commercial Launcher System Development

Science.gov (United States)

Hempsell, M.; Bond, A.

SKYLON is a reusable single stage to orbit spaceplane that can take off from a runway, reach a 300 km altitude low earth orbit with a payload of 15 tonnes and then return to earth for a runway landing. The feature that enables this is the Synergistic AirBreathing Rocket Engine (SABRE) which has both air breathing and pure rocket modes. The project has been conceived as a commercial venture with the objective that the price charged for the launch, covers all operational and acquisition cost with profit. That means access to space becomes a pure economic activity without the need for public subsidy of the development or day to day running costs of the launch activity. A key way to achieve this objective is the separation of the supplier of the SKYLON system and the operator, following the model in the air transport industry where airliner manufacturers build aircraft that are then sold to many different competing airlines. This approach allows commercial development operations without any assumptions about growth in the market for space launches.

Assessing public exposure in commercial flights in Brazil

Energy Technology Data Exchange (ETDEWEB)

Alves, Vanusa A.; Rochedo, Elaine R.R.; Prado, Nadya M.P.D. [Instituto Militar de Engenharia, Pc. Gen. Tiburcio, 80, Praia Vermelha, Rio de Janeiro, 22290-270 RJ (Brazil); Wasserman, Maria Angelica V. [Instituto de Engenharia Nuclear, Cidade Universitaria, Ilha do Fundao, 21941-906, Rio de Janeiro RJ (Brazil)

2014-07-01

The exposure to cosmic radiation in aircraft travel is higher than at ground level and varies with the year, the latitude, the altitude of flight and the flight time. The aim of this work was to estimate the contribution of cosmic radiation exposure on commercial flights to the Brazilian population. A database, including about 4000 domestic flights was implemented in Excel spreadsheet. The computer program CARI-6, developed by the U.S. Federal Aviation Administration, was used to calculate doses received in each route. Individual effective doses for commercial flights within Brazil ranged from 0.3 to 8.8 μSv, with a total collective annual dose of 312 man Sv. This value is low, about 5 % of the collective dose estimated for domestic flights in US and about 20 % of the collective doses from all flights in UK. This work shall serve as a baseline for future comparisons of exposures due to the growth of civil aviation in the country and open discussions on the concept of risk and its public acceptance, which are relevant aspects for defining radiological protection guidelines. (authors)

8 CFR 1280.21 - Seizure of aircraft.

Science.gov (United States)

2010-01-01

... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Seizure of aircraft. 1280.21 Section 1280... REGULATIONS IMPOSITION AND COLLECTION OF FINES § 1280.21 Seizure of aircraft. Seizure of an aircraft under the... that its value is less than the amount of the fine which may be imposed. If seizure of an aircraft for...

8 CFR 280.21 - Seizure of aircraft.

Science.gov (United States)

2010-01-01

... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Seizure of aircraft. 280.21 Section 280.21... OF FINES § 280.21 Seizure of aircraft. Seizure of an aircraft under the authority of section 239 of... than the amount of the fine which may be imposed. If seizure of an aircraft for violation of section...

Application of the concept of dynamic trim control and nonlinear system inverses to automatic control of a vertical attitude takeoff and landing aircraft

Science.gov (United States)

Smith, G. A.; Meyer, G.

1981-01-01

A full envelope automatic flight control system based on nonlinear inverse systems concepts has been applied to a vertical attitude takeoff and landing (VATOL) fighter aircraft. A new method for using an airborne digital aircraft model to perform the inversion of a nonlinear aircraft model is presented together with the results of a simulation study of the nonlinear inverse system concept for the vertical-attitude hover mode. The system response to maneuver commands in the vertical attitude was found to be excellent; and recovery from large initial offsets and large disturbances was found to be very satisfactory.

GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS

Directory of Open Access Journals (Sweden)

Stanislav Vladimirovich Daletskiy

2017-01-01

Full Text Available The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is realized in Maintenance and Repair System which does not include maintenance organization and planning and is a set of related elements: aircraft, Maintenance and Repair measures, executors and documentation that sets rules of their interaction for maintaining of the aircraft reliability and readiness for flight. The aircraft organizational and technical states are considered, their characteristics and heuristic estimates of connection in knots and arcs of graphs and of aircraft organi- zational states during regular maintenance and at technical state failure are given. It is shown that in real conditions of air- craft maintenance, planned aircraft technical state control and maintenance control through it, is only defined by Mainte- nance and Repair conditions at a given Maintenance and Repair type and form structures, and correspondingly by setting principles of Maintenance and Repair work types to the execution, due to maintenance, by aircraft and all its units mainte- nance and reconstruction strategies. The realization of planned Maintenance and Repair process determines the one of the constant maintenance component. The proposed graphical models allow to reveal quantitative correlations between graph knots to improve maintenance processes by statistical research methods, what reduces manning, timetable and expenses for providing safe civil aviation aircraft maintenance.

Interactions of Aircraft Design and Control: Actuators Sizing and Optimization for an Unstable Blended Wing-Body

OpenAIRE

Denieul , Yann; Alazard , Daniel; Bordeneuve-Guibé , Joël; Toussaint , Clément; Taquin , Gilles

2015-01-01

International audience; In this paper the problem of integrated design and control for a civil blended wing-body aircraft is addressed. Indeed this configuration faces remarkable challenges relatedto handling qualities: namely the aircraft configuration in this study features a strong longitudinal instability for some specific flight points. Moreover it may lack control efficiency despite large and redundant movables. Stabilizing such a configuration may then lead to high control surfaces rat...

Principles for Aircraft Energy Mapping

OpenAIRE

Berg, Frederick T N

2013-01-01

An increasing emphasis on energy eciency in aircraft systems has in recentyears led to greater interest in integrated design and optimisation withinthe industry. New tools are needed to understand, compare and manage energyuse of an aircraft throughout its design and operation. This thesis describes a new methodology to meet this need: aircraft exergy mapping.The choice of exergy, a 2nd law metric, to describe the energy ows is fundamental to the methodology, providing numerous advantages ove...

NDT applications in the aircraft industry

International Nuclear Information System (INIS)

Aguilar, E.C.

1994-01-01

Non-destructive testing (NDT) in the aircraft industry is used primarily to detect process defects in the manufacturing stage and failure defects in the in-service stage. Inspection techniques such as X- or gamma ray radiography are used for examination. Eddy current and ultrasonic are applied for examination, fluorescent penetrant and magnetic particles are applied for examination of aircraft and engine. With the wide scope of application, this paper discussed one type of NDT that is much used in aircraft being the latest technique in aircraft manufacturing. 1 fig

Composite materials for aircraft structures

National Research Council Canada - National Science Library

Baker, A. A; Dutton, Stuart; Kelly, Donald

2004-01-01

... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...

Process component inventory in a large commercial reprocessing facility

International Nuclear Information System (INIS)

Canty, M.J.; Berliner, A.; Spannagel, G.

1983-01-01

Using a computer simulation program, the equilibrium operation of the Pu-extraction and purification processes of a reference commercial reprocessing facility was investigated. Particular attention was given to the long-term net fluctuations of Pu inventories in hard-to-measure components such as the solvent extraction contractors. Comparing the variance of these inventories with the measurement variance for Pu contained in feed, analysis and buffer tanks, it was concluded that direct or indirect periodic estimation of contactor inventories would not contribute significantly to improving the quality of closed material balances over the process MBA

Perseus A High Altitude Remotely Piloted Aircraft being Towed in Flight

Science.gov (United States)

1994-01-01

aircraft again crashed on Oct. 1, 1999, near Barstow, California, suffering moderate damage to the aircraft but no property damage, fire, or injuries in the area of the crash. Perseus B is flown remotely by a pilot from a mobile flight control station on the ground. A Global Positioning System (GPS) unit provides navigation data for continuous and precise location during flight. The ground control station features dual independent consoles for aircraft control and systems monitoring. A flight termination system, required for all remotely piloted aircraft being flown in military-restricted airspace, includes a parachute system deployed on command plus a C-Band radar beacon and a Mode-C transponder to aid in location. Dryden has provided hanger and office space for the Perseus B aircraft and for the flight test development team when on site for flight or ground testing. NASA's ERAST project is developing aeronautical technologies for a new generation of remotely piloted and autonomous aircraft for a variety of upper-atmospheric science missions and commercial applications. Dryden is the lead center in NASA for ERAST management and operations. Perseus B is approximately 25 feet long, has a wingspan of 71.5 feet, and stands 12 feet high. Perseus B is powered by a Rotax 914, four-cylinder piston engine mounted in the mid-fuselage area and integrated with an Aurora-designed three-stage turbocharger, connected to a lightweight two-blade propeller.

A Commercialization Roadmap for Carbon-Negative Energy Systems

Science.gov (United States)

Sanchez, D.

2016-12-01

The Intergovernmental Panel on Climate Change (IPCC) envisages the need for large-scale deployment of net-negative CO2 emissions technologies by mid-century to meet stringent climate mitigation goals and yield a net drawdown of atmospheric carbon. Yet there are few commercial deployments of BECCS outside of niche markets, creating uncertainty about commercialization pathways and sustainability impacts at scale. This uncertainty is exacerbated by the absence of a strong policy framework, such as high carbon prices and research coordination. Here, we propose a strategy for the potential commercial deployment of BECCS. This roadmap proceeds via three steps: 1) via capture and utilization of biogenic CO2 from existing bioenergy facilities, notably ethanol fermentation, 2) via thermochemical co-conversion of biomass and fossil fuels, particularly coal, and 3) via dedicated, large-scale BECCS. Although biochemical conversion is a proven first market for BECCS, this trajectory alone is unlikely to drive commercialization of BECCS at the gigatonne scale. In contrast to biochemical conversion, thermochemical conversion of coal and biomass enables large-scale production of fuels and electricity with a wide range of carbon intensities, process efficiencies and process scales. Aside from systems integration, primarily technical barriers are involved in large-scale biomass logistics, gasification and gas cleaning. Key uncertainties around large-scale BECCS deployment are not limited to commercialization pathways; rather, they include physical constraints on biomass cultivation or CO2 storage, as well as social barriers, including public acceptance of new technologies and conceptions of renewable and fossil energy, which co-conversion systems confound. Despite sustainability risks, this commercialization strategy presents a pathway where energy suppliers, manufacturers and governments could transition from laggards to leaders in climate change mitigation efforts.

Accounting and Tax Issues Concerning Commercial Discounts

Directory of Open Access Journals (Sweden)

Sava Raluca

2015-12-01

Full Text Available Commercial discounts accounting presents a particular importance because, on the one hand, of their widely spread on a large scale in the commercial activity and on the second hand, due to the influence of the accounting and reporting method over the value added tax. The paper theoretically addresses commercial reductions and also their reflection in the accounting according with the latest regulations in force.

Design definition study of a lift/cruise fan technology V/STOL aircraft. Volume 1: Navy operational aircraft

Science.gov (United States)

1975-01-01

Aircraft were designed and sized to meet Navy mission requirements. Five missions were established for evaluation: anti-submarine warfare (ASW), surface attack (SA), combat search and rescue (CSAR), surveillance (SURV), and vertical on-board delivery (VOD). All missions were performed with a short takeoff and a vertical landing. The aircraft were defined using existing J97-GE gas generators or reasonable growth derivatives in conjunction with turbotip fans reflecting LF460 type technology. The multipurpose aircraft configuration established for U.S. Navy missions utilizes the turbotip driven lift/cruise fan concept for V/STOL aircraft.

Unmanned aircraft systems in wildlife research: Current and future applications of a transformative technology

Science.gov (United States)

Christie, Katherine S.; Gilbert, Sophie L.; Brown, Casey L.; Hatfield, Michael; Hanson, Leanne

2016-01-01

Unmanned aircraft systems (UAS) – also called unmanned aerial vehicles (UAVs) or drones – are an emerging tool that may provide a safer, more cost-effective, and quieter alternative to traditional research methods. We review examples where UAS have been used to document wildlife abundance, behavior, and habitat, and illustrate the strengths and weaknesses of this technology with two case studies. We summarize research on behavioral responses of wildlife to UAS, and discuss the need to understand how recreational and commercial applications of this technology could disturb certain species. Currently, the widespread implementation of UAS by scientists is limited by flight range, regulatory frameworks, and a lack of validation. UAS are most effective when used to examine smaller areas close to their launch sites, whereas manned aircraft are recommended for surveying greater distances. The growing demand for UAS in research and industry is driving rapid regulatory and technological progress, which in turn will make them more accessible and effective as analytical tools.

Robustness of mission plans for unmanned aircraft

Science.gov (United States)

Niendorf, Moritz

This thesis studies the robustness of optimal mission plans for unmanned aircraft. Mission planning typically involves tactical planning and path planning. Tactical planning refers to task scheduling and in multi aircraft scenarios also includes establishing a communication topology. Path planning refers to computing a feasible and collision-free trajectory. For a prototypical mission planning problem, the traveling salesman problem on a weighted graph, the robustness of an optimal tour is analyzed with respect to changes to the edge costs. Specifically, the stability region of an optimal tour is obtained, i.e., the set of all edge cost perturbations for which that tour is optimal. The exact stability region of solutions to variants of the traveling salesman problems is obtained from a linear programming relaxation of an auxiliary problem. Edge cost tolerances and edge criticalities are derived from the stability region. For Euclidean traveling salesman problems, robustness with respect to perturbations to vertex locations is considered and safe radii and vertex criticalities are introduced. For weighted-sum multi-objective problems, stability regions with respect to changes in the objectives, weights, and simultaneous changes are given. Most critical weight perturbations are derived. Computing exact stability regions is intractable for large instances. Therefore, tractable approximations are desirable. The stability region of solutions to relaxations of the traveling salesman problem give under approximations and sets of tours give over approximations. The application of these results to the two-neighborhood and the minimum 1-tree relaxation are discussed. Bounds on edge cost tolerances and approximate criticalities are obtainable likewise. A minimum spanning tree is an optimal communication topology for minimizing the cumulative transmission power in multi aircraft missions. The stability region of a minimum spanning tree is given and tolerances, stability balls

Real-Time Risk Assessment Framework for Unmanned Aircraft System (UAS) Traffic Management (UTM)

Science.gov (United States)

Ancel, Ersin; Capristan, Francisco M.; Foster, John V.; Condotta, Ryan

2017-01-01

The new Federal Aviation Administration (FAA) Small Unmanned Aircraft rule (Part 107) marks the first national regulations for commercial operation of small unmanned aircraft systems (sUAS) under 55 pounds within the National Airspace System (NAS). Although sUAS flights may not be performed beyond visual line-of-sight or over non- participant structures and people, safety of sUAS operations must still be maintained and tracked at all times. Moreover, future safety-critical operation of sUAS (e.g., for package delivery) are already being conceived and tested. NASA's Unmanned Aircraft System Trac Management (UTM) concept aims to facilitate the safe use of low-altitude airspace for sUAS operations. This paper introduces the UTM Risk Assessment Framework (URAF) which was developed to provide real-time safety evaluation and tracking capability within the UTM concept. The URAF uses Bayesian Belief Networks (BBNs) to propagate off -nominal condition probabilities based on real-time component failure indicators. This information is then used to assess the risk to people on the ground by calculating the potential impact area and the effects of the impact. The visual representation of the expected area of impact and the nominal risk level can assist operators and controllers with dynamic trajectory planning and execution. The URAF was applied to a case study to illustrate the concept.

Hazards from aircraft

International Nuclear Information System (INIS)

Grund, J.E.; Hornyik, K.

1975-01-01

The siting of nuclear power plants has created innumerable environmental concerns. Among the effects of the ''man-made environment'' one of increasing importance in recent nuclear plant siting hazards analysis has been the concern about aircraft hazards to the nuclear plant. These hazards are of concern because of the possibility that an aircraft may have a malfunction and crash either near the plant or directly into it. Such a crash could be postulated to result, because of missile and/or fire effects, in radioactive releases which would endanger the public health and safety. The majority of studies related to hazards from air traffic have been concerned with the determination of the probability associated with an aircraft striking vulnerable portions of a given plant. Other studies have focused on the structural response to such a strike. This work focuses on the problem of strike probability. 13 references

Aircraft Carriers

DEFF Research Database (Denmark)

Nødskov, Kim; Kværnø, Ole

as their purchases of aircraft carrier systems, makes it more than likely that the country is preparing such an acquisition. China has territorial disputes in the South China Sea over the Spratly Islands and is also worried about the security of its sea lines of communications, by which China transports the majority......, submarines, aircraft and helicopters, is not likely to be fully operational and war-capable until 2020, given the fact that China is starting from a clean sheet of paper. The United States of America (USA), the United Kingdom (UK), Russia and India are currently building or have made decisions to build new...

FDS simulation of the fuel fireball from a hypothetical commercial airliner crash on a generic nuclear power plant

International Nuclear Information System (INIS)

Luther, W.; Mueller, C.; Zocher, O.

2008-01-01

Before September 11, 2001 nuclear installations were designed to withstand the impact of a typical aircraft fighter of that time. In the aftermath of 9/11 it became clear that any new NPP (Nuclear Power Plant) must be designed sufficiently robust against terrorist attack and that the impact of a fast flying commercial airliner hitting the NPP can no longer be excluded as a potential external hazard threatening the NPP safety. The lesson learnt from the WTC and Pentagon attack is that the impact of the aircraft and the onboard jet fuel can cause structural damage, a fireball and a consecutive fire. This paper deals with the simulation of the fireball and its consequence for the NPP safety. (orig.)

Small Transport Aircraft Technology /STAT/ Propulsion Study

Science.gov (United States)

Heldenbrand, R. W.; Baerst, C. F.; Rowse, J. H.

1980-01-01

The NASA Small Transport Aircraft Technology (STAT) Propulsion Study was established to identify technology requirements and define the research and development required for new commuter aircraft. Interim results of the studies defined mission and design characteristics for 30- and 50-passenger aircraft. Sensitivities were defined that relate changes in engine specific fuel consumption (SFC), weight, and cost (including maintenance) to changes in the aircraft direct operating cost (DOC), takeoff gross weight, and empty weight. A comparison of performance and economic characteristics is presented between aircraft powered by 1980 production engines and those powered by a 1990 advanced technology baseline engine.

X-36 Tailless Fighter Agility Research Aircraft on lakebed during high-speed taxi tests

Science.gov (United States)

1996-01-01

The NASA/McDonnell Douglas Corporation (MDC) X-36 Tailless Fighter Agility Research Aircraft undergoes high-speed taxi tests on Rogers Dry Lake at NASA Dryden Flight Research Center, Edwards, California, on October 17, 1996. The aircraft was tested at speeds up to 85 knots. Normal takeoff speed would be 110 knots. The NASA/Boeing X-36 Tailless Fighter Agility Research Aircraft program successfully demonstrated the tailless fighter design using advanced technologies to improve the maneuverability and survivability of possible future fighter aircraft. The program met or exceeded all project goals. For 31 flights during 1997 at the Dryden Flight Research Center, Edwards, California, the project team examined the aircraft's agility at low speed / high angles of attack and at high speed / low angles of attack. The aircraft's speed envelope reached up to 206 knots (234 mph). This aircraft was very stable and maneuverable. It handled very well. The X-36 vehicle was designed to fly without the traditional tail surfaces common on most aircraft. Instead, a canard forward of the wing was used as well as split ailerons and an advanced thrust-vectoring nozzle for directional control. The X-36 was unstable in both pitch and yaw axes, so an advanced, single-channel digital fly-by-wire control system (developed with some commercially available components) was put in place to stabilize the aircraft. Using a video camera mounted in the nose of the aircraft and an onboard microphone, the X-36 was remotely controlled by a pilot in a ground station virtual cockpit. A standard fighter-type head-up display (HUD) and a moving-map representation of the vehicle's position within the range in which it flew provided excellent situational awareness for the pilot. This pilot-in-the-loop approach eliminated the need for expensive and complex autonomous flight control systems and the risks associated with their inability to deal with unknown or unforeseen phenomena in flight. Fully fueled the X

Aircraft vulnerability analysis by modeling and simulation