WorldWideScience

Sample records for aircraft separation

  1. Probabilistic Modeling of Aircraft Trajectories for Dynamic Separation Volumes

    Science.gov (United States)

    Lewis, Timothy A.

    2016-01-01

    With a proliferation of new and unconventional vehicles and operations expected in the future, the ab initio airspace design will require new approaches to trajectory prediction for separation assurance and other air traffic management functions. This paper presents an approach to probabilistic modeling of the trajectory of an aircraft when its intent is unknown. The approach uses a set of feature functions to constrain a maximum entropy probability distribution based on a set of observed aircraft trajectories. This model can be used to sample new aircraft trajectories to form an ensemble reflecting the variability in an aircraft's intent. The model learning process ensures that the variability in this ensemble reflects the behavior observed in the original data set. Computational examples are presented.

  2. Time-Based Separation for Aircraft Landing Using Danger Value Distribution Flow Model

    Directory of Open Access Journals (Sweden)

    Ta-Chung Wang

    2012-01-01

    Full Text Available This study proposes a flow model using a modified Lighthill-Whitham-Richards highway model. The proposed model treats each aircraft on an airway as a continuous distribution of air collision probability, which is called the danger value distribution. With the proposed flow model, collision can be easily predicted by the peak value of the overlap of the danger value distribution of each aircraft. The study further proposes a velocity adjustment method that can be used to resolve the conflict. The proposed method can be applied for aircraft separation during the landing process, in which the separation time is different for different combinations of aircraft types.

  3. Aerodynamics of powered missile separation from F/A-18 aircraft

    Science.gov (United States)

    Ahmad, J. U.; Shanks, S. P.; Buning, P. G.

    1993-01-01

    A 3D dynamic 'chimera' algorithm that solves the thin-layer Navier-Stokes equations over multiple moving bodies was modified to numerically simulate the aerodynamics, missile dynamics, and missile plume interactions of a missile separating from a generic wing and from an F/A-18 aircraft in transonic flow. The missile is mounted below the wing for missile separation from the wing and on the F/A-18 fuselage at the engine inlet side for missile separation from aircraft. Static and powered missile separation cases are considered to examine the influence of the missile and plume on the wing and F/A-18 fuselage and engine inlet. The aircraft and missile are at two degrees angle of attack, Reynolds number of 10 million, freestream Mach number of 1.05 and plume Mach number of 3.0. The computational results show the details of the flow field.

  4. Prediction of flow separation from aircraft tails using a RSM turbulence model

    Science.gov (United States)

    Masi, Andrea; Benton, Jeremy; Tucker, Paul G.

    2014-11-01

    Enhancing engineers' capability to predict flow separation would generate important benefits in aircraft design. In this study the attention is focused on the vertical tail plane (VTP), which consists of a fixed part (the fin) and a moveable control surface (the rudder). For standard two-engine aircraft configurations, the size of the VTP is driven by the condition of loss of an engine during takeoff and low speed climb: in this condition the fin and the rudder have to be sufficient in size to balance the aircraft. Due to uncertainties in prediction of VTP effectiveness, aircraft designers keep to a conservative approach, risking specifying a larger size for the VTP than it is probably necessary. Uncertainties come from difficulties in predicting the separation of the flow from the surfaces of the aircraft using current CFD techniques, which are based on the use of RANS equations with eddy viscosity turbulence models. The CFD simulations presented in this study investigate the use of a RSM turbulence model with RANS and URANS. The introduction of a time-dependency gives benefits in the accuracy of the flow solution in presence of massive flow separation. This leads to the investigation of hybrid RANS/LES techniques with the aim of improving the solution of the detached flow. EU FP7 project ANADE (Grant Agreement Number 289428).

  5. Aircraft

    Science.gov (United States)

    Hibbs, Bart D.; Lissaman, Peter B. S.; Morgan, Walter R.; Radkey, Robert L.

    1998-01-01

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gasses for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well.

  6. A new measurement method for separating airborne and structureborne noise radiated by aircraft type panels

    Science.gov (United States)

    Mcgary, M. C.

    1982-01-01

    The theoretical basis for and experimental validation of a measurement method for separating airborne and structure borne noise radiated by aircraft type panels are presented. An extension of the two microphone, cross spectral, acoustic intensity method combined with existing theory of sound radiation of thin shell structures of various designs, is restricted to the frequency range below the coincidence frequency of the structure. Consequently, the method lends itself to low frequency noise problems such as propeller harmonics. Both an aluminum sheet and two built up aircraft panel designs (two aluminum panels with frames and stringers) with and without added damping were measured. Results indicate that the method is quick, reliable, inexpensive, and can be applied to thin shell structures of various designs.

  7. Aircraft deconfliction responsibility across en-route sectors in NextGen separation assurance

    Science.gov (United States)

    Cabrall, Christopher D.

    The subject of the current research is a Next Generation Air Transportation System (NextGen) concept that involves automated separation assurance developed to enable controllers to provide both safe and efficient air traffic services at much higher traffic densities than possible today. The study investigated the issue of how responsibility should be handled between controllers for the resolution of a conflict that is predicted to occur in a sector other than where it was detected. Two possibilities, a De-Conflicting AirPlanes procedure (DCAP) versus a De-Conflicting AirSpace procedure (DCAS), were examined under human-in-the-loop simulations with scripted aircraft conflicts. Results showed that the DCAS procedure was preferred and that participants experienced less verbal coordination and took less time to resolve conflicts. The results, however, did not reveal significant differences among other plane performance metrics between DCAP and DCAS. These results indicate that the demands of NextGen separation assurance might still be met with ownership and coordination procedures (e.g., DCAP) similar to today. Reducing verbal coordination requirements, however, and allowing separation assurance responsibilities to extend more seamlessly across sector boundaries (e.g., DCAS) would evidently be more acceptable to controllers.

  8. The Two-Phase Flow Separator Experiment Breadboard Model: Reduced Gravity Aircraft Results

    Science.gov (United States)

    Rame, E; Sharp, L. M.; Chahine, G.; Kamotani, Y.; Gotti, D.; Owens, J.; Gilkey, K.; Pham, N.

    2015-01-01

    Life support systems in space depend on the ability to effectively separate gas from liquid. Passive cyclonic phase separators use the centripetal acceleration of a rotating gas-liquid mixture to carry out phase separation. The gas migrates to the center, while gas-free liquid may be withdrawn from one of the end plates. We have designed, constructed and tested a breadboard that accommodates the test sections of two independent principal investigators and satisfies their respective requirements, including flow rates, pressure and video diagnostics. The breadboard was flown in the NASA low-gravity airplane in order to test the system performance and design under reduced gravity conditions.

  9. Unmanned Aircraft Systems Human-in-the-Loop Controller and Pilot Acceptability Study: Collision Avoidance, Self-Separation, and Alerting Times (CASSAT)

    Science.gov (United States)

    Comstock, James R., Jr.; Ghatas, Rania W.; Vincent, Michael J.; Consiglio, Maria C.; Munoz, Cesar; Chamberlain, James P.; Volk, Paul; Arthur, Keith E.

    2016-01-01

    The Federal Aviation Administration (FAA) has been mandated by the Congressional funding bill of 2012 to open the National Airspace System (NAS) to Unmanned Aircraft Systems (UAS). With the growing use of unmanned systems, NASA has established a multi-center "UAS Integration in the NAS" Project, in collaboration with the FAA and industry, and is guiding its research efforts to look at and examine crucial safety concerns regarding the integration of UAS into the NAS. Key research efforts are addressing requirements for detect-and-avoid (DAA), self-separation (SS), and collision avoidance (CA) technologies. In one of a series of human-in-the-loop experiments, NASA Langley Research Center set up a study known as Collision Avoidance, Self-Separation, and Alerting Times (CASSAT). The first phase assessed active air traffic controller interactions with DAA systems and the second phase examined reactions to the DAA system and displays by UAS Pilots at a simulated ground control station (GCS). Analyses of the test results from Phase I and Phase II are presented in this paper. Results from the CASSAT study and previous human-in-the-loop experiments will play a crucial role in the FAA's establishment of rules, regulations, and procedures to safely, efficiently, and effectively integrate UAS into the NAS.

  10. 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 ...

  11. Separation of airborne and structureborne noise radiated by plates constructed of conventional and composite materials with applications for prediction of interior noise paths in propeller driven aircraft. Ph.D. Thesis

    Science.gov (United States)

    Mcgary, M. C.

    1986-01-01

    The anticipated application of advanced turboprop propulsion systems and use of composite materials in primary structure is expected to increase the interior noise of future aircraft to unacceptability high levels. The absence of technically and economically feasible noise source-path diagnostic tools has been a primer obstacle in the development of efficient noise control treatments for propeller driven aircraft. A new diagnostic method which permits the separation and prediction of the fully coherent airborne and structureborne components of the sound radiated by plates or thin shells has been developed. Analytical and experimental studies of the proposed method were performed on plates constructed of both conventional and composite materials. The results of the study indicate that the proposed method can be applied to a variety of aircraft materials, could be used in flight, and has fewer encumbrances than the other diagnostic tools currently available. The study has also revealed that the noise radiation of vibrating plates in the low frequency regime due to combined airborne and structureborne inputs possesses a strong synergistic nature. The large influence of the interaction between the airborne and structureborne terms has been hitherto ignored by researchers of aircraft interior noise problems.

  12. The effect of viewing time, time to encounter, and practice on perception of aircraft separation on a cockpit display of traffic information

    Science.gov (United States)

    Oconnor, S.; Palmer, E. A.; Baty, D.; Jago, S.

    1980-01-01

    The concept of a cockpit display of traffic information (CDTI) includes the integration of air traffic, navigation, and other pertinent information in a single electronic display in the cockpit. Two studies were conducted to develop a clear and concise display format for use in later full-mission simulator evaluations of the CDTI concept. Subjects were required to monitor a CDTI for specified periods of time and to make perceptual judgments concerning the future position of a single intruder aircraft in relationship to their own aircraft. Experimental variables included: type of predictor information displayed on the two aircraft symbols; time to encounter point; length of time subjects viewed the display; amount of practice; and type of encounter (straight or turning). Results show that length of viewing time had little or no effect on performance; time to encounter influenced performance with the straight predictor but did not with the curved predictor; and that learning occurred under all conditions.

  13. Effect of display update interval, update type, and background on perception of aircraft separation on a cockpit display on traffic information

    Science.gov (United States)

    Jago, S.; Baty, D.; Oconnor, S.; Palmer, E.

    1981-01-01

    The concept of a cockpit display of traffic information (CDTI) includes the integration of air traffic, navigation, and other pertinent information in a single electronic display in the cockpit. Concise display symbology was developed for use in later full-mission simulator evaluations of the CDTI concept. Experimental variables used included the update interval motion of the aircraft, the update type, (that is, whether the two aircraft were updated at the same update interval or not), the background (grid pattern or no background), and encounter type (straight or curved). Only the type of encounter affected performance.

  14. Amphibious Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — A brief self composed research article on Amphibious Aircrafts discussing their use, origin and modern day applications along with their advantages and...

  15. Aircraft Data Acquisition

    Directory of Open Access Journals (Sweden)

    Elena BALMUS

    2016-03-01

    Full Text Available The introduction of digital systems instead of analog ones has created a major separation in the aviation technology. Although the digital equipment made possible that the increasingly faster controllers take over, we should say that the real world remains essentially analogue [4]. Fly-by-wire designers attempting to control and measure the real feedback of an aircraft were forced to find a way to connect the analogue environment to their digital equipment. In order to manage the implications of this division in aviation, data optimization and comparison has been quite an important task. The interest in using data acquisition boards is being driven by the technology and design standards in the new generation of aircraft and the ongoing efforts of reducing weight and, in some cases addressing the safety risks. This paper presents a sum of technical report data from post processing and diversification of data acquisition from Arinc 429 interface on a research aircraft platform. Arinc 429 is by far the most common data bus in use on civil transport aircraft, regional jets and executive business jets today. Since its introduction on the Boeing 757/767 and Airbus aircraft in the early 1980s hardly any aircraft has been produced without the use of this data bus. It was used widely by the air transport indu

  16. Aircraft Noise

    Science.gov (United States)

    Michel, Ulf; Dobrzynski, Werner; Splettstoesser, Wolf; Delfs, Jan; Isermann, Ullrich; Obermeier, Frank

    Aircraft industry is exposed to increasing public pressure aiming at a continuing reduction of aircraft noise levels. This is necessary to both compensate for the detrimental effect on noise of the expected increase in air traffic and improve the quality of living in residential areas around airports.

  17. Aircraft Design

    Science.gov (United States)

    Bowers, Albion H. (Inventor); Uden, Edward (Inventor)

    2016-01-01

    The present invention is an aircraft wing design that creates a bell shaped span load, which results in a negative induced drag (induced thrust) on the outer portion of the wing; such a design obviates the need for rudder control of an aircraft.

  18. Phenomenological aspects of quasi-stationary controlled and uncontrolled three-dimensional flow separations. [in relation to aircraft design considerations and swept wings

    Science.gov (United States)

    Peake, D. J.

    1978-01-01

    Quasi-steady three dimensional separated flows about bodies of large fineness ratio operating at large angles of incidence or yaw are discussed. The general character of the three dimensional attached boundary layer, the concept of limiting streamlines, and the physics of three dimensional separation and reattachment are among the factors considered. Specific examples are given. The advantages of swept, sharp edges that generate controlled (or fixed) three dimensional flow separations on a vehicle, due to the qualitatively unchanging flow field developed throughout the range of flight conditions, are emphasized.

  19. Aircraft cybernetics

    Science.gov (United States)

    1977-01-01

    The use of computers for aircraft control, flight simulation, and inertial navigation is explored. The man-machine relation problem in aviation is addressed. Simple and self-adapting autopilots are described and the assets and liabilities of digital navigation techniques are assessed.

  20. Method and device for landing aircraft dependent on runway occupancy time

    Science.gov (United States)

    Ghalebsaz Jeddi, Babak (Inventor)

    2012-01-01

    A technique for landing aircraft using an aircraft landing accident avoidance device is disclosed. The technique includes determining at least two probability distribution functions; determining a safe lower limit on a separation between a lead aircraft and a trail aircraft on a glide slope to the runway; determining a maximum sustainable safe attempt-to-land rate on the runway based on the safe lower limit and the probability distribution functions; directing the trail aircraft to enter the glide slope with a target separation from the lead aircraft corresponding to the maximum sustainable safe attempt-to-land rate; while the trail aircraft is in the glide slope, determining an actual separation between the lead aircraft and the trail aircraft; and directing the trail aircraft to execute a go-around maneuver if the actual separation approaches the safe lower limit. Probability distribution functions include runway occupancy time, and landing time interval and/or inter-arrival distance.

  1. APPLICATION FOR AIRCRAFT TRACKING

    OpenAIRE

    Ostroumov, Ivan; Kuz’menko, Natalia

    2011-01-01

    Abstract. In the article the important problems of software development for aircraft tracking have beendiscussed. Position reports of ACARS have been used for aircraft tracking around the world.An algorithm of aircraft coordinates decoding and visualization of aircraft position on the map has beenrepresented.Keywords: ACARS, aircraft, internet, position, software, tracking.

  2. Flight Control Design for a Tailless Aircraft Using Eigenstructure Assignment

    OpenAIRE

    Clara Nieto-Wire; Kenneth Sobel

    2011-01-01

    We apply eigenstructure assignment to the design of a flight control system for a wind tunnel model of a tailless aircraft. The aircraft, known as the innovative control effectors (ICEs) aircraft, has unconventional control surfaces plus pitch and yaw thrust vectoring. We linearize the aircraft in straight and level flight at an altitude of 15,000 feet and Mach number 0.4. Then, we separately design flight control systems for the longitudinal and lateral dynamics. We use a control allocation ...

  3. 微型涡流发生器控制增升装置流动分离研究%Controlling Flow Separation of High Lift Transport Aircraft with Micro Vortex Generators

    Institute of Scientific and Technical Information of China (English)

    褚胡冰; 张彬乾; 陈迎春; 李亚林

    2011-01-01

    针对大型飞机增升装置大偏度状态出现的流动分离问题,采用数值模拟方法,研究使用微型涡流发生器控制其附面层分离的作用机理及流动控制效果.结合风洞实验结果,验证了数值方法的可靠性,并以某型号运输机二维增升构型为对象,系统分析了微型涡流发生器尺寸、安装角、安装位置、排列方式等参数对其流动控制效能的影响规律,获得了设计原则,给出了流动控制方案,为实现三维增升装置流动分离控制的微型涡流发生器研究奠定了基础.%The operating mechanism and the influences of parameters of micro vortex generators in controlling flow separation of high lift transport aircraft are investigated in this paper. Section 1 of the full paper explores the operating mechanism. After researching with computational fluid dynamics the influences of a series of parameters including size (subsection 3. 1) , fixing angle (subsection 3.2), fixing position ( subsection 3. 3) and fixing way ( subsection 3.4) , we obtain the design principles as follows; (1) the principle of controlling flow separation is to inject vortices to the bottom of boundary layer; (2) as the fixing angle decides vortex strength and drag, it has to be chosen properly; (3) vortex generators should be fixed before separation point but as close to it as possible; (4 ) counter-rotating vortex generators have better control efficiency than co-rotating vortex generators. Based on these principles, subsection 3.5 offers a control scheme to improve the lift performance of a 4-element airfoil; ( 1) Fig. 11 shows that we successfully eliminate the flap separation of take-off and landing configurations at angle of 0° ~ 14°; (2) atot =8°, Sf= 25°, the lift is increased by 14%, L/D increased by 30% (Fig. 12); (3) at a = 10°,5/ = 50°, the lift is increased by 24% , L/D increased by 34% (Fig. 12) ; (4) micro vortex generators cannot improve stall characteristics because the flow

  4. Exploratory flight investigation of aircraft response to the wing vortex wake generated by the augmentor wing jet STOL research aircraft

    Science.gov (United States)

    Jacobsen, R. A.; Drinkwater, F. J., III

    1975-01-01

    A brief exploratory flight program was conducted at Ames Research Center to investigate the vortex wake hazard of a powered-lift STOL aircraft. The study was made by flying an instrumented Cessna 210 aircraft into the wake of the augmentor wing jet STOL research aircraft at separation distances from 1 to 4 n.mi. Characteristics of the wake were evaluated in terms of the magnitude of the upset of the probing aircraft. Results indicated that within 1 n.mi. separation the wake could cause rolling moments in excess of roll control power and yawing moments equivalent to rudder control power of the probe aircraft. Subjective evaluations by the pilots of the Cessna 210 aircraft, supported by response measurements, indicated that the upset caused by the wake of the STOL aircraft was comparable to that of a DC-9 in the landing configuration.

  5. Aircraft type influence on contrail properties

    Directory of Open Access Journals (Sweden)

    P. Jeßberger

    2013-05-01

    Full Text Available The investigation of the impact of aircraft parameters on contrail properties helps to better understand the climate impact from aviation. Yet, in observations, it is a challenge to separate aircraft and meteorological influences on contrail formation. During the CONCERT campaign in November 2008, contrails from 3 Airbus passenger aircraft of type A319-111, A340-311 and A380-841 were probed at cruise under similar meteorological conditions with in-situ instruments on board the DLR research aircraft Falcon. Within the 2 min old contrails detected near ice saturation, we find similar effective diameters Deff (5.2–5.9 μm, but differences in particle number densities nice (162–235 cm−3 and in vertical contrail extensions (120–290 m, resulting in large differences in contrail optical depths τ (0.25–0.94. Hence larger aircraft produce optically thicker contrails. Based on the observations, we apply the EULAG-LCM model with explicit ice microphysics and in addition the Contrail and Cirrus Prediction model CoCiP to calculate the aircraft type impact on young contrails under identical meteorological conditions. The observed increase in τ for heavier aircraft is confirmed by the models, yet for generally smaller τ. An aircraft dependence of climate relevant contrail properties persists during contrail lifetime, adding importance to aircraft dependent model initialization. We finally derive an analytical relationship between contrail, aircraft and meteorological parameters. Near ice saturation, contrail width × τ scales linearly with fuel flow rate as confirmed by observations. For higher saturation ratios approximations from theory suggest a non-linear increase in the form (RHI–12/3. Summarized our combined results could help to more accurately assess the climate impact from aviation using an aircraft dependent contrail parameterization.

  6. Active structural acoustic control of aircraft interior flow noise via the use of active trim panels

    OpenAIRE

    Mahnken, Brian W.

    1996-01-01

    Modem jet aircraft interior noise can be categorized into two main types: tonal noise caused by engine imbalance or blade passage, and mid frequency broadband noise resulting from turbulent flow. This project addresses aircraft interior flow noise caused by a flow separation over the crown of the aircraft. The noise control approach is to mount piezoelectric actuators to the aircraft interior cockpit crown trim panel and use them to actively control aircraft interior noise with...

  7. 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.

  8. Designing A Conventional Aircraft

    OpenAIRE

    Sonei, Arash

    2014-01-01

    This paper is explaining the important design phases of dimensioning an unmanned conventional aircraft from scratch and will also design one according to a few chosen requirements. The design phases discussed will be all from wing dimensioning to stability and spin recovery, aircraft performance requirements and how to select a motor which overcomes these. As well as the optimal rate of climb for improved efficiency is discussed. In the end an aircraft which manages the set requirements and i...

  9. Lightning effects on aircraft

    Science.gov (United States)

    1977-01-01

    Direct and indirect effects of lightning on aircraft were examined in relation to aircraft design. Specific trends in design leading to more frequent lightning strikes were individually investigated. These trends included the increasing use of miniaturized, solid state components in aircraft electronics and electric power systems. A second trend studied was the increasing use of reinforced plastics and other nonconducting materials in place of aluminum skins, a practice that reduces the electromagnetic shielding furnished by a conductive skin.

  10. Cable Tensiometer for Aircraft

    Science.gov (United States)

    Nunnelee, Mark (Inventor)

    2008-01-01

    The invention is a cable tensiometer that can be used on aircraft for real-time, in-flight cable tension measurements. The invention can be used on any aircraft cables with high precision. The invention is extremely light-weight, hangs on the cable being tested and uses a dual bending beam design with a high mill-volt output to determine tension.

  11. 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.

  12. 边界层分离点实时数据采集与处理系统的设计与实现%Real Time Signal Collection and Processing System for Detecting Boundary Layer Separation Point of Micro-Aircraft

    Institute of Scientific and Technical Information of China (English)

    丁英涛; 李博; 王竹萍; 仲顺安

    2011-01-01

    通过分析实时数据采集与处理的基本原理和系统构架,搭建了适用于微型飞行器边界层分离点检测的实时信号采集与处理系统.该系统主要由模拟低通滤波电路、模数转换电路(ADC)、场可编程门阵列(FPGA)控制电路及USB接口电路构成.测试结果为:基准电平0.1mV,峰峰值407 mV,频率1 kHz,满足边界层分离点实时检测和判定的要求.%The accurate detection of the boundary layer separation point in real time has a great benefit to improve micro-aircraft's climb, maneuvering and pneumatic abilities. By analyzing the principle and framework of real time data collecting and processing system, a real time signal collecting and processing system, which could be applied to detect the boundary layer separation point of micro-aircrafts, has been proposed and developed. The system mainly consists of analog low-pass filter, analog to digital converter (ADC), FPGA controlling circuits and USB interface circuits. The testing results show that the performance of developed system is good, which is well suitable for detecting and estimating the boundary layer separation point in real time.

  13. 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 ...

  14. Aircraft Fire Protection Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Navy Aircraft Protection Laboratory provides complete test support for all Navy air vehicle fire protection systems. The facility allows for the simulation of a...

  15. 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.

  16. 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.

  17. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-01-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

  18. AEROSTATIC AND AERODYNAMIC MODULES OF A HYBRID BUOYANT AIRCRAFT: AN ANALYTICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Anwar Ul Haque

    2015-05-01

    Full Text Available An analytical approach is essential for the estimation of the requirements of aerodynamic and aerostatic lift for a hybrid buoyant aircraft. Such aircrafts have two different modules to balance the weight of aircraft; aerostatic module and aerodynamic module. Both these modules are to be treated separately for estimation of the mass budget of propulsion systems and required power. In the present work, existing relationships of aircraft and airship are reviewed for its further application for these modules. Limitations of such relationships are also disussed and it is precieved that it will provide a strating point for better understanding of design anatomy of such aircraft.

  19. Research on Data Distribution Service for Aircraft Collaborative Design System

    Directory of Open Access Journals (Sweden)

    Huaxing Bian

    2014-01-01

    Full Text Available Aircraft designing is a complex, multi-disciplinary process, while the applications are separated from each other due to their particular design and analysis tools. The separated applications are unable to meet the collaborative designing requirements. One of the fundamental problems in Aircraft Collaborative Design System is that how to make each subsystem collaborate. The known solutions, using Existing middlewares to unify data formats, are not reliable due to the tightly coupled architecture, poor portability and reusability, large update latency, etc. To solve this problem, the paper propose that apply DDS into Aircraft Collaborative Design System, and give the solution that how to use open source projects OpenDDS in Aircraft Collaborative Design System.

  20. Weighted Marginal Fisher Analysis with Spatially Smooth for aircraft recognition

    OpenAIRE

    Wei Zhenzhong; Liu Chang; Li Nan

    2014-01-01

    Due to limitations to extract invariant features for recognition when the aircraft presents various poses and lacks enough samples for training, a novel algorithm called Weighted Marginal Fisher Analysis with Spatially Smooth (WMFA-SS) for extracting invariant features in aircraft recognition is proposed. According to the Graph Embedding (GE) framework, Heat Kernel function is firstly introduced to characterize the interclass separability when choosing the weights of penalty graph. Furthermor...

  1. IDENTIFICATION OF AIRCRAFT HAZARDS

    International Nuclear Information System (INIS)

    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)

  2. Aircraft Operations Classification System

    Science.gov (United States)

    Harlow, Charles; Zhu, Weihong

    2001-01-01

    Accurate data is important in the aviation planning process. In this project we consider systems for measuring aircraft activity at airports. This would include determining the type of aircraft such as jet, helicopter, single engine, and multiengine propeller. Some of the issues involved in deploying technologies for monitoring aircraft operations are cost, reliability, and accuracy. In addition, the system must be field portable and acceptable at airports. A comparison of technologies was conducted and it was decided that an aircraft monitoring system should be based upon acoustic technology. A multimedia relational database was established for the study. The information contained in the database consists of airport information, runway information, acoustic records, photographic records, a description of the event (takeoff, landing), aircraft type, and environmental information. We extracted features from the time signal and the frequency content of the signal. A multi-layer feed-forward neural network was chosen as the classifier. Training and testing results were obtained. We were able to obtain classification results of over 90 percent for training and testing for takeoff events.

  3. Identification of Aircraft Hazards

    International Nuclear Information System (INIS)

    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)

  4. IDENTIFICATION OF AIRCRAFT HAZARDS

    Energy Technology Data Exchange (ETDEWEB)

    K.L. Ashley

    2005-03-23

    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).

  5. 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).

  6. Advanced Aircraft Material

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Prince

    2013-06-01

    Full Text Available There has been long debate on “advanced aircraft material” from past decades & researchers too came out with lots of new advanced material like composites and different aluminum alloys. Now days a new advancement that is in great talk is third generation Aluminum-lithium alloy. Newest Aluminum-lithium alloys are found out to have low density, higher elastic modulus, greater stiffness, greater cryogenic toughness, high resistance to fatigue cracking and improved corrosion resistance properties over the earlier used aircraft material as mentioned in Table 3 [1-5]. Comparison had been made with nowadays used composite material and is found out to be more superior then that

  7. Auralization of novel aircraft configurations

    OpenAIRE

    Arntzen, M.; Bertsch, E.L.; Simons, D.G.

    2015-01-01

    A joint initiative of NLR, DLR, and TU Delft has been initiated to streamline the process of generating audible impressions of novel aircraft configurations. The integrated approach adds to the value of the individual tools and allows predicting the sound of future aircraft before they actually fly. Hence, an existing process for the aircraft design and system noise prediction at DLR has been upgraded to generate the required input data for an aircraft auralization framework developed by NLR ...

  8. Aircraft noise prediction

    Science.gov (United States)

    Filippone, Antonio

    2014-07-01

    This contribution addresses the state-of-the-art in the field of aircraft noise prediction, simulation and minimisation. The point of view taken in this context is that of comprehensive models that couple the various aircraft systems with the acoustic sources, the propagation and the flight trajectories. After an exhaustive review of the present predictive technologies in the relevant fields (airframe, propulsion, propagation, aircraft operations, trajectory optimisation), the paper addresses items for further research and development. Examples are shown for several airplanes, including the Airbus A319-100 (CFM engines), the Bombardier Dash8-Q400 (PW150 engines, Dowty R408 propellers) and the Boeing B737-800 (CFM engines). Predictions are done with the flight mechanics code FLIGHT. The transfer function between flight mechanics and the noise prediction is discussed in some details, along with the numerical procedures for validation and verification. Some code-to-code comparisons are shown. It is contended that the field of aircraft noise prediction has not yet reached a sufficient level of maturity. In particular, some parametric effects cannot be investigated, issues of accuracy are not currently addressed, and validation standards are still lacking.

  9. Robots for Aircraft Maintenance

    Science.gov (United States)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  10. Ultracapacitor separator

    Science.gov (United States)

    Wei, Chang; Jerabek, Elihu Calvin; LeBlanc, Jr., Oliver Harris

    2001-03-06

    An ultracapacitor includes two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. The electrolyte is a polar aprotic organic solvent and a salt. The porous separator comprises a wet laid cellulosic material.

  11. Braking performance of aircraft tires

    Science.gov (United States)

    Agrawal, Satish K.

    This paper brings under one cover the subject of aircraft braking performance and a variety of related phenomena that lead to aircraft hydroplaning, overruns, and loss of directional control. Complex processes involving tire deformation, tire slipping, and fluid pressures in the tire-runway contact area develop the friction forces for retarding the aircraft; this paper describes the physics of these processes. The paper reviews the past and present research efforts and concludes that the most effective way to combat the hazards associated with aircraft landings and takeoffs on contaminated runways is by measuring and displaying in realtime the braking performance parameters in the aircraft cockpit.

  12. 19 CFR 10.183 - Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components...

    Science.gov (United States)

    2010-04-01

    ... Duty-free entry of civil aircraft, aircraft engines, ground flight simulators, parts, components, and... aircraft, aircraft engines, and ground flight simulators, including their parts, components, and... United States (HTSUS) by meeting the following requirements: (1) The aircraft, aircraft engines,...

  13. Mission management aircraft operations manual

    Science.gov (United States)

    1992-01-01

    This manual prescribes the NASA mission management aircraft program and provides policies and criteria for the safe and economical operation, maintenance, and inspection of NASA mission management aircraft. The operation of NASA mission management aircraft is based on the concept that safety has the highest priority. Operations involving unwarranted risks will not be tolerated. NASA mission management aircraft will be designated by the Associate Administrator for Management Systems and Facilities. NASA mission management aircraft are public aircraft as defined by the Federal Aviation Act of 1958. Maintenance standards, as a minimum, will meet those required for retention of Federal Aviation Administration (FAA) airworthiness certification. Federal Aviation Regulation Part 91, Subparts A and B, will apply except when requirements of this manual are more restrictive.

  14. Ozone-Initiated Chemistry in an Occupied Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Wisthaler, Armin; Cowlin, Shannon;

    2007-01-01

    We have used multiple analytical methods to characterize the gas-phase products formed when ozone was added to cabin air during simulated 4-hour flights that were conducted in a reconstructed section of a B-767 aircraft containing human occupants. Two separate groups of 16 females were each exposed...

  15. Pilot and Controller Evaluations of Separation Function Allocation in Air Traffic Management

    Science.gov (United States)

    Wing, David; Prevot, Thomas; Morey, Susan; Lewis, Timothy; Martin, Lynne; Johnson, Sally; Cabrall, Christopher; Como, Sean; Homola, Jeffrey; Sheth-Chandra, Manasi; Mercer, Joey

    2013-01-01

    Two human-in-the-loop simulation experiments were conducted in coordinated fashion to investigate the allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). Ground-based separation was provided by air traffic controllers without automation tools, with tools, or by ground-based automation with controllers in a managing role. Airborne self-separation was provided by airline pilots using self-separation automation enabled by airborne surveillance technology. The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations, assuming the starting point of current-day operations and modeling an emergence of NextGen technologies and procedures. In the controller-focused experiment, the impact of mixed operations on controller performance was assessed at four stages of NextGen implementation. In the pilot-focused experiment, the limits to which pilots with automation tools could take full responsibility for separation from ground-controlled aircraft were tested. Results indicate that the presence of self-separating aircraft had little impact on the controllers' ability to provide separation services for ground-controlled aircraft. Overall performance was best in the most automated environment in which all aircraft were data communications equipped, ground-based separation was highly automated, and self-separating aircraft had access to trajectory intent information for all aircraft. In this environment, safe, efficient, and highly acceptable operations could be achieved for twice today's peak airspace throughput. In less automated environments, reduced trajectory intent exchange and manual air traffic control limited the safely achievable airspace throughput and

  16. A Performance Assessment of a Tactical Airborne Separation Assistance System using Realistic, Complex Traffic Flows

    Science.gov (United States)

    Smith, Jeremy C.; Neitzke, Kurt W.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of aspects of an Airborne Separation Assistance System (ASAS) under varying demand levels using realistic traffic patterns. This study only addresses the tactical aspects of an ASAS using aircraft state data (latitude, longitude, altitude, heading and speed) to detect and resolve projected conflicts. The main focus of this paper is to determine the extent to which sole reliance on the proposed tactical ASAS can maintain aircraft separation at demand levels up to three times current traffic. The effect of mixing ASAS equipped aircraft with non-equipped aircraft that do not have the capability to self-separate is also investigated.

  17. 19 CFR 122.64 - Other aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Other aircraft. 122.64 Section 122.64 Customs... AIR COMMERCE REGULATIONS Clearance of Aircraft and Permission To Depart § 122.64 Other aircraft. Clearance or permission to depart shall be requested by the aircraft commander or agent for aircraft...

  18. Guidance Systems of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    K.N. Rajanikanth

    2005-07-01

    Full Text Available Mission performance of a fighter aircraft is crucial for survival and strike capabilities in todays' aerial warfare scenario. The guidance functions of such an aircraft play a vital role inmeeting the requirements and accomplishing the mission success. This paper presents the requirements of precision guidance for various missions of a fighter aircraft. The concept ofguidance system as a pilot-in-loop system is pivotal in understanding and designing such a system. Methodologies of designing such a system are described.

  19. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  20. Hydrogen aircraft technology

    Science.gov (United States)

    Brewer, G. D.

    1991-01-01

    A comprehensive evaluation is conducted of the technology development status, economics, commercial feasibility, and infrastructural requirements of LH2-fueled aircraft, with additional consideration of hydrogen production, liquefaction, and cryostorage methods. Attention is given to the effects of LH2 fuel cryotank accommodation on the configurations of prospective commercial transports and military airlifters, SSTs, and HSTs, as well as to the use of the plentiful heatsink capacity of LH2 for innovative propulsion cycles' performance maximization. State-of-the-art materials and structural design principles for integral cryotank implementation are noted, as are airport requirements and safety and environmental considerations.

  1. Structural integrity in aircraft.

    Science.gov (United States)

    Hardrath, H. F.

    1973-01-01

    The paper reviews briefly the current design philosophies for achieving long, efficient, and reliable service in aircraft structures. The strengths and weaknesses of these design philosophies and their demonstrated records of success are discussed. The state of the art has not been developed to the point where designing can be done without major test inspection and maintenance programs. A broad program of research is proposed through which a viable computerized design scheme will be provided during the next decade. The program will organize and correlate existing knowledge on fatigue and fracture behavior, identify gaps in this knowledge, and guide specific research to upgrade design capabilities.

  2. Radial cylinder aircraft engines

    OpenAIRE

    Šimíček, Petr

    2015-01-01

    Práce je zaměřena na konstrukční řešení letadlových hvězdicových motorů. Úvod je pojednáním o historii letadlových hvězdicových motorů a jejich vývoji v historickém kontextu. Druhá část je zaměřena na konstrukci letadlových hvězdicových motorů, následně jsou uvedena některá zajímavá konstrukční řešení a porovnání s motorem jiného druhu konstrukce. The bachelor's thesis is focused on design of aircraft radial engines. Home is a treatise on the history of aircraft radial engines and their de...

  3. Aircraft landing using GPS

    Science.gov (United States)

    Lawrence, David Gary

    The advent of the Global Positioning System (GPS) is revolutionizing the field of navigation. Commercial aviation has been particularly influenced by this worldwide navigation system. From ground vehicle guidance to aircraft landing applications, GPS has the potential to impact many areas of aviation. GPS is already being used for non-precision approach guidance; current research focuses on its application to more critical regimes of flight. To this end, the following contributions were made: (1) Development of algorithms and a flexible software architecture capable of providing real-time position solutions accurate to the centimeter level with high integrity. This architecture was used to demonstrate 110 automatic landings of a Boeing 737. (2) Assessment of the navigation performance provided by two GPS-based landing systems developed at Stanford, the Integrity Beacon Landing System, and the Wide Area Augmentation System. (3) Preliminary evaluation of proposed enhancements to traditional techniques for GPS positioning, specifically, dual antenna positioning and pseudolite augmentation. (4) Introduction of a new concept for positioning using airport pseudolites. The results of this research are promising, showing that GPS-based systems can potentially meet even the stringent requirements of a Category III (zero visibility) landing system. Although technical and logistical hurdles still exist, it is likely that GPS will soon provide aircraft guidance in all phases of flight, including automatic landing, roll-out, and taxi.

  4. Aviation industry-research in aircraft finance

    OpenAIRE

    Ehrenthal, Joachim C.F.

    2010-01-01

    Aircraft values are key to aircraft financing decisions: Aircraft values act as a source of security for providers of debt capital and lessors failing to re-place aircraft, and as a source of upside potential to equity investors. Yet, aircraft values cannot be precisely and continuously monitored. This is because neither actual primary nor secondary aircraft transaction prices are disclosed. Various types of third party valuation estimates exist, but relying solely on third party appraisa...

  5. MISSILES AND AIRCRAFT (PART1

    Directory of Open Access Journals (Sweden)

    C.M. Meyer

    2012-02-01

    Full Text Available Many sources maintain that the role played by air power in the 1973 Yom Kippur War was important. Other interpretations state that control of air space over the battlefield areas, (either by aircraft or anti-aircraft defences, was vital.

  6. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  7. Aircraft radar antennas

    Science.gov (United States)

    Schrank, Helmut E.

    1987-04-01

    Many changes have taken place in airborne radar antennas since their beginnings over forty years ago. A brief historical review of the advances in technology is presented, from mechanically scanned reflectors to modern multiple function phased arrays. However, emphasis is not on history but on the state-of-the-art technology and trends for future airborne radar systems. The status of rotating surveillance antennas is illustrated by the AN/APY-1 Airborne Warning and Control System (AWACS) slotted waveguide array, which achieved a significant breakthrough in sidelobe suppression. Gimballed flat plate arrays in nose radomes are typified by the AN/APG-66 (F-16) antenna. Multifunction phased arrays are presented by the Electronically Agile Radar (EAR) antenna, which has achieved significant advances in performance versatility and reliability. Trends toward active aperture, adaptive, and digital beamforming arrays are briefly discussed. Antennas for future aircraft radar systems must provide multiple functions in less aperture space, and must perform more reliably.

  8. 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,...

  9. 76 FR 45011 - Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test...

    Science.gov (United States)

    2011-07-27

    ... from Aircraft and Aircraft Engines; Emission Standards and Test Procedures;'' Final Rule, 62 FR 25356... From Aircraft and Aircraft Engines; Proposed Emission Standards and Test Procedures; Proposed Rule #0... and Aircraft Engines; Proposed Emission Standards and Test Procedures AGENCY: Environmental...

  10. Separations chemistry

    International Nuclear Information System (INIS)

    Results of studies on the photochemistry of aqueous Pu solutions and the stability of iodine in liquid and gaseous CO2 are reported. Progress is reported in studies on: the preparation of macroporous bodies filled with oxides and sulfides to be used as adsorbents; the beneficiation of photographic wastes; the anion exchange adsorption of transition elements from thiosulfate solutions; advanced filtration applications of energy significance; high-resolution separations; and, the examination of the separation agents, octylphenylphosphoric acid (OPPA) and trihexyl phosphate (THP)

  11. Product separator

    Science.gov (United States)

    Welsh, Robert A.; Deurbrouck, Albert W.

    1976-01-20

    A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.

  12. 36 CFR 331.14 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 331.14 Section 331..., KENTUCKY AND INDIANA § 331.14 Aircraft. (a) The operation of aircraft on WCA lands and waters is prohibited... prohibited. (c) The provisions of this section shall not be applicable to aircraft engaged on...

  13. 48 CFR 246.408-71 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Aircraft. 246.408-71... Aircraft. (a) The Federal Aviation Administration (FAA) has certain responsibilities and prerogatives in connection with some commercial aircraft and of aircraft equipment and accessories (Pub. L. 85-726 (72...

  14. 36 CFR 327.4 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 327.4 Section 327.4... Aircraft. (a) This section pertains to all aircraft including, but not limited to, airplanes, seaplanes, helicopters, ultra-light aircraft, motorized hang gliders, hot air balloons, any non-powered flight devices...

  15. 14 CFR 141.39 - Aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft. 141.39 Section 141.39 Aeronautics... CERTIFICATED AGENCIES PILOT SCHOOLS Personnel, Aircraft, and Facilities Requirements § 141.39 Aircraft. (a... certificate or provisional pilot school certificate must show that each aircraft used by the school for...

  16. 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 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES General Provisions § 87.6 Aircraft safety. The provisions...

  17. 14 CFR 43.7 - Persons authorized to approve aircraft, airframes, aircraft engines, propellers, appliances, or...

    Science.gov (United States)

    2010-01-01

    ..., airframes, aircraft engines, propellers, appliances, or component parts for return to service after..., REBUILDING, AND ALTERATION § 43.7 Persons authorized to approve aircraft, airframes, aircraft engines... Administrator, may approve an aircraft, airframe, aircraft engine, propeller, appliance, or component part...

  18. 78 FR 54385 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Science.gov (United States)

    2013-09-04

    ... Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration... directive (AD) for various aircraft equipped with Rotax Aircraft Engines 912 A Series Engine. This AD...; phone: +43 7246 601 0; fax: +43 7246 601 9130; Internet: http://www.rotax-aircraft-engines.com . You...

  19. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Science.gov (United States)

    2010-01-01

    ... 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... provisions of §§ 21.183(c), 21.184(b), or 21.185(c); and (2) New aircraft engines or propellers...

  20. Western Pacific Typhoon Aircraft Fixes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Western Pacific typhoon aircraft reconnaissance data from the years 1946 - 1965 and 1978, excluding 1952, were transcribed from original documents, or copy of...

  1. Aircraft recognition and tracking device

    Science.gov (United States)

    Filis, Dimitrios P.; Renios, Christos I.

    2011-11-01

    The technology of aircraft recognition and tracking has various applications in all areas of air navigation, be they civil or military, spanning from air traffic control and regulation at civilian airports to anti-aircraft weapon handling and guidance for military purposes.1, 18 The system presented in this thesis is an alternative implementation of identifying and tracking flying objects, which benefits from the optical spectrum by using an optical camera built into a servo motor (pan-tilt unit). More specifically, through the purpose-developed software, when a target (aircraft) enters the field of view of the camera18, it is both detected and identified.5, 22 Then the servo motor, being provided with data on target position and velocity, tracks the aircraft while it is in constant communication with the camera (Fig. 1). All the features are so designed as to operate under real time conditions.

  2. VTOL to Transonic Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The cyclogyro, an aircraft propulsion concept with the potential for VTOL to the lower bounds of transonic flight, is conceptually simple but structurally and...

  3. Electromagnetic Interference In New Aircraft

    Science.gov (United States)

    Larsen, William E.

    1991-01-01

    Report reviews plans to develop tests and standards to ensure that digital avionics systems in new civil aircraft immune to electromagnetic interference (EMI). Updated standards reflect more severe environment and vulnerabilities of modern avionics.

  4. Alloy design for aircraft engines

    Science.gov (United States)

    Pollock, Tresa M.

    2016-08-01

    Metallic materials are fundamental to advanced aircraft engines. While perceived as mature, emerging computational, experimental and processing innovations are expanding the scope for discovery and implementation of new metallic materials for future generations of advanced propulsion systems.

  5. Challenges in Aircraft Noise Prediction

    OpenAIRE

    Filippone A

    2014-01-01

    This contribution addresses the problem of aircraft noise prediction using theoretical methods. The problem is set in context with the needs at several levels to produce noise characterisation from commercial aircraft powered by gas turbine engines. We describe very briefly the computational model (whilst referring the reader to the appropriate literature), and provide examples of noise predictions and comparisons with measured data, where possible. We focus on the issue of stochastic analysi...

  6. Neural networks for aircraft control

    Science.gov (United States)

    Linse, Dennis

    1990-01-01

    Current research in Artificial Neural Networks indicates that networks offer some potential advantages in adaptation and fault tolerance. This research is directed at determining the possible applicability of neural networks to aircraft control. The first application will be to aircraft trim. Neural network node characteristics, network topology and operation, neural network learning and example histories using neighboring optimal control with a neural net are discussed.

  7. Optimization in fractional aircraft ownership

    Science.gov (United States)

    Septiani, R. D.; Pasaribu, H. M.; Soewono, E.; Fayalita, R. A.

    2012-05-01

    Fractional Aircraft Ownership is a new concept in flight ownership management system where each individual or corporation may own a fraction of an aircraft. In this system, the owners have privilege to schedule their flight according to their needs. Fractional management companies (FMC) manages all aspects of aircraft operations, including utilization of FMC's aircraft in combination of outsourced aircrafts. This gives the owners the right to enjoy the benefits of private aviations. However, FMC may have complicated business requirements that neither commercial airlines nor charter airlines faces. Here, optimization models are constructed to minimize the number of aircrafts in order to maximize the profit and to minimize the daily operating cost. In this paper, three kinds of demand scenarios are made to represent different flight operations from different types of fractional owners. The problems are formulated as an optimization of profit and a daily operational cost to find the optimum flight assignments satisfying the weekly and daily demand respectively from the owners. Numerical results are obtained by Genetic Algorithm method.

  8. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  9. Parabolic aircraft solidification experiments

    Science.gov (United States)

    Workman, Gary L. (Principal Investigator); Smith, Guy A.; OBrien, Susan

    1996-01-01

    A number of solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental environment which minimizes variables in solidification experiments. Two techniques of interest are directional solidification and isothermal casting. Because of the wide-spread use of these experimental techniques in space-based research, several MSAD experiments have been manifested for space flight. In addition to the microstructural analysis for interpretation of the experimental results from previous work with parabolic flights, it has become apparent that a better understanding of the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible. Our university has performed in several experimental studies such as this in recent years. The most recent was in visualizing the effect of convective flow phenomena on the KC-135 and prior to that were several successive contracts to perform directional solidification and isothermal casting experiments on the KC-135. Included in this work was the modification and utilization of the Convective Flow Analyzer (CFA), the Aircraft Isothermal Casting Furnace (ICF), and the Three-Zone Directional Solidification Furnace. These studies have contributed heavily to the mission of the Microgravity Science and Applications' Materials Science Program.

  10. Process analysis of the modelled 3-D mesoscale impact of aircraft emissions on the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Hendricks, J.; Ebel, A.; Lippert, E.; Petry, H. [Koeln Univ. (Germany). Inst. fuer Geophysik und Meterorologie

    1997-12-31

    A mesoscale chemistry transport model is applied to study the impact of aircraft emissions on the atmospheric trace gas composition. A special analysis of the simulations is conducted to separate the effects of chemistry, transport, diffusion and cloud processes on the transformation of the exhausts of a subsonic fleet cruising over the North Atlantic. The aircraft induced ozone production strongly depends on the tropopause height and the cruise altitude. Aircraft emissions may undergo an effective downward transport under the influence of stratosphere-troposphere exchange activity. (author) 12 refs.

  11. 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.

  12. GPS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  13. HRS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  14. Component Separations

    OpenAIRE

    Heller, Lior; McNichols, Colton H.; Ramirez, Oscar M.

    2012-01-01

    Component separation is a technique used to provide adequate coverage for midline abdominal wall defects such as a large ventral hernia. This surgical technique is based on subcutaneous lateral dissection, fasciotomy lateral to the rectus abdominis muscle, and dissection on the plane between external and internal oblique muscles with medial advancement of the block that includes the rectus muscle and its fascia. This release allows for medial advancement of the fascia and closure of up to 20-...

  15. Component separations.

    Science.gov (United States)

    Heller, Lior; McNichols, Colton H; Ramirez, Oscar M

    2012-02-01

    Component separation is a technique used to provide adequate coverage for midline abdominal wall defects such as a large ventral hernia. This surgical technique is based on subcutaneous lateral dissection, fasciotomy lateral to the rectus abdominis muscle, and dissection on the plane between external and internal oblique muscles with medial advancement of the block that includes the rectus muscle and its fascia. This release allows for medial advancement of the fascia and closure of up to 20-cm wide defects in the midline area. Since its original description, components separation technique underwent multiple modifications with the ultimate goal to decrease the morbidity associated with the traditional procedure. The extensive subcutaneous lateral dissection had been associated with ischemia of the midline skin edges, wound dehiscence, infection, and seroma. Although the current trend is to proceed with minimally invasive component separation and to reinforce the fascia with mesh, the basic principles of the techniques as described by Ramirez et al in 1990 have not changed over the years. Surgeons who deal with the management of abdominal wall defects are highly encouraged to include this technique in their collection of treatment options. PMID:23372455

  16. Analysis of aircraft maintenance models

    Directory of Open Access Journals (Sweden)

    Vlada S. Sokolović

    2011-10-01

    Full Text Available This paper addressed several organizational models of aircraft maintenance. All models presented so far have been in use in Air Forces, so that the advantages and disadvantages of different models are known. First it shows the current model of aircraft maintenance as well as its basic characteristics. Then the paper discusses two organizational models of aircraft maintenance with their advantages and disadvantages. The advantages and disadvantages of different models are analyzed based on the criteria of operational capabilities of military units. In addition to operational capabilities, the paper presents some other criteria which should be taken into account in the evaluation and selection of an optimal model of aircraft maintenance. Performing a qualitative analysis of some models may not be sufficient for evaluating the optimum choice for models of maintenance referring to the selected set of criteria from the scope of operational capabilities. In order to choose the optimum model, it is necessary to conduct a detailed economic and technical analysis of individual tactical model maintenance. A high-quality aircraft maintenance organization requires the highest state and army authorities to be involved. It is necessary to set clear objectives for all the elements of modern air force technical support programs based on the given evaluation criteria.

  17. Wind Information Uplink to Aircraft Performing Interval Management Operations

    Science.gov (United States)

    Ahmad, Nashat N.; Barmore, Bryan E.; Swieringa, Kurt A.

    2016-01-01

    Interval Management (IM) is an ADS-B-enabled suite of applications that use ground and flight deck capabilities and procedures designed to support the relative spacing of aircraft (Barmore et al., 2004, Murdoch et al. 2009, Barmore 2009, Swieringa et al. 2011; Weitz et al. 2012). Relative spacing refers to managing the position of one aircraft to a time or distance relative to another aircraft, as opposed to a static reference point such as a point over the ground or clock time. This results in improved inter-aircraft spacing precision and is expected to allow aircraft to be spaced closer to the applicable separation standard than current operations. Consequently, if the reduced spacing is used in scheduling, IM can reduce the time interval between the first and last aircraft in an overall arrival flow, resulting in increased throughput. Because IM relies on speed changes to achieve precise spacing, it can reduce costly, low-altitude, vectoring, which increases both efficiency and throughput in capacity-constrained airspace without negatively impacting controller workload and task complexity. This is expected to increase overall system efficiency. The Flight Deck Interval Management (FIM) equipment provides speeds to the flight crew that will deliver them to the achieve-by point at the controller-specified time, i.e., assigned spacing goal, after the target aircraft crosses the achieve-by point (Figure 1.1). Since the IM and target aircraft may not be on the same arrival procedure, the FIM equipment predicts the estimated times of arrival (ETA) for both the IM and target aircraft to the achieve-by point. This involves generating an approximate four-dimensional trajectory for each aircraft. The accuracy of the wind data used to generate those trajectories is critical to the success of the IM operation. There are two main forms of uncertainty in the wind information used by the FIM equipment. The first is the accuracy of the forecast modeling done by the weather

  18. Modeling aircraft noise induced sleep disturbance

    Science.gov (United States)

    McGuire, Sarah M.

    occurrence of rapid eye movements, sleep spindles, and slow wave sleep. Using these features an approach for classifying sleep stages every one second during the night was developed. From observation of the results of the sleep stage classification, it was determined how to add faster dynamics to the nonlinear dynamic model. Slow and fast REM activity are modeled separately and the activity in the gamma frequency band of the EEG signal is used to model both spontaneous and noise-induced awakenings. The nonlinear model predicts changes in sleep structure similar to those found by other researchers and reported in the sleep literature and similar to those found in obtained survey data. To compare sleep disturbance model predictions, flight operations data from US airports were obtained and sleep disturbance in communities was predicted for different operations scenarios using the modified Markov model, the nonlinear dynamic model, and other aircraft noise awakening models. Similarities and differences in model predictions were evaluated in order to determine if the use of the developed sleep structure model leads to improved predictions of the impact of nighttime noise on communities.

  19. MATE. Multi Aircraft Training Environment

    DEFF Research Database (Denmark)

    Hauland, G.; Bove, T.; Andersen, Henning Boje;

    2002-01-01

    in the MATE prototype was compared with the effects of traditional training that included the use of realaircraft. The experimental group (EXP) trained the pre-start checklist and the engine start checklist for the Saab 340 commuter aircraft in a MATE prototype. The control group (CTR) trained the same...... procedures using the aircraft (a/c) for training the prestart and a desktop computer tool (power plant trainer) for training engine starts. Performance on the pre-start checklist was compared in a formal checkout that took place in the a/c. Performance on the engine start procedure was compared......A medium fidelity and low cost training device for pilots, called the Multi Aircraft Training Environment (MATE), is developed to replace other low fidelity stand-alone training devices and integrate them into a flexible environment, primarily aimed attraining pilots in checklist procedures...

  20. Vision assisted aircraft lateral navigation

    Science.gov (United States)

    Mohideen, Mohamed Ibrahim; Ramegowda, Dinesh; Seiler, Peter

    2013-05-01

    Surface operation is currently one of the least technologically equipped phases of aircraft operation. The increased air traffic congestion necessitates more aircraft operations in degraded weather and at night. The traditional surface procedures worked well in most cases as airport surfaces have not been congested and airport layouts were less complex. Despite the best efforts of FAA and other safety agencies, runway incursions continue to occur frequently due to incorrect surface operation. Several studies conducted by FAA suggest that pilot induced error contributes significantly to runway incursions. Further, the report attributes pilot's lack of situational awareness - local (e.g., minimizing lateral deviation), global (e.g., traffic in the vicinity) and route (e.g., distance to next turn) - to the problem. An Enhanced Vision System (EVS) is one concept that is being considered to resolve these issues. These systems use on-board sensors to provide situational awareness under poor visibility conditions. In this paper, we propose the use of an Image processing based system to estimate the aircraft position and orientation relative to taxiway markings to use as lateral guidance aid. We estimate aircraft yaw angle and lateral offset from slope of the taxiway centerline and horizontal position of vanishing line. Unlike automotive applications, several cues such as aircraft maneuvers along assigned route with minimal deviations, clear ground markings, even taxiway surface, limited aircraft speed are available and enable us to implement significant algorithm optimizations. We present experimental results to show high precision navigation accuracy with sensitivity analysis with respect to camera mount, optics, and image processing error.

  1. Magnetic separator

    OpenAIRE

    Křupka, Jiří

    2015-01-01

    Cílem bakalářské práce je návrh konstrukčního řešení magnetického separátoru určeného k separaci drobného průmyslového odpadu. Tato zpráva obsahuje přehled zařízení světových výrobců, která slouží k magnetické separaci ocelového odpadu. Dále pak posouzení variant technických řešení konstrukčních uzlů magnetického separátoru a následný výběr konkrétního řešení. Dle vstupních parametrů jsou vypočteny všechny parametry potřebné ke správnému návrhu stroje. Ve výpočtech jsou zahrnuty i odůvodnění ...

  2. 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

  3. Introduction to unmanned aircraft systems

    CERN Document Server

    Marshall, Douglas M; Hottman, Stephen B; Shappee, Eric; Most, Michael Thomas

    2011-01-01

    Introduction to Unmanned Aircraft Systems is the editors' response to their unsuccessful search for suitable university-level textbooks on this subject. A collection of contributions from top experts, this book applies the depth of their expertise to identify and survey the fundamentals of unmanned aircraft system (UAS) operations. Written from a nonengineering civilian operational perspective, the book starts by detailing the history of UASs and then explores current technology and what is expected for the future. Covering all facets of UAS elements and operation-including an examination of s

  4. Composite components on commercial aircraft

    Science.gov (United States)

    Dexter, H. B.

    1980-01-01

    The paper considers the use of composite components in commercial aircraft. NASA has been active in sponsoring flight service programs with advanced composites for the last 10 years, with 2.5 million total composite component hours accumulated since 1970 on commercial transports and helicopters with no significant degradation in residual strength of composite components. Design, inspection, and maintenance procedures have been developed; a major NASA/US industry technology program has been developed to reduce fuel consumption of commercial transport aircraft through the use of advanced composites.

  5. Versatile Electric Propulsion Aircraft Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An all-electric aircraft testbed is proposed to provide a dedicated development environment for the rigorous study and advancement of electrically powered aircraft....

  6. 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

  7. 75 FR 28504 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Science.gov (United States)

    2010-05-21

    ... Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal... 912 A series engine installed in various aircraft does not have an engine type certificate; instead, the engine is part of the aircraft type design. You may obtain further information by examining...

  8. 77 FR 1626 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Science.gov (United States)

    2012-01-11

    ... Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration (FAA), DOT... various aircraft equipped with Rotax Aircraft Engines 912 A series engine. This AD results from mandatory... Rotax Aircraft Engines BRP has issued Alert Service Bulletin ASB- 912-059 and ASB-914-042...

  9. 76 FR 31465 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Science.gov (United States)

    2011-06-01

    ... Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration...://www.rotax-aircraft-engines.com . You may review copies of the referenced service information at the... by examining the MCAI in the AD docket. Relevant Service Information Rotax Aircraft Engines...

  10. Residents' Annoyance Responses to Aircraft Noise Events

    OpenAIRE

    United States, National Aeronautics and Space Administration

    1983-01-01

    In a study conducted in the vicinity of Salt Lake City International Airport, community residents reported their annoyance with individual aircraft flyovers during rating sessions conducted in their homes. Annoyance ratings were obtained at different times of the day. Aircraft noise levels were measured, and other characteristics of the aircraft were noted by trained observers. Metrics commonly used for assessing aircraft noise were compared, but none performed significantly better than A-...

  11. The NASA Aircraft Energy Efficiency program

    Science.gov (United States)

    Klineberg, J. M.

    1979-01-01

    A review is provided of the goals, objectives, and recent progress in each of six aircraft energy efficiency programs aimed at improved propulsive, aerodynamic and structural efficiency for future transport aircraft. Attention is given to engine component improvement, an energy efficient turbofan engine, advanced turboprops, revolutionary gains in aerodynamic efficiency for aircraft of the late 1990s, laminar flow control, and composite primary aircraft structures.

  12. System for determination of separation minima

    OpenAIRE

    Carranca, Mário Rui Silva

    2011-01-01

    In the current paradigm of Air Navigation, in which the increase in airspace density is accompanies by an increase in number and complexity of available Surveillance infrastructures, it becomes imperative to optimize all resources in order to continue to provide excellent services in Air Traffic Control. For this to happen, the separation between aircraft must be kept at a minimum, whilst still abiding by the worldwide security requirements that make us all feel safer on board an airpla...

  13. Policy and the evaluation of aircraft noise

    NARCIS (Netherlands)

    Kroesen, M.; Molin, E.J.E.; Van Wee, G.P.

    2010-01-01

    In this paper, we hypothesize and test the ideas that (1) people’s subjectivity in relation to aircraft noise is shaped by the policy discourse, (2) this results in a limited number of frames towards aircraft noise, (3) the frames inform people how to think and feel about aircraft noise and (4) the

  14. 19 CFR 122.37 - Precleared aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Precleared aircraft. 122.37 Section 122.37 Customs... AIR COMMERCE REGULATIONS Landing Requirements § 122.37 Precleared aircraft. (a) Application. This section applies when aircraft carrying crew, passengers and baggage, or merchandise which has...

  15. 14 CFR 252.13 - Small aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Small aircraft. 252.13 Section 252.13 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.13 Small aircraft. Air carriers shall prohibit smoking on...

  16. 43 CFR 423.41 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Aircraft. 423.41 Section 423.41 Public... Aircraft. (a) You must comply with any applicable Federal, State, and local laws, and with any additional... this part 423, with respect to aircraft landings, takeoffs, and operation on or in the proximity...

  17. 14 CFR 21.127 - Tests: aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft. 21.127 Section 21.127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate Only § 21.127 Tests: aircraft. (a)...

  18. 50 CFR 27.34 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Aircraft. 27.34 Section 27.34 Wildlife and... WILDLIFE REFUGE SYSTEM PROHIBITED ACTS Disturbing Violations: With Vehicles § 27.34 Aircraft. The unauthorized operation of aircraft, including sail planes, and hang gliders, at altitudes resulting...

  19. 36 CFR 13.1004 - Aircraft use.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Aircraft use. 13.1004 Section... § 13.1004 Aircraft use. In extraordinary cases where no reasonable alternative exists, local rural residents who permanently reside in the following exempted community(ies) may use aircraft for access...

  20. 48 CFR 908.7102 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Special Items 908.7102 Aircraft. Acquisition of aircraft shall be in accordance with DOE-PMR 41 CFR 109-38.5205. ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Aircraft. 908.7102...

  1. 47 CFR 32.2113 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Aircraft. 32.2113 Section 32.2113... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2113 Aircraft. This account shall include the original cost of aircraft and any associated equipment and furnishings...

  2. 14 CFR 91.117 - Aircraft speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft speed. 91.117 Section 91.117... speed. (a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10... than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed....

  3. Fiber optic hardware for transport aircraft

    Science.gov (United States)

    White, John A.

    1994-10-01

    Aircraft manufacturers are developing fiber optic technology to exploit the benefits in system performance and manufacturing cost reduction. The fiber optic systems have high bandwidths and exceptional Electromagnetic Interference immunity that exceeds all new aircraft design requirements. Additionally, aircraft manufacturers have shown production readiness of fiber optic systems and design feasibility.

  4. HUMAN FACTOR IMPACT IN MILITARY AIRCRAFT MAINTENANCE

    OpenAIRE

    MARINKOVIC SRBOLJUB J.; DRENOVAC ALEKSANDAR Z.

    2015-01-01

    Aircraft maintenance, as a specific field of military materiel maintenance, is characterized by high reliability standards, based on regulations and technical standards. A system approach to maintenance represents the key element of maintenance quality, while aircraft maintenance staff has a crucial influence on the final outcome of aircraft maintenance.

  5. Human Response to Aircraft Noise

    NARCIS (Netherlands)

    Kroesen, M.

    2011-01-01

    How can it be that one person is extremely annoyed by the sounds of aircrafts, while his neighbour claims not to be bothered at all? The present thesis attempts to explain this observation by applying a range of quantitative methods to field data gathered among residents living near large airports.

  6. Aircraft Simulators and Pilot Training.

    Science.gov (United States)

    Caro, Paul W.

    Flight simulators are built as realistically as possible, presumably to enhance their training value. Yet, their training value is determined by the way they are used. Traditionally, simulators have been less important for training than have aircraft, but they are currently emerging as primary pilot training vehicles. This new emphasis is an…

  7. Aircraft Lightning Electromagnetic Environment Measurement

    Science.gov (United States)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

    2011-01-01

    This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

  8. Survival analysis of aging aircraft

    Science.gov (United States)

    Benavides, Samuel

    This study pushes systems engineering of aging aircraft beyond the boundaries of empirical and deterministic modeling by making a sharp break with the traditional laboratory-derived corrosion prediction algorithms that have shrouded real-world failures of aircraft structure. At the heart of this problem is the aeronautical industry's inability to be forthcoming in an accurate model that predicts corrosion failures in aircraft in spite of advances in corrosion algorithms or improvements in simulation and modeling. The struggle to develop accurate corrosion probabilistic models stems from a multitude of real-world interacting variables that synergistically influence corrosion in convoluted and complex ways. This dissertation, in essence, offers a statistical framework for the analysis of structural airframe corrosion failure by utilizing real-world data while considering the effects of interacting corrosion variables. This study injects realism into corrosion failures of aging aircraft systems by accomplishing four major goals related to the conceptual and methodological framework of corrosion modeling. First, this work connects corrosion modeling from the traditional, laboratory derived algorithms to corrosion failures in actual operating aircraft. This work augments physics-based modeling by examining the many confounding and interacting variables, such as environmental, geographical and operational, that impact failure of airframe structure. Examined through the lens of censored failure data from aircraft flying in a maritime environment, this study enhances the understanding between the triad of the theoretical, laboratory and real-world corrosion. Secondly, this study explores the importation and successful application of an advanced biomedical statistical tool---survival analysis---to model censored corrosion failure data. This well-grounded statistical methodology is inverted from a methodology that analyzes survival to one that examines failures. Third, this

  9. Laser Powered Aircraft Takes Flight

    Science.gov (United States)

    2003-01-01

    A team of NASA researchers from Marshall Space Flight Center (MSFC) and Dryden Flight Research center have proven that beamed light can be used to power an aircraft, a first-in-the-world accomplishment to the best of their knowledge. Using an experimental custom built radio-controlled model aircraft, the team has demonstrated a system that beams enough light energy from the ground to power the propeller of an aircraft and sustain it in flight. Special photovoltaic arrays on the plane, similar to solar cells, receive the light energy and convert it to electric current to drive the propeller motor. In a series of indoor flights this week at MSFC, a lightweight custom built laser beam was aimed at the airplane `s solar panels. The laser tracks the plane, maintaining power on its cells until the end of the flight when the laser is turned off and the airplane glides to a landing. The laser source demonstration represents the capability to beam more power to a plane so that it can reach higher altitudes and have a greater flight range without having to carry fuel or batteries, enabling an indefinite flight time. The demonstration was a collaborative effort between the Dryden Center at Edward's, California, where the aircraft was designed and built, and MSFC, where integration and testing of the laser and photovoltaic cells was done. Laser power beaming is a promising technology for consideration in new aircraft design and operation, and supports NASA's goals in the development of revolutionary aerospace technologies. Photographed with their invention are (from left to right): David Bushman and Tony Frackowiak, both of Dryden; and MSFC's Robert Burdine.

  10. Factors influencing aircraft ground handling performance

    Science.gov (United States)

    Yager, T. J.

    1983-01-01

    Problems associated with aircraft ground handling operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from tests with instrumented ground vehicles and aircraft, and aircraft wet runway accident investigation are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

  11. Erosion Testing of Coatings for V-22 Aircraft Applications

    Directory of Open Access Journals (Sweden)

    G. Y. Richardson

    2003-01-01

    Full Text Available High-velocity (183 m/sec sand erosion tests in a wind tunnel were conducted to evaluate developmental coatings from three separate companies under funding by the Navy's phase I small business innovative research program. The purpose of the coatings was to address a particular problem the V-22 tilt-rotor aircraft (Osprey was having with regard to ingestion of sand particles by a titanium impeller that was associated with the aircraft's environmental control system. The three coatings that were deposited on titanium substrates and erosion-tested included (1 SixCy/DLC multilayers deposited by chemical vapor deposition (CVD; (2 WC/TaC/TiC processed by electrospark deposition; and (3 polymer ceramic mixtures applied by means of an aqueous synthesis. The erosion test results are presented; they provided the basis for assessing the suitability of some of these coatings for the intended application.

  12. Predictions of F-111 TACT aircraft buffet response

    Science.gov (United States)

    Cunningham, Atlee M., Jr.; Coe, Charles F.

    1990-01-01

    A summary is presented for the prediction method development and correlations of predicted response with flight test measurements. The prediction method was based on refinements to the method described by Cunningham. One improvement made use of direct time integration of the correlated fluctuating pressure data to obtain buffet excitation for the various modes of interest. Another improvement incorporated a hybrid technique for scaling measured wind tunnel damping data to full-scale for the modes of interest. A third improvement made use of the diagonalized form of the fully coupled equations of motion. Finally, a mechanism was described for explaining an apparent coupling between the aircraft wing torsion modes and shock induced trailing edge separation that led to very high wing motion on the aircraft that was not observed on the wind tunnel model.

  13. Aircraft noise and birth weight

    Energy Technology Data Exchange (ETDEWEB)

    Knipschild, P.; Meijer, H.; Salle, H.

    1981-05-01

    Data from six infant welfare centres in the vicinity of Amsterdam airport were analysed. Birth weights of 902 infants were related to aircraft noise levels to which the mother was exposed in pregnancy. The analysis was restricted to deliveries in hospital, single births and mothers aged 20-34 years. In high noise areas the mean birth weight was 69 g lower than in low noise areas. Of the infants in high noise areas 24% had a birth weight less than 3000 g, compared with 18% in low noise areas. In the analysis the effect of sex of the infant, birth order and to some extent socio-economic status were taken into account. An effect of smoking seemed unlikely. The results, together with existing knowledge, give some suggestion that aircraft noise can decrease birth weight.

  14. Perception of aircraft Deviation Cues

    Science.gov (United States)

    Martin, Lynne; Azuma, Ronald; Fox, Jason; Verma, Savita; Lozito, Sandra

    2005-01-01

    To begin to address the need for new displays, required by a future airspace concept to support new roles that will be assigned to flight crews, a study of potentially informative display cues was undertaken. Two cues were tested on a simple plan display - aircraft trajectory and flight corridor. Of particular interest was the speed and accuracy with which participants could detect an aircraft deviating outside its flight corridor. Presence of the trajectory cue significantly reduced participant reaction time to a deviation while the flight corridor cue did not. Although non-significant, the flight corridor cue seemed to have a relationship with the accuracy of participants judgments rather than their speed. As this is the second of a series of studies, these issues will be addressed further in future studies.

  15. Aircraft systems design methodology and dispatch reliability prediction

    OpenAIRE

    Bineid, Mansour

    2005-01-01

    Aircraft despatch reliability was the main subject of this research in the wider content of aircraft reliability. The factors effecting dispatch reliability, aircraft delay, causes of aircraft delays, and aircraft delay costs and magnitudes were examined. Delay cost elements and aircraft delay scenarios were also studied. It concluded that aircraft dispatch reliability is affected by technical and non-technical factors, and that the former are under the designer's control. It showed that ...

  16. Challenges of aircraft design integration

    OpenAIRE

    Kafyeke, F.; Abdo, M.; Pepin, F; Piperni, P.; Laurendeau, E.

    2007-01-01

    The design of a modern airplane brings together many disciplines: structures, aerodynamics, controls, systems, propulsion with complex interdependencies and many variables. Recent aircraft programs, such as Bombardier's Continental Jet program use participants located around the world and selected for their cost, quality and delivery capability. These participants share the risk on the program and must therefore be fully implicated in the design. A big challenge is to provide information on c...

  17. PREDICTION OF AIRCRAFT NOISE LEVELS

    Science.gov (United States)

    Clark, B. J.

    1994-01-01

    Methods developed at the NASA Lewis Research Center for predicting the noise contributions from various aircraft noise sources have been incorporated into a computer program for predicting aircraft noise levels either in flight or in ground test. The noise sources accounted for include fan inlet and exhaust, jet, flap (for powered lift), core (combustor), turbine, and airframe. Noise propagation corrections are available in the program for atmospheric attenuation, ground reflections, extra ground attenuation, and shielding. The capacity to solve the geometrical relationships between an aircraft in flight and an observer on the ground has been included in the program to make it useful in evaluating noise estimates and footprints for various proposed engine installations. The program contains two main routines for employing the noise prediction routines. The first main routine consists of a procedure to calculate at various observer stations the time history of the noise from an aircraft flying at a specified set of speeds, orientations, and space coordinates. The various components of the noise are computed by the program. For each individual source, the noise levels are free field with no corrections for propagation losses other than spherical divergence. The total spectra may then be corrected for the usual effects of atmospheric attenuation, extra ground attenuation, ground reflection, and aircraft shielding. Next, the corresponding values of overall sound pressure level, perceived noise level, and tone-weighted perceived noise level are calculated. From the time history at each point, true effective perceived noise levels are calculated. Thus, values of effective perceived noise levels, maximum perceived noise levels, and tone-weighted perceived noise levels are found for a grid of specified points on the ground. The second main routine is designed to give the usual format of one-third octave sound pressure level values at a fixed radius for a number of user

  18. A Complexity Metric for Automated Separation

    Science.gov (United States)

    Aweiss, Arwa

    2009-01-01

    A metric is proposed to characterize airspace complexity with respect to an automated separation assurance function. The Maneuver Option metric is a function of the number of conflict-free trajectory change options the automated separation assurance function is able to identify for each aircraft in the airspace at a given time. By aggregating the metric for all aircraft in a region of airspace, a measure of the instantaneous complexity of the airspace is produced. A six-hour simulation of Fort Worth Center air traffic was conducted to assess the metric. Results showed aircraft were twice as likely to be constrained in the vertical dimension than the horizontal one. By application of this metric, situations found to be most complex were those where level overflights and descending arrivals passed through or merged into an arrival stream. The metric identified high complexity regions that correlate well with current air traffic control operations. The Maneuver Option metric did not correlate with traffic count alone, a result consistent with complexity metrics for human-controlled airspace.

  19. 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

  20. The Chorus Conflict and Loss of Separation Resolution Algorithms

    Science.gov (United States)

    Butler, Ricky W.; Hagen, George E.; Maddalon, Jeffrey M.

    2013-01-01

    The Chorus software is designed to investigate near-term, tactical conflict and loss of separation detection and resolution concepts for air traffic management. This software is currently being used in two different problem domains: en-route self- separation and sense and avoid for unmanned aircraft systems. This paper describes the core resolution algorithms that are part of Chorus. The combination of several features of the Chorus program distinguish this software from other approaches to conflict and loss of separation resolution. First, the program stores a history of state information over time which enables it to handle communication dropouts and take advantage of previous input data. Second, the underlying conflict algorithms find resolutions that solve the most urgent conflict, but also seek to prevent secondary conflicts with the other aircraft. Third, if the program is run on multiple aircraft, and the two aircraft maneuver at the same time, the result will be implicitly co-ordinated. This implicit coordination property is established by ensuring that a resolution produced by Chorus will comply with a mathematically-defined criteria whose correctness has been formally verified. Fourth, the program produces both instantaneous solutions and kinematic solutions, which are based on simple accel- eration models. Finally, the program provides resolutions for recovery from loss of separation. Different versions of this software are implemented as Java and C++ software programs, respectively.

  1. 78 FR 65554 - Exhaust Emission Standards for New Aircraft Turbine Engines and Identification Plate for Aircraft...

    Science.gov (United States)

    2013-11-01

    ... Aircraft Turbine Engines and Identification Plate for Aircraft Engines Correction In rule document 2013... for Subsonic Engines'', in the third column, in the last row, the entry ``rO > 26.7'' is corrected...

  2. 14 CFR 91.111 - Operating near other aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Operating near other aircraft. 91.111... § 91.111 Operating near other aircraft. (a) No person may operate an aircraft so close to another aircraft as to create a collision hazard. (b) No person may operate an aircraft in formation flight...

  3. Choice of Aircraft Size - Explanations and Implications

    OpenAIRE

    Givoni, Moshe; Rietveld, Piet

    2006-01-01

    To keep load factors high while offering high frequency service, airlines tend to reduce the size of the aircraft they use. At many of the world’s largest airports there are fewer than 100 passengers per air transport movement, although congestion and delays are growing. Furthermore, demand for air transport is predicted to continue growing but aircraft size is not. This paper aims to investigate and explain this phenomenon, the choice of relatively small aircraft. It seems that this choice i...

  4. Neural Networks Based Aircraft Fault Tolerant Control

    OpenAIRE

    Zhong, Lunlong; Mora-Camino, Félix

    2012-01-01

    The purpose of this communication is to deal with the case in which an aerodynamic actuator failure occurs to an aircraft while it has to perform guidance maneuvers. The problem considered deals with the reallocation of redundant actuators to perform the required maneuvers and maintain the structural integrity of the aircraft. A Nonlinear Inverse Control technique is used to generate online nominal moment along the three axis of the aircraft. Then, taking into account all material and structu...

  5. Separation of aqueous two-phase polymer systems in microgravity

    Science.gov (United States)

    Vanalstine, J. M.; Harris, J. M.; Synder, S.; Curreri, P. A.; Bamberger, S. B.; Brooks, D. E.

    1984-01-01

    Phase separation of polymer systems in microgravity is studied in aircraft flights to prepare shuttle experiments. Short duration (20 sec) experiments demonstrate that phase separation proceeds rapidly in low gravity despite appreciable phase viscosities and low liquid interfacial tensions (i.e., 50 cP, 10 micro N/m). Ostwald ripening does not appear to be a satisfactory model for the phase separation mechanism. Polymer coated surfaces are evaluated as a means to localize phases separated in low gravity. Contact angle measurements demonstrate that covalently coupling dextran or PEG to glass drastically alters the 1-g wall wetting behavior of the phases in dextran-PEG two phase systems.

  6. 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

  7. 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...

  8. Policy and the evaluation of aircraft noise

    OpenAIRE

    Kroesen, M.; Molin, E.J.E.; Van Wee, G.P.

    2010-01-01

    In this paper, we hypothesize and test the ideas that (1) people’s subjectivity in relation to aircraft noise is shaped by the policy discourse, (2) this results in a limited number of frames towards aircraft noise, (3) the frames inform people how to think and feel about aircraft noise and (4) the distribution of the frames in the population is dependent on structural variables related to the individual. To reveal subjects’ frames of aircraft noise a latent class model is estimated based on ...

  9. Research on Emerging and Descending Aircraft Noise

    Directory of Open Access Journals (Sweden)

    Monika Bartkevičiūtė

    2013-12-01

    Full Text Available Along with an increase in the aircraft engine power and growth in air traffic, noise level at airports and their surrounding environs significantly increases. Aircraft noise is high level noise spreading within large radius and intensively irritating the human body. Air transport is one of the main sources of noise having a particularly strong negative impact on the environment. The article deals with activities and noises taking place in the largest nationwide Vilnius International Airport.The level of noise and its dispersion was evaluated conducting research on the noise generated by emerging and descending aircrafts in National Vilnius Airport. Investigation was carried out at 2 measuring points located in a residential area. There are different types of aircrafts causing different sound levels. It has been estimated the largest exceedances that occur when an aircraft is approaching. In this case, the noisiest types of aircrafts are B733, B738 and AT72. The sound level varies from 70 to 85 dBA. The quietest aircrafts are RJ1H and F70. When taking off, the equivalent of the maximum sound level value of these aircrafts does not exceed the authorized limits. The paper describes the causes of noise in aircrafts, the sources of origin and the impact of noise on humans and the environment.Article in Lithuanian

  10. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  11. Challenges for the aircraft structural integrity program

    Science.gov (United States)

    Lincoln, John W.

    1994-01-01

    Thirty-six years ago the United States Air Force established the USAF Aircraft Structural Integrity Program (ASIP) because flight safety had been degraded by fatigue failures of operational aircraft. This initial program evolved, but has been stable since the issuance of MIL-STD-1530A in 1975. Today, the program faces new challenges because of a need to maintain aircraft longer in an environment of reduced funding levels. Also, there is increased pressure to reduce cost of the acquisition of new aircraft. It is the purpose of this paper to discuss the challenges for the ASIP and identify the changes in the program that will meet these challenges in the future.

  12. Radiation survey of aircraft and heavy machinery scrap.

    Science.gov (United States)

    Idriss, Hajo; Salih, Isam; Gumaa, Elsadig; Yassin, Abbas; Yousif, E H; Abdel Hamid, Saad Eldeen M; Sam, A K

    2012-12-01

    This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of (90)Sr and one of (226)Ra in aircraft scrap. Of course, (90)Sr sources are used in military aircraft as temperature sensors while (226)Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1m from the source fall within the range of 25.1-40.2 μSv/h with an average value of 33.52 ± 4.06 μSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing.

  13. 75 FR 50865 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Science.gov (United States)

    2010-08-18

    ... Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal Aviation Administration (FAA... 912 A series engine installed in various aircraft does not have an engine type certificate; instead, the engine is part of the aircraft type design. Comments We gave the public the opportunity...

  14. 75 FR 70098 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Science.gov (United States)

    2010-11-17

    ... Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal Aviation Administration (FAA... Aircraft Engines 912 A series engine with a crankcase assembly S/N up to and including S/N 27811, certificated in any category: ] Type certificate holder Aircraft model Engine model Aeromot-Industria...

  15. 75 FR 32315 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engines

    Science.gov (United States)

    2010-06-08

    ... Equipped With Rotax Aircraft Engines 912 A Series Engines AGENCY: Federal Aviation Administration (FAA... certificated in the United States. However, the Model 912 A series engine installed in various aircraft does not have an engine type certificate; instead, the engine is part of the aircraft type design. You...

  16. 76 FR 40219 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Science.gov (United States)

    2011-07-08

    ... Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration (FAA), DOT... Rotax Aircraft Engines Mandatory Service Bulletin SB-912-058 SB-914-041, dated April 15, 2011, listed in... 601 0; fax: +43 7246 601 9130; Internet: http://www.rotax-aircraft-engines.com . You may review...

  17. Program to compute the positions of the aircraft and of the aircraft sensor footprints

    Science.gov (United States)

    Paris, J. F. (Principal Investigator)

    1982-01-01

    The positions of the ground track of the aircraft and of the aircraft sensor footprints, in particular the metric camera and the radar scatterometer on the C-130 aircraft, are estimated by a program called ACTRK. The program uses the altitude, speed, and attitude informaton contained in the radar scatterometer data files to calculate the positions. The ACTRK program is documented.

  18. 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.

  19. An Initial Examination for Verifying Separation Algorithms by Simulation

    Science.gov (United States)

    White, Allan L.; Neogi, Natasha; Herencia-Zapana, Heber

    2012-01-01

    An open question in algorithms for aircraft is what can be validated by simulation where the simulation shows that the probability of undesirable events is below some given level at some confidence level. The problem is including enough realism to be convincing while retaining enough efficiency to run the large number of trials needed for high confidence. The paper first proposes a goal based on the number of flights per year in several regions. The paper examines the probabilistic interpretation of this goal and computes the number of trials needed to establish it at an equivalent confidence level. Since any simulation is likely to consider the algorithms for only one type of event and there are several types of events, the paper examines under what conditions this separate consideration is valid. This paper is an initial effort, and as such, it considers separation maneuvers, which are elementary but include numerous aspects of aircraft behavior. The scenario includes decisions under uncertainty since the position of each aircraft is only known to the other by broadcasting where GPS believes each aircraft to be (ADS-B). Each aircraft operates under feedback control with perturbations. It is shown that a scenario three or four orders of magnitude more complex is feasible. The question of what can be validated by simulation remains open, but there is reason to be optimistic.

  20. The Small Aircraft Transportation System (SATS), Higher Volume Operations (HVO) Off-Nominal Operations

    Science.gov (United States)

    Baxley, B.; Williams, D.; Consiglio, M.; Conway, S.; Adams, C.; Abbott, T.

    2005-01-01

    The ability to conduct concurrent, multiple aircraft operations in poor weather, at virtually any airport, offers an important opportunity for a significant increase in the rate of flight operations, a major improvement in passenger convenience, and the potential to foster growth of charter operations at small airports. The Small Aircraft Transportation System, (SATS) Higher Volume Operations (HVO) concept is designed to increase traffic flow at any of the 3400 nonradar, non-towered airports in the United States where operations are currently restricted to one-in/one-out procedural separation during Instrument Meteorological Conditions (IMC). The concept's key feature is pilots maintain their own separation from other aircraft using procedures, aircraft flight data sent via air-to-air datalink, cockpit displays, and on-board software. This is done within the Self-Controlled Area (SCA), an area of flight operations established during poor visibility or low ceilings around an airport without Air Traffic Control (ATC) services. The research described in this paper expands the HVO concept to include most off-nominal situations that could be expected to occur in a future SATS environment. The situations were categorized into routine off-nominal operations, procedural deviations, equipment malfunctions, and aircraft emergencies. The combination of normal and off-nominal HVO procedures provides evidence for an operational concept that is safe, requires little ground infrastructure, and enables concurrent flight operations in poor weather.

  1. Technology for aircraft energy efficiency

    Science.gov (United States)

    Klineberg, J. M.

    1977-01-01

    Six technology programs for reducing fuel use in U.S. commercial aviation are discussed. The six NASA programs are divided into three groups: Propulsion - engine component improvement, energy efficient engine, advanced turboprops; Aerodynamics - energy efficient transport, laminar flow control; and Structures - composite primary structures. Schedules, phases, and applications of these programs are considered, and it is suggested that program results will be applied to current transport derivatives in the early 1980s and to all-new aircraft of the late 1980s and early 1990s.

  2. Aircraft empennage structural detail design

    Science.gov (United States)

    Meholic, Greg; Brown, Rhonda; Hall, Melissa; Harvey, Robert; Singer, Michael; Tella, Gustavo

    1993-01-01

    This project involved the detailed design of the aft fuselage and empennage structure, vertical stabilizer, rudder, horizontal stabilizer, and elevator for the Triton primary flight trainer. The main design goals under consideration were to illustrate the integration of the control systems devices used in the tail surfaces and their necessary structural supports as well as the elevator trim, navigational lighting system, electrical systems, tail-located ground tie, and fuselage/cabin interface structure. Accommodations for maintenance, lubrication, adjustment, and repairability were devised. Weight, fabrication, and (sub)assembly goals were addressed. All designs were in accordance with the FAR Part 23 stipulations for a normal category aircraft.

  3. Autonomous Aircraft Operations using RTCA Guidelines for Airborne Conflict Management

    Science.gov (United States)

    Krishnamurthy, Karthik; Wing, David J.; Barmore, Bryan E.; Barhydt, Richard; Palmer, Michael T.; Johnson, Edward J.; Ballin, Mark G.; Eischeid, Todd M.

    2003-01-01

    A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of DAG-TM autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special-use airspace (SUA) regions on either side of the pilot's planned route. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. Key guidelines from the RTCA Airborne Conflict Management (ACM) concept were applied to autonomous aircraft operations for this experiment. These concepts included the RTCA ACM definitions of distinct conflict detection and collision avoidance zones, and the use of a graded system of conflict alerts for the flight crew. Three studies were conducted in the course of the experiment. The first study investigated the effect of hazard proximity upon pilot ability to meet constraints and solve conflict situations. The second study investigated pilot use of the airborne tools when faced with an unexpected loss of separation (LOS). The third study explored pilot interactions in an over-constrained conflict situation, with and without priority rules dictating who should move first. Detailed results from these studies were presented at the 5th USA/Europe Air Traffic Management R&D Seminar (ATM2003). This overview paper focuses on the integration of the RTCA ACM concept into autonomous aircraft operations in highly constrained situations, and provides an overview of the results presented at the ATM2003 seminar. These results, together with previously reported studies, continue to support the feasibility of autonomous aircraft operations.

  4. 77 FR 58301 - Technical Amendment; Airworthiness Standards: Aircraft Engines; Correction

    Science.gov (United States)

    2012-09-20

    ... Technical Amendment entitled, ``Airworthiness Standards: Aircraft Engine'' (77 FR 39623). In that technical... Administration 14 CFR Part 33 RIN 2120-AF57 Technical Amendment; Airworthiness Standards: Aircraft Engines... technical amendment, the FAA clarified aircraft engine vibration test requirements in the...

  5. 77 FR 39623 - Airworthiness Standards: Aircraft Engines; Technical Amendment

    Science.gov (United States)

    2012-07-05

    ... Federal Aviation Administration 14 CFR Part 33 Airworthiness Standards: Aircraft Engines; Technical.... SUMMARY: This amendment clarifies aircraft engine vibration test requirements in the airworthiness... 33--AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES 0 1. The authority citation for part 33 continues...

  6. LCC-OPS: Life Cycle Cost Application in Aircraft Operations

    NARCIS (Netherlands)

    Suwondo, E.

    2007-01-01

    Observation of current practices in aircraft operations and maintenance shows limited consideration of cost savings applied by aircraft modifications, maintenance program optimisation and aircraft selection. This is due to hidden (maintenance dependent) costs and difficulties in quantifying the util

  7. Multispectral imaging of aircraft exhaust

    Science.gov (United States)

    Berkson, Emily E.; Messinger, David W.

    2016-05-01

    Aircraft pollutants emitted during the landing-takeoff (LTO) cycle have significant effects on the local air quality surrounding airports. There are currently no inexpensive, portable, and unobtrusive sensors to quantify the amount of pollutants emitted from aircraft engines throughout the LTO cycle or to monitor the spatial-temporal extent of the exhaust plume. We seek to thoroughly characterize the unburned hydrocarbon (UHC) emissions from jet engine plumes and to design a portable imaging system to remotely quantify the emitted UHCs and temporally track the distribution of the plume. This paper shows results from the radiometric modeling of a jet engine exhaust plume and describes a prototype long-wave infrared imaging system capable of meeting the above requirements. The plume was modeled with vegetation and sky backgrounds, and filters were selected to maximize the detectivity of the plume. Initial calculations yield a look-up chart, which relates the minimum amount of emitted UHCs required to detect the presence of a plume to the noise-equivalent radiance of a system. Future work will aim to deploy the prototype imaging system at the Greater Rochester International Airport to assess the applicability of the system on a national scale. This project will help monitor the local pollution surrounding airports and allow better-informed decision-making regarding emission caps and pollution bylaws.

  8. Aircraft Emission Inventories of The Second Generation

    Science.gov (United States)

    Brunner, Ing. B.; Pabst, H.; Döpelheuer, Ing. A.; Plohr, M.

    Higher requirements of science and politics forced an additional temporal and bet- ter local allocation of air traffic and their emissions. Within the last years a pro- gram (FATE: Four-dimensional calculation of Aircraft Trajectories and Emissions) has been developed in the DLR Institute of Transport Research, which is able to pro- duce air traffic movements and emissions inventories with a four-dimensional reso- lution. To calculate an emission inventory FATE adapts fuel and emission profiles which were generated by the DLR Institute of Propulsion Technology to the real air traffic movements data. The emission profiles were calculated for each aircraft/engine- combination and include NOX, SOX, CO, UHC, and SOOT data. The results have been obtained with detailed variable reference calculation procedures. At the moment the most common resolutions are 1x1x1kmx1h or 0.5x0.5x1kmx1h (longitude and latitude in degree, one kilometre in height and one hour in time). The values for the flown distance, the fuel used up and the time needed, as well as the emitted gasses and particulate matter are indicated for each time coded air cell. The three- dimensional position calculation is the standard mode of this program. The possibility of time coding and emission allocation can be used -each separately or in conjunction- as an additional feature. This new calculation method replaces the simple great circle calculation (a great circle is the shortest way from point A to B on a spherical sur- face) of the first generation of air traffic inventories by flight trajectory calculation on waypoint basis using equations of spherical trigonometry. Selected work results shall give an impression of the versatility and the applica- tion possibilities of FATE. Depending on the request of the scientific research the various modes of the program have been used for: a) deviation from great circle without time and emission calculation, b) four-dimensional global inventory with a 2,8x2,8x1kmx2h

  9. Noise control mechanisms of inside aircraft

    Science.gov (United States)

    Zverev, A. Ya.

    2016-07-01

    World trends in the development of methods and approaches to noise reduction in aircraft cabins are reviewed. The paper discusses the mechanisms of passive and active noise and vibration control, application of "smart" and innovative materials, new approaches to creating all fuselage-design elements, and other promising directions of noise control inside aircraft.

  10. Study on Impedance Characteristics of Aircraft Cables

    Directory of Open Access Journals (Sweden)

    Weilin Li

    2016-01-01

    Full Text Available Voltage decrease and power loss in distribution lines of aircraft electric power system are harmful to the normal operation of electrical equipment and may even threaten the safety of aircraft. This study investigates how the gap distance (the distance between aircraft cables and aircraft skin and voltage frequency (variable frequency power supply will be adopted for next generation aircraft will affect the impedance of aircraft cables. To be more precise, the forming mechanism of cable resistance and inductance is illustrated in detail and their changing trends with frequency and gap distance are analyzed with the help of electromagnetic theoretical analysis. An aircraft cable simulation model is built with Maxwell 2D and the simulation results are consistent with the conclusions drawn from the theoretical analysis. The changing trends of the four core parameters of interest are analyzed: resistance, inductance, reactance, and impedance. The research results can be used as reference for the applications in Variable Speed Variable Frequency (VSVF aircraft electric power system.

  11. Wireless Network Simulation in Aircraft Cabins

    Science.gov (United States)

    Beggs, John H.; Youssef, Mennatoallah; Vahala, Linda

    2004-01-01

    An electromagnetic propagation prediction tool was used to predict electromagnetic field strength inside airplane cabins. A commercial software package, Wireless Insite, was used to predict power levels inside aircraft cabins and the data was compared with previously collected experimental data. It was concluded that the software could qualitatively predict electromagnetic propagation inside the aircraft cabin environment.

  12. Cycle Counting Methods of the Aircraft Engine

    Science.gov (United States)

    Fedorchenko, Dmitrii G.; Novikov, Dmitrii K.

    2016-01-01

    The concept of condition-based gas turbine-powered aircraft operation is realized all over the world, which implementation requires knowledge of the end-of-life information related to components of aircraft engines in service. This research proposes an algorithm for estimating the equivalent cyclical running hours. This article provides analysis…

  13. Laminar flow control for transport aircraft applications

    Science.gov (United States)

    Wagner, R. D.

    1986-01-01

    The incorporation of laminar flow control into transport aircraft is discussed. Design concepts for the wing surface panel of laminar flow control transport aircraft are described. The development of small amounts of laminar flow on small commercial transports with natural or hybrid flow control is examined. Techniques for eliminating the insect contamination problem in the leading-edge region are proposed.

  14. 19 CFR 122.42 - Aircraft entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Aircraft entry. 122.42 Section 122.42 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements...

  15. 14 CFR 135.125 - Aircraft security.

    Science.gov (United States)

    2010-01-01

    ....125 Aircraft security. Certificate holders conducting operators conducting operations under this part must comply with the applicable security requirements in 49 CFR chapter XII. ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft security. 135.125 Section...

  16. 14 CFR 121.538 - Aircraft security.

    Science.gov (United States)

    2010-01-01

    ..., FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.538 Aircraft security. Certificate holders conducting operations under this part must comply with the applicable security requirements in 49 CFR chapter... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft security. 121.538 Section...

  17. An Adaptive Nonlinear Aircraft Maneuvering Envelope Estimation Approach for Online Applications

    Science.gov (United States)

    Schuet, Stefan R.; Lombaerts, Thomas Jan; Acosta, Diana; Wheeler, Kevin; Kaneshige, John

    2014-01-01

    A nonlinear aircraft model is presented and used to develop an overall unified robust and adaptive approach to passive trim and maneuverability envelope estimation with uncertainty quantification. The concept of time scale separation makes this method suitable for the online characterization of altered safe maneuvering limitations after impairment. The results can be used to provide pilot feedback and/or be combined with flight planning, trajectory generation, and guidance algorithms to help maintain safe aircraft operations in both nominal and off-nominal scenarios.

  18. A Turbo-Brayton Cryocooler for Aircraft Superconducting Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hybrid turboelectric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft...

  19. An Instrument to Measure Aircraft Sulfate Particle Emissions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft particle emissions contribute a modest, but growing, portion of the overall particle emissions budget. Characterizing aircraft particle emissions is...

  20. Aircraft Stand Allocation with Associated Resource Scheduling

    DEFF Research Database (Denmark)

    Justesen, Tor Fog; Larsen, Jesper; Lusby, Richard Martin;

    An aircraft turn-round refers to the set of processes taking place from when an aircraft parks at its arrival stand until the time it departs from its departure stand. When handling a turn-round, the different processes involved (arrival, disembarkation of passengers, cleaning, etc.) require...... different ground handling resources (taxiways, aircraft stands, gates, etc) at different times. Each resource can be claimed by at most one turn-round at a time. The aircraft stand allocation problem with associated resource scheduling is the problem of allocating the required ground handling resources...... to handle a given set of aircraft turn-rounds. We develop a set packing-based model formulation of the problem which is both flexible in the sense that it can encapsulate any type of resource required during the handling of a turn-round and strong in the sense that conflicts that occur when two or more turn...

  1. A process for the quantification of aircraft noise and emissions interdependencies

    Science.gov (United States)

    de Luis, Jorge

    The main purpose of this dissertation is to develop a process to improve actual policy-making procedures in terms of aviation environmental effects. This research work expands current practices with physics based publicly available models. The current method uses solely information provided by industry members, and this information is usually proprietary, and not physically intuitive. The process herein proposed provides information regarding the interdependencies between the environmental effects of aircraft. These interdependencies are also tied to the actual physical parameters of the aircraft and the engine, making it more intuitive for decision-makers to understand the impacts to the vehicle due to different policy scenarios. These scenarios involve the use of fleet analysis tools in which the existing aircraft are used to predict the environmental effects of imposing new stringency levels. The aircraft used are reduced to a series of coefficients that represent their performance, in terms of flight characteristics, fuel burn, noise, and emissions. These coefficients are then utilized to model flight operations and calculate what the environmental impacts of those aircraft are. If a particular aircraft does not meet the stringency to be analyzed, a technology response is applied to it, in order to meet that stringency. Depending on the level of reduction needed, this technology response can have an effect on the fuel burn characteristic of the aircraft. Another important point of the current stringency analysis process is that it does not take into account both noise and emissions concurrently, but instead, it considers them separately, one at a time. This assumes that the interdependencies between the two do not exists, which is not realistic. The latest stringency process delineated in 2004 imposed a 2% fuel burn penalty for any required improvements on NOx, no matter the type of aircraft or engine, assuming that no company had the ability to produce a

  2. A Performance Assessment of an Airborne Separation Assistance System Using Realistic Complex Traffic Flows

    Science.gov (United States)

    Smith, Jeremy C.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of a tactical Airborne Separation Assistance System (ASAS) in en route airspace, under varying demand levels, with realistic traffic flows. The ASAS concept studied here allows flight crews of equipped aircraft to perform separation from other air traffic autonomously. This study addresses the tactical aspects of an ASAS using aircraft state data (i.e. position and velocity) to detect and resolve projected conflicts. In addition, use of a conflict prevention system helps ASAS-equipped aircraft avoid maneuvers that may cause new conflicts. ASAS-capable aircraft are equipped with satellite-based navigation and Automatic Dependent Surveillance Broadcast (ADS-B) for transmission and receipt of aircraft state data. In addition to tactical conflict detection and resolution (CD&R), a complete, integrated ASAS is likely to incorporate a strategic CD&R component with a longer look-ahead time, using trajectory intent information. A system-wide traffic flow management (TFM) component, located at the FAA command center helps aircraft to avoid regions of excessive traffic density and complexity. A Traffic Alert and Collision Avoidance System (TCAS), as used today is the system of last resort. This integrated approach avoids sole reliance on the use of the tactical CD&R studied here, but the tactical component remains a critical element of the complete ASAS. The focus of this paper is to determine to what extent the proposed tactical component of ASAS alone can maintain aircraft separation at demand levels up to three times that of current traffic. The study also investigates the effect of mixing ASAS-equipped aircraft with unequipped aircraft (i.e. current day) that do not have the capability to self-separate. Position and velocity data for unequipped aircraft needs to be available to ASASequipped. Most likely, for this future concept, state data would be available from instrument flight rules (IFR

  3. Aircraft wing structure detail design

    Science.gov (United States)

    Sager, Garrett L.; Roberts, Ron; Mallon, Bob; Alameri, Mohamed; Steinbach, Bill

    1993-01-01

    The provisions of this project call for the design of the structure of the wing and carry-through structure for the Viper primary trainer, which is to be certified as a utility category trainer under FAR part 23. The specific items to be designed in this statement of work were Front Spar, Rear Spar, Aileron Structure, Wing Skin, and Fuselage Carry-through Structure. In the design of these parts, provisions for the fuel system, electrical system, and control routing were required. Also, the total weight of the entire wing planform could not exceed 216 lbs. Since this aircraft is to be used as a primary trainer, and the SOW requires a useful life of 107 cycles, it was decided that all of the principle stresses in the structural members would be kept below 10 ksi. The only drawback to this approach is a weight penalty.

  4. Aircraft measurements of wave cloud

    Directory of Open Access Journals (Sweden)

    Z. Cui

    2012-05-01

    Full Text Available In this paper, aircraft measurements are presented of liquid phase (ice-free wave clouds made at temperatures greater than −5 °C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15–45 μm. A small proportion of the drops were drizzle. A new definition of a mountain-wave cloud is given, based on the measurements presented here and previous studies. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and clouds.

  5. Separation anxiety in children

    Science.gov (United States)

    ... the child experiences anxiety when separated from the primary caregiver (usually the mother). ... Excessive distress when separated from the primary caregiver ... of separation Reluctance to go to sleep without the primary ...

  6. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... 5 Things to Know About Zika & Pregnancy Separation Anxiety KidsHealth > For Parents > Separation Anxiety Print A A ... both of you get through it. How Separation Anxiety Develops Babies adapt pretty well to other caregivers. ...

  7. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    2012-01-01

    Separation logic formalizes the idea of local reasoning for heap-manipulating programs via the frame rule and the separating conjunction P * Q, which describes states that can be split into \\emph{separate} parts, with one satisfying P and the other satisfying Q. In standard separation logic...... overlap. We demonstrate, via a range of examples, how fictional separation logic can be used to reason locally and modularly about mutable abstract data types, possibly implemented using sophisticated sharing. Fictional separation logic is defined on top of standard separation logic, and both the meta......, separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...

  8. Turboprop aircraft against terrorism: a SWOT analysis of turboprop aircraft in CAS operations

    Science.gov (United States)

    Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

    2012-06-01

    Today, the threat perception is changing. Not only for countries but also for defence organisations like NATO, new threat perception is pointing terrorism. Many countries' air forces become responsible of fighting against terorism or Counter-Insurgency (COIN) Operations. Different from conventional warfare, alternative weapon or weapon systems are required for such operatioins. In counter-terrorism operations modern fighter jets are used as well as helicopters, subsonic jets, Unmanned Aircraft Systems (UAS), turboprop aircraft, baloons and similar platforms. Succes and efficiency of the use of these platforms can be determined by evaluating the conditions, the threats and the area together. Obviously, each platform has advantages and disadvantages for different cases. In this research, examples of turboprop aircraft usage against terrorism and with a more general approach, turboprop aircraft for Close Air Support (CAS) missions from all around the world are reviewed. In this effort, a closer look is taken at the countries using turboprop aircraft in CAS missions while observing the fields these aircraft are used in, type of operations, specifications of the aircraft, cost and the maintenance factors. Thus, an idea about the convenience of using these aircraft in such operations can be obtained. A SWOT analysis of turboprop aircraft in CAS operations is performed. This study shows that turboprop aircraft are suitable to be used in counter-terrorism and COIN operations in low threat environment and is cost benefical compared to jets.

  9. Aircraft impact on a spherical shell

    International Nuclear Information System (INIS)

    For nuclear power plants located in the immediate vicinity of cities and airports safeguarding against an accidental aircraft strike is important. Because of the complexity of such an aircraft crash the building is ordinarily designed for loading by an idealized dynamical load F(t), which follows from measurements (aircraft striking a rigid wall). The extent to which the elastic displacements of a structure influence the impact load F(t) is investigatd in this paper. The aircraft is idealized by a linear mass-spring-dashpot combination which can easily be treated in computations and which can suffer elastic as well as plastic deformations. This 'aircraft' normally strikes a spherical shell at the apex. The time-dependent reactions of the shell as a function of the unknown impact load F(t) are expanded in terms of the normal modes, which are Legendre functions. The continuity condition at the impact point leads to an integral equation for F(t) which may be solved by Laplace transformation. F(t) is computed for hemispheres with several ratios of thickness to radius, several edge conditions and several 'aircraft' parameters. In all cases F(t) differs very little from that function obtained for the case of the aircraft striking a rigid wall. (Auth.)

  10. Improved portable lighting for visual aircraft inspection

    Energy Technology Data Exchange (ETDEWEB)

    Shagam, R.N. [Sandia National Lab., Albuquerque, NM (United States); Lerner, J.; Shie, R. [Physical Optics Corp., Torrance, CA (United States)

    1995-04-01

    The most common tool used by aircraft inspectors is the personal flashlight. While it is compact and very portable, it is generally typified by poor beam quality which can interfere with the ability for an inspector to detect small defects and anomalies, such as cracks and corrosion sites, which may be indicators of major structural problems. A Light Shaping Diffuser{trademark} (LSD) installed in a stock flashlight as a replacement to the lens can improve the uniformity of an average flashlight and improve the quality of the inspection. Field trials at aircraft maintenance facilities have demonstrated general acceptance of the LSD by aircraft inspection and maintenance personnel.

  11. Improved portable lighting for visual aircraft inspection

    Science.gov (United States)

    Shagam, Richard N.; Lerner, Jeremy M.; Shie, Rick

    1995-07-01

    The most common tool used by aircraft inspectors is the personal flashlight. While it is compact and very portable, it is generally typified by poor beam quality which can interfere with the ability for an inspector to detect small defects and anomalies, such as cracks and corrosion sites, which may be indicators of major structural problems. A Light Shaping Diffuser TM (LSD) installed in a stock flashlight as a replacement to the lens can improve the uniformity of an average flashlight and improve the quality of the inspection. Field trials at aircraft maintenance facilities have demonstrated general acceptance of the LSD by aircraft inspection and maintenance personnel.

  12. Aircraft Loss-of-Control Accident Analysis

    Science.gov (United States)

    Belcastro, Christine M.; Foster, John V.

    2010-01-01

    Loss of control remains one of the largest contributors to fatal aircraft accidents worldwide. Aircraft loss-of-control accidents are complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence, there is no single intervention strategy to prevent these accidents. To gain a better understanding into aircraft loss-of-control events and possible intervention strategies, this paper presents a detailed analysis of loss-of-control accident data (predominantly from Part 121), including worst case combinations of causal and contributing factors and their sequencing. Future potential risks are also considered.

  13. Aircraft Energy Efficiency (ACEE) status report

    Science.gov (United States)

    Nored, D. L.; Dugan, J. F., Jr.; Saunders, N. T.; Ziemianski, J. A.

    1979-01-01

    Fuel efficiency in aeronautics, for fuel conservation in general as well as for its effect on commercial aircraft operating economics is considered. Projects of the Aircraft Energy Efficiency Program related to propulsion are emphasized. These include: (1) engine component improvement, directed at performance improvement and engine diagnostics for prolonged service life; (2) energy efficient engine, directed at proving the technology base for the next generation of turbofan engines; and (3) advanced turboprop, directed at advancing the technology of turboprop powered aircraft to a point suitable for commercial airline service. Progress in these technology areas is reported.

  14. Processing infrared images of aircraft lapjoints

    Science.gov (United States)

    Syed, Hazari; Winfree, William P.; Cramer, K. E.

    1992-01-01

    Techniques for processing IR images of aging aircraft lapjoint data are discussed. Attention is given to a technique for detecting disbonds in aircraft lapjoints which clearly delineates the disbonded region from the bonded regions. The technique is weak on unpainted aircraft skin surfaces, but can be overridden by using a self-adhering contact sheet. Neural network analysis on raw temperature data has been shown to be an effective tool for visualization of images. Numerical simulation results show the above processing technique to be an effective tool in delineating the disbonds.

  15. Sensitivity of transport aircraft performance and economics to advanced technology and cruise Mach number

    Science.gov (United States)

    Ardema, M. D.

    1974-01-01

    Sensitivity data for advanced technology transports has been systematically collected. This data has been generated in two separate studies. In the first of these, three nominal, or base point, vehicles designed to cruise at Mach numbers .85, .93, and .98, respectively, were defined. The effects on performance and economics of perturbations to basic parameters in the areas of structures, aerodynamics, and propulsion were then determined. In all cases, aircraft were sized to meet the same payload and range as the nominals. This sensitivity data may be used to assess the relative effects of technology changes. The second study was an assessment of the effect of cruise Mach number. Three families of aircraft were investigated in the Mach number range 0.70 to 0.98: straight wing aircraft from 0.70 to 0.80; sweptwing, non-area ruled aircraft from 0.80 to 0.95; and area ruled aircraft from 0.90 to 0.98. At each Mach number, the values of wing loading, aspect ratio, and bypass ratio which resulted in minimum gross takeoff weight were used. As part of the Mach number study, an assessment of the effect of increased fuel costs was made.

  16. 32 CFR 855.15 - Detaining an aircraft.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Detaining an aircraft. 855.15 Section 855.15 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits § 855.15 Detaining an...

  17. 42 CFR 71.44 - Disinsection of aircraft.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Disinsection of aircraft. 71.44 Section 71.44... Disinsection of aircraft. (a) The Director may require disinsection of an aircraft if it has left a foreign area that is infected with insect-borne communicable disease and the aircraft is suspected of...

  18. 9 CFR 91.41 - Cleaning and disinfecting of aircraft.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfecting of aircraft... INSPECTION AND HANDLING OF LIVESTOCK FOR EXPORTATION Cleaning and Disinfecting of Aircraft § 91.41 Cleaning and disinfecting of aircraft. Prior to loading of animals, the stowage area of aircraft to be used...

  19. 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 authority of section 239 of the Act and § 1280.2 will not be made if such aircraft is damaged to an...

  20. 14 CFR 375.11 - Other foreign civil aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Other foreign civil aircraft. 375.11... PROCEEDINGS) SPECIAL REGULATIONS NAVIGATION OF FOREIGN CIVIL AIRCRAFT WITHIN THE UNITED STATES Authorization § 375.11 Other foreign civil aircraft. A foreign civil aircraft other than those referred to in §...

  1. 14 CFR 47.51 - Triennial aircraft registration report.

    Science.gov (United States)

    2010-01-01

    ... in the United States; or (iii) A corporation (other than a corporation which is a citizen of the... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Triennial aircraft registration report. 47... AIRCRAFT AIRCRAFT REGISTRATION Certificates of Aircraft Registration § 47.51 Triennial...

  2. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft

    Science.gov (United States)

    Keiter, I. D.

    1982-01-01

    Studies of several General Aviation aircraft indicated that the application of advanced technologies to General Aviation propellers can reduce fuel consumption in future aircraft by a significant amount. Propeller blade weight reductions achieved through the use of composites, propeller efficiency and noise improvements achieved through the use of advanced concepts and improved propeller analytical design methods result in aircraft with lower operating cost, acquisition cost and gross weight.

  3. Safety Performance of Airborne Separation: Preliminary Baseline Testing

    Science.gov (United States)

    Consiglio, Maria C.; Hoadley, Sherwood T.; Wing, David J.; Baxley, Brian T.

    2007-01-01

    The Safety Performance of Airborne Separation (SPAS) study is a suite of Monte Carlo simulation experiments designed to analyze and quantify safety behavior of airborne separation. This paper presents results of preliminary baseline testing. The preliminary baseline scenario is designed to be very challenging, consisting of randomized routes in generic high-density airspace in which all aircraft are constrained to the same flight level. Sustained traffic density is varied from approximately 3 to 15 aircraft per 10,000 square miles, approximating up to about 5 times today s traffic density in a typical sector. Research at high traffic densities and at multiple flight levels are planned within the next two years. Basic safety metrics for aircraft separation are collected and analyzed. During the progression of experiments, various errors, uncertainties, delays, and other variables potentially impacting system safety will be incrementally introduced to analyze the effect on safety of the individual factors as well as their interaction and collective effect. In this paper we report the results of the first experiment that addresses the preliminary baseline condition tested over a range of traffic densities. Early results at five times the typical traffic density in today s NAS indicate that, under the assumptions of this study, airborne separation can be safely performed. In addition, we report on initial observations from an exploration of four additional factors tested at a single traffic density: broadcast surveillance signal interference, extent of intent sharing, pilot delay, and wind prediction error.

  4. Directional monitoring terminal for aircraft noise

    Science.gov (United States)

    Genescà, M.

    2016-07-01

    This paper presents a concept of an aircraft noise monitoring terminal (NMT) that reduces background noise and the influence of ground reflection, in comparison with a single microphone. Also, it automatically identifies aircraft sound events based on the direction of arrival of the sound rather than on the sound pressure level (or radar data). And moreover, it provides an indicator of the quality of the sound pressure level measurement, i.e. if it is possibly disturbed by extraneous sources. The performance of this NMT is experimentally tested under real conditions in a measurement site close to Zurich airport. The results show that the NMT unambiguously identifies the noise events generated by the target aircraft, correctly detects those aircraft noise events that may be disturbed by the presence of other sources, and offers a substantial reduction in background and ground reflected sound.

  5. Modular Electric Propulsion Test Bed Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An all electric aircraft test bed is proposed to provide a dedicated development environment for the rigorous study and advancement of electrically powered...

  6. Smart structure application for the Challenger aircraft

    Science.gov (United States)

    Grenier, L.; Blaha, Franz A.

    1994-09-01

    The Challenger aircraft fleet of the Canadian Forces will fly demanding missions, requiring the implementation of a fatigue management program based on the monitoring of in-flight aircraft load conditions. Conventional sensing techniques experience problems arising from severe electromagnetic interference (EMI). This paper describes the development of an EMI- insensitive smart-structure sensing concept for loads monitoring. Fiber-optic strain sensors, incorporated at critical structural locations, are used to monitor the fatigue life of the aircraft wing, fuselage, and empennage. A fiber-optic accelerometer is also incorporated in the system. A long-term plan is presented for the development of an advanced smart-structure concept which can support the continuous monitoring of fatigue-prone components, and provide the aircraft with near real-time damage location and assessment.

  7. Modular Electric Propulsion Test Bed Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A hybrid electric aircraft simulation system and test bed is proposed to provide a dedicated development environment for the rigorous study and advancement of...

  8. The drive for Aircraft Energy Efficiency

    Science.gov (United States)

    James, R. L., Jr.; Maddalon, D. V.

    1984-01-01

    NASA's Aircraft Energy Efficiency (ACEE) program, which began in 1976, has mounted a development effort in four major transport aircraft technology fields: laminar flow systems, advanced aerodynamics, flight controls, and composite structures. ACEE has explored two basic methods for achieving drag-reducing boundary layer laminarization: the use of suction through the wing structure (via slots or perforations) to remove boundary layer turbulence, and the encouragement of natural laminar flow maintenance through refined design practices. Wind tunnel tests have been conducted for wide bodied aircraft equipped with high aspect ratio supercritical wings and winglets. Maneuver load control and pitch-active stability augmentation control systems reduce fuel consumption by reducing the drag associated with high aircraft stability margins. Composite structures yield lighter airframes that in turn call for smaller wing and empennage areas, reducing induced drag for a given payload. In combination, all four areas of development are expected to yield a fuel consumption reduction of 40 percent.

  9. Engineering students win NASA aircraft design competition

    OpenAIRE

    Crumbley, Liz

    2004-01-01

    Centuria," a single-engine jet aircraft designed by undergraduate engineering students from Virginia Tech and their counterparts at Loughborough University in the U.K., has won the Best Overall Award in NASA's 2004 Revolutionary Vehicles and Concepts Competition.

  10. Aircraft Nodal Data Acquisition System (ANDAS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an Aircraft Nodal Data Acquisition System (ANDAS) is proposed. The proposed methodology employs the development of a very thin (135m) hybrid...

  11. Aircraft Nodal Data Acquisition System (ANDAS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an Aircraft Nodal Data Acquisition System (ANDAS) based upon the short haul Zigbee networking standard is proposed. It employs a very thin (135 um)...

  12. Investigation of aircraft vortex wake structure

    Science.gov (United States)

    Baranov, N. A.; Turchak, L. I.

    2014-11-01

    In this work we analyze the mechanisms of formation of the vortex wake structure of aircraft with different wing shape in the plan flying close to or away from the underlying surface cleaned or released mechanization wing.

  13. Titanium in fatigue critical military aircraft structure

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, F.

    1999-07-01

    This paper discusses the effect of fatigue requirements on titanium structure in military aircraft applications, specifically, fighter aircraft. The discussion covers how fatigue affects the design and analysis of detail parts, and how manufacturing processes affect the fatigue performance of titanium structure. Criteria for designing fighter aircraft have evolved from simple strength calculations to extremely complex computer generated analyses involving strength, durability, damage tolerance and fatigue. Fatigue life prediction is an important part of these analyses and dramatically affects the design and weight of fighter aircraft. Manufacturing processes affect fatigue performance both in a positive and negative manner. Designers must allow for the effect of these processes on titanium structure and consider the efficiency and economy of adding processes that increase fatigue life.

  14. Thermal Management System for Superconducting Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft powered by hydrogen power plants or gas turbines driving electric generators connected to distributed electric motors for propulsion have the potential to...

  15. Tips for Travel and Aircraft Flight

    Science.gov (United States)

    ... Knowledge and support Tips for Travel and Aircraft Flight Category: FAQ's Tags: Risks Archives Breast Cancer Survivors ... limb carefully) and apply pressure as needed. DURING FLIGHT Keep your seat belt loosely fastened so that ...

  16. Design of heavy lift cargo aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the bird of the skies of the future. The heavy lift cargo aircraft which is currently being developed by me has twice the payload capacity of an Antonov...

  17. 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.

  18. 77 FR 36341 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

    Science.gov (United States)

    2012-06-18

    ... and Aircraft Engines; Emission Standards and Test Procedures;'' Final Rule, 70 FR 2521, November 17... From Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final Rule #0;#0;Federal...: Final rule. SUMMARY: EPA is adopting several new aircraft engine emission standards for oxides...

  19. Aircraft Noise and Quality of Life around Frankfurt Airport

    OpenAIRE

    Thomas Eikmann; Christin Peschel; Cara Kahl; Dirk Schreckenberg; Markus Meis

    2010-01-01

    In a survey of 2,312 residents living near Frankfurt Airport aircraft noise annoyance and disturbances as well as environmental (EQoL) and health-related quality of life (HQoL) were assessed and compared with data on exposure due to aircraft, road traffic, and railway noise. Results indicate higher noise annoyance than predicted from general exposure-response curves. Beside aircraft sound levels source-related attitudes were associated with reactions to aircraft noise. Furthermore, aircraft n...

  20. Maintenance program developmentandImport /Export of Aircraft in USA

    OpenAIRE

    Takele, Teklu

    2009-01-01

    AbstractThis thesis discuss how United Parcel Service (UPS) develop its aircraft maintenanceprogram after import of McDonnell Douglas MD-11aircraft and the process of exporting newMD-11 aircraft from manufacturer in USA to European operator as passenger aircraft. It alsodiscusses the process of importing the same types of aircraft as freight carrier. The aircraftundergo, through different modifications at Singapore Technologies Aerospace (STA)conversion from passenger to freight carrier, a pr...

  1. Aircraft Noise: Annoyance, House Prices and Valuation

    OpenAIRE

    Brooker, Peter

    2006-01-01

    “Nobody wants to buy your house. It’s the aircraft noise. You’ll have to reduce the price a lot.” Aircraft noise around airports causes annoyance, and tends to reduce the price of affected properties. Can annoyance be ‘costed’ by examining house price reductions? Are there other ways of valuing annoyance in monetary terms? This short paper summarises key research results and poses some questions.

  2. Research on Emerging and Descending Aircraft Noise

    OpenAIRE

    Monika Bartkevičiūtė; Raimondas Grubliauskas

    2013-01-01

    Along with an increase in the aircraft engine power and growth in air traffic, noise level at airports and their surrounding environs significantly increases. Aircraft noise is high level noise spreading within large radius and intensively irritating the human body. Air transport is one of the main sources of noise having a particularly strong negative impact on the environment. The article deals with activities and noises taking place in the largest nationwide Vilnius International Airport.T...

  3. Incidence of Fungal attack on Aircraft Fuselage

    Directory of Open Access Journals (Sweden)

    H. M. Dayal

    1968-10-01

    Full Text Available Incidence of fungal attack on the fuselage of a few Vampire aircraft has been observed. The fungus isolated from the infected regions has been tentatively indentified as TorulaSp. Laboratory experiments have revealed that within four weeks this fungus causes about 44 percent loss in the tensile strength of the brich plywood used in the manufacture of the fuselage of the aircraft.

  4. An Optimization Model for Aircraft Service Logistics

    Institute of Scientific and Technical Information of China (English)

    Angus; Cheung; W; H; Ip; Angel; Lai; Eva; Cheung

    2002-01-01

    Scheduling is one of the most difficult issues in t he planning and operations of the aircraft services industry. In this paper, t he various scheduling problems in ground support operation of an aircraft mainte nance service company are addressed. The authors developed a set of vehicle rout ings to cover each schedule flights; the objectives pursued are the maximization of vehicle and manpower utilization and minimization of operation time. To obta in the goals, an integer-programming model with geneti...

  5. Review of Aircraft Engine Fan Noise Reduction

    Science.gov (United States)

    VanZante, Dale

    2008-01-01

    Aircraft turbofan engines incorporate multiple technologies to enhance performance and durability while reducing noise emissions. Both careful aerodynamic design of the fan and proper installation of the fan into the system are requirements for achieving the performance and acoustic objectives. The design and installation characteristics of high performance aircraft engine fans will be discussed along with some lessons learned that may be applicable to spaceflight fan applications.

  6. Aircraft Wake Vortex Evolution and Prediction

    OpenAIRE

    Holzäpfel, Frank

    2005-01-01

    Aircraft trailing vortices constitute both a kaleidoscope of instructive fluid dynamics phenomena and a challenge for the sustained development of safety and capacity of the air-transportation industry. The current manuscript gives an overview on the wake vortex issue which commences at its historical roots and concludes with the current status of knowledge regarding the nature and characteristics, and the modeling of aircraft wakes. The incentive of today's wake vortex research still re...

  7. Anti-aircraft Missiles and Gun Control

    OpenAIRE

    BLOCK, Walter

    2016-01-01

    Abstract. Gun control is a highly debatable topic both in the popular and scholarly media. But what about anti-aircraft missiles? Should they be banned? On the one hand, there are fewer of them around, so their challenge is more tractable. On the other hand, they can do far more damage than handguns. The present paper is an attempt to wrestle with this challenge.Keywords. Gun control, Second amendment, Libertarianism, Anti-aircraft missiles.JEL. K15.

  8. Computer Aided Visual Inspection of Aircraft Surfaces

    OpenAIRE

    Rafia Mumtaz; Mustafa Mumtaz; Atif Bin Mansoor; Hassan Masood

    2012-01-01

    Non Destructive Inspections (NDI) plays a vital role in aircraft industry as it determines the structural integrity of aircraft surface and material characterization. The existing NDI methods are time consuming, we propose a new NDI approach using Digital Image Processing that has the potential to substantially decrease the inspection time. Automatic Marking of cracks have been achieved through application of Thresholding, Gabor Filter and Non Subsampled Contourlet transform. For a novel meth...

  9. Smart fastener technology for aging aircraft

    Science.gov (United States)

    Schoess, Jeffrey N.; Paul, Clare A.

    1995-04-01

    Hidden and inaccessible corrosion in aircraft structures is the number 1 logistics problem for the Air Force, with an estimated maintenance cost of greater than one billion dollars per year. The smart aircraft fastener evaluation (SAFE) system is being developed to detect and characterize corrosion factors in hidden locations of aircraft structures. The SAFE concept is a novel `in-situ' measurement approach that measures and autonomously records several environmental factors (i.e., pH, temperature, chloride) associated with corrosion. The SAFE system integrated an electrochemical-based microsensor array directly into the aircraft structure to measure the evidence of active corrosion as an in-situ measurement without reducing aircraft structural integrity. The long term-payoff for the SAFE system will be in predictive maintenance for fixed and rotary wing aircraft structures, industrial tanks, and 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.

  10. Solar Radiation Measurements Onboard the Research Aircraft HALO

    Science.gov (United States)

    Lohse, I.; Bohn, B.; Werner, F.; Ehrlich, A.; Wendisch, M.

    2014-12-01

    Airborne measurements of the separated upward and downward components of solar spectral actinic flux densities for the determination of photolysis frequencies and of upward nadir spectral radiance were performed with the HALO Solar Radiation (HALO-SR) instrument package onboard the High Altitude and Long Range Research Aircraft (HALO). The instrumentation of HALO-SR is characterized and first measurement data from the Next-generation Aircraft Remote-Sensing for Validation Studies (NARVAL) campaigns in 2013 and 2014 are presented. The measured data are analyzed in the context of the retrieved microphysical and optical properties of clouds which were observed underneath the aircraft. Detailed angular sensitivities of the two optical actinic flux receivers were determined in the laboratory. The effects of deviations from the ideal response are investigated using radiative transfer calculations of atmospheric radiance distributions under various atmospheric conditions and different ground albedos. Corresponding correction factors are derived. Example photolysis frequencies are presented, which were sampled in the free troposphere and lower stratosphere over the Atlantic Ocean during the 2013/14 HALO NARVAL campaigns. Dependencies of photolysis frequencies on cloud cover, flight altitude and wavelength range of the photolysis process are investigated. Calculated actinic flux densities in the presence of clouds benefit from the measured spectral radiances. Retrieved cloud optical thicknesses and effective droplet radii are used as model input for the radiative transfer calculations. By comparison with the concurrent measurements of actinic flux densities the retrieval approach is validated. Acknowledgements: Funding by the Deutsche Forschungsgemeinschaft within the priority program HALO (BO 1580/4-1, WE 1900/21-1) is gratefully acknowledged.

  11. High altitude aircraft flight tests

    Science.gov (United States)

    Helmken, Henry; Emmons, Peter; Homeyer, David

    1996-03-01

    In order to make low earth orbit L-band propagation measurements and test new voice communication concepts, a payload was proposed and accepted for flight aboard the COMET (now METEOR) spacecraft. This Low Earth Orbiting EXperiment payload (LEOEX) was designed and developed by Motorola Inc. and sponsored by the Space Communications Technology Center (SCTC), a NASA Center for the Commercial Development of Space (CCDS) located at Florida Atlantic University. In order to verify the LEOEX payload for satellite operation and obtain some preliminary propagation data, a series of 9 high altitude aircraft (SR-71 and ER-2) flight tests were conducted. These flights took place during a period of 7 months, from October 1993 to April 1994. This paper will summarize the operation of the LEOEX payload and the particular configuration used for these flights. The series of flyby tests were very successful and demonstrated how bi-directional, Time Division Multiple Access (TDMA) voice communication will work in space-to-ground L-band channels. The flight tests also acquired propagation data which will be representative of L-band Low Earth Orbiting (LEO) communication systems. In addition to verifying the LEOEX system operation, it also uncovered and ultimately aided the resolution of several key technical issues associated with the payload.

  12. Beamforming for aircraft noise measurements

    Science.gov (United States)

    Dougherty, Robert P.

    2003-10-01

    Phased array beamforming for aircraft noise source location has a long history, including early work on jet noise, wind tunnel measurements, and flyover testing. In the last 10 years, advancements in sparse 2-D and 3-D arrays, wind tunnel test techniques, and computer power have made phased array measurements almost common. Large aerospace companies and national research institutes have an advantage in access to major facilities and hundreds of measurement microphones, but universities and even consulting companies can perform tests with electret microphones and PC data acquisition systems. The type of testing remains a blend of science and art. A complex noise source is approximated by a mathematical model, and the microphones are deployed to evaluate the parameters of the model. For example, the simplest, but often the best, approach is to assume a distribution of mutually incoherent monopoles. This leads to an imaging process analogous to photography. Other models include coherent distributions of multipoles or duct modes. It is sometimes important to simulate the results that would have been obtained from single microphone measurements of part of the airplane in an ideal environment, had such measurements been feasible.

  13. Intelligent control of agile aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Mohler, R.R.; Zakrzewski, R.R. [Dept. of Electrical and Computer Engineering, Corvallis, OR (United States)

    1994-12-31

    A brief overview of adaptive and computer-aided flight control is presented as background for the evolution of recent research on nonlinear intelligent control. Here, several nonlinear control algorithms are investigated but emphasis is given to nearly time-optimal, neural-net generated feedback control which is trained on ideal minimum-time, open-loop trajectories. The minimum-time policies are computed by a new version of the switching-line-variational method (gradient algorithm). Critical control constraints and a benchmark for performance as well as a basis for training are obtained for the system design. This further demonstrates the need for an integrated controls and aircraft system design for full utilization of nonlinear control capability. Complex nonlinear simulations show the effectiveness of the derived nonlinear feedback controller for the high-angle-of-attack research vehicle (HARV) with stabilator and thrust-vector control. For example, angle of attack is controlled from near zero to sixty degrees in about two seconds with appropriate trim conditions at both ends. Such control greatly enhances maneuverability and general flight envelope admissibility.

  14. Estimation of Separation Buffers for Wind-Prediction Error in an Airborne Separation Assistance System

    Science.gov (United States)

    Consiglio, Maria C.; Hoadley, Sherwood T.; Allen, B. Danette

    2009-01-01

    Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.

  15. Wind-tunnel investigation of surface-pressure fluctuations associated with aircraft buffet

    Science.gov (United States)

    Riddle, D. W.

    1975-01-01

    Fluctuating pressures and forces that cause aircraft buffeting have been measured on a semispan rigid-wing model of a typical variable-sweep fighter-type aircraft at transonic speeds. The rms spectral and spatial correlation characteristics of wing fluctuating pressures, fluctuating pressure summations, and structural responses are presented and discussed for a Mach number of 0.85, wing sweep angles of 26 and 72 deg, and angles of attack up to 12 deg. The fluctuating pressure characteristics beneath wing shock waves and leading-edge vortices and in regions of attached and separated flows are presented. Results indicate that: (1) the mean and fluctuating static pressure characteristics are related; (2) a circulation oscillation exists for attached flow conditions below buffet onset; and (3) a significant coupling exists between the wing shock-wave oscillation and the wing first torsional mode when shock-induced separation is present.

  16. Method Evaluating the Durability of Aircraft Piston Engines

    Directory of Open Access Journals (Sweden)

    Luca PIANCASTELLI

    2012-12-01

    Full Text Available A significant issue in aircraft engines is quantifying residual life to overhaul. The algorithm described in this paper calculates with a good level of reliability the residual life of a petrol piston engine. The method was tested on small, latest-generation, naturally-aspirated aircraft and racing piston engines, and has been effective in several experiments. This method is implemented directly on the electronic control system of the engine with very few lines of C-code. The method can also be used in many industrial engines. This innovative method assumes that only two main factors (power level and wear affect engine durability or time between overhauls. These two factors are considered as separate and combined with worst case criteria. The wear is assumed to follow a logarithmic law and a formula similar to the Miner’s law for material fatigue is used, making it possible to calculate the power-level curve with knowledge of only two points. The wear-curve is also related to elapsed engine cycles. The algorithm is very simple and can be implemented with just a few lines of software code accessing data collected from existing sensors. The system is currently used to evaluate actual residual life of racing engines.

  17. Isotope separation principles

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, Manson

    1963-03-15

    Isotope separation theory of ideal cascades is discussed. It is shown how the most important characteristics of an isotope separation process can be worked out from the compositions and flow rates of the feed and product streams. These characteristics include plant size, dependence of product rate on product purity, minimum power consumption, costs of isotope separation, minimum time for reaching steady production, and effect of third component on process performance and product costs. The concepts of value functions, separative power, and separative work are used to derive the characteristics, and the analogy between isotope separation theory and thermodynamics is emphasized. (D.L.C.)

  18. Common factors in the withdrawal of European aircraft manufacturers from the regional aircraft market

    NARCIS (Netherlands)

    Heerkens, Hans; Bruijn, de Erik J.; Steenhuis, Harm-Jan

    2010-01-01

    We investigate whether there were common causes for the withdrawal from the regional aircraft market of three established manufacturers (BAE Systems, Fokker and Saab), while competitors thrived. We focus on the markets for 50- and 100-seat aircraft. One cause concerning the 50-seat market was the in

  19. 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.

  20. 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.

  1. Magnetic Separation in Romania

    OpenAIRE

    Rezlescu, Nicolae; Bradu, Elena-Brandusa; Iacob, Gheorghe; Badescu, Vasile; Iacob, Lavinia

    1986-01-01

    The utilization of the magnetic separators of foreign and Romanian source is presented and the most important achievements in research, engineering design and manufacturing activity concerning the magnetic separation in Romania are reviewed.

  2. Magnetic Separation in Czechoslovakia

    OpenAIRE

    Hencl, Vladimir

    1991-01-01

    The use of magnetic separation in various mineral processing facilities in Czechoslovakia is described. The manufacture of assorted types of magnetic separation machines is highlighted. Potential applications and research and development activities are discussed.

  3. Magnetic separation of algae

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  4. On the methods and examples of aircraft impact analysis

    International Nuclear Information System (INIS)

    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

  5. Transonic buffet behavior of Northrop F-5A aircraft

    Science.gov (United States)

    Hwang, C.; Pi, W. S.

    1975-01-01

    Flight tests were performed on an extensively instrumented F-5A aircraft to investigate the dynamic buffet pressure distribution on the wing surfaces and the responses during a series of transonic maneuvers called the windup turns. The maneuvers to maximum lift were performed at three Mach number-altitude combinations with a constant 'q' of approximately 14,360 N/sq m (300 psf). The fluctuating buffet pressure data at 24 stations on the right wing of the F-5A were acquired by miniaturized semiconductor type pressure transducers mounted on the wing. A new transducer mounting and wiring technique was applied where the interference with the natural flow condition was minimized. The data acquired in this manner were found adequate to trace the shock origin, the movement of the shock front and the development of the separated flow (shock induced or leading edge induced) on the wing surface.

  6. Enhanced Imaging of Corrosion in Aircraft Structures with Reverse Geometry X-ray(registered tm)

    Science.gov (United States)

    Winfree, William P.; Cmar-Mascis, Noreen A.; Parker, F. Raymond

    2000-01-01

    The application of Reverse Geometry X-ray to the detection and characterization of corrosion in aircraft structures is presented. Reverse Geometry X-ray is a unique system that utilizes an electronically scanned x-ray source and a discrete detector for real time radiographic imaging of a structure. The scanned source system has several advantages when compared to conventional radiography. First, the discrete x-ray detector can be miniaturized and easily positioned inside a complex structure (such as an aircraft wing) enabling images of each surface of the structure to be obtained separately. Second, using a measurement configuration with multiple detectors enables the simultaneous acquisition of data from several different perspectives without moving the structure or the measurement system. This provides a means for locating the position of flaws and enhances separation of features at the surface from features inside the structure. Data is presented on aircraft specimens with corrosion in the lap joint. Advanced laminographic imaging techniques utilizing data from multiple detectors are demonstrated to be capable of separating surface features from corrosion in the lap joint and locating the corrosion in multilayer structures. Results of this technique are compared to computed tomography cross sections obtained from a microfocus x-ray tomography system. A method is presented for calibration of the detectors of the Reverse Geometry X-ray system to enable quantification of the corrosion to within 2%.

  7. Small Autonomous Aircraft Servo Health Monitoring

    Science.gov (United States)

    Quintero, Steven

    2008-01-01

    Small air vehicles offer challenging power, weight, and volume constraints when considering implementation of system health monitoring technologies. In order to develop a testbed for monitoring the health and integrity of control surface servos and linkages, the Autonomous Aircraft Servo Health Monitoring system has been designed for small Uninhabited Aerial Vehicle (UAV) platforms to detect problematic behavior from servos and the air craft structures they control, This system will serve to verify the structural integrity of an aircraft's servos and linkages and thereby, through early detection of a problematic situation, minimize the chances of an aircraft accident. Embry-Riddle Aeronautical University's rotary-winged UAV has an Airborne Power management unit that is responsible for regulating, distributing, and monitoring the power supplied to the UAV's avionics. The current sensing technology utilized by the Airborne Power Management system is also the basis for the Servo Health system. The Servo Health system measures the current draw of the servos while the servos are in Motion in order to quantify the servo health. During a preflight check, deviations from a known baseline behavior can be logged and their causes found upon closer inspection of the aircraft. The erratic behavior nay include binding as a result of dirt buildup or backlash caused by looseness in the mechanical linkages. Moreover, the Servo Health system will allow elusive problems to be identified and preventative measures taken to avoid unnecessary hazardous conditions in small autonomous aircraft.

  8. Improving Aircraft Design Robustness with Scenario Methods

    Directory of Open Access Journals (Sweden)

    A. Strohmayer

    2001-01-01

    Full Text Available Compared to other industries, the aerospace sector is characterized by long product cycles in a very complex environment. The aircraft manufacturer has to base his product strategy on a long-term view of risks and opportunities in the transport industry but he cannot predict the development of relevant factors in this market environment with any certainty. In this situation, scenario methods offer a pragmatic way to limit the uncertainties and to work them up methodically, in order to derive recommendations for cost-intensive strategic decisions like for example the go-ahead for a new aircraft concept. By including scenario methods in the aircraft design cycle, the ‘design robustness’ can be improved, i.e. the design is not optimised for a prognosticated operating environment, but can cope with various possible future developments. The paper will explain the three fundamental aspects in applying scenario planning to the aircraft design process: requirement definition, design evaluation and technology identification. For each aspect, methods will be shown, which connect the rather qualitative results of a scenario process with aircraft design, which typically demands a qualitative input.

  9. Design of a spanloader cargo aircraft

    Science.gov (United States)

    1989-01-01

    With a growing demand for fast international freight service, the slow-moving cargo ships currently in use will soon find a substantial portion of their clients looking elsewhere. One candidate for filling this expected gap in the freight market is a span-loading aircraft (or 'flying wing') capable of long-range operation with extremely large payloads. This report summarizes the design features of an aircraft capable of fulfilling a long-haul, high-capacity cargo mission. The spanloader seeks to gain advantage over conventional aircraft by eliminating the aircraft fuselage and thus reducing empty weight. The primary disadvantage of this configuration is that the cargo-containing wing tends to be thick, thus posing a challenge to the airfoil designer. It also suffers from stability and control problems not encountered by conventional aircraft. The result is an interesting, challenging exercise in unconventional design. The report that follows is a student written synopsis of an effort judged to be the best of eight designs developed during the year 1988-1989.

  10. Control strategies for aircraft airframe noise reduction

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Xunnian; Zhang Dejiu

    2013-01-01

    With the development of low-noise aircraft engine,airframe noise now represents a major noise source during the commercial aircraft's approach to landing phase.Noise control efforts have therefore been extensively focused on the airframe noise problems in order to further reduce aircraft overall noise.In this review,various control methods explored in the last decades for noise reduction on airframe components including high-lift devices and landing gears are summarized.We introduce recent major achievements in airframe noise reduction with passive control methods such as fairings,deceleration plates,splitter plates,acoustic liners,slat cove cover and side-edge replacements,and then discuss the potential and control mechanism of some promising active flow control strategies for airframe noise reduction,such as plasma technique and air blowing/suction devices.Based on the knowledge gained throughout the extensively noise control testing,a few design concepts on the landing gear,high-lift devices and whole aircraft are provided for advanced aircraft low-noise design.Finally,discussions and suggestions are given for future research on airframe noise reduction.

  11. Aircraft Combat Survivability Estimation and Synthetic Tradeoff Methods

    Institute of Scientific and Technical Information of China (English)

    LI Shu-lin; LI Shou-an; LI Wei-ji; LI Dong-xia; FENG Feng

    2005-01-01

    A new concept is proposed that susceptibility, vulnerability, reliability, maintainability and supportability should be essential factors of aircraft combat survivability. A weight coefficient method and a synthetic method are proposed to estimate aircraft combat survivability based on the essential factors. Considering that it takes cost to enhance aircraft combat survivability, a synthetic tradeoff model between aircraft combat survivability and life cycle cost is built. The aircraft combat survivability estimation methods and synthetic tradeoff with a life cycle cost model will be helpful for aircraft combat survivability design and enhancement.

  12. Improvements in Aircraft Gas Turbine Engines for the 90s

    Directory of Open Access Journals (Sweden)

    Arun Prasad

    1993-10-01

    Full Text Available The gas turbine propulsion system has been playing the most significant role in the evolution and development of present-day aircraft, and has become the limiting technology for developing most new aircraft. However, the jet engine still remains the preferred propulsion choice. Aircraft gas turbines in one form or the other, viz. turbojet, turbofan, turboprop or turboshaft, have been used in commercial passenger aircraft, high performance military aircraft and in rotary wing aircraft (helicopters. The emphasis in engine development programmes world over seems to be in reducing fuel consumption, increasing thrust and in reducing weight.

  13. Impact of Tactical and Strategic Weather Avoidance on Separation Assurance

    Science.gov (United States)

    Refai, Mohamad S.; Windhorst, Robert

    2011-01-01

    The ability to keep flights away from weather hazards while maintaining aircraft-to-aircraft separation is critically important. The Advanced Airspace Concept is an automation concept that implements a ground-based strategic conflict resolution algorithm for management of aircraft separation. The impact of dynamic and uncertain weather avoidance on this concept is investigated. A strategic weather rerouting system is integrated with the Advanced Airspace Concept, which also provides a tactical weather avoidance algorithm, in a fast time simulation of the Air Transportation System. Strategic weather rerouting is used to plan routes around weather in the 20 minute to two-hour time horizon. To address forecast uncertainty, flight routes are revised at 15 minute intervals. Tactical weather avoidance is used for short term trajectory adjustments (30 minute planning horizon) that are updated every minute to address any weather conflicts (instances where aircraft are predicted to pass through weather cells) that are left unresolved by strategic weather rerouting. The fast time simulation is used to assess the impact of tactical weather avoidance on the performance of automated conflict resolution as well as the impact of strategic weather rerouting on both conflict resolution and tactical weather avoidance. The results demonstrate that both tactical weather avoidance and strategic weather rerouting increase the algorithm complexity required to find aircraft conflict resolutions. Results also demonstrate that tactical weather avoidance is prone to higher airborne delay than strategic weather rerouting. Adding strategic weather rerouting to tactical weather avoidance reduces total airborne delays for the reported scenario by 18% and reduces the number of remaining weather violations by 13%. Finally, two features are identified that have proven important for strategic weather rerouting to realize these benefits; namely, the ability to revise reroutes and the use of maneuvers

  14. Aircraft System Design and Integration

    Directory of Open Access Journals (Sweden)

    D. P. Coldbeck

    2000-01-01

    Full Text Available In the 1980's the British aircraft industry changed its approach to the management of projects from a system where a project office would manage a project and rely on a series of specialist departments to support them to a more process oriented method, using systems engineering models, whose most outwardly visible signs were the introduction of multidisciplinary product teams. One of the problems with the old method was that the individual departments often had different priorities and projects would get uneven support. The change in the system was only made possible for complex designs by the electronic distribution of data giving instantaneous access to all involved in the project. In 1997 the Defence and Aerospace Foresight Panel emphasised the need for a system engineering approach if British industry was to remain competitive. The Royal Academy of Engineering recognised that the change in working practices also changed what was required of a chartered engineer and redefined their requirements in 1997 [1]. The result of this is that engineering degree courses are now judged against new criteria with more emphasis placed on the relevance to industry rather than on purely academic content. At the University of Glasgow it was realized that the students ought to be made aware of current working practices and that there ought to be a review to ensure that the degrees give students the skills required by industry. It was decided to produce a one week introduction course in systems engineering for Masters of Engineering (MEng students to be taught by both university lecturers and practitioners from a range of companies in the aerospace industry with the hope of expanding the course into a module. The reaction of the students was favourable in terms of the content but it seems ironic that the main criticism was that there was not enough discussion involving the students. This paper briefly describes the individual teaching modules and discusses the

  15. Separation Monitoring with Four Types of Predictors on a Cockpit Display of Traffic Information

    Science.gov (United States)

    Jago, S.; Palmer, E.

    1982-01-01

    A clear and concise display format for use in later full mission simulator evaluation of the cockpit display of traffic information (CDTI) concept was studied. This experiment required airline pilots to monitor a CDTI and make perceptual judgments concerning the future position of a single intruder aircraft in relationship to their own aircraft (ownship). The main experimental variable was the type of predictor used to display future position of each aircraft. Predictors were referenced to the ground or to ownship and they either included turn rate information or did not. Other variables were the aircraft's separation distance when the judgment was required and the type of encounter (straight or turning). Results indicate that under these experimental conditions fewer errors were made when the predictor included turn rate information. There was little difference in overall error rate for the curved ground referenced and the ownship referenced predictors.

  16. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  17. Aircraft induced contrail cirrus over Europe

    Energy Technology Data Exchange (ETDEWEB)

    Mannstein, H.; Schumann, U. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Inst. fuer Physik der Atmosphaere, Oberpfaffenhofen (Germany)

    2005-08-01

    Condensation trails (contrails) and aircraft induced cirrus are nowadays a common feature at the mid latitude skies. Previously the impact of aircraft induced cirrus changes has been roughly estimated from observed decadal trends in cirrus cover but the direct attribution of observed cirrus changes to changes in aviation activity remains uncertain. In this paper the amount of additional cirrus induced from spreading contrails in humid air is estimated from the direct correlation between observed cirrus cover derived with suitable methods from METEOSAT data and aviation flight density reported by EUROCONTROL at high spatial and temporal resolution from June 22 to July 27, 1998 and September 27 to October 21, 2000. The results indicate that the aircraft induced cirrus cover over Europe is about ten times larger than that of linear contrails in the same region. Radiative forcing from the additional cirrus may be more than 10 times higher than that of linear contrails and aviation induced CO{sub 2} increases. (orig.)

  18. Static aeroelastic analysis for generic configuration aircraft

    Science.gov (United States)

    Lee, IN; Miura, Hirokazu; Chargin, Mladen K.

    1987-01-01

    A static aeroelastic analysis capability that can calculate flexible air loads for generic configuration aircraft was developed. It was made possible by integrating a finite element structural analysis code (MSC/NASTRAN) and a panel code of aerodynamic analysis based on linear potential flow theory. The framework already built in MSC/NASTRAN was used and the aerodynamic influence coefficient matrix is computed externally and inserted in the NASTRAN by means of a DMAP program. It was shown that deformation and flexible airloads of an oblique wing aircraft can be calculated reliably by this code both in subsonic and supersonic speeds. Preliminary results indicating importance of flexibility in calculating air loads for this type of aircraft are presented.

  19. ANASE: measuring aircraft noise annoyance very unreliably.

    OpenAIRE

    Brooker, Peter

    2008-01-01

    Does anyone who lives under a flight-path like aircraft noise? It is a political hot potato as well as a peace-destroyer. Tens of thousands of people will hear the noise from any third runway at Heathrow. So, when a study commissioned by the government claimed that people are becoming less tolerant of aircraft noise, it made highly unpleasant reading for supporters of a third runway. But the Department for Transport rejected the report as unreliable. Peter Brooker senses the vibrations.

  20. A strategic planning methodology for aircraft redesign

    Science.gov (United States)

    Romli, Fairuz Izzuddin

    Due to a progressive market shift to a customer-driven environment, the influence of engineering changes on the product's market success is becoming more prominent. This situation affects many long lead-time product industries including aircraft manufacturing. Derivative development has been the key strategy for many aircraft manufacturers to survive the competitive market and this trend is expected to continue in the future. Within this environment of design adaptation and variation, the main market advantages are often gained by the fastest aircraft manufacturers to develop and produce their range of market offerings without any costly mistakes. This realization creates an emphasis on the efficiency of the redesign process, particularly on the handling of engineering changes. However, most activities involved in the redesign process are supported either inefficiently or not at all by the current design methods and tools, primarily because they have been mostly developed to improve original product development. In view of this, the main goal of this research is to propose an aircraft redesign methodology that will act as a decision-making aid for aircraft designers in the change implementation planning of derivative developments. The proposed method, known as Strategic Planning of Engineering Changes (SPEC), combines the key elements of the product redesign planning and change management processes. Its application is aimed at reducing the redesign risks of derivative aircraft development, improving the detection of possible change effects propagation, increasing the efficiency of the change implementation planning and also reducing the costs and the time delays due to the redesign process. To address these challenges, four research areas have been identified: baseline assessment, change propagation prediction, change impact analysis and change implementation planning. Based on the established requirements for the redesign planning process, several methods and

  1. Aerodynamics/ACEE: Aircraft energy efficiency

    Science.gov (United States)

    1981-01-01

    An overview is presented of a 10 year program managed by NASA which seeks to make possible the most efficient use of energy for aircraft propulsion and lift as well as provide a technology that can be used by U.S. manufacturers of air transports and engines. Supercritical wings, winglets, vortex drag reduction, high lift, active control, laminar flow control, and aerodynamics by computer are among the topics discussed. Wind tunnel models in flight verification of advanced technology, and the design, construction and testing of various aircraft structures are also described.

  2. Advanced materials for aircraft engine applications.

    Science.gov (United States)

    Backman, D G; Williams, J C

    1992-02-28

    A review of advances for aircraft engine structural materials and processes is presented. Improved materials, such as superalloys, and the processes for making turbine disks and blades have had a major impact on the capability of modern gas turbine engines. New structural materials, notably composites and intermetallic materials, are emerging that will eventually further enhance engine performance, reduce engine weight, and thereby enable new aircraft systems. In the future, successful aerospace manufacturers will combine product design and materials excellence with improved manufacturing methods to increase production efficiency, enhance product quality, and decrease the engine development cycle time.

  3. Titanium alloys Russian aircraft and aerospace applications

    CERN Document Server

    Moiseyev, Valentin N

    2005-01-01

    This text offers previously elusive information on state-of-the-art Russian metallurgic technology of titanium alloys. It details their physical, mechanical, and technological properties, as well as treatments and applications in various branches of modern industry, particularly aircraft and aerospace construction. Titanium Alloys: Russian Aircraft and Aerospace Applications addresses all facets of titanium alloys in aerospace and aviation technology, including specific applications, fundamentals, composition, and properties of commercial alloys. It is useful for all students and researchers interested in the investigation and applications of titanium.

  4. Ageing aircraft research in the Netherlands

    Science.gov (United States)

    Dejonge, J. B.; Bartelds, G.

    1992-01-01

    The problems of aging aircraft are worldwide. Hence, international cooperative actions to overcome or prevent problems should be taken. The Federal Aviation Administration (FAA) and the Netherlands Civil Aviation Department (RLD) signed a Memorandum of Cooperation in the area of structural integrity, with specific reference to research on problems in the area of aging aircraft. Here, an overview is given of aging research that is going on in the Netherlands. The work described is done largely at the National Aerospace Laboratory; much of the research is part of the forementioned cooperative agreement.

  5. Conversion of the dual training aircraft (DC into single control advanced training aircraft (SC. Part I

    Directory of Open Access Journals (Sweden)

    Ioan ŞTEFĂNESCU

    2011-03-01

    Full Text Available Converting the DC school jet aircraft into SC advanced training aircraft - and use them forthe combat training of military pilots from the operational units, has become a necessity due to thebudget cuts for Air Force, with direct implications on reducing the number of hours of flight assignedto operating personnel for preparing and training.The purpose of adopting such a program is to reduce the number of flight hours allocated annuallyfor preparing and training in advanced stages of instruction, for every pilot, by more intensive use ofthis type of aircraft, which has the advantage of lower flight hour costs as compared to a supersoniccombat plane.

  6. The contribution of aircraft emissions to the atmospheric sulfur budget

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, E. [Stockholm Univ. (Sweden). Dept. of Meteorology; Feichter, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Sausen, R.; Hein, R. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-01-01

    An atmospheric general circulation model including the atmospheric sulfur cycle has been used to investigate the impact of aircraft sulfur emissions on the global sulfur budget of the atmosphere. The relative contribution from aircraft sulfur to the atmospheric sulfate burden is larger than the ratio between aircraft emissions and surface emissions due to the calculated long turn-over time of aircraft sulfate (about 12 days). However, in terms of the sulfate mass balance, aircraft emissions are small, contributing about 1% of the total sulfate mass north of 40 deg C where the aircraft emissions are largest. Despite this small contribution to sulfate mass, the aircraft emissions could potentially significantly enhance the background number concentration of aerosol particles. Based on the model calculations the increased stratospheric background aerosol mass observed during the last decades can not be explained by increased aircraft sulfur emissions 50 refs, 9 figs, 4 tabs

  7. Distributed Data Mining for Aircraft Health Management Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA, DoD, and commercial aircraft operators need to transform vast amounts of aircraft data accumulated in distributed databases into actionable knowledge. We...

  8. A Turbo-Brayton Cryocooler for Aircraft Superconducting Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hybrid turbo-electric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft...

  9. Distributed Data Mining for Aircraft Health Management Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft Flight Operations Quality Assurance (FOQA) programs are implemented by most of the aircraft operators. Vast amounts of FOQA data are distributed between...

  10. Aircraft detection based on probability model of structural elements

    Science.gov (United States)

    Chen, Long; Jiang, Zhiguo

    2014-11-01

    Detecting aircrafts is important in the field of remote sensing. In past decades, researchers used various approaches to detect aircrafts based on classifiers for overall aircrafts. However, with the development of high-resolution images, the internal structures of aircrafts should also be taken into consideration now. To address this issue, a novel aircrafts detection method for satellite images based on probabilistic topic model is presented. We model aircrafts as the connected structural elements rather than features. The proposed method contains two major steps: 1) Use Cascade-Adaboost classier to identify the structural elements of aircraft firstly. 2) Connect these structural elements to aircrafts, where the relationships between elements are estimated by hierarchical topic model. The model places strict spatial constraints on structural elements which can identify differences between similar features. The experimental results demonstrate the effectiveness of the approach.

  11. Practical Voice Recognition for the Aircraft Cockpit Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal responds to the urgent need for improved pilot interfaces in the modern aircraft cockpit. Recent advances in aircraft equipment bring tremendous...

  12. Fault Tolerance, Diagnostics, and Prognostics in Aircraft Flight

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract In modern fighter aircraft with statically unstable airframe designs, the flight control system is considered flight critical, i.e. the aircraft will...

  13. Auralization of NASA N+2 Aircraft Concepts from System Noise Predictions

    Science.gov (United States)

    Rizzi, Stephen A.; Burley, Casey L.; Thomas, Russel H.

    2016-01-01

    Auralization of aircraft flyover noise provides an auditory experience that complements integrated metrics obtained from system noise predictions. Recent efforts have focused on auralization methods development, specifically the process by which source noise information obtained from semi-empirical models, computational aeroacoustic analyses, and wind tunnel and flight test data, are used for simulated flyover noise at a receiver on the ground. The primary focus of this work, however, is to develop full vehicle auralizations in order to explore the distinguishing features of NASA's N+2 aircraft vis-à-vis current fleet reference vehicles for single-aisle and large twin-aisle classes. Some features can be seen in metric time histories associated with aircraft noise certification, e.g., tone-corrected perceived noise level used in the calculation of effective perceived noise level. Other features can be observed in sound quality metrics, e.g., loudness, sharpness, roughness, fluctuation strength and tone-to-noise ratio. A psychoacoustic annoyance model is employed to establish the relationship between sound quality metrics and noise certification metrics. Finally, the auralizations will serve as the basis for a separate psychoacoustic study aimed at assessing how well aircraft noise certification metrics predict human annoyance for these advanced vehicle concepts.

  14. Maintenance-free lead acid battery for inertial navigation systems aircraft

    Science.gov (United States)

    Johnson, William R.; Vutetakis, David G.

    1995-05-01

    Historically, Aircraft Inertial Navigation System (INS) Batteries have utilized vented nickel-cadmium batteries for emergency DC power. The United States Navy and Air Force developed separate systems during their respective INS developments. The Navy contracted with Litton Industries to produce the LTN-72 and Air Force contracted with Delco to produce the Carousel IV INS for the large cargo and specialty aircraft applications. Over the years, a total of eight different battery national stock numbers (NSNs) have entered the stock system along with 75 battery spare part NSNs. The Standard Hardware Acquisition and Reliability Program is working with the Aircraft Battery Group at Naval Surface Warfare Center Crane Division, Naval Air Systems Command (AIR 536), Wright Laboratory, Battelle Memorial Institute, and Concorde Battery Corporation to produce a standard INS battery. This paper discusses the approach taken to determine whether the battery should be replaced and to select the replacement chemistry. The paper also discusses the battery requirements, aircraft that the battery is compatible with, and status of Navy flight evaluation. Projected savings in avoided maintenance in Navy and Air Force INS Systems is projected to be $14.7 million per year with a manpower reduction of 153 maintenance personnel. The new INS battery is compatible with commercially sold INS systems which represents 66 percent of the systems sold.

  15. Recent advance in nonlinear aeroelastic analysis and control of the aircraft

    Institute of Scientific and Technical Information of China (English)

    Xiang Jinwu; Yan Yongju; Li Daochun

    2014-01-01

    A review on the recent advance in nonlinear aeroelasticity of the aircraft is presented in this paper. The nonlinear aeroelastic problems are divided into three types based on different research objects, namely the two dimensional airfoil, the wing, and the full aircraft. Different non-linearities encountered in aeroelastic systems are discussed firstly, where the emphases is placed on new nonlinear model to describe tested nonlinear relationship. Research techniques, especially new theoretical methods and aeroelastic flutter control methods are investigated in detail. The route to chaos and the cause of chaotic motion of two-dimensional aeroelastic system are summarized. Var-ious structural modeling methods for the high-aspect-ratio wing with geometric nonlinearity are dis-cussed. Accordingly, aerodynamic modeling approaches have been developed for the aeroelastic modeling of nonlinear high-aspect-ratio wings. Nonlinear aeroelasticity about high-altitude long-endurance (HALE) and fight aircrafts are studied separately. Finally, conclusions and the chal-lenges of the development in nonlinear aeroelasticity are concluded. Nonlinear aeroelastic problems of morphing wing, energy harvesting, and flapping aircrafts are proposed as new directions in the future.

  16. Recent advance in nonlinear aeroelastic analysis and control of the aircraft

    Directory of Open Access Journals (Sweden)

    Xiang Jinwu

    2014-02-01

    Full Text Available A review on the recent advance in nonlinear aeroelasticity of the aircraft is presented in this paper. The nonlinear aeroelastic problems are divided into three types based on different research objects, namely the two dimensional airfoil, the wing, and the full aircraft. Different nonlinearities encountered in aeroelastic systems are discussed firstly, where the emphases is placed on new nonlinear model to describe tested nonlinear relationship. Research techniques, especially new theoretical methods and aeroelastic flutter control methods are investigated in detail. The route to chaos and the cause of chaotic motion of two-dimensional aeroelastic system are summarized. Various structural modeling methods for the high-aspect-ratio wing with geometric nonlinearity are discussed. Accordingly, aerodynamic modeling approaches have been developed for the aeroelastic modeling of nonlinear high-aspect-ratio wings. Nonlinear aeroelasticity about high-altitude long-endurance (HALE and fight aircrafts are studied separately. Finally, conclusions and the challenges of the development in nonlinear aeroelasticity are concluded. Nonlinear aeroelastic problems of morphing wing, energy harvesting, and flapping aircrafts are proposed as new directions in the future.

  17. CAD SIMULATION & FEM ANALYSIS OF AIRCRAFT LANDING GEAR MECHANISM

    OpenAIRE

    Nilesh W. Nirwan; Dilip G. Gangwani,

    2015-01-01

    Aircraft landing gear supports the entire weight of an aircraft during landing and ground operations. They are attached to primary structural members of the aircraft. The type of gear depends on the aircraft design and its intended use. Most landing gear has wheels to facilitate operation to and from hard surfaces, such as airport runways. Other gear feature skids for this purpose, such as those found on helicopters, balloon gondolas, and in the tail area of some tail dragger airc...

  18. A measurement method to discriminate aircraft fly-over noise

    OpenAIRE

    Genesca Francitorra, Meritxell; Romeu Garbí, Jordi; Pàmies Gómez, Teresa

    2010-01-01

    Currently aircraft noise monitoring systems use a mesh of single microphones distributed around an airport to continuously sample the noise level. This fact requires a manual process of aircraft noise event detection and classification in order to distinguish aircraft events from the rest of noise events in the recording. In the present paper a 3-meter-long 12-microphone linear array is used to automatically obtain a background noise free aircraft noise recording. The beamforming process sepa...

  19. Light shaping diffusers{trademark} improve aircraft inspection

    Energy Technology Data Exchange (ETDEWEB)

    Shagam, R.N. [Sandia National Labs., Albuquerque, NM (United States); Shie, R.; Lerner, J. [Physical Optics Corp., Torrance, CA (United States)

    1994-11-01

    Physical Optical Corporation has introduced a Light Shaping Diffuser{trademark} (LSD) for the specialized illumination requirements of aircraft inspection. Attached to a handheld, battery-powered flashlight, this light-weight, holographic diffuser element provides bright, even illumination as aircraft inspectors perform the important task of visually examining aircraft for possible structural defects. Field trials conducted by the Aging Aircraft Program at Sandia National Laboratories confirm that the LSD-equipped flashlights are preferred by visual inspectors over stock flashlights.

  20. 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 the Act and § 280.2 will not be made if such aircraft is damaged to an extent that its value is...

  1. 49 CFR 172.448 - CARGO AIRCRAFT ONLY label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false CARGO AIRCRAFT ONLY label. 172.448 Section 172.448... SECURITY PLANS Labeling § 172.448 CARGO AIRCRAFT ONLY label. (a) Except for size and color, the CARGO AIRCRAFT ONLY label must be as follows: ER14JA09.001 (b) The CARGO AIRCRAFT ONLY label must be black on...

  2. Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

    OpenAIRE

    Gino Rinaldi; Trisha Huber; Heather McIntosh; Les Lebrun; Heping Ding; John Weber

    2012-01-01

    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 p...

  3. Stem Cell Separation Technologies

    OpenAIRE

    Zhu, Beili; Murthy, Shashi K

    2013-01-01

    Stem cell therapy and translational stem cell research require large-scale supply of stem cells at high purity and viability, thus leading to the development of stem cell separation technologies. This review covers key technologies being applied to stem cell separation, and also highlights exciting new approaches in this field. First, we will cover conventional separation methods that are commercially available and have been widely adapted. These methods include Fluorescence-activated cell so...

  4. [Separation anxiety. Theoretical considerations].

    Science.gov (United States)

    Blandin, N; Parquet, P J; Bailly, D

    1994-01-01

    The interest in separation anxiety is nowadays increasing: this disorder appearing during childhood may predispose to the occurrence of anxiety disorders (such as panic disorder and agoraphobia) and major depression into adulthood. Psychoanalytic theories differ on the nature of separation anxiety and its place in child development. For some authors, separation anxiety must be understood as resulting from the unconscious internal conflicts inherent in the individuation process and gradual attainment of autonomy. From this point of view, the fear of loss of mother by separation is not regarded as resulting from a real danger. However, Freud considers the primary experience of separation from protecting mother as the prototype situation of anxiety and compares the situations generating fear to separation experiences. For him, anxiety originates from two factors: the physiological fact is initiated at the time of birth but the primary traumatic situation is the separation from mother. This point of view may be compared with behavioral theories. Behavioral theories suggest that separation anxiety may be conditioned or learned from innate fears. In Freud's theory, the primary situation of anxiety resulting from the separation from mother plays a role comparable to innate fears. Grappling with the problem of separation anxiety, Bowlby emphasizes then the importance of the child's attachment to one person (mother or primary caregiver) and the fact that this attachment is instinctive. This point of view, based on the watch of infants, is akin to ethological theories on behaviour of non human primates. Bowlby especially shows that the reactions of infant separated from mother evolve on three stages: the phase of protestation which may constitute the prototype of adulthood anxiety, the phase of desperation which may be the prototype of depression, and the phase of detachment. He emphasizes so the role of early separations in the development of vulnerability to depression

  5. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

  6. Entrainment separator performance

    International Nuclear Information System (INIS)

    Clean and dust-loaded ACS entrainment separators mounted upstream of HEPA filters were exposed to a combination of fine water mist and steam at about 700C from one to four hours. In every trial, the ACS entrainment separator prevented measurable deterioration of performance in the following HEPA filter. Droplet size-efficiency evaluation of the ACS entrainment separators showed that, within the accuracy of the measurements, they meet all service requirements and are fully equal to the best separator units available for service on pressurized water reactors

  7. 75 FR 9327 - Aircraft Noise Certification Documents for International Operations

    Science.gov (United States)

    2010-03-02

    ... Administration 14 CFR Part 91 RIN 2120-AJ31 Aircraft Noise Certification Documents for International Operations... operating rules to require U.S. operators flying outside the United States to carry aircraft noise..., Subpart III, Section 44715, Controlling aircraft noise and sonic boom. Under that section, the FAA...

  8. 10 CFR 70.14 - Foreign military aircraft.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Foreign military aircraft. 70.14 Section 70.14 Energy....14 Foreign military aircraft. The regulations in this part do not apply to persons who carry special nuclear material (other than plutonium) in aircraft of the armed forces of foreign nations subject to 49...

  9. 47 CFR 90.423 - Operation on board aircraft.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Operation on board aircraft. 90.423 Section 90... PRIVATE LAND MOBILE RADIO SERVICES Operating Requirements § 90.423 Operation on board aircraft. (a) Except... after September 14, 1973, under this part may be operated aboard aircraft for air-to-mobile,...

  10. 19 CFR 122.86 - Substitution of aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Substitution of aircraft. 122.86 Section 122.86... Substitution of aircraft. (a) Application. The residue cargo procedure applies when an airline must substitute aircraft to reach a destination due to weather conditions or operational factors which prevent an...

  11. 75 FR 70074 - Consensus Standards, Light-Sport Aircraft

    Science.gov (United States)

    2010-11-16

    ... Federal Aviation Administration Consensus Standards, Light-Sport Aircraft AGENCY: Federal Aviation... provisions of the Sport Pilot and Light-Sport Aircraft rule issued July 16, 2004, and effective September 1, 2004. ASTM International Committee F37 on Light Sport Aircraft developed the revised standards...

  12. 76 FR 45647 - Consensus Standards, Light-Sport Aircraft

    Science.gov (United States)

    2011-07-29

    ... revision process. Background: Under the provisions of the Sport Pilot and Light-Sport Aircraft rule, 69 FR... Federal Aviation Administration Consensus Standards, Light-Sport Aircraft AGENCY: Federal Aviation... to the provisions of the Sport Pilot and Light-Sport Aircraft rule issued July 16, 2004,...

  13. 14 CFR 45.31 - Marking of export aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Marking of export aircraft. 45.31 Section 45.31 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT IDENTIFICATION AND REGISTRATION MARKING Nationality and Registration Marks § 45.31 Marking of export aircraft....

  14. 14 CFR 135.145 - Aircraft proving and validation tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft proving and validation tests. 135... Aircraft and Equipment § 135.145 Aircraft proving and validation tests. (a) No certificate holder may... safely and in compliance with applicable regulatory standards. Validation tests are required for...

  15. Licencing and Training Reform in the Australian Aircraft Maintenance Industry

    Science.gov (United States)

    Hampson, Ian; Fraser, Doug

    2016-01-01

    The training and licencing of aircraft maintenance engineers fulfils a crucial protective function since it is they who perform and supervise aircraft maintenance and certify that planes are safe afterwards. In Australia, prior to training reform, a trades-based system of aircraft maintenance engineer training existed in an orderly relation with…

  16. 14 CFR 21.128 - Tests: aircraft engines.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft engines. 21.128 Section 21.128 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... engines. (a) Each person manufacturing aircraft engines under a type certificate only shall subject...

  17. 14 CFR 91.325 - Primary category aircraft: Operating limitations.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Primary category aircraft: Operating... Flight Operations § 91.325 Primary category aircraft: Operating limitations. (a) No person may operate a primary category aircraft carrying persons or property for compensation or hire. (b) No person may...

  18. Disruption Management for an Airline - Rescheduling of aircraft

    DEFF Research Database (Denmark)

    Larsen, Jesper; Løve, Michael; Sørensen, Kim Riis;

    2002-01-01

    The Aircraft Recovery Problem (ARP) involves decisions concerning aircraft to flight assignments in situations where unforseen events have disrupted the existing flight schedule, e.g. bad weather causing flight delays. The aircraft recovery problem aims to recover these flight schedules through a...

  19. Using heuristics to solve the dedicated aircraft recovery problem

    DEFF Research Database (Denmark)

    Løve, Michael; Sørensen, Kim Riis; Larsen, Jesper;

    2001-01-01

    The Dedicated Aircraft Recovery Problem (DARP) involves decisions concerning aircraft to flight assignments in situations where unforeseen events have disrupted the existing flight schedule, e.g. bad weather causing flight delays. The dedicated aircraft recovery problem aims to recover these flig...

  20. Northwest to Accelerate Retirement of Dc10 Aircraft

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Northwest Airlines announced that it will accelerate the retirement of its remaining 12DC10-30 aircraft in service. The airline said that during the next seven months,it will replace DC10 aircraft with new Airbus A330s and Boeing 747-400aircraft being returned to service.Currently, seven routes are served with the DC10.

  1. Smart Sensor System for NDE or Corrosion in Aging Aircraft

    Science.gov (United States)

    Bar-Cohen, Y.; Marzwell, N.; Osegueda, R.; Ferregut, C.

    1998-01-01

    The extension of the operation life of military and civilian aircraft rather than replacing them with new ones is increasing the probability of aircraft component failure as a result of aging. Aircraft that already have endured a long srvice life of more than 40 years are now being considered for another 40 years of service.

  2. Recognition of aircraft using HRR features

    NARCIS (Netherlands)

    Kossen, A.S.

    2008-01-01

    Automated target recognition (ATR) based on high resolution radar (HRR) features can be used to increase the confidence in aircraft class. Standard radar systems are not designed for performing classification and uses additional identification systems. It is shown that with the use of features the a

  3. 78 FR 67309 - Earth Stations Aboard Aircraft

    Science.gov (United States)

    2013-11-12

    ...), and (d) published at 78 FR 14920 on March 8, 2013, are effective on November 12, 2013. FOR FURTHER...-161, published at 78 FR 14920, March 8, 2013. The OMB Control Number is 3060-1187. The Commission... COMMISSION 47 CFR Part 25 Earth Stations Aboard Aircraft AGENCY: Federal Communications Commission....

  4. Tactical aircraft optical cable plant program plan

    Science.gov (United States)

    Weaver, Thomas L.; Murdock, John K.; Ide, James R.

    1995-05-01

    A program was created with joint industry and government funding to apply fiber optic technologies to tactical aircraft. The technology offers many potential benefits, including increased electromagnetic interference immunity and the possibility of reduced weight, increased reliability, and enlarged capability from redesigning architectures to use the large bandwidth of fiber optics. Those benefits will only be realized if fiber optics meets the unique requirements of aircraft networks. The application of fiber optics to tactical aircraft presents challenges to physical components which can only be met by a methodical attention to what is required, what are the conditions of use, and how will the components be produced in the broad context of a fiber optics using economy. For this purpose, the FLASH program has outlined a plan, and developed a team to evaluate requirements, delineate environmental and use conditions, and design practical, low cost components for tactical aircraft fiber optic cable plants including cables, connectors, splices, backplanes, manufacturing and installation methods, and test and maintenance methods.

  5. Perspectives of civil aircraft avionics development

    OpenAIRE

    Наумов, А. В.

    1999-01-01

    Considered are main directions for civil avionics development. General requirements for airborne equipment functions. Analysis of airborne avionics selection per architecture and economical effectiveness in made. Proposed is the necessity of new approach to integrated avionics complex design, first of all, on basis of mathematical method for aircraft equipment and technical characteristics definition

  6. Stratospheric aircraft: Impact on the stratosphere

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, H.

    1992-02-01

    The steady-state distribution of natural stratospheric ozone is primarily maintained through production by ultraviolet photolysis of molecular oxygen, destruction by a catalytic cycle involving nitrogen oxides (NO{sub x}), and relocation by air motions within the stratosphere. Nitrogen oxides from the exhausts of a commercially viable fleet of supersonic transports would exceed the natural source of stratospheric nitrogen oxides if the t should be equipped with 1990 technology jet engines. This model-free comparison between a vital natural global ingredient and a proposed new industrial product shows that building a large fleet of passenger stratospheric aircraft poses a significant global problem. NASA and aircraft industries have recognized this problem and are studying the redesign of jet aircraft engines in order to reduce the nitrogen oxides emissions. In 1989 atmospheric models identified two other paths by which the ozone destroying effects of stratospheric aircraft might be reduced or eliminated: (1) Use relatively low supersonic Mach numbers and flight altitudes. For a given rate of nitrogen oxides injection into the stratosphere, the calculated reduction of total ozone is a strong function of altitude, and flight altitudes well below 20 kilometers give relatively low calculated ozone reductions. (2) Include heterogeneous chemistry in the two-dimensional model calculations. Necessary conditions for answering the question on the title above are to improve the quality of our understanding of the lower stratosphere and to broaden our knowledge of hetergeneous stratospheric chemistry. This article reviews recently proposed new mechanisms for heterogeneous reactions on the global stratospheric sulfate aerosols.

  7. Stratospheric aircraft: Impact on the stratosphere?

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, H.

    1992-02-01

    The steady-state distribution of natural stratospheric ozone is primarily maintained through production by ultraviolet photolysis of molecular oxygen, destruction by a catalytic cycle involving nitrogen oxides (NO{sub x}), and relocation by air motions within the stratosphere. Nitrogen oxides from the exhausts of a commercially viable fleet of supersonic transports would exceed the natural source of stratospheric nitrogen oxides if the t should be equipped with 1990 technology jet engines. This model-free comparison between a vital natural global ingredient and a proposed new industrial product shows that building a large fleet of passenger stratospheric aircraft poses a significant global problem. NASA and aircraft industries have recognized this problem and are studying the redesign of jet aircraft engines in order to reduce the nitrogen oxides emissions. In 1989 atmospheric models identified two other paths by which the ozone destroying effects of stratospheric aircraft might be reduced or eliminated: (1) Use relatively low supersonic Mach numbers and flight altitudes. For a given rate of nitrogen oxides injection into the stratosphere, the calculated reduction of total ozone is a strong function of altitude, and flight altitudes well below 20 kilometers give relatively low calculated ozone reductions. (2) Include heterogeneous chemistry in the two-dimensional model calculations. Necessary conditions for answering the question on the title above are to improve the quality of our understanding of the lower stratosphere and to broaden our knowledge of hetergeneous stratospheric chemistry. This article reviews recently proposed new mechanisms for heterogeneous reactions on the global stratospheric sulfate aerosols.

  8. Automation tools for flexible aircraft maintenance.

    Energy Technology Data Exchange (ETDEWEB)

    Prentice, William J.; Drotning, William D.; Watterberg, Peter A.; Loucks, Clifford S.; Kozlowski, David M.

    2003-11-01

    This report summarizes the accomplishments of the Laboratory Directed Research and Development (LDRD) project 26546 at Sandia, during the period FY01 through FY03. The project team visited four DoD depots that support extensive aircraft maintenance in order to understand critical needs for automation, and to identify maintenance processes for potential automation or integration opportunities. From the visits, the team identified technology needs and application issues, as well as non-technical drivers that influence the application of automation in depot maintenance of aircraft. Software tools for automation facility design analysis were developed, improved, extended, and integrated to encompass greater breadth for eventual application as a generalized design tool. The design tools for automated path planning and path generation have been enhanced to incorporate those complex robot systems with redundant joint configurations, which are likely candidate designs for a complex aircraft maintenance facility. A prototype force-controlled actively compliant end-effector was designed and developed based on a parallel kinematic mechanism design. This device was developed for demonstration of surface finishing, one of many in-contact operations performed during aircraft maintenance. This end-effector tool was positioned along the workpiece by a robot manipulator, programmed for operation by the automated planning tools integrated for this project. Together, the hardware and software tools demonstrate many of the technologies required for flexible automation in a maintenance facility.

  9. Weed detection using unmanned aircraft vehicles

    Directory of Open Access Journals (Sweden)

    Pflanz, Michael

    2014-03-01

    Full Text Available In contrast to agricultural remote sensing technologies, which are based on images from satellites or manned aircrafts, photogrammetry at low altitude from unmanned aircraft vehicles lead to higher spatial resolution, real-time processing and lower costs. Moreover multicopter aircrafts are suitable vehicles to perform precise path or stationary flights. In terms of vegetation photogrammetry this minimises motion blur and provide better image overlapping for stitching and mapping procedures. Through improved image analyses and through the recent increase in the availability of powerful batteries, microcontrollers and multispectral cameras, it can be expected in future that spatial mapping of weeds from low altitudes will be promoted. A small unmanned aircraft vehicle with a modified RGB camera was tested taking images from agricultural fields. A microcopter with six rotors was applied. The hexacopter in particular is GPS controlled and operates within predefined areas at given altitudes (from 5 to 10 m. Different scenarios of photogrammetrically weed detection have been carried out regarding to variable altitude, image resolution, weed and crop growth stages. First experiences with microcopter showed a high potential for site-specific weed control. Images analyses with regards to recognition of weed patches can be used to adapt herbicide applications to varying weed occurrence across a field.

  10. 14 CFR 34.6 - Aircraft safety.

    Science.gov (United States)

    2010-01-01

    ...) Consistent with 40 CFR 87.6, if the FAA Administrator determines that any emission control regulation in this... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Aircraft safety. 34.6 Section 34.6... safety. (a) The provisions of this part will be revised if at any time the Administrator determines...

  11. Towards Intelligent Control for Next Generation Aircraft

    Science.gov (United States)

    Acosta, Diana Michelle; KrishnaKumar, Kalmanje Srinvas; Frost, Susan Alane

    2008-01-01

    NASA Aeronautics Subsonic Fixed Wing Project is focused on mitigating the environmental and operation impacts expected as aviation operations triple by 2025. The approach is to extend technological capabilities and explore novel civil transport configurations that reduce noise, emissions, fuel consumption and field length. Two Next Generation (NextGen) aircraft have been identified to meet the Subsonic Fixed Wing Project goals - these are the Hybrid Wing-Body (HWB) and Cruise Efficient Short Take-Off and Landing (CESTOL) aircraft. The technologies and concepts developed for these aircraft complicate the vehicle s design and operation. In this paper, flight control challenges for NextGen aircraft are described. The objective of this paper is to examine the potential of state-of-the-art control architectures and algorithms to meet the challenges and needed performance metrics for NextGen flight control. A broad range of conventional and intelligent control approaches are considered, including dynamic inversion control, integrated flight-propulsion control, control allocation, adaptive dynamic inversion control, data-based predictive control and reinforcement learning control.

  12. Developing aircraft photonic networks for airplane systems

    DEFF Research Database (Denmark)

    White, Henry J.; Brownjohn, Nick; Baptista, João;

    2013-01-01

    Achieving affordable high speed fiber optic communication networks for airplane systems has proved to be challenging. In this paper we describe a summary of the EU Framework 7 project DAPHNE (Developing Aircraft Photonic Networks). DAPHNE aimed to exploit photonic technology from terrestrial comm...

  13. Emergency Landing Planning for Damaged Aircraft

    Science.gov (United States)

    Meuleau, Nicolas; Plaunt, Christian John; Smith, David E.

    2008-01-01

    Considerable progress has been made over the last 15 years on building adaptive control systems to assist pilots in flying damaged aircraft. Once a pilot has regained control of a damaged aircraft, the next problem is to determine the best site for an emergency landing. In general, the decision depends on many factors including the actual control envelope of the aircraft, distance to the site, weather en route, characteristics of the approach path, characteristics of the runway or landing site, and emergency facilities at the site. All of these influence the risk to the aircraft, to the passengers and crew, and to people and property on the ground. We describe an ongoing project to build and demonstrate an emergency landing planner that takes these various factors into consideration and proposes possible routes and landing sites to the pilot, ordering them according to estimated risk. We give an overview of the system architecture and input data, describe our preliminary modeling of risk, and describe how we search the space of landing sites and routes.

  14. Ultrawideband Electromagnetic Interference to Aircraft Radios

    Science.gov (United States)

    Ely, Jay J.; Fuller, Gerald L.; Shaver, Timothy W.

    2002-01-01

    A very recent FCC Final Rule now permits marketing and operation of new products that incorporate Ultrawideband (UWB) technology into handheld devices. Wireless product developers are working to rapidly bring this versatile, powerful and expectedly inexpensive technology into numerous consumer wireless devices. Past studies addressing the potential for passenger-carried portable electronic devices (PEDs) to interfere with aircraft electronic systems suggest that UWB transmitters may pose a significant threat to aircraft communication and navigation radio receivers. NASA, United Airlines and Eagles Wings Incorporated have performed preliminary testing that clearly shows the potential for handheld UWB transmitters to cause cockpit failure indications for the air traffic control radio beacon system (ATCRBS), blanking of aircraft on the traffic alert and collision avoidance system (TCAS) displays, and cause erratic motion and failure of instrument landing system (ILS) localizer and glideslope pointers on the pilot horizontal situation and attitude director displays. This paper provides details of the preliminary testing and recommends further assessment of aircraft systems for susceptibility to UWB electromagnetic interference.

  15. Computer Aided Visual Inspection of Aircraft Surfaces

    Directory of Open Access Journals (Sweden)

    Rafia Mumtaz

    2012-02-01

    Full Text Available Non Destructive Inspections (NDI plays a vital role in aircraft industry as it determines the structural integrity of aircraft surface and material characterization. The existing NDI methods are time consuming, we propose a new NDI approach using Digital Image Processing that has the potential to substantially decrease the inspection time. Automatic Marking of cracks have been achieved through application of Thresholding, Gabor Filter and Non Subsampled Contourlet transform. For a novel method of NDI, the aircraft imagery is analyzed by three methods i.e Neural Networks, Contourlet Transform (CT and Discrete Cosine Transform (DCT. With the help of Contourlet Transform the two dimensional (2-D spectrum is divided into fine slices, using iterated directional filterbanks. Next, directional energy components for each block of the decomposed subband outputs are computed. These energy values are used to distinguish between the crack and scratch images using the Dot Product classifier. In next approach, the aircraft imagery is decomposed into high and low frequency components using DCT and the first order moment is determined to form feature vectors.A correlation based approach is then used for distinction between crack and scratch surfaces. A comparative examination between the two techniques on a database of crack and scratch images revealed that texture analysis using the combined transform based approach gave the best results by giving an accuracy of 96.6% for the identification of crack surfaces and 98.3% for scratch surfaces.

  16. Using Synthetic Kerosene in Civil Jet Aircraft

    NARCIS (Netherlands)

    Snijders, T.A.; Melkert, J.A.

    2008-01-01

    TU Delft in the Netherlands is performing research into the effects of the use of synthetic kerosene in aircraft. The research program consists of both desk research and tests. In the desk research gas turbine simulations will be combined with payload range performance calculations to show engine ef

  17. Incident response monitoring technologies for aircraft cabin

    NARCIS (Netherlands)

    Havermans, J.B.G.A.; Houtzager, M.M.G.; Jacobs, P.

    2015-01-01

    The Netherlands Organization for Applied Scientific Research (TNO) was granted by ASHRAE (1306-RP) to conduct scientfic review and feasibility analysis of technologies and methods for measuring aircraft power system contaminants in the cabin air during unanticipated adverse incidents. In particular,

  18. 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

  19. Aircraft engine performance and integration in a flying wing aircraft conceptual design

    OpenAIRE

    Miao, Zhisong.

    2012-01-01

    The increasing demand of more economical and environmentally friendly aero engines leads to the proposal of a new concept – geared turbofan. In this thesis, the characteristics of this kind of engine and relevant considerations of integration on a flying wing aircraft were studied. The studies can be divided into four levels: GTF-11 engine modelling and performance simulation; aircraft performance calculation; nacelle design and aerodynamic performance evaluation; preliminar...

  20. The separation of adult separation anxiety disorder.

    Science.gov (United States)

    Baldwin, David S; Gordon, Robert; Abelli, Marianna; Pini, Stefano

    2016-08-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) categorization of mental disorders places "separation anxiety disorder" within the broad group of anxiety disorders, and its diagnosis no longer rests on establishing an onset during childhood or adolescence. In previous editions of DSM, it was included within the disorders usually first diagnosed in infancy, childhood, or adolescence, with the requirement for an onset of symptoms before the age of 18 years: symptomatic adults could only receive a retrospective diagnosis, based on establishing this early onset. The new position of separation anxiety disorder is based upon the findings of epidemiological studies that revealed the unexpectedly high prevalence of the condition in adults, often in individuals with an onset of symptoms after the teenage years; its prominent place within the DSM-5 group of anxiety disorders should encourage further research into its epidemiology, etiology, and treatment. This review examines the clinical features and boundaries of the condition, and offers guidance on how it can be distinguished from other anxiety disorders and other mental disorders in which "separation anxiety" may be apparent.

  1. The separation of adult separation anxiety disorder.

    Science.gov (United States)

    Baldwin, David S; Gordon, Robert; Abelli, Marianna; Pini, Stefano

    2016-08-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) categorization of mental disorders places "separation anxiety disorder" within the broad group of anxiety disorders, and its diagnosis no longer rests on establishing an onset during childhood or adolescence. In previous editions of DSM, it was included within the disorders usually first diagnosed in infancy, childhood, or adolescence, with the requirement for an onset of symptoms before the age of 18 years: symptomatic adults could only receive a retrospective diagnosis, based on establishing this early onset. The new position of separation anxiety disorder is based upon the findings of epidemiological studies that revealed the unexpectedly high prevalence of the condition in adults, often in individuals with an onset of symptoms after the teenage years; its prominent place within the DSM-5 group of anxiety disorders should encourage further research into its epidemiology, etiology, and treatment. This review examines the clinical features and boundaries of the condition, and offers guidance on how it can be distinguished from other anxiety disorders and other mental disorders in which "separation anxiety" may be apparent. PMID:27503572

  2. Aircraft Design Analysis, CFD And Manufacturing

    Directory of Open Access Journals (Sweden)

    Haifa El-Sadi

    2016-09-01

    Full Text Available Aircraft design, manufacturing and CFD analysis as part of aerodynamic course, the students achieve sizing from a conceptual sketch, select the airfoil geometry and the tail geometry, calculate thrust to weight ratio and wing loading, use initial sizing and calculate the aerodynamic forces. The students design their aircraft based on the geometrical dimensions resulted from the calculations and use the model to build a prototype, test it in wind tunnel and achieve CFD analysis to be compared with the experimental results. The theory of aerodynamic is taught and applied as a project based. In this paper, the design process, aircraft manufacturing and CFD analysis are presented to show the effect of project based on student’s learning of aerodynamic course. This project based learning has improved and accelerated students understanding of aerodynamic concepts and involved students in a constructive exploration. The analysis of the aircraft resulted in a study that revolved around the lift and drag generation of this particular aircraft. As to determine the lift and drag forces generated by this plane, a model was created in Solidworks a 3-D model-rendering program. After this model was created it was 3-D printed in a reduced scale, and subjected to wind tunnel testing. The results from the wind tunnel lab experiment were recorded. For accuracy, the same 3-D model was then simulated using CFD simulation software within Solidworks and compared with the results from the wind tunnel test. The values derived from both the simulation and the wind tunnel tests were then compared with the theoretical calculations for further proof of accuracy.

  3. Method for separating isotopes

    Science.gov (United States)

    Jepson, B.E.

    1975-10-21

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether.

  4. Nonterminal Separating Macro Grammars

    NARCIS (Netherlands)

    Hogendorp, Jan Anne; Asveld, P.R.J.; Nijholt, A.; Verbeek, Leo A.M.

    1987-01-01

    We extend the concept of nonterminal separating (or NTS) context-free grammar to nonterminal separating $m$-macro grammar where the mode of derivation $m$ is equal to "unrestricted". "outside-in' or "inside-out". Then we show some (partial) characterization results for these NTS $m$-macro grammars.

  5. Social Separation in Monkeys.

    Science.gov (United States)

    Mineka, Susan; Suomi, Stephen J.

    1978-01-01

    Reviews phenomena associated with social separation from attachment objects in nonhuman primates. Evaluates four theoretical treatments of separation in light of existing data: Bowlby's attachment-object-loss theory, Kaufman's conservation-withdrawal theory, Seligman's learned helplessness theory, and Solomon and Corbit's opponent-process theory.…

  6. Kinematic GPS solutions for aircraft trajectories: Identifying and minimizing systematic height errors associated with atmospheric propagation delays

    Science.gov (United States)

    Shan, S.; Bevis, M.; Kendrick, E.; Mader, G.L.; Raleigh, D.; Hudnut, K.; Sartori, M.; Phillips, D.

    2007-01-01

    When kinematic GPS processing software is used to estimate the trajectory of an aircraft, unless the delays imposed on the GPS signals by the atmosphere are either estimated or calibrated via external observations, then vertical height errors of decimeters can occur. This problem is clearly manifested when the aircraft is positioned against multiple base stations in areas of pronounced topography because the aircraft height solutions obtained using different base stations will tend to be mutually offset, or biased, in proportion to the elevation differences between the base stations. When performing kinematic surveys in areas with significant topography it should be standard procedure to use multiple base stations, and to separate them vertically to the maximum extent possible, since it will then be much easier to detect mis-modeling of the atmosphere. Copyright 2007 by the American Geophysical Union.

  7. Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

    Science.gov (United States)

    Du, Hai; Shi, Zhiwei; Cheng, Keming; Wei, Dechen; Li, Zheng; Zhou, Danjie; He, Haibo; Yao, Junkai; He, Chengjun

    2016-06-01

    Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

  8. L-split marker for augmented reality in aircraft assembly

    Science.gov (United States)

    Han, Pengfei; Zhao, Gang

    2016-04-01

    In order to improve the performance of conventional square markers widely used by marker-based augmented reality systems in aircraft assembly environments, an L-split marker is proposed. Every marker consists of four separate L-shaped parts and each of them contains partial information about the marker. Geometric features of the L-shape, which are more discriminate than the symmetrical square shape adopted by conventional markers, are used to detect proposed markers from the camera images effectively. The marker is split into four separate parts in order to improve the robustness to occlusion and curvature to some extent. The registration process can be successfully completed as long as three parts are detected (up to about 80% of the area could be occluded). Moreover, when we attach the marker on nonplanar surfaces, the curvature status of the marker can be roughly analyzed with every part's normal direction, which can be obtained since their six corners have been explicitly determined in the previous detection process. And based on the marker design, new detection and recognition algorithms are proposed and detailed. The experimental results show that the marker and the algorithms are effective.

  9. Separators for flywheel rotors

    Science.gov (United States)

    Bender, Donald A.; Kuklo, Thomas C.

    1998-01-01

    A separator forms a connection between the rotors of a concentric rotor assembly. This separator allows for the relatively free expansion of outer rotors away from inner rotors while providing a connection between the rotors that is strong enough to prevent disassembly. The rotor assembly includes at least two rotors referred to as inner and outer flywheel rings or rotors. This combination of inner flywheel ring, separator, and outer flywheel ring may be nested to include an arbitrary number of concentric rings. The separator may be a segmented or continuous ring that abuts the ends of the inner rotor and the inner bore of the outer rotor. It is supported against centrifugal loads by the outer rotor and is affixed to the outer rotor. The separator is allowed to slide with respect to the inner rotor. It is made of a material that has a modulus of elasticity that is lower than that of the rotors.

  10. Review of factors affecting aircraft wet runway performance

    Science.gov (United States)

    Yager, T. J.

    1983-01-01

    Problems associated with aircraft operations on wet runways are discussed and major factors which influence tire/runway braking and cornering traction capability are identified including runway characteristics, tire hydroplaning, brake system anomalies, and pilot inputs. Research results from investigations conducted at the Langley Aircraft Landing Loads and Traction Facility and from tests with instrumented ground vehicles and aircraft are summarized to indicate the effects of different aircraft, tire, and runway parameters. Several promising means are described for improving tire/runway water drainage capability, brake system efficiency, and pilot training to help optimize aircraft traction performance on wet runways.

  11. Turboelectric Aircraft Drive Key Performance Parameters and Functional Requirements

    Science.gov (United States)

    Jansen, Ralph H.; Brown, Gerald V.; Felder, James L.; Duffy, Kirsten P.

    2016-01-01

    The purpose of this paper is to propose specific power and efficiency as the key performance parameters for a turboelectric aircraft power system and investigate their impact on the overall aircraft. Key functional requirements are identified that impact the power system design. Breguet range equations for a base aircraft and a turboelectric aircraft are found. The benefits and costs that may result from the turboelectric system are enumerated. A break-even analysis is conducted to find the minimum allowable electric drive specific power and efficiency that can preserve the range, initial weight, operating empty weight, and payload weight of the base aircraft.

  12. Review of Aircraft Electric Power Systems and Architectures

    DEFF Research Database (Denmark)

    Zhao, Xin; Guerrero, Josep M.; Wu, Xiaohao

    2014-01-01

    In recent years, the electrical power capacity is increasing rapidly in more electric aircraft (MEA), since the conventional mechanical, hydraulic and pneumatic energy systems are partly replaced by electrical power system. As a consequence, capacity and complexity of aircraft electric power...... systems (EPS) will increase dramatically and more advanced aircraft EPSs need to be developed. This paper gives a brief description of the constant frequency (CF) EPS, variable frequency (VF) EPS and advanced high voltage (HV) EPS. Power electronics in the three EPS is overviewed. Keywords: Aircraft Power...... System, More Electric Aircraft, Constant Frequency, Variable Frequency, High Voltage....

  13. The interference aerodynamics caused by the wing elasticity during store separation

    Science.gov (United States)

    Lei, Yang; Zheng-yin, Ye

    2016-04-01

    Air-launch-to-orbit is the technology that has stores carried aloft and launched the store from the plane to the orbit. The separation between the aircraft and store is one of the most important and difficult phases in air-launch-to-orbit technology. There exists strong aerodynamic interference between the aircraft and the store in store separation. When the aspect ratio of the aircraft is large, the elastic deformations of the wing must be considered. The main purpose of this article is to study the influence of the interference aerodynamics caused by the elastic deformations of the wing to the unsteady aerodynamics of the store. By solving the coupled functions of unsteady Navier-Stokes equations, six degrees of freedom dynamic equations and structural dynamic equations simultaneously, the store separation with the elastic deformation of the aircraft considered is simulated numerically. And the interactive aerodynamic forces are analyzed. The study shows that the interference aerodynamics is obvious at earlier time during the separation, and the dominant frequency of the elastic wing determines the aerodynamic forces frequencies of the store. Because of the effect of the interference aerodynamics, the roll angle response and pitch angle response increase. When the store is mounted under the wingtip, the additional aerodynamics caused by the wingtip vortex is obvious, which accelerate the divergence of the lateral force and the lateral-directional attitude angle of the store. This study supports some beneficial conclusions to the engineering application of the air-launch-to-orbit.

  14. Intercomparison of aircraft instruments on board the C-130 and Falcon 20 over southern Germany during EXPORT 2000

    Directory of Open Access Journals (Sweden)

    H. Huntrieser

    2003-07-01

    Full Text Available In the summer 2000 Export aircraft campaign (European eXport of Precursors and Ozone by long-Range Transport, two comprehensively instrumented research aircraft measuring a variety of chemical species flew wing tip to wing tip for a period of one and a quarter hours. During this interval a comparison was undertaken of the measurements of nitrogen oxide (NO, odd nitrogen species (NOy, carbon monoxide (CO and ozone (O3. The comparison was performed at two different flight levels, which provided a 10-fold variation in the concentrations of both NO (10 to 1000 parts per trillion by volume (pptv and NOy (200 to over 2500 pptv. Large peaks of NO and NOy observed from the Falcon 20, which were at first thought to be from the exhaust of the C-130, were also detected on the 4 channel NOx,y instrument aboard the C-130. These peaks were a good indication that both aircraft were in the same air mass and that the Falcon 20 was not in the exhaust plume of the C-130. Correlations and statistical analysis are presented between the instruments used on the two separate aircraft platforms. These were found to be in good agreement giving a high degree of correlation for the ambient air studied. Any deviations from the correlations are accounted for in the estimated inaccuracies of the instruments. These results help to establish that the instruments aboard the separate aircraft are reliably able to measure the corresponding chemical species in the range of conditions sampled and that data collected by both aircraft can be co-ordinated for purposes of interpretation.

  15. Intercomparison of aircraft instruments on board the C-130 and Falcon 20 over southern Germany during EXPORT 2000

    Directory of Open Access Journals (Sweden)

    N. Brough

    2003-01-01

    Full Text Available In the summer 2000 EXPORT aircraft campaign (European eXport of Precursors and Ozone by long-Range Transport, two comprehensively instrumented research aircraft measuring a variety of chemical species flew wing tip to wing tip for a period of one and a quarter hours. During this interval a comparison was undertaken of the measurements of nitrogen oxide (NO, odd nitrogen species (NOy, carbon monoxide (CO and ozone (O3. The comparison was performed at two different flight levels, which provided a 10-fold variation in the concentrations of both NO (10 to 1000 parts per trillion by volume (pptv and NOy (200 to over 2500 pptv. Large peaks of NO and NOy observed from the Falcon 20, which were at first thought to be from the exhaust of the C-130, were also detected on the 4 channel NOxy instrument aboard the C-130. These peaks were a good indication that both aircraft were in the same air mass and that the Falcon 20 was not in the exhaust plume of the C-130. Correlations and statistical analysis are presented between the instruments used on the two separate aircraft platforms. These were found to be in good agreement giving a high degree of correlation for the ambient air studied. Any deviations from the correlations are accounted for in the estimated inaccuracies of the instruments. These results help to establish that the instruments aboard the separate aircraft are reliably able to measure the corresponding chemical species in the range of conditions sampled and that data collected by both aircraft can be co-ordinated for purposes of interpretation.

  16. Distributed Turboelectric Propulsion for Hybrid Wing Body Aircraft

    Science.gov (United States)

    Kim, Hyun Dae; Brown, Gerald V.; Felder, James L.

    2008-01-01

    Meeting future goals for aircraft and air traffic system performance will require new airframes with more highly integrated propulsion. Previous studies have evaluated hybrid wing body (HWB) configurations with various numbers of engines and with increasing degrees of propulsion-airframe integration. A recently published configuration with 12 small engines partially embedded in a HWB aircraft, reviewed herein, serves as the airframe baseline for the new concept aircraft that is the subject of this paper. To achieve high cruise efficiency, a high lift-to-drag ratio HWB was adopted as the baseline airframe along with boundary layer ingestion inlets and distributed thrust nozzles to fill in the wakes generated by the vehicle. The distributed powered-lift propulsion concept for the baseline vehicle used a simple, high-lift-capable internally blown flap or jet flap system with a number of small high bypass ratio turbofan engines in the airframe. In that concept, the engine flow path from the inlet to the nozzle is direct and does not involve complicated internal ducts through the airframe to redistribute the engine flow. In addition, partially embedded engines, distributed along the upper surface of the HWB airframe, provide noise reduction through airframe shielding and promote jet flow mixing with the ambient airflow. To improve performance and to reduce noise and environmental impact even further, a drastic change in the propulsion system is proposed in this paper. The new concept adopts the previous baseline cruise-efficient short take-off and landing (CESTOL) airframe but employs a number of superconducting motors to drive the distributed fans rather than using many small conventional engines. The power to drive these electric fans is generated by two remotely located gas-turbine-driven superconducting generators. This arrangement allows many small partially embedded fans while retaining the superior efficiency of large core engines, which are physically separated

  17. Perceived Noise Analysis for Offset Jets Applied to Commercial Supersonic Aircraft

    Science.gov (United States)

    Huff, Dennis L.; Henderson, Brenda S.; Berton, Jeffrey J.; Seidel, Jonathan A.

    2016-01-01

    A systems analysis was performed with experimental jet noise data, engine/aircraft performance codes and aircraft noise prediction codes to assess takeoff noise levels and mission range for conceptual supersonic commercial aircraft. A parametric study was done to identify viable engine cycles that meet NASA's N+2 goals for noise and performance. Model scale data from offset jets were used as input to the aircraft noise prediction code to determine the expected sound levels for the lateral certification point where jet noise dominates over all other noise sources. The noise predictions were used to determine the optimal orientation of the offset nozzles to minimize the noise at the lateral microphone location. An alternative takeoff procedure called "programmed lapse rate" was evaluated for noise reduction benefits. Results show there are two types of engines that provide acceptable mission range performance; one is a conventional mixed-flow turbofan and the other is a three-stream variable-cycle engine. Separate flow offset nozzles reduce the noise directed toward the thicker side of the outer flow stream, but have less benefit as the core nozzle pressure ratio is reduced. At the systems level for a three-engine N+2 aircraft with full throttle takeoff, there is a 1.4 EPNdB margin to Chapter 3 noise regulations predicted for the lateral certification point (assuming jet noise dominates). With a 10% reduction in thrust just after clearing the runway, the margin increases to 5.5 EPNdB. Margins to Chapter 4 and Chapter 14 levels will depend on the cumulative split between the three certification points, but it appears that low specific thrust engines with a 10% reduction in thrust (programmed lapse rate) can come close to meeting Chapter 14 noise levels. Further noise reduction is possible with engine oversizing and derated takeoff, but more detailed mission studies are needed to investigate the range impacts as well as the practical limits for safety and takeoff

  18. HAI: A new TDLAS hygrometer for the HALO research aircraft

    Science.gov (United States)

    Klostermann, Tim; Afchine, Armin; Barthel, Jochen; Höh, Matthias; Wagner, Steven; Witzel, Oliver; Saathoff, Harald; Schiller, Cornelius; Ebert, Volker

    2010-05-01

    Water vapor is the most important greenhouse gas in the Earth's atmosphere and a key component for several physical and chemical processes. Therefore it is a key parameter to be measured during most research campaigns. The Hygrometer for Atmospheric Investigations (HAI) is especially designed for operations on the research aircraft HALO (High Altitude and LOng range research aircraft). HAI permits both, the in-situ measurement of water vapor with an open-path cell and the measurement of total water with an extractive close-path absorption cell. We are using TDLAS (Tunable Diode Laser Absorption Spectroscopy) in two water absorption bands with different line strength to increase the dynamical range. With this concept it is possible to measure from the middle troposphere up to the stratosphere. The open-path cell outside of the fuselage consists of a robust, aerodynamically designed aluminum structure with a single integrated White-cell for both laser beams. Although the mirror separation is only 15cm the cell allows an open absorption path of 4.8m. The detection of higher H2O concentrations is realized with a fiber coupled 1.4µm DFB diode laser. Inside the UTLS layer were small concentrations in the low ppm range are common, we employ up to 20 times stronger fundamental ro-vibration lines of the water molecule near 2.6µm. To supply this, the fiber coupled 2.6µm laser setup was developed and is a part of the HAI. Both detection wavelengths are introduced in the same open path cell via glass fibers which provide water measurements with a minimum of parasitic absorption. We will present the spectrometer design for high-quality airborne water measurements. Furthermore, first laboratory measurements will be shown.

  19. Reinterpreting aircraft measurements in anisotropic scaling turbulence

    Directory of Open Access Journals (Sweden)

    S. J. Hovde

    2009-07-01

    Full Text Available Due to both systematic and turbulent induced vertical fluctuations, the interpretation of atmospheric aircraft measurements requires a theory of turbulence. Until now virtually all the relevant theories have been isotropic or "quasi isotropic" in the sense that their exponents are the same in all directions. However almost all the available data on the vertical structure shows that it is scaling but with exponents different from the horizontal: the turbulence is scaling but anisotropic. In this paper, we show how such turbulence can lead to spurious breaks in the scaling and to the spurious appearance of the vertical scaling exponent at large horizontal lags.

    We demonstrate this using 16 legs of Gulfstream 4 aircraft near the top of the troposphere following isobars each between 500 and 3200 km in length. First we show that over wide ranges of scale, the horizontal spectra of the aircraft altitude are nearly k-5/3. In addition, we show that the altitude and pressure fluctuations along these fractal trajectories have a high degree of coherence with the measured wind (especially with its longitudinal component. There is also a strong phase relation between the altitude, pressure and wind fluctuations; for scales less than ≈40 km (on average the wind fluctuations lead the pressure and altitude, whereas for larger scales, the pressure fluctuations leads the wind. At the same transition scale, there is a break in the wind spectrum which we argue is caused by the aircraft starting to accurately follow isobars at the larger scales. In comparison, the temperature and humidity have low coherencies and phases and there are no apparent scale breaks, reinforcing the hypothesis that it is the aircraft trajectory that is causally linked to the scale breaks in the wind measurements.

    Using spectra and structure functions for the wind, we then estimate their exponents (β, H at small (5/3, 1/3 and large scales (2

  20. Control of Next Generation Aircraft and Wind Turbines

    Science.gov (United States)

    Frost, Susan

    2010-01-01

    The first part of this talk will describe some of the exciting new next generation aircraft that NASA is proposing for the future. These aircraft are being designed to reduce aircraft fuel consumption and environmental impact. Reducing the aircraft weight is one approach that will be used to achieve these goals. A new control framework will be presented that enables lighter, more flexible aircraft to maintain aircraft handling qualities, while preventing the aircraft from exceeding structural load limits. The second part of the talk will give an overview of utility-scale wind turbines and their control. Results of collaboration with Dr. Balas will be presented, including new theory to adaptively control the turbine in the presence of structural modes, with the focus on the application of this theory to a high-fidelity simulation of a wind turbine.

  1. Aircraft Noise and Quality of Life around Frankfurt Airport

    Directory of Open Access Journals (Sweden)

    Thomas Eikmann

    2010-08-01

    Full Text Available In a survey of 2,312 residents living near Frankfurt Airport aircraft noise annoyance and disturbances as well as environmental (EQoL and health-related quality of life (HQoL were assessed and compared with data on exposure due to aircraft, road traffic, and railway noise. Results indicate higher noise annoyance than predicted from general exposure-response curves. Beside aircraft sound levels source-related attitudes were associated with reactions to aircraft noise. Furthermore, aircraft noise affected EQoL in general, although to a much smaller extent. HQoL was associated with aircraft noise annoyance, noise sensitivity and partly with aircraft noise exposure, in particular in the subgroup of multimorbid residents. The results suggest a recursive relationship between noise and health, yet this cannot be tested in cross-sectional studies. Longitudinal studies would be recommendable to get more insight in the causal paths underlying the noise-health relationship.

  2. Delayed detached eddy simulations of fighter aircraft at high angle of attack

    Science.gov (United States)

    Xu, Guoliang; Jiang, Xiong; Liu, Gang

    2016-08-01

    The massively separated flows over a realistic aircraft configuration at 40°, 50°, and 60° angles of attack are studied using the delayed detached eddy simulation (DDES). The calculations are carried out at experimental conditions corresponding to a mean aerodynamic chord-based Reynolds number of 8.93× 105 and Mach number of 0.088. The influence of the grid size is investigated using two grids, 20.0× 106 cells and 31.0× 106 cells. At the selected conditions, the lift, drag, and pitching moment from DDES predictions agree with the experimental data better than that from the Reynolds-averaged Navier-Stokes. The effect of angle of attack on the flow structure over the general aircraft is also studied, and it is found that the dominated frequency associated with the vortex shedding process decreases with increasing angle of attack.

  3. Delayed detached eddy simulations of fighter aircraft at high angle of attack

    Institute of Scientific and Technical Information of China (English)

    Guoliang Xu; Xiong Jiang; Gang Liu

    2016-01-01

    The massively separated flows over a realistic air-craft configuration at 40◦, 50◦, and 60◦angles of attack are studied using the delayed detached eddy simulation (DDES). The calculations are carried out at experimental conditions corresponding to a mean aerodynamic chord-based Reynolds number of 8.93 × 105 and Mach number of 0.088. The influ-ence of the grid size is investigated using two grids, 20.0×106 cells and 31.0 × 106 cells. At the selected conditions, the lift, drag, and pitching moment from DDES predictions agree with the experimental data better than that from the Reynolds-averaged Navier–Stokes. The effect of angle of attack on the flow structure over the general aircraft is also studied, and it is found that the dominated frequency associated with the vortex shedding process decreases with increasing angle of attack.

  4. Hybrid Genetic-cuckoo Search Algorithm for Solving Runway Dependent Aircraft Landing Problem

    Directory of Open Access Journals (Sweden)

    Peigang Guo

    2013-07-01

    Full Text Available As the demand for air transportation continues to grow, some flights cannot land at their preferred landing times because the airport is near its runway capacity. Therefore, devising a method for tackling the Aircraft Landing Problem (ALP in order to optimize the usage of existing runways at airports is the focus of this study. This study, a hybrid Genetic-Cuckoo Search (GCS algorithm for optimization the ALP with runway is proposed. The numerical results showed that the proposed GCS algorithm can effectively and efficiently determine the runway allocation, sequence and landing time for arriving aircraft for the three test cases by minimizing total delays under the separation constraints in comparison with the outcomes yielded by previous studies.

  5. D-558-2 Aircraft on lakebed

    Science.gov (United States)

    1955-01-01

    Viewed in this 1955 photograph is the NACA High Speed Flight Station D-558-2 #2 (144) Skyrocket, an all-rocket powered vehicle. The Skyrocket is parked on Rogers Dry Lakebed at Edwards Air Force Base. This aircraft, NACA 144/Navy 37974, was the first to reach Mach 2 (see project description). The Douglas D-558-2 'Skyrockets' were among the early transonic research airplanes like the X-1, X-4, X-5, and X-92A. Three of the single-seat, swept-wing aircraft flew from 1948 to 1956 in a joint program involving the National Advisory Committee for Aeronautics (NACA), with its flight research done at the NACA's Muroc Flight Test Unit in Calif., redesignated in 1949 the High-Speed Flight Research Station (HSFRS); the Navy-Marine Corps; and the Douglas Aircraft Co. The HSFRS became the High-Speed Flight Station in 1954 and is now known as the NASA Dryden Flight Research Center. The Skyrocket made aviation history when it became the first airplane to fly twice the speed of sound. The 2 in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program, with the phase-one aircraft having straight wings. The third phase, which never came to fruition, would have involved constructing a mock-up of a combat-type aircraft embodying the results from the testing of the phase one and two aircraft. Douglas pilot John F. Martin made the first flight at Muroc Army Airfield (later renamed Edwards Air Force Base) in Calif. on February 4, 1948. The goals of the program were to investigate the characteristics of swept-wing aircraft at transonic and supersonic speeds with particular attention to pitch-up (uncommanded rotation of the nose of the airplane upwards)--a problem prevalent in high-speed service aircraft of that era, particularly at low speeds during take-off and landing and in tight turns. The three aircraft gathered a great deal of data about pitch-up and the coupling of lateral (yaw) and

  6. Reinterpreting aircraft measurements in anisotropic scaling turbulence

    Directory of Open Access Journals (Sweden)

    S. Lovejoy

    2009-02-01

    Full Text Available Due to unavoidable vertical fluctuations, the interpretation of atmospheric aircraft measurements requires a theory of turbulence. Until now virtually all the relevant theories have been isotropic. However almost all the available data on the vertical structure shows that it is scaling but with exponents different from the horizontal: the turbulence is anisotropic not isotropic. In this paper, we show how this can lead to spurious breaks in the scaling and to the spurious appearance of the vertical scaling exponent at large horizontal lags.

    We demonstrate this using 16 legs of Gulfstream 4 tropospheric data following isobars each between 500 and 3200 km in length. First we show that the horizontal spectra of the aircraft altitude are nearly k−5/3 (although smoothed by aircraft intertia at scales <3 km. In addition, we show that the altitude and pressure fluctuations along these fractal trajectories have a high degree of coherence with the measured wind (especially with its longitudinal component. There is also a strong phase relation between the altitude, pressure and wind fluctuations with all of these effects occurring over the entire range of scales so that the trajectories influence the wind measurements over large ranges of scale. In comparison, the temperature and humidity have no apparent scale breaks and the corresponding coherencies and phases are low reinforcing the hypothesis that it is the aircraft trajectory that is causally linked to the scale breaks in the wind measurements.

    Using spectra and structure functions we then estimate the small and large scale exponents finding that they are close to the Kolmogorov values (5/3, 1/3 and the vertical values (2.4, 0.73 respectively (for the spectral and real space scaling exponents (β, H the latter are close to those estimated by drop sondes (2.4, 0.75 in the vertical direction. In addition, for each leg we estimate the energy flux, the sphero

  7. Structural analysis at aircraft conceptual design stage

    Science.gov (United States)

    Mansouri, Reza

    In the past 50 years, computers have helped by augmenting human efforts with tremendous pace. The aircraft industry is not an exception. Aircraft industry is more than ever dependent on computing because of a high level of complexity and the increasing need for excellence to survive a highly competitive marketplace. Designers choose computers to perform almost every analysis task. But while doing so, existing effective, accurate and easy to use classical analytical methods are often forgotten, which can be very useful especially in the early phases of the aircraft design where concept generation and evaluation demands physical visibility of design parameters to make decisions [39, 2004]. Structural analysis methods have been used by human beings since the very early civilization. Centuries before computers were invented; the pyramids were designed and constructed by Egyptians around 2000 B.C, the Parthenon was built by the Greeks, around 240 B.C, Dujiangyan was built by the Chinese. Persepolis, Hagia Sophia, Taj Mahal, Eiffel tower are only few more examples of historical buildings, bridges and monuments that were constructed before we had any advancement made in computer aided engineering. Aircraft industry is no exception either. In the first half of the 20th century, engineers used classical method and designed civil transport aircraft such as Ford Tri Motor (1926), Lockheed Vega (1927), Lockheed 9 Orion (1931), Douglas DC-3 (1935), Douglas DC-4/C-54 Skymaster (1938), Boeing 307 (1938) and Boeing 314 Clipper (1939) and managed to become airborne without difficulty. Evidencing, while advanced numerical methods such as the finite element analysis is one of the most effective structural analysis methods; classical structural analysis methods can also be as useful especially during the early phase of a fixed wing aircraft design where major decisions are made and concept generation and evaluation demands physical visibility of design parameters to make decisions

  8. Rotary drum separator system

    Science.gov (United States)

    Barone, Michael R. (Inventor); Murdoch, Karen (Inventor); Scull, Timothy D. (Inventor); Fort, James H. (Inventor)

    2009-01-01

    A rotary phase separator system generally includes a step-shaped rotary drum separator (RDS) and a motor assembly. The aspect ratio of the stepped drum minimizes power for both the accumulating and pumping functions. The accumulator section of the RDS has a relatively small diameter to minimize power losses within an axial length to define significant volume for accumulation. The pumping section of the RDS has a larger diameter to increase pumping head but has a shorter axial length to minimize power losses. The motor assembly drives the RDS at a low speed for separating and accumulating and a higher speed for pumping.

  9. On separable Pauli equations

    OpenAIRE

    Zhalij, Alexander

    2002-01-01

    We classify (1+3)-dimensional Pauli equations for a spin-1/2 particle interacting with the electro-magnetic field, that are solvable by the method of separation of variables. As a result, we obtain the eleven classes of vector-potentials of the electro-magnetic field A(t,x) providing separability of the corresponding Pauli equations. It is established, in particular, that the necessary condition for the Pauli equation to be separable into second-order matrix ordinary differential equations is...

  10. Laser-Beam Separator

    Science.gov (United States)

    Mcdermid, I. S.

    1984-01-01

    Train of prisms and optical stop separate fundamental beam of laser from second and higher order harmonics of beam produced in certain crystals and by stimulated Raman scattering in gases and liquids.

  11. Molten salt electrolyte separator

    Science.gov (United States)

    Kaun, Thomas D.

    1996-01-01

    A molten salt electrolyte/separator for battery and related electrochemical systems including a molten electrolyte composition and an electrically insulating solid salt dispersed therein, to provide improved performance at higher current densities and alternate designs through ease of fabrication.

  12. Separator for alkaline batteries

    Science.gov (United States)

    Hoyt, H. W.; Pfluger, H. L.

    1968-01-01

    Separator compositions have been tested as components of three-plate silver-zinc oxide cells in a standard cycling test. Six materials meet imposed requirements, giving cycling performance superior to cellophane.

  13. Distal humeral epiphyseal separation.

    Science.gov (United States)

    Moucha, Calin S; Mason, Dan E

    2003-10-01

    Distal humeral epiphyseal separation is an uncommon injury that is often misdiagnosed upon initial presentation. To make a timely, correct diagnosis, the treating physician must have a thorough understanding of basic anatomical relationships and an awareness of the existence of this injury. This is a case of a child who sustained a separation of the distal humeral epiphysis, as well as multiple other bony injuries, secondary to child abuse.

  14. Chiral separation in microflows

    OpenAIRE

    Kostur, Marcin; Schindler, Michael; Talkner, Peter; Hänggi, Peter

    2005-01-01

    Molecules that only differ by their chirality, so called enantiomers, often possess different properties with respect to their biological function. Therefore, the separation of enantiomers presents a prominent challenge in molecular biology and belongs to the ``Holy Grail'' of organic chemistry. We suggest a new separation technique for chiral molecules that is based on the transport properties in a microfluidic flow with spatially variable vorticity. Because of their size the thermal fluctua...

  15. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael; Xie, Xiaobing; Evenson, IV, Carl; Grimmer, Paul; Wright, Harold

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  16. Artificial Intelligence for Controlling Robotic Aircraft

    Science.gov (United States)

    Krishnakumar, Kalmanje

    2005-01-01

    A document consisting mostly of lecture slides presents overviews of artificial-intelligence-based control methods now under development for application to robotic aircraft [called Unmanned Aerial Vehicles (UAVs) in the paper] and spacecraft and to the next generation of flight controllers for piloted aircraft. Following brief introductory remarks, the paper presents background information on intelligent control, including basic characteristics defining intelligent systems and intelligent control and the concept of levels of intelligent control. Next, the paper addresses several concepts in intelligent flight control. The document ends with some concluding remarks, including statements to the effect that (1) intelligent control architectures can guarantee stability of inner control loops and (2) for UAVs, intelligent control provides a robust way to accommodate an outer-loop control architecture for planning and/or related purposes.

  17. Fundamentals of aircraft and rocket propulsion

    CERN Document Server

    El-Sayed, Ahmed F

    2016-01-01

    This book provides a comprehensive basics-to-advanced course in an aero-thermal science vital to the design of engines for either type of craft. The text classifies engines powering aircraft and single/multi-stage rockets, and derives performance parameters for both from basic aerodynamics and thermodynamics laws. Each type of engine is analyzed for optimum performance goals, and mission-appropriate engines selection is explained. Fundamentals of Aircraft and Rocket Propulsion provides information about and analyses of: thermodynamic cycles of shaft engines (piston, turboprop, turboshaft and propfan); jet engines (pulsejet, pulse detonation engine, ramjet, scramjet, turbojet and turbofan); chemical and non-chemical rocket engines; conceptual design of modular rocket engines (combustor, nozzle and turbopumps); and conceptual design of different modules of aero-engines in their design and off-design state. Aimed at graduate and final-year undergraduate students, this textbook provides a thorough grounding in th...

  18. On separable Pauli equations

    International Nuclear Information System (INIS)

    We classify (1+3)-dimensional Pauli equations for a spin-(1/2) particle interacting with the electro-magnetic field, that are solvable by the method of separation of variables. As a result, we obtain the 11 classes of vector-potentials of the electro-magnetic field A(t,x(vector sign))=(A0(t,x(vector sign)), A(vector sign)(t,x(vector sign))) providing separability of the corresponding Pauli equations. It is established, in particular, that the necessary condition for the Pauli equation to be separable into second-order matrix ordinary differential equations is its equivalence to the system of two uncoupled Schroedinger equations. In addition, the magnetic field has to be independent of spatial variables. We prove that coordinate systems and the vector-potentials of the electro-magnetic field providing the separability of the corresponding Pauli equations coincide with those for the Schroedinger equations. Furthermore, an efficient algorithm for constructing all coordinate systems providing the separability of Pauli equation with a fixed vector-potential of the electro-magnetic field is developed. Finally, we describe all vector-potentials A(t,x(vector sign)) that (a) provide the separability of Pauli equation, (b) satisfy vacuum Maxwell equations without currents, and (c) describe non-zero magnetic field

  19. Identifying tacit strategies in aircraft maneuvers

    Science.gov (United States)

    Lewis, Charles M.; Heidorn, P. B.

    1991-01-01

    Two machine-learning methods are presently used to characterize the avoidance strategies used by skilled pilots in simulated aircraft encounters, and a general framework for the characterization of the strategic components of skilled behavior via qualitative representation of situations and responses is presented. Descriptions of pilot maneuvers that were 'conceptually equivalent' were ascertained by a concept-learning algorithm in conjunction with a classifier system that employed a generic algorithm; satisficing and 'buggy' strategies were thereby revealed.

  20. Trajectory management for aircraft noise mitigation

    OpenAIRE

    Prats Menéndez, Xavier; Quevedo Casín, Joseba Jokin; Puig Cayuela, Vicenç

    2009-01-01

    Comunicació convidada This paper gives an overview of aircraft trajectory management aimed at producing noise abatementprocedures. Area Navigation (RNAV) concepts play an important role in the design of flexible and, therefore, noise friendly depart or approach procedures. In addition, the lowest dispersion of RNAV tracks help to contain noise footprints in a smaller area if compared with footprints that are produced when conventional procedures are flown. However, RNAV turns still produce...

  1. Review Article: Influenza Transmission on Aircraft

    Science.gov (United States)

    Adlhoch, Cornelia

    2016-01-01

    Background: Air travel is associated with the spread of influenza through infected passengers and potentially through in-flight transmission. Contact tracing after exposure to influenza is not performed systematically. We performed a systematic literature review to evaluate the evidence for influenza transmission aboard aircraft. Methods: Using PubMed and EMBASE databases, we identified and critically appraised identified records to assess the evidence of such transmission to passengers seated in close proximity to the index cases. We also developed a bias assessment tool to evaluate the quality of evidence provided in the retrieved studies. Results: We identified 14 peer-reviewed publications describing contact tracing of passengers after possible exposure to influenza virus aboard an aircraft. Contact tracing during the initial phase of the influenza A(H1N1)pdm09 pandemic was described in 11 publications. The studies describe the follow-up of 2,165 (51%) of 4,252 traceable passengers. Altogether, 163 secondary cases were identified resulting in an overall secondary attack rate among traced passengers of 7.5%. Of these secondary cases, 68 (42%) were seated within two rows of the index case. Conclusion: We found an overall moderate quality of evidence for transmission of influenza virus aboard an aircraft. The major limiting factor was the comparability of the studies. A majority of secondary cases was identified at a greater distance than two rows from the index case. A standardized approach for initiating, conducting, and reporting contact tracing could help to increase the evidence base for better assessing influenza transmission aboard aircraft. PMID:27253070

  2. Project ADIOS: Aircraft Deployable Ice Observation System

    Science.gov (United States)

    Gudmundsson, G. H.

    2013-12-01

    Regions of the Antarctic that are of scientific interest are often too heavily crevassed to enable a plane to land, or permit safe access from a field camp. We have developed an alternative strategy for instrumenting these regions: a sensor that can be dropped from an overflying aircraft. Existing aircraft deployable sensors are not suitable for long term operations in areas where snow accumulates, as they are quickly buried. We have overcome this problem by shaping the sensor like an aerodynamic mast with fins and a small parachute. After being released from the aircraft, the sensor accelerates to 42m/s and stabilizes during a 10s descent. On impact with the snow surface the sensor package buries itself to a depth of 1m then uses the large surface area of the fins to stop it burying further. This leaves a 1.5m mast protruding high above the snow surface to ensure a long operating life. The high impact kinetic energy and robust fin braking mechanism ensure that the design works in both soft and hard snow. Over the past two years we have developed and tested our design with a series of aircraft and wind tunnel tests. Last season we used this deployment strategy to successfully install a network of 31 single band GPS sensors in regions where crevassing has previously prevented science operations: Pine Island Glacier, West Antarctica, and Scar Inlet, Antarctic Peninsula. This season we intend to expand on this network by deploying a further 25 single and dual band GPS sensors on Thwaites Glacier, West Antarctica.

  3. Study of hydrogen as an aircraft fuel

    OpenAIRE

    Ciaravino, John S.

    2003-01-01

    Approved for public release; distribution is unlimited The conversion to hydrogen as a naval aviation fuel would allow for independence on fuel cost and supply, as hydrogen is globally accessible. The biggest obstacle to using hydrogen is its very low density, a property that even combined with hydrogen's high heat of combustion still results in very large fuel tanks. Liquid hydrogen (LH2) with its higher density would still require a larger volume than kerosene for the aircraft to achieve...

  4. Fuel consumption and exhaust emissions of aircrafts

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, R. [Institute of Flightmechanics, Braunschweig (Germany)

    1997-12-31

    The reduction of contamination of sensitive atmospheric layers by improved flight planning steps, is investigated. Calculated results have shown, that a further development of flight track planning allows considerable improvements on fuel consumption and exhaust emissions. Even if air traffic will further increase, optimistic investigations forecast a reduction of the environmental damage by aircraft exhausts, if the effects of improved flight track arrangement and engine innovations will be combined. (R.P.) 4 refs.

  5. Speed stress and the aircraft pilot

    Directory of Open Access Journals (Sweden)

    W.T.V. Adiseshiah

    1958-07-01

    Full Text Available When the human component in a man-machine system of pushed beyond the limits of human capacity in grasping information presented to senses or in executing a series of actions correctly, a condition of "speed stress" may be said to occur. Conditions encountered by aircraft at high speeds, make a consideration of the forms of speed stress, and of the measures to alleviate them, extremely important.

  6. Route optimization model for strike aircraft

    OpenAIRE

    Lee, Steve H. K.

    1995-01-01

    A model is designed and implemented to construct a 'flyable,' least- risk route for strike aircraft from takeoff to target, through enemy radars, in a defined area of operations. A network is fust constructed by discretizing the airspace into a three-dimensional grid of nodes and then connecting adjacent nodes with arcs. A shortest-path model in this network is then constructed with arc lengths that are a function of the probability of detection by radars monitoring t...

  7. Digital adaptive control laws for VTOL aircraft

    Science.gov (United States)

    Hartmann, G. L.; Stein, G.

    1979-01-01

    Honeywell has designed a digital self-adaptive flight control system for flight test in the VALT Research Aircraft (a modified CH-47). The final design resulted from a comparison of two different adaptive concepts: one based on explicit parameter estimates from a real-time maximum likelihood estimation algorithm and the other based on an implicit model reference adaptive system. The two designs are compared on the basis of performance and complexity.

  8. Structural ballistic armour for transport aircraft

    OpenAIRE

    Horsfall, I; Austin, S J; Bishop, W.

    2000-01-01

    This paper describes the structural response of a current ceramic-faced composite armour system and a proposed structural armour system for aircraft use. The proposed structural ballistic armour system is shown to be capable of providing significant structural integrity even after ballistic impact whilst providing ballistic protection equivalent to an existing applique system. The addition of a carbon fibre reinforced plastic front panel to the existing ceramic faced composite armour system i...

  9. Active Noise Control in Propeller Aircraft

    OpenAIRE

    Johansson, Sven; Claesson, Ingvar

    2001-01-01

    A noisy environment dominated by low frequency noise can often be improved through the use of active noise control. This situation arises naturally in propeller aircraft where the propellers induce periodic low frequency noise inside the cabin. The cabin noise is typically rather high, and the passenger flight comfort could be improved considerably if this level were significantly reduced. This paper addresses same design aspects for multiple-reference active noise control systems based on th...

  10. The Physical Model of Magnetic Separation in a Plate Separator

    OpenAIRE

    Brożek, M.

    1999-01-01

    The results of magnetic separation depend on many factors, such as physical properties of particles of the separated mixture, magnetic intensity, particle sizes, separation conditions (constant or alternating field, dry or wet separation) and others. The formulae representing the dependence of separation results on the above mentioned factors are obtained from the model. The mathematical model presents only some general dependences of separations results on time or length of the separation pa...

  11. Assessment of NASA's Aircraft Noise Prediction Capability

    Science.gov (United States)

    Dahl, Milo D. (Editor)

    2012-01-01

    A goal of NASA s Fundamental Aeronautics Program is the improvement of aircraft noise prediction. This document provides an assessment, conducted from 2006 to 2009, on the current state of the art for aircraft noise prediction by carefully analyzing the results from prediction tools and from the experimental databases to determine errors and uncertainties and compare results to validate the predictions. The error analysis is included for both the predictions and the experimental data and helps identify where improvements are required. This study is restricted to prediction methods and databases developed or sponsored by NASA, although in many cases they represent the current state of the art for industry. The present document begins with an introduction giving a general background for and a discussion on the process of this assessment followed by eight chapters covering topics at both the system and the component levels. The topic areas, each with multiple contributors, are aircraft system noise, engine system noise, airframe noise, fan noise, liner physics, duct acoustics, jet noise, and propulsion airframe aeroacoustics.

  12. Aircraft noise and its nearfield propagation computations

    Science.gov (United States)

    Zhang, Xin

    2012-08-01

    Noise generated by civil transport aircraft during take-off and approach-to-land phases of operation is an environmental problem. The aircraft noise problem is firstly reviewed in this article. The review is followed by a description and assessment of a number of sound propagation methods suitable for applications with a background mean flow field pertinent to aircraft noise. Of the three main areas of the noise problem, i.e. generation, propagation, and radiation, propagation provides a vital link between near-field noise generation and far-field radiation. Its accurate assessment ensures the overall validity of a prediction model. Of the various classes of propagation equations, linearised Euler equations are often casted in either time domain or frequency domain. The equations are often solved numerically by computational aeroacoustics techniques, bur are subject to the onset of Kelvin-Helmholtz (K-H) instability modes which may ruin the solutions. Other forms of linearised equations, e.g. acoustic perturbation equations have been proposed, with differing degrees of success.

  13. 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.

  14. Advanced Aerostructural Optimization Techniques for Aircraft Design

    Directory of Open Access Journals (Sweden)

    Yingtao Zuo

    2015-01-01

    Full Text Available Traditional coupled aerostructural design optimization (ASDO of aircraft based on high-fidelity models is computationally expensive and inefficient. To improve the efficiency, the key is to predict aerostructural performance of the aircraft efficiently. The cruise shape of the aircraft is parameterized and optimized in this paper, and a methodology named reverse iteration of structural model (RISM is adopted to get the aerostructural performance of cruise shape efficiently. A new mathematical explanation of RISM is presented in this paper. The efficiency of RISM can be improved by four times compared with traditional static aeroelastic analysis. General purpose computing on graphical processing units (GPGPU is adopted to accelerate the RISM further, and GPU-accelerated RISM is constructed. The efficiency of GPU-accelerated RISM can be raised by about 239 times compared with that of the loosely coupled aeroelastic analysis. Test shows that the fidelity of GPU-accelerated RISM is high enough for optimization. Optimization framework based on Kriging model is constructed. The efficiency of the proposed optimization system can be improved greatly with the aid of GPU-accelerated RISM. An unmanned aerial vehicle (UAV is optimized using this framework and the range is improved by 4.67% after optimization, which shows effectiveness and efficiency of this framework.

  15. Aircraft noise and its nearfield propagation computations

    Institute of Scientific and Technical Information of China (English)

    Xin Zhang

    2012-01-01

    Noise generated by civil transport aircraft during take-off and approach-to-land phases of operation is an environmental problem.The aircraft noise problem is firstly reviewed in this article.The review is followed by a description and assessment of a number of sound propagation methods suitable for applications with a background mean flow field pertinent to aircraft noise.Of the three main areas of the noise problem,i.e.generation,propagation,and radiation,propagation provides a vital link between near-field noise generation and far-field radiation.Its accurate assessment ensures the overall validity of a prediction model.Of the various classes of propagation equations,linearised Euler equations are often casted in either time domain or frequency domain.The equations are often solved numerically by computational aeroacoustics techniques,bur are subject to the onset of Kelvin-Helmholtz (K-H) instability modes which may ruin the solutions. Other forms of linearised equations,e.g.acoustic perturbation equations have been proposed,with differing degrees of success.

  16. Application of Satellite Based Augmentation Systems to Altitude Separation

    Science.gov (United States)

    Magny, Jean Pierre

    This paper presents the application of GNSS1, or more precisely of Satellite Based Augmentation Systems (SBAS), to vertical separation for en-route, approach and landing operations. Potential improvements in terms of operational benefit and of safety are described for two main applications. First, vertical separation between en-route aircraft, which requires a system available across wide areas. SBAS (EGNOS, WAAS, and MSAS) are very well suited for this purpose before GNSS2 becomes available. And secondly, vertical separation from the ground during approach and landing, for which preliminary design principles of instrument approach procedures and safety issues are presented. Approach and landing phases are the subject of discussions within ICAO GNSS-P. En-route phases have been listed as GNSS-P future work and by RTCA for development of new equipments.

  17. 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.

  18. Separably injective Banach spaces

    CERN Document Server

    Avilés, Antonio; Castillo, Jesús M F; González, Manuel; Moreno, Yolanda

    2016-01-01

    This monograph contains a detailed exposition of the up-to-date theory of separably injective spaces: new and old results are put into perspective with concrete examples (such as l∞/c0 and C(K) spaces, where K is a finite height compact space or an F-space, ultrapowers of L∞ spaces and spaces of universal disposition). It is no exaggeration to say that the theory of separably injective Banach spaces is strikingly different from that of injective spaces. For instance, separably injective Banach spaces are not necessarily isometric to, or complemented subspaces of, spaces of continuous functions on a compact space. Moreover, in contrast to the scarcity of examples and general results concerning injective spaces, we know of many different types of separably injective spaces and there is a rich theory around them. The monograph is completed with a preparatory chapter on injective spaces, a chapter on higher cardinal versions of separable injectivity and a lively discussion of open problems and further lines o...

  19. Organic Separation Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

    2014-09-22

    Separable organics have been defined as “those organic compounds of very limited solubility in the bulk waste and that can form a separate liquid phase or layer” (Smalley and Nguyen 2013), and result from three main solvent extraction processes: U Plant Uranium Recovery Process, B Plant Waste Fractionation Process, and Plutonium Uranium Extraction (PUREX) Process. The primary organic solvents associated with tank solids are TBP, D2EHPA, and NPH. There is concern that, while this organic material is bound to the sludge particles as it is stored in the tanks, waste feed delivery activities, specifically transfer pump and mixer pump operations, could cause the organics to form a separated layer in the tank farms feed tank. Therefore, Washington River Protection Solutions (WRPS) is experimentally evaluating the potential of organic solvents separating from the tank solids (sludge) during waste feed delivery activities, specifically the waste mixing and transfer processes. Given the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste acceptance criteria per the Waste Feed Acceptance Criteria document (24590-WTP-RPT-MGT-11-014) that there is to be “no visible layer” of separable organics in the waste feed, this would result in the batch being unacceptable to transfer to WTP. This study is of particular importance to WRPS because of these WTP requirements.

  20. Gulf stream separation dynamics

    Science.gov (United States)

    Schoonover, Joseph

    Climate models currently struggle with the more traditional, coarse ( O(100 km) ) representation of the ocean. In these coarse ocean simulations, western boundary currents are notoriously difficult to model accurately. The modeled Gulf Stream is typically seen exhibiting a mean pathway that is north of observations, and is linked to a warm sea-surface temperature bias in the Mid-Atlantic Bight. Although increased resolution ( O(10 km) ) improves the modeled Gulf Stream position, there is no clean recipe for obtaining the proper pathway. The 70 year history of literature on the Gulf Stream separation suggests that we have not reached a resolution on the dynamics that control the current's pathway just south of the Mid-Atlantic Bight. Without a concrete knowledge on the separation dynamics, we cannot provide a clean recipe for accurately modeling the Gulf Stream at increased resolutions. Further, any reliable parameterization that yields a realistic Gulf Stream path must express the proper physics of separation. The goal of this dissertation is to determine what controls the Gulf Stream separation. To do so, we examine the results of a model intercomparison study and a set of numerical regional terraforming experiments. It is argued that the separation is governed by local dynamics that are most sensitive to the steepening of the continental shelf, consistent with the topographic wave arrest hypothesis of Stern (1998). A linear extension of Stern's theory is provided, which illustrates that wave arrest is possible for a continuously stratified fluid.

  1. 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

  2. Nitrogen oxides at the UTLS: Combining observations from research aircraft and in-service aircraft

    Science.gov (United States)

    Ziereis, Helmut; Stratmann, Greta; Schlager, Hans; Gottschaldt, Klaus-Dirk; Rauthe-Schöch, Armin; Zahn, Andreas; Hoor, Peter; van, Peter

    2016-04-01

    Nitrogen oxides have a decisive influence on the chemistry of the upper troposphere and lower stratosphere. They are key constituents of several reaction chains influencing the production of ozone. They also play an essential role in the cycling of hydroxyl radicals and therefore influence the lifetime of methane. Due to their short lifetime and their variety of sources there is still a high uncertainty about the abundance of nitrogen oxides in the UTLS. Dedicated aircraft campaigns aim to study specific atmospheric questions like lightning, long range transport or aircraft emissions. Usually, within a short time period comprehensive measurements are performed within a more or less restricted region. Therefore, especially trace constituents like nitrogen oxides with short lifetime and a variety of different sources are not represented adequately. On the other hand, routine measurements from in-service aircraft allow observations over longer time periods and larger regions. However, it is nearly impossible to influence the scheduling of in-service aircraft and thereby time and space of the observations. Therefore, the combination of dedicated aircraft campaigns and routine observations might supplement each other. For this study we combine nitrogen oxides data sets obtained with the IAGOS-CARIBIC (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container) flying laboratory and with the German research aircraft HALO (High altitude and long range research aircraft). Data have been acquired within the IAGOS-CARIBIC project on a monthly base using a Lufthansa Airbus A340-600 since December 2004. About four flights are performed each month covering predominantly northern mid-latitudes. Additional flights have been conducted to destinations in South America and South Africa. Since 2012 HALO has been operational. Nitrogen oxides measurements have been performed during six missions covering mid latitudes, tropical as well as Polar

  3. 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.

  4. 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.

  5. Mass Separation by Metamaterials.

    Science.gov (United States)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2016-02-25

    Being able to manipulate mass flow is critically important in a variety of physical processes in chemical and biomolecular science. For example, separation and catalytic systems, which requires precise control of mass diffusion, are crucial in the manufacturing of chemicals, crystal growth of semiconductors, waste recovery of biological solutes or chemicals, and production of artificial kidneys. Coordinate transformations and metamaterials are powerful methods to achieve precise manipulation of molecular diffusion. Here, we introduce a novel approach to obtain mass separation based on metamaterials that can sort chemical and biomolecular species by cloaking one compound while concentrating the other. A design strategy to realize such metamaterial using homogeneous isotropic materials is proposed. We present a practical case where a mixture of oxygen and nitrogen is manipulated using a metamaterial that cloaks nitrogen and concentrates oxygen. This work lays the foundation for molecular mass separation in biophysical and chemical systems through metamaterial devices.

  6. Mass Separation by Metamaterials

    Science.gov (United States)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2016-02-01

    Being able to manipulate mass flow is critically important in a variety of physical processes in chemical and biomolecular science. For example, separation and catalytic systems, which requires precise control of mass diffusion, are crucial in the manufacturing of chemicals, crystal growth of semiconductors, waste recovery of biological solutes or chemicals, and production of artificial kidneys. Coordinate transformations and metamaterials are powerful methods to achieve precise manipulation of molecular diffusion. Here, we introduce a novel approach to obtain mass separation based on metamaterials that can sort chemical and biomolecular species by cloaking one compound while concentrating the other. A design strategy to realize such metamaterial using homogeneous isotropic materials is proposed. We present a practical case where a mixture of oxygen and nitrogen is manipulated using a metamaterial that cloaks nitrogen and concentrates oxygen. This work lays the foundation for molecular mass separation in biophysical and chemical systems through metamaterial devices.

  7. The Calculation of Collision Risk on Air-Routes Based on Variable Nominal Separation

    Institute of Scientific and Technical Information of China (English)

    QU Yu-ling; HAN Song-chen

    2010-01-01

    In this paper, a new method to calculate collision risk of air-routes, based on variable nominal separation, is proposed. The collision risk model of air-routes, based on the time variable and initial time interval variable, is given. Because the distance and the collision probability vary with time when the nominal relative speed between aircraft is not zero for a fixed initial time interval, the distance, the variable nominal separation, and the collision probability at any time can be expressed as functions of time and initial time interval. By the probabilistic theory, a model for calculating collision risk is acquired based on initial time interval distribution, flow rates, and the proportion of aircraft type. From the results of calculations, the collision risk can be characterized by the model when the nominal separation changes with time. As well the roles of parameters can be shown more readily.

  8. Separation membrane development

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.W. [Savannah River Technology Center, Aiken, SC (United States)

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  9. SULFIDE METHOD PLUTONIUM SEPARATION

    Science.gov (United States)

    Duffield, R.B.

    1958-08-12

    A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

  10. WET FLUORIDE SEPARATION METHOD

    Science.gov (United States)

    Seaborg, G.T.; Gofman, J.W.; Stoughton, R.W.

    1958-11-25

    The separation of U/sup 233/ from thorium, protactinium, and fission products present in neutron-irradiated thorium is accomplished by dissolving the irradiated materials in aqueous nitric acid, adding either a soluble fluoride, iodate, phosphate, or oxalate to precipltate the thorium, separating the precipltate from the solution, and then precipitating uranlum and protactinium by alkalizing the solution. The uranium and protactinium precipitate is removcd from the solution and dissolved in nitric acid. The uranyl nitrate may then be extracted from the acid solution by means of ether, and the protactinium recovered from the aqueous phase.

  11. Spiral Flow Separator

    Science.gov (United States)

    Robertson, Glen A.

    1993-01-01

    Proposed liquid-separating device relies on centrifugal force in liquid/liquid or liquid/solid mixture in spiral path. Operates in continuous flow at relatively high rates. Spiral tubes joined in sequence, with outlet tubes connected to joints. Cross-sectional areas of successive spiral tubes decreases by cross-sectional areas of outlet tubes. Centrifugal force pushes denser particles or liquids to outer edge of spiral, where removed from flow. Principle exploited to separate solids from wastewater, oil from fresh or salt water, or contaminants from salt water before evaporation. Also used to extract such valuable materials as precious metals from slurries.

  12. Spiral fluid separator

    Science.gov (United States)

    Robertson, Glen A. (Inventor)

    1993-01-01

    A fluid separator for separating particulate matter such as contaminates is provided which includes a series of spiral tubes of progressively decreasing cross sectional area connected in series. Each tube has an outlet on the outer curvature of the spiral. As fluid spirals down a tube, centrifugal force acts to force the heavier particulate matter to the outer wall of the tube, where it exits through the outlet. The remaining, and now cleaner, fluid reaches the next tube, which is smaller in cross sectional area, where the process is repeated. The fluid which comes out the final tube is diminished of particulate matter.

  13. Unity Through Separation

    DEFF Research Database (Denmark)

    Dabelsteen, Hans B.

    analysis, Dabelsteen study Danish secularism as an ideological concept. He finds that the conceptual structure of Danish secularism holds separation-as-principled distance at its core. Institutionally this particularly pertains to the establishment arrangement, and in practice it translates...... into the principle of treating everybody equally (with religious freedom, equality and Danish peoplehood as the most important principles adjacent to secularism). In a study of the historical roots of the separation doctrine and two current policy cases (same-sex marriage and reforms of church governance...

  14. 78 FR 52848 - Occupational Safety and Health Standards for Aircraft Cabin Crewmembers

    Science.gov (United States)

    2013-08-27

    ... conditions of aircraft cabin crew while they are onboard aircraft in operation. DATES: This action becomes... the working conditions of aircraft cabin crewmembers while they are onboard aircraft in operation... enforcement onboard the aircraft. The FAA agrees with the proposed recommendation. Specific procedures...

  15. Using doppler radar images to estimate aircraft navigational heading error

    Science.gov (United States)

    Doerry, Armin W.; Jordan, Jay D.; Kim, Theodore J.

    2012-07-03

    A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

  16. UNOLS now oversees research aircraft facilities for ocean science

    OpenAIRE

    Bane, John M.; Bluth, Robert; Flagg, Charles; Jonsson, Haflidi; Melville, W. Kendall; Prince, Mike; Riemer, Daniel

    2004-01-01

    In recognition of the increasing importance and value of aircraft as observational platforms in oceanographic research, the University National Oceanographic Laboratory System (UNOLS) has established the Scientific Committee for Oceanographic Aircraft Research (SCOAR).SCOAR aims to establish procedures for research aircraft that follow the present UNOLS practices for research vessel use, with the goal of making it understandable, and easy, and thus desirable, for...

  17. Influence of environmental factors on corrosion damage of aircraft structure

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Corrosion is one of the important structural integrity concerns of aging aircraft, and it is estimated that a significant portion of airframe maintenance budgets is directed towards corrosion-related problems for both military and commercial aircraft. In order to better understand how environmental factors influence the corrosion damage initiation and propagation on aircraft structure and to predict pre-corrosion test pieces of fatigue life and structural integrity of an effective approach, this paper uses ...

  18. Dedicated Solutions for Structural Health Monitoring of Aircraft Components

    OpenAIRE

    Pitropakis, Ioannis

    2015-01-01

    Aircraft structures, like any other mechanical structure, are subjected to various external factors that influence their lifetime. Mechanicalnbsp;and the environment are only some of the factors that can degrade the structure of aircraft components. Monitoring of these degradations by regular inspections or automated data recording is vital for the structural health of the critical components of an aircraft. This research proposes a number of dedicated solutions for structural health monitori...

  19. Aircraft Engine Exhaust Nozzle System for Jet Noise Reduction

    Science.gov (United States)

    Thomas, Russell H. (Inventor); Czech, Michael J. (Inventor); Elkoby, Ronen (Inventor)

    2014-01-01

    The aircraft exhaust engine nozzle system includes a fan nozzle to receive a fan flow from a fan disposed adjacent to an engine disposed above an airframe surface of the aircraft, a core nozzle disposed within the fan nozzle and receiving an engine core flow, and a pylon structure connected to the core nozzle and structurally attached with the airframe surface to secure the engine to the aircraft.

  20. Review of Aircraft Electric Power Systems and Architectures

    OpenAIRE

    Zhao, Xin; Guerrero, Josep M.; Wu, Xiaohao

    2014-01-01

    In recent years, the electrical power capacity is increasing rapidly in more electric aircraft (MEA), since the conventional mechanical, hydraulic and pneumatic energy systems are partly replaced by electrical power system. As a consequence, capacity and complexity of aircraft electric power systems (EPS) will increase dramatically and more advanced aircraft EPSs need to be developed. This paper gives a brief description of the constant frequency (CF) EPS, variable frequency (VF) EPS and adva...

  1. Investigation of cross flow fan propulsion for lightweight VTOL aircraft.

    OpenAIRE

    Gossett, Dean H.

    2000-01-01

    As world population increases, road and airport congestion will become increasingly prevalent. A small, cheap vTOL aircraft which can be flown from a driveway to the workplace parking lot would reduce traffic congestion and travel time. A lightweight, single seat commuter type VTOL aircraft is envisioned as the solution to this problem. To achieve a goal of minimum weight, the aircraft aerodynamic design should be optimized for forward flight. Vertical thrust augmentation from a propulsion un...

  2. Structural resource of the aircraft IAR-99 SOIM

    OpenAIRE

    Radu BISCA; Dorin LOZICI-BRINZEI

    2012-01-01

    Aircraft structure fatigue monitoring has been developed over decades presently reaching the stage where it became mandatory for all combat aircraft to be equipped with an airborne fatigue monitoring system. These systems usually collect operational data for calculating the safe fatigue life or inspection interval for the aircraft structure. This paper presents an analysis of the current state of fatigue monitoring systems on the IAR-99 SOIM based on the experience of international fatigue mo...

  3. Aircraft fault tolerant control based on active set method

    OpenAIRE

    Zhong, Lunlong; Mora-Camino, Félix

    2013-01-01

    This communication considers the case in which an aerodynamic actuator failure occurs to an aircraft while it has to perform a guidance manoeuver. The problem considered deals with the reassignment of the remaining actuators to continue to perform the maneuver while maintaining the structural integrity of the aircraft. A nonlinear inverse control technique is used to generate online nominal moments along the three main axes of the aircraft. Then, taking into account all material and structura...

  4. Collection and valuation of numerical models with the aim to investigate the impact of aircraft emissions

    International Nuclear Information System (INIS)

    Numerical models which are used to simulate the dynamics and chemistry of the Earth atmosphere are an important expedient to improve the knowledge of atmospheric processes. With such models it is possible to investigate single effects separately and to estimate their meaning for the whole system. It is possible to make sensitivity studies as well as calculations of different scenarios. This paper aims to describe different models which are available in the present time and which can be used for investigations dealing with the impact of aircraft emission on the Earth climate. Actual deficits of the modelling of atmospheric processes are discussed and the subsequent conclusions are presented. (orig.) 49 refs

  5. Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 1: Sections 1 through 6

    Science.gov (United States)

    Sakata, I. F.; Davis, G. W.

    1975-01-01

    The structural approach best suited for the design of a Mach 2.7 arrow-wing supersonic cruise aircraft was investigated. Results, procedures, and principal justification of results are presented. Detailed substantiation data are given. In general, each major analysis is presented sequentially in separate sections to provide continuity in the flow of the design concepts analysis effort. In addition to the design concepts evaluation and the detailed engineering design analyses, supporting tasks encompassing: (1) the controls system development; (2) the propulsion-airframe integration study; and (3) the advanced technology assessment are presented.

  6. Unsteady features of jets in lift and cruise modes for VTOL aircraft

    Science.gov (United States)

    Kibens, V.; Saripalli, K. R.; Wlezien, R. W.; Kegelman, J. T.

    1988-01-01

    Experiments were performed to simulate jet plume effects associated with VTOL aircraft in takeoff and cruise modes. A water facility was used to investigate the influence of inclination angle and separation distance on the three-dimensional fountain flowfield generated by two impinging jets operating at a jet Reynolds number of 250,000. Substantial differences in the flow features were observed for different spacings between the jets. Plume effects in cruise mode were simulated by a supersonic unheated jet parallel to a wall. Variation of the distance between the wall and the edge of the plume is shown to have a major controlling effect on the supersonic screech instability.

  7. Advanced Acoustic Blankets for Improved Aircraft Interior Noise Reduction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this project advanced acoustic blankets for improved low frequency interior noise control in aircraft will be developed and demonstrated. The improved...

  8. Research on aircraft emissions. Need for future work

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, A. [German Aerospace Establishment, Cologne (Germany). Transport Research Div.

    1997-12-31

    Reflecting the present status of the research on aircraft emissions and their impacts upon the atmosphere, task-fields for a work programme for the research on aircraft emissions can be derived. Most important measures are to support the efforts to define adequate reduction measures, and (with highest priority) scenario-writing for the long-term development in aircraft emissions, to be able to include into the decision making process the aspect of in-time-reaction against unwanted future. Besides that, a steady monitoring of global aircraft emissions will be necessary. (author) 5 refs.

  9. Escorting commercial aircraft to reduce the MANPAD threat

    Science.gov (United States)

    Hock, Nicholas; Richardson, M. A.; Butters, B.; Walmsley, R.; Ayling, R.; Taylor, B.

    2005-11-01

    This paper studies the Man-Portable Air Defence System (MANPADS) threat against large commercial aircraft using flight profile analysis, engagement modelling and simulation. Non-countermeasure equipped commercial aircraft are at risk during approach and departure due to the large areas around airports that would need to be secured to prevent the use of highly portable and concealable MANPADs. A software model (CounterSim) has been developed and was used to simulate an SA-7b and large commercial aircraft engagement. The results of this simulation have found that the threat was lessened when a escort fighter aircraft is flown in the 'Centreline Low' position, or 25 m rearward from the large aircraft and 15 m lower, similar to the Air-to-Air refuelling position. In the model a large aircraft on approach had a 50% chance of being hit or having a near miss (within 20m) whereas escorted by a countermeasure equipped F-16 in the 'Centerline Low' position, this was reduced to only 14%. Departure is a particularly vulnerable time for large aircraft due to slow climb rates and the inability to fly evasive manoeuvres. The 'Centreline Low' escorted departure greatly reduced the threat to 16% hit or near miss from 62% for an unescorted heavy aircraft. Overall the CounterSim modelling has showed that escorting a civilian aircraft on approach and departure can reduce the MANPAD threat by 3 to 4 times.

  10. An Overview of NASA's Subsonic Research Aircraft Testbed (SCRAT)

    Science.gov (United States)

    Baumann, Ethan; Hernandez, Joe; Ruhf, John C.

    2013-01-01

    National Aeronautics and Space Administration Dryden Flight Research Center acquired a Gulfstream III (GIII) aircraft to serve as a testbed for aeronautics flight research experiments. The aircraft is referred to as SCRAT, which stands for SubsoniC Research Aircraft Testbed. The aircraft's mission is to perform aeronautics research; more specifically raising the Technology Readiness Level (TRL) of advanced technologies through flight demonstrations and gathering high-quality research data suitable for verifying the technologies, and validating design and analysis tools. The SCRAT has the ability to conduct a range of flight research experiments throughout a transport class aircraft's flight envelope. Experiments ranging from flight-testing of a new aircraft system or sensor to those requiring structural and aerodynamic modifications to the aircraft can be accomplished. The aircraft has been modified to include an instrumentation system and sensors necessary to conduct flight research experiments along with a telemetry capability. An instrumentation power distribution system was installed to accommodate the instrumentation system and future experiments. An engineering simulation of the SCRAT has been developed to aid in integrating research experiments. A series of baseline aircraft characterization flights has been flown that gathered flight data to aid in developing and integrating future research experiments. This paper describes the SCRAT's research systems and capabilities.

  11. Integrated Network of Optimizations for Aircraft Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft design is a complex process requiring interactions and exchange of information among multiple disciplines such as aerodynamics, strength, fatigue,...

  12. Model Updating in Online Aircraft Prognosis Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Diagnostic and prognostic algorithms for many aircraft subsystems are steadily maturing. Unfortunately there is little experience integrating these technologies...

  13. Analysis of Virtual Sensors for Predicting Aircraft Fuel Consumption

    Data.gov (United States)

    National Aeronautics and Space Administration — Previous research described the use of machine learning algorithms to predict aircraft fuel consumption. This technique, known as Virtual Sensors, models fuel...

  14. Aircraft Structural Analysis, Design Optimization, and Manufacturing Tool Integration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovative research is proposed in integrating fundamental aircraft design processes with an emphasis on composite structures. Efficient, lightweight composite...

  15. A New Cryogenic Air Separation Process with Flash Separator

    OpenAIRE

    Barakat, Taj Alasfia M.; Rabah, Ali A.; Khalel, Zeinab A. M.

    2013-01-01

    A new cryogenic air separation process with flash separator is developed. A flash separator is added to the conventional double-column cryogenic air separation process. The flash separator is used to replace the turbine required to recover a portion of the energy in the double-column air separation process. The flash separator served dual purposes of throttling and separation. Both the conventional and the new processes are simulated using Aspen Plus version 11.1 the model air flow rate and c...

  16. Combustion noise from gas turbine aircraft engines measurement of far-field levels

    Science.gov (United States)

    Krejsa, Eugene A.

    1987-01-01

    Combustion noise can be a significant contributor to total aircraft noise. Measurement of combustion noise is made difficult by the fact that both jet noise and combustion noise exhibit broadband spectra and peak in the same frequency range. Since in-flight reduction of jet noise is greater than that of combustion noise, the latter can be a major contributor to the in-flight noise of an aircraft but will be less evident, and more difficult to measure, under static conditions. Several methods for measuring the far-field combustion noise of aircraft engines are discussed in this paper. These methods make it possible to measure combustion noise levels even in situations where other noise sources, such as jet noise, dominate. Measured far-field combustion noise levels for several turbofan engines are presented. These levels were obtained using a method referred to as three-signal coherence, requiring that fluctuating pressures be measured at two locations within the engine core in addition to the far-field noise measurement. Cross-spectra are used to separate the far-field combustion noise from far-field noise due to other sources. Spectra and directivities are presented. Comparisons with existing combustion noise predictions are made.

  17. Aerodynamic Modeling of Transonic Aircraft Using Vortex Lattice Coupled with Transonic Small Disturbance for Conceptual Design

    Science.gov (United States)

    Chaparro, Daniel; Fujiwara, Gustavo E. C.; Ting, Eric; Nguyen, Nhan

    2016-01-01

    The need to rapidly scan large design spaces during conceptual design calls for computationally inexpensive tools such as the vortex lattice method (VLM). Although some VLM tools, such as Vorview have been extended to model fully-supersonic flow, VLM solutions are typically limited to inviscid, subcritical flow regimes. Many transport aircraft operate at transonic speeds, which limits the applicability of VLM for such applications. This paper presents a novel approach to correct three-dimensional VLM through coupling of two-dimensional transonic small disturbance (TSD) solutions along the span of an aircraft wing in order to accurately predict transonic aerodynamic loading and wave drag for transport aircraft. The approach is extended to predict flow separation and capture the attenuation of aerodynamic forces due to boundary layer viscosity by coupling the TSD solver with an integral boundary layer (IBL) model. The modeling framework is applied to the NASA General Transport Model (GTM) integrated with a novel control surface known as the Variable Camber Continuous Trailing Edge Flap (VCCTEF).

  18. Aircraft panel with sensorless active sound power reduction capabilities through virtual mechanical impedances

    Science.gov (United States)

    Boulandet, R.; Michau, M.; Micheau, P.; Berry, A.

    2016-01-01

    This paper deals with an active structural acoustic control approach to reduce the transmission of tonal noise in aircraft cabins. The focus is on the practical implementation of the virtual mechanical impedances method by using sensoriactuators instead of conventional control units composed of separate sensors and actuators. The experimental setup includes two sensoriactuators developed from the electrodynamic inertial exciter and distributed over an aircraft trim panel which is subject to a time-harmonic diffuse sound field. The target mechanical impedances are first defined by solving a linear optimization problem from sound power measurements before being applied to the test panel using a complex envelope controller. Measured data are compared to results obtained with sensor-actuator pairs consisting of an accelerometer and an inertial exciter, particularly as regards sound power reduction. It is shown that the two types of control unit provide similar performance, and that here virtual impedance control stands apart from conventional active damping. In particular, it is clear from this study that extra vibrational energy must be provided by the actuators for optimal sound power reduction, mainly due to the high structural damping in the aircraft trim panel. Concluding remarks on the benefits of using these electrodynamic sensoriactuators to control tonal disturbances are also provided.

  19. Gas centrifugal separator

    International Nuclear Information System (INIS)

    Object: To enhance separating performance by jointly using separating action of impulse wave without increasing peripheral speed of a gas centrifugal separator and lengthening a cylindrical portion thereof. Structure: A mixed gas is introduced into a rotating cylinder from a mixed gas pipe and is separated into gas rich in light component and gas decreased in light component, these gases being taken outside the rotating cylinder through a product opening and a fixed waste pipe, respectively. A fixed product recycling pipe is disposed between an upper end plate and an upper buffer plate of the rotating cylinder the recycling pipe having an opening formed at the leading end so as to oppose to the rotating mixed gas, and the gas introduced from the opening is re-introduced into the central portion of the rotating cylinder for recirculation. A waste pipe is disposed between a lower end plate and a lower buffer plate of the rotating cylinder, and the gas not introduced into the opening of the waste pipe is circulated within the rotating cylinder. (Kamimura, M.)

  20. Fathering After Marital Separation

    Science.gov (United States)

    Keshet, Harry Finkelstein; Rosenthal, Kristine M.

    1978-01-01

    Deals with experiences of a group of separated or divorced fathers who chose to remain fully involved in the upbringing of their children. As they underwent transition from married parenthood to single fatherhood, these men learned that meeting demands of child care contributed to personal stability and growth. (Author)

  1. Lunar Soil Particle Separator

    Science.gov (United States)

    Berggren, Mark

    2010-01-01

    The Lunar Soil Particle Separator (LSPS) beneficiates soil prior to in situ resource utilization (ISRU). It can improve ISRU oxygen yield by boosting the concentration of ilmenite, or other iron-oxide-bearing materials found in lunar soils, which can substantially reduce hydrogen reduction reactor size, as well as drastically decreasing the power input required for soil heating

  2. Electrostatically Enhanced Vortex Separator

    Science.gov (United States)

    Collins, Earl R.

    1993-01-01

    Proposed device removes fine particles from high-pressure exhaust gas of chemical reactor. Negatively charged sectors on rotating disks in vortex generator attracts positively charged particles from main stream of exhaust gas. Electrostatic charge enhances particle-separating action of vortex. Gas without particles released to atmosphere.

  3. diffusive phase separation

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kenmochi

    1996-01-01

    w is constrained to have double obstacles σ*≤w≤σ* (i.e., σ* and σ* are the threshold values of w. The objective of this paper is to discuss the semigroup {S(t} associated with the phase separation model, and construct its global attractor.

  4. Alkaline battery, separator therefore

    Science.gov (United States)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  5. Separation of Concerns

    DEFF Research Database (Denmark)

    Ernst, Erik

    2003-01-01

    Separation of concerns is a crucial concept in discussions about software engineering consequences of programming language design decisions, especially in AOSD. This paper proposes a way to formalize this concept, and argues that the given formalization is useful even if it is used primarily in an...

  6. Isotope hydrograph separation

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, P. [UFZ-Umweltforschungszentrum, Centre of Environmental Research Leipzig-Halle, Leipzig (Germany)

    2000-07-01

    Storm-runoff thus reflects the complex hydraulic behaviour of drainage basins and water-links of such systems. Water of different origin may participate in the events and in this lecture, the application of isotope techniques to separate storm hydrographs into different components will be presented.

  7. Development of Polyimide Foam for Aircraft Sidewall Applications

    Science.gov (United States)

    Silcox, Richard; Cano, Roberto J.; Howerton, Brian M.; Bolton, J. Stuart; Kim, Nicholas N.

    2013-01-01

    In this paper, the use of polyimide foam as a lining in double panel applications is considered. It is being investigated here as a replacement for aircraft grade glass fiber and has a number of attractive functional attributes, not the least of which is its high fire resistance. The test configuration studied here consisted of two 1mm (0.04 in.) thick, flat aluminum panels separated by 12.7 cm (5.0 in.) with a 7.6 cm (3.0 in.) thick layer of foam centered in that space. Random incidence transmission loss measurements were conducted on this buildup, and conventional poro-elastic models were used to predict the performance of the lining material. Results from two densities of foam are considered. The Biot parameters of the foam were determined by a combination of direct measurement (for density, flow resistivity and Young s modulus) and inverse characterization procedures (for porosity, tortuosity, viscous and thermal characteristic length, Poisson s ratio and loss factor). The inverse characterization procedure involved matching normal incidence standing wave tube measurements of absorption coefficient and transmission loss of the isolated foam with finite element predictions. When the foam parameters determined in this way were used to predict the performance of the complete double panel system, reasonable agreement was obtained between the measured transmission loss and predictions made using a commercial statistical energy analysis code.

  8. Separation science and technology

    International Nuclear Information System (INIS)

    The focus of this project is the demonstration and advancement of membrane-based separation and destruction technologies. The authors are exploring development of membrane systems for gas separations, selective metal ion recovery, and for separation or destruction of hazardous organics. They evaluated existing polymers and polymer formulations for recovery of toxic oxyanionic metals such as chromate and arsenate from selected waste streams and developed second-generation water-soluble polymeric systems for highly selective oxyanion removal and recovery. They optimized the simultaneous removal of radioactive strontium and cesium from aqueous solutions using the new nonhazardous separations agents, and developed recyclable, redox-active extractants that permitted recovery of the radioactive ions into a minimal waste volume. They produced hollow fibers and fabricated prototype hollow-fiber membrane modules for applications to gas separations and the liquid-liquid extraction and recovery of actinides and nuclear materials from process streams. They developed and fabricated cyclodextrin-based microporous materials that selectively absorb organic compounds in an aqueous environment; the resultant products gave pure water with organics at less than 0.05 parts per billion. They developed new, more efficient, membrane-based electrochemical reactors for use in organic destruction in process waste treatment. They addressed the need for advanced oxidation technologies based on molecular-level materials designs that selectively remove or destroy target species. They prepared and characterized surface-modified TiO2 thin films using different linking approaches to attach ruthenium photosensitizers, and they started the measurement of the photo-degradation products generated using surface modified TiO2 films in reaction with chlorophenol

  9. Separation science and technology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.F.; Sauer, N.; Chamberlin, R.M.; Gottesfeld, S.; Mattes, B.R.; Li, D.Q.; Swanson, B.

    1998-12-31

    The focus of this project is the demonstration and advancement of membrane-based separation and destruction technologies. The authors are exploring development of membrane systems for gas separations, selective metal ion recovery, and for separation or destruction of hazardous organics. They evaluated existing polymers and polymer formulations for recovery of toxic oxyanionic metals such as chromate and arsenate from selected waste streams and developed second-generation water-soluble polymeric systems for highly selective oxyanion removal and recovery. They optimized the simultaneous removal of radioactive strontium and cesium from aqueous solutions using the new nonhazardous separations agents, and developed recyclable, redox-active extractants that permitted recovery of the radioactive ions into a minimal waste volume. They produced hollow fibers and fabricated prototype hollow-fiber membrane modules for applications to gas separations and the liquid-liquid extraction and recovery of actinides and nuclear materials from process streams. They developed and fabricated cyclodextrin-based microporous materials that selectively absorb organic compounds in an aqueous environment; the resultant products gave pure water with organics at less than 0.05 parts per billion. They developed new, more efficient, membrane-based electrochemical reactors for use in organic destruction in process waste treatment. They addressed the need for advanced oxidation technologies based on molecular-level materials designs that selectively remove or destroy target species. They prepared and characterized surface-modified TiO{sub 2} thin films using different linking approaches to attach ruthenium photosensitizers, and they started the measurement of the photo-degradation products generated using surface modified TiO{sub 2} films in reaction with chlorophenol.

  10. The ARCTAS aircraft mission: design and execution

    Directory of Open Access Journals (Sweden)

    D. J. Jacob

    2009-08-01

    Full Text Available The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS mission was conducted in two 3-week deployments based in Alaska (April 2008 and western Canada (June–July 2008. The goal of ARCTAS was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1 transport of mid-latitude pollution, (2 boreal forest fires, (3 aerosol radiative forcing, and (4 chemical processes. ARCTAS involved three aircraft: a DC-8 with detailed chemical payload, a P-3 with extensive aerosol payload, and a B-200 with aerosol remote sensing instrumentation. The aircraft augmented satellite observations of Arctic atmospheric composition, in particular from the NASA A-Train, by (1 validating the data, (2 improving constraints on retrievals, (3 making correlated observations, and (4 characterizing chemical and aerosol processes. The April flights (ARCTAS-A sampled pollution plumes from all three mid-latitude continents, fire plumes from Siberia and Southeast Asia, and halogen radical events. The June-July flights (ARCTAS-B focused on boreal forest fire influences and sampled fresh fire plumes from northern Saskatchewan as well as older fire plumes from Canada, Siberia, and California. The June–July deployment was preceded by one week of flights over California sponsored by the California Air Resources Board (ARCTAS-CARB. The ARCTAS-CARB goals were to (1 improve state emission inventories for greenhouse gases and aerosols, (2 provide observations to test and improve models of ozone and aerosol pollution. Extensive sampling across southern California and the Central Valley characterized emissions from urban centers, offshore shipping lanes, agricultural crops, feedlots, industrial sources, and wildfires.

  11. Forecasting for a Lagrangian aircraft campaign

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2004-01-01

    Full Text Available A forecast system has been developed in preparation for an upcoming aircraft measurement campaign, where the same air parcels polluted by emissions over North America shall be sampled repeatedly as they leave the continent, during transport over the Atlantic, and upon their arrival over Europe. This paper describes the model system in advance of the campaign, in order to make the flight planners familiar with the novel model output. The aim of a Lagrangian strategy is to infer changes in the chemical composition and aerosol distribution occurring en route by measured upwind/downwind differences. However, guiding aircraft repeatedly into the same polluted air parcels requires careful forecasting, for which no suitable model system exists to date. This paper describes a procedure using both Eulerian-type (i.e. concentration fields and Lagrangian-type (i.e. trajectories model output from the Lagrangian particle dispersion model FLEXPART to predict the best opportunities for a Lagrangian experiment. The best opportunities are defined as being highly polluted air parcels which receive little or no emission input after the first measurement, which experience relatively little mixing, and which are reachable by as many aircraft as possible. For validation the system was applied to the period of the NARE 97 campaign where approximately the same air masses were sampled on different flights. Measured upwind/downwind differences in carbon monoxide (CO and ozone (O3 decreased significantly as the threshold values used for accepting cases as Lagrangian were tightened. This proves that the model system can successfully identify Lagrangian opportunities.

  12. Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

    Science.gov (United States)

    Condon, E. P.; Vedder, J. F.

    1984-01-01

    Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

  13. Radiant Energy Power Source for Jet Aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Doellner, O.L.

    1992-02-01

    This report beings with a historical overview on the origin and early beginnings of Radiant Energy Power Source for Jet Aircraft. The report reviews the work done in Phase I (Grant DE-FG01-82CE-15144) and then gives a discussion of Phase II (Grant DE-FG01-86CE-15301). Included is a reasonably detailed discussion of photovoltaic cells and the research and development needed in this area. The report closes with a historical perspective and summary related to situations historically encountered on projects of this nature. 15 refs.

  14. Recent Progress in Aircraft Noise Research

    Science.gov (United States)

    Envia, Edmane; Thomas, Russell

    2007-01-01

    An overview of the acoustics research at NASA under the Subsonic Fixed Wing project is given. The presentation describes the rationale behind the noise reduction goals of the project in the context of the next generation air transportation system, and the emphasis placed on achieving these goals through a combination of the in-house and collaborative efforts with industry, universities and other government agencies. The presentation also describes the in-house research plan which is focused on the development of advanced noise and flow diagnostic techniques, next generation noise prediction tools, and novel noise reduction techniques that are applicable across a wide range of aircraft.

  15. Climatic impact of aircraft induced ozone changes

    Energy Technology Data Exchange (ETDEWEB)

    Sausen, R.; Feneberg, B.; Ponater, M. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    The effect of aircraft induced ozone changes on the global climate is studied by means of the general circulation model ECHAM4. The zonal mean temperature signal is considered. In order to estimate the statistical significance of the climatic impact a multivariate statistical test hierarchy combined with the fingerprint method has been applied. Sensitivity experiments show a significant coherent temperature response pattern in the northern extra-tropics for mid-latitude summer conditions. It consists of a tropospheric warming of about 0.2 K with a corresponding stratospheric cooling of the same magnitude. (author) 16 refs.

  16. Sensor Technology and Futuristic Of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    Emmanuel Rugambage Ndayishimiye

    2016-08-01

    Full Text Available The Next Generation fighter Aircraft seeks a fighter with higher abilities in areas such as reach, persistence, survivability, net-centricity, situation awareness, human system integration and weapons effects. The future system will have to counter foe armed with next generation advanced electronic attack, sophisticated integrated air defense systems, directed energy weapons, passive detection, integrated self-protection and cyber-attack capabilities. It must be capable to operate in the anti-access area-denial (A2/AD environment that will exist in the next coming years.

  17. Squeeze Film Damping for Aircraft Gas Turbines

    Directory of Open Access Journals (Sweden)

    R. W. Shende

    1988-10-01

    Full Text Available Modern aircraft gas turbine engines depend heavily on squeeze film damper supports at the bearings for abatement of vibrations caused by a number of probable excitation sources. This design ultimately results in light-weight construction together with higher efficiency and reliability of engines. Many investigations have been reported during past two decades concerning the functioning of the squeeze film damper, which is simple in construction yet complex in behaviour with its non-linearity and multiplicity of variables. These are reviewed in this article to throw light on the considerations involved in the design of rotor-bearing-casing systems incorporating squeeze film dampers.

  18. Extreme Loading of Aircraft Fan Blade

    CERN Document Server

    Datta, Dibakar

    2013-01-01

    The response of an aircraft fan blade manufactured by composites under the action of static and impact load has been studied in this report. The modeling and analysis of the geometry has been done using CASTEM 2007 version. For the quasi static analysis, the pressure has been incrementally applied until it satisfies the failure criteria. The deformed configuration, strain, Von-Mises stress, and the deflection of the blade have been studied. The response of the system e.g. deformation time history due to the impact of the projectile has been studied where the Newmark method for the dynamic problem has been implemented.

  19. Swarms of UAVs and fighter aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, M.W.; Wagner, J.S.; Stantz, K.M.; Gray, P.C.; Robinett, R.

    1998-11-01

    This paper describes a method of modeling swarms of UAVs and/or fighter aircraft using particle simulation concepts. Recent investigations into the use of genetic algorithms to design neural networks for the control of autonomous vehicles (i.e., robots) led to the examination of methods of simulating large collections of robots. This paper describes the successful implementation of a model of swarm dynamics using particle simulation concepts. Several examples of the complex behaviors achieved in a target/interceptor scenario are presented.

  20. Nonlinear dynamics of a vectored thrust aircraft

    DEFF Research Database (Denmark)

    Sørensen, C.B; Mosekilde, Erik

    1996-01-01

    With realistic relations for the aerodynamic coefficients, numerical simulations are applied to study the longitudional dynamics of a thrust vectored aircraft. As function of the thrust magnitude and the thrust vectoring angle the equilibrium state exhibits two saddle-node bifurcations and three...... Hopf bifurcations. Even when the equilibrium state is stable, weakly damped oscillations occur with a period of 1 min. If, in an attempt to compensate for these oscillations, the thrust deflection is periodically adjusted, a complicated structure of overlapping torus, saddle-node and period......-doubling bifurcations arises. This structure is investigated by combining brute force bifurcation diagrams with one- and two-dimensional continuation analyses....

  1. Aircraft gas turbine materials and processes.

    Science.gov (United States)

    Kear, B H; Thompson, E R

    1980-05-23

    Materials and processing innovations that have been incorporated into the manufacture of critical components for high-performance aircraft gas turbine engines are described. The materials of interest are the nickel- and cobalt-base superalloys for turbine and burner sections of the engine, and titanium alloys and composites for compressor and fan sections of the engine. Advanced processing methods considered include directional solidification, hot isostatic pressing, superplastic foring, directional recrystallization, and diffusion brazing. Future trends in gas turbine technology are discussed in terms of materials availability, substitution, and further advances in air-cooled hardware.

  2. Eddy current separation apparatus, separation module, separation method and method for adjusting an eddy current separation apparatus

    OpenAIRE

    Rem, P.C.; Bakker, M.C.M.; Berkhout, S.P.M.; Rahman, M.A.

    2012-01-01

    Eddy current separation apparatus (1) for separating particles (20) from a particle stream (w), wherein the apparatus (1) comprises a separator drum (4) adapted to create a first particle fraction (21) and a second particle fraction (23), a feeding device (2) upstream of the separator drum (4) for supplying particles (20) to said separator drum (4), and a splitter element (14) provided downstream of the separator drum (4) for splitting the respective fractions (21,23), wherein the apparatus (...

  3. Facilities of determination of socio-economic efficiency of aircrafts and ways of their increase

    Directory of Open Access Journals (Sweden)

    Mahir Halid Naif Hilyal

    2015-06-01

    Full Text Available Determination of efficiency of facilities of labour, including aircrafts that have wide distribution, is an important task. Level of appropriate methodological base largely influences on the creation of optimal product design and saving all kinds of resources. In this regard, the analysis of domestic and foreign sources to assess the effectiveness of innovations is conducted. It is shown that mainly four well-known indexes of calculation of effect of innovations are examined such, as a net present value, internal rate of return, internal rate of return, pay-back period. For today the index of profitability, which is very important for the estimation of both development and introduction of separate innovations and estimation of activity of business entities, absents in vast majority of official methodical materials. The impossibility of identifying of indexes of profit and net present value is shown. It is exposed, that in existent methodical materials is given insufficient attention to the calculation of effect in the field of consumption of innovations, where their actual final effect is defined. Methods of an assessment of social and economic efficiency of application of innovations in different types of productions, determination of efficiency from decrease in size of risk at realization of means of labor are demanded further development. The analysis of theoretical and methodological bases of determination of effect of aircrafts is executed also. The necessity of further development of socio-economic estimation of increase of major consumer properties of airplanes is set such, as their reliability and longevity. Paid attention to requirement of improvement of methods of calculation of expenses in exploitation of aircrafts, of establishment their numeral, including normative values. Similar recommendations are also belonged to the estimation of efficiency of small aircrafts.

  4. Microgravity Passive Phase Separator

    Science.gov (United States)

    Paragano, Matthew; Indoe, William; Darmetko, Jeffrey

    2012-01-01

    A new invention disclosure discusses a structure and process for separating gas from liquids in microgravity. The Microgravity Passive Phase Separator consists of two concentric, pleated, woven stainless- steel screens (25-micrometer nominal pore) with an axial inlet, and an annular outlet between both screens (see figure). Water enters at one end of the center screen at high velocity, eventually passing through the inner screen and out through the annular exit. As gas is introduced into the flow stream, the drag force exerted on the bubble pushes it downstream until flow stagnation or until it reaches an equilibrium point between the surface tension holding bubble to the screen and the drag force. Gas bubbles of a given size will form a front that is moved further down the length of the inner screen with increasing velocity. As more bubbles are added, the front location will remain fixed, but additional bubbles will move to the end of the unit, eventually coming to rest in the large cavity between the unit housing and the outer screen (storage area). Owing to the small size of the pores and the hydrophilic nature of the screen material, gas does not pass through the screen and is retained within the unit for emptying during ground processing. If debris is picked up on the screen, the area closest to the inlet will become clogged, so high-velocity flow will persist farther down the length of the center screen, pushing the bubble front further from the inlet of the inner screen. It is desired to keep the velocity high enough so that, for any bubble size, an area of clean screen exists between the bubbles and the debris. The primary benefits of this innovation are the lack of any need for additional power, strip gas, or location for venting the separated gas. As the unit contains no membrane, the transport fluid will not be lost due to evaporation in the process of gas separation. Separation is performed with relatively low pressure drop based on the large surface

  5. Mission Analysis and Aircraft Sizing of a Hybrid-Electric Regional Aircraft

    Science.gov (United States)

    Antcliff, Kevin R.; Guynn, Mark D.; Marien, Ty V.; Wells, Douglas P.; Schneider, Steven J.; Tong, Michael T.

    2016-01-01

    The purpose of this study was to explore advanced airframe and propulsion technologies for a small regional transport aircraft concept (approximately 50 passengers), with the goal of creating a conceptual design that delivers significant cost and performance advantages over current aircraft in that class. In turn, this could encourage airlines to open up new markets, reestablish service at smaller airports, and increase mobility and connectivity for all passengers. To meet these study goals, hybrid-electric propulsion was analyzed as the primary enabling technology. The advanced regional aircraft is analyzed with four levels of electrification, 0 percent electric with 100 percent conventional, 25 percent electric with 75 percent conventional, 50 percent electric with 50 percent conventional, and 75 percent electric with 25 percent conventional for comparison purposes. Engine models were developed to represent projected future turboprop engine performance with advanced technology and estimates of the engine weights and flowpath dimensions were developed. A low-order multi-disciplinary optimization (MDO) environment was created that could capture the unique features of parallel hybrid-electric aircraft. It is determined that at the size and range of the advanced turboprop: The battery specific energy must be 750 watt-hours per kilogram or greater for the total energy to be less than for a conventional aircraft. A hybrid vehicle would likely not be economically feasible with a battery specific energy of 500 or 750 watt-hours per kilogram based on the higher gross weight, operating empty weight, and energy costs compared to a conventional turboprop. The battery specific energy would need to reach 1000 watt-hours per kilogram by 2030 to make the electrification of its propulsion an economically feasible option. A shorter range and/or an altered propulsion-airframe integration could provide more favorable results.

  6. 77 FR 20012 - Federal Acquisition Regulation; Information Collection; Corporate Aircraft Costs

    Science.gov (United States)

    2012-04-03

    ... Regulation; Information Collection; Corporate Aircraft Costs AGENCY: Department of Defense (DOD), General... collection requirement concerning corporate aircraft costs. Public comments are particularly invited on..., Corporate Aircraft Costs, by any of the following methods: Regulations.gov :...

  7. A NASA study of the impact of technology on future multimission aircraft

    Science.gov (United States)

    Samuels, Jeffrey J.

    1992-01-01

    A conceptual aircraft design study was recently completed which compared three supersonic multimission tactical aircraft. The aircraft were evaluated in two technology timeframes and were sized with consistent methods and technology assumptions so that the aircraft could be compared in operational utility or cost analysis trends. The three aircraft are a carrier-based Fighter/Attack aircraft, a land-based Multirole Fighter, and a Short Takeoff/Vertical Landing (STOVL) aircraft. This paper describes the design study ground rules used and the aircraft designed. The aircraft descriptions include weights, dimensions and layout, design mission and maneuver performance, and fallout mission performance. The effect of changing technology and mission requirements on the STOVL aircraft and the impact of aircraft navalization are discussed. Also discussed are the effects on the STOVL aircraft of both Thrust/Weight required in hover and design mission radius.

  8. Lithium isotope separation

    International Nuclear Information System (INIS)

    Published methods for 6Li-7Li lithium isotope separation have been reviewed. Future demand for 6Li, whose main use will be as a tritium breeder in blankets surrounding the core of DT fusion power reactors, is likely to exceed 5 Mg/a in the next century. The applicability of the various available methods to such a large scale production rate has been assessed. Research on improving the effectiveness of current lithium isotope separation processes has been carried out worldwide in several major areas during the past decade; these include two-phase chemical exchange systems, ion exchange resin chromatography, highly isotope-selective techniques like laser photoactivation and radiofrequency spectroscopy. Chemical exchange systems appear to offer good potential in the near term for 6Li enrichment

  9. High gradient magnetic separation

    International Nuclear Information System (INIS)

    In a process in which magnetic material is trapped in a filter disposed in a magnetic field, and is unloaded by passing a fluid through the filter in the absence of the initial magnetic field, the magnetic field is first reduced to an intermediate value to allow unloading of the more weakly magnetic particles, the more strongly magnetic particles being retained and subsequently unloaded by further reduction of the magnetic field. Stage by stage reduction of the magnetic field during unloading allows separation of different species from the mixture. As an example the method can be applied to the separation of uranium compounds from mine ores. The uranium compounds are magnetic, while most of the other constituents of the ore are non-magnetic. The starting material is a suspension of the ore. Water is used for unloading. The filter material in this case is stainless steel balls. (author)

  10. Steam separator latch assembly

    Science.gov (United States)

    Challberg, Roy C.; Kobsa, Irvin R.

    1994-01-01

    A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof.

  11. Composite battery separator

    Science.gov (United States)

    Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)

    1987-01-01

    A composite battery separator comprises a support element (10) having an open pore structure such as a ribbed lattice and at least one liquid permeable sheet (20,22) to distribute the compressive force evenly onto the surfaces of the layers (24, 26) of negative active material and positive active material. In a non-flooded battery cell the compressible, porous material (18), such as a glass mat which absorbs the electrolyte, is compressed into a major portion of the pores or openings (16) in the support element. The unfilled pores in the material (18) form a gas diffusion path as the channels (41) formed between adjacent ribs in the lattice element (30,36). Facing two lattice elements (30, 31) with acute angled cross-ribs (34, 38) facing each other prevents the elements from interlocking and distorting a porous, separator (42) disposed between the lattice elements.

  12. Battery separator manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, N.I.; Sugarman, N.

    1974-12-27

    A battery with a positive plate, a negative plate, and a separator of polymeric resin having a degree of undesirable hydrophobia, solid below 180/sup 0/F, extrudable as a hot melt, and resistant to degradation by at least either acids or alkalies positioned between the plates is described. The separator comprises a nonwoven mat of fibers, the fibers being comprised of the polymeric resin and a wetting agent in an amount of 0.5 to 20 percent by weight based on the weight of the resin with the amount being incompatible with the resin below the melting point of the resin such that the wetting agent will bloom over a period of time at ambient temperatures in a battery, yet being compatible with the resin at the extrusion temperature and bringing about blooming to the surface of the fibers when the fibers are subjected to heat and pressure.

  13. Nylon separators. [thermal degradation

    Science.gov (United States)

    Lim, H. S.

    1977-01-01

    A nylon separator was placed in a flooded condition in K0H solution and heated at various high temperatures ranging from 60 C to 110 C. The weight decrease was measured and the molecular weight and decomposition product were analyzed to determine: (1) the effect of K0H concentration on the hydrolysis rate; (2) the effect of K0H concentration on nylon degradation; (3) the activation energy at different K0H concentrations; and (4) the effect of oxygen on nylon degradation. The nylon hydrolysis rate is shown to increase as K0H concentration is decreased 34%, giving a maximum rate at about 16%. Separator hydrolysis is confirmed by molecular weight decrease in age of the batteries, and the reaction of nylon with molecular oxygen is probably negligible, compared to hydrolysis. The extrapolated rate value from the high temperature experiment correlates well with experimental values at 35 degrees.

  14. Selective separation of uranium

    International Nuclear Information System (INIS)

    A process for the selective separation of uranium from elements accompanying it in a uranium-containing ore is claimed. It comprises preparing a uranium-containing solution; adding hydrochloric acid in an amount sufficient to form complex anions of the type (UO2Clsub(n))sup(2-n) where n is 3 or 4, or sulfuric acid in an amount sufficient to form complex anions of the type UO2(SO4)sub(m)sup(2-2m) where m is 2 or 3; adding a cationic surface active agent which forms a difficultly soluble precipitate with the complex anion; subjecting the solution to a gas flotation step to produce a foam fraction containing the pecipitate and a liquid fraction; separating the two fractions; and recovering uranium from the foam fraction

  15. HRS Separator HD

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  16. GPS Separator HD

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  17. Nuclear isomer separation

    International Nuclear Information System (INIS)

    Pure specimens of nuclear isomers are required for gamma-ray lasers. The author has selectively photoionized atoms containing isomeric nuclei of 197Hg. The isomers were produced by the 197Au(d, 2n)197Hg reaction and distilled. Three pulsed dye lasers were used to selectively ionize mercury atoms by double resonant three-step photoionization. Other isomer separation techniques and their limitations are discussed. (author)

  18. Separation of enantiomers

    CERN Document Server

    Todd , Matthew H

    2014-01-01

    In one handy volume this handbook summarizes the most common synthetic methods for the separation of racemic mixtures, allowing an easy comparison of the different strategies described in the literature.Alongside classical methods, the authors also consider kinetic resolutions, dynamic kinetic resolutions, divergent reactions of a racemic mixture, and a number of ""neglected"" cases not covered elsewhere, such as the use of circularly polarized light, polymerizations, ""ripening"" processes, dynamic combinatorial chemistry, and several thermodynamic processes. The result is a thorough introdu

  19. Materials separation and enrichment

    International Nuclear Information System (INIS)

    This volume supplies information in 16 individual contributions on projects sponsored by the Federal Ministry for Research and Technology (BMFT) with regard to the above mentioned topic, on the state of the art, on new technologies, and on international cooperation; two of the contributions have been recorded separately for the databases INIS and ENERGY. The contributions are supplemented by a survey of the projects sponsored and by a list of publications which have resulted from the sponsored projects. (EF)

  20. A Generic Nonlinear Aerodynamic Model for Aircraft

    Science.gov (United States)

    Grauer, Jared A.; Morelli, Eugene A.

    2014-01-01

    A generic model of the aerodynamic coefficients was developed using wind tunnel databases for eight different aircraft and multivariate orthogonal functions. For each database and each coefficient, models were determined using polynomials expanded about the state and control variables, and an othgonalization procedure. A predicted squared-error criterion was used to automatically select the model terms. Modeling terms picked in at least half of the analyses, which totalled 45 terms, were retained to form the generic nonlinear aerodynamic (GNA) model. Least squares was then used to estimate the model parameters and associated uncertainty that best fit the GNA model to each database. Nonlinear flight simulations were used to demonstrate that the GNA model produces accurate trim solutions, local behavior (modal frequencies and damping ratios), and global dynamic behavior (91% accurate state histories and 80% accurate aerodynamic coefficient histories) under large-amplitude excitation. This compact aerodynamics model can be used to decrease on-board memory storage requirements, quickly change conceptual aircraft models, provide smooth analytical functions for control and optimization applications, and facilitate real-time parametric system identification.

  1. Signal processing of aircraft flyover noise

    Science.gov (United States)

    Kelly, J. J.

    1993-01-01

    A detailed analysis of signal processing concerns for measuring aircraft flyover noise is presented. Development of a de-Dopplerization scheme for both corrected time history and spectral data is discussed along with an analysis of motion effects on measured spectra. A computer code was written to implement the de-Dopplerization scheme. Input to the code is the aircraft position data and the pressure time histories. To facilitate ensemble averaging, a level uniform flyover is considered in the study, but the code can accept more general flight profiles. The effects of spectral smearing and its removal are discussed. Using test data acquired from an XV-15 tilt-rotor flyover, comparisons are made between the measured and corrected spectra. Frequency shifts are accurately accounted for by the de-Dopplerization procedure. It is shown that by correcting for spherical spreading and Doppler amplitude, along with frequency, can give some idea about noise source directivity. The analysis indicated that smearing increases with frequency and is more severe on approach than recession.

  2. Overview of Aircraft Noise Prediction Tools Assessment

    Science.gov (United States)

    Dahl, Milo D.

    2007-01-01

    The acoustic assessment task for both the Subsonic Fixed Wing and the Supersonic projects under NASA s Fundamental Aeronautics Program was designed to assess the current state-of-the-art in noise prediction capability and to establish baselines for gauging future progress. The documentation of our current capabilities included quantifying the differences between predictions of noise from computer codes and measurements of noise from experimental tests. Quantifying the accuracy of both the computed and experimental results further enhanced the credibility of the assessment. This presentation gives sample results from codes representative of NASA s capabilities in aircraft noise prediction at the system level and at the component level. These include semi-empirical, statistical, analytical, and numerical codes. An example of system level results is shown for an aircraft. Component level results are shown for airframe flaps and landing gear, for jet noise from a variety of nozzles, and for broadband fan noise. Additional results are shown for modeling of the acoustic behavior of duct acoustic lining and the attenuation of sound in lined ducts with flow.

  3. Damage Propagation Modeling for Aircraft Engine Prognostics

    Science.gov (United States)

    Saxena, Abhinav; Goebel, Kai; Simon, Don; Eklund, Neil

    2008-01-01

    This paper describes how damage propagation can be modeled within the modules of aircraft gas turbine engines. To that end, response surfaces of all sensors are generated via a thermo-dynamical simulation model for the engine as a function of variations of flow and efficiency of the modules of interest. An exponential rate of change for flow and efficiency loss was imposed for each data set, starting at a randomly chosen initial deterioration set point. The rate of change of the flow and efficiency denotes an otherwise unspecified fault with increasingly worsening effect. The rates of change of the faults were constrained to an upper threshold but were otherwise chosen randomly. Damage propagation was allowed to continue until a failure criterion was reached. A health index was defined as the minimum of several superimposed operational margins at any given time instant and the failure criterion is reached when health index reaches zero. Output of the model was the time series (cycles) of sensed measurements typically available from aircraft gas turbine engines. The data generated were used as challenge data for the Prognostics and Health Management (PHM) data competition at PHM 08.

  4. MULTI-CONTROLLER STRUCTURE OF SUPERMANEUVERABLE AIRCRAFT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper proposes a method of using multi-controllers to control supermaneuverable aircraft. A nonlinear dynamic-inversion controller is used for supermaneuver. A gain-scheduled controller is used for routine maneuver. A switch algorithm is designed to switch the controllers. The flight envelopes of the controllers are different but have a common area in which the controllers are switched from one to the other. In the common area, some special boundaries are selected to decide switch conditions. The controllers all use vector-thrust for lower velocity maneuver control. Unlike the variation-structure theory to use a single boundary, this paper uses two boundaries for switching between the two controllers. One boundary is used for switching from dynamic-inversion to gain-scheduling, while the other is used for switching from gain-scheduling to dynamic-inversion. This can effectively avoid the system vibration caused by switching repeatedly at a single boundary. The method is very easy for engineering. It can reduce the risk of design of the supermaneuverable aircraft.

  5. Radiation exposure monitoring in civil aircraft

    Science.gov (United States)

    Schrewe, Ulrich J.

    1999-02-01

    Based on the 1990 Recommendation of the ICRP (ICRP Publication 60, Pergamon Press, Oxford, 1991) a European Directive [Official J. Eur. Communities 19 (1996) L159, 1-114] commits the European Union (EU) member states to revise their national radiation protection laws by the year 2000 such that the exposure of aircrews to the increased cosmic radiation prevailing at aviation flight altitudes will be treated as occupational risks. A consequence will be that employers must assess the aircrew exposure. The ACREM (Air Crew Radiation Exposure Monitoring) research project intends to investigate practically methods for aircraft dose equivalent determination. The in-flight measurements were carried out on cargo aircraft. Field calibrations were performed using Tissue-Equivalent Proportional Counters (TEPC) as the reference instrument. Various monitors were used to investigate the spatial doserate distribution. The measured data were collated according to the different altitudes and geomagnetic latitudes. The results obtained from various in-flight measurements are reported and a concept for a future routine dose assessment for aircrew is proposed.

  6. Monitoring Aircraft Motion at Airports by LIDAR

    Science.gov (United States)

    Toth, C.; Jozkow, G.; Koppanyi, Z.; Young, S.; Grejner-Brzezinska, D.

    2016-06-01

    Improving sensor performance, combined with better affordability, provides better object space observability, resulting in new applications. Remote sensing systems are primarily concerned with acquiring data of the static components of our environment, such as the topographic surface of the earth, transportation infrastructure, city models, etc. Observing the dynamic component of the object space is still rather rare in the geospatial application field; vehicle extraction and traffic flow monitoring are a few examples of using remote sensing to detect and model moving objects. Deploying a network of inexpensive LiDAR sensors along taxiways and runways can provide both geometrically and temporally rich geospatial data that aircraft body can be extracted from the point cloud, and then, based on consecutive point clouds motion parameters can be estimated. Acquiring accurate aircraft trajectory data is essential to improve aviation safety at airports. This paper reports about the initial experiences obtained by using a network of four Velodyne VLP- 16 sensors to acquire data along a runway segment.

  7. Human Factors of Remotely Piloted Aircraft

    Science.gov (United States)

    Hobbs, Alan Neville

    2014-01-01

    The civilian use of remotely piloted, or unmanned aircraft is expected to increase rapidly in the years ahead. Despite being referred to as unmanned some of the major challenges confronting this emerging sector relate to human factors. As unmanned aircraft systems (UAS) are introduced into civil airspace, a failure to adequately consider human factors could result in preventable accidents that may not only result in loss of life, but may also undermine public confidence in remotely piloted operations. Key issues include pilot situational awareness, collision avoidance in the absence of an out-the-window view, the effects of time delays in communication and control systems, control handovers, the challenges of very long duration flights, and the design of the control station. Problems have included poor physical layout of controls, non-intuitive automation interfaces, an over-reliance on text displays, and complicated sequences of menu selection to perform routine tasks. Some of the interface problems may have been prevented had an existing regulation or cockpit design principle been applied. In other cases, the design problems may indicate a lack of suitable guidance material.

  8. An Immunized Aircraft Maneuver Selection System

    Science.gov (United States)

    Karr, Charles L.

    2003-01-01

    The objective of this project, as stated in the original proposal, was to develop an immunized aircraft maneuver selection (IAMS) system. The IAMS system was to be composed of computational and informational building blocks that resemble structures in natural immune systems. The ultimate goal of the project was to develop a software package that could be flight tested on aircraft models. This report describes the work performed in the first year of what was to have been a two year project. This report also describes efforts that would have been made in the final year to have completed the project, had it been continued for the final year. After introductory material is provided in Section 2, the end-of-year-one status of the effort is discussed in Section 3. The remainder of the report provides an accounting of first year efforts. Section 4 provides background information on natural immune systems while Section 5 describes a generic ar&itecture developed for use in the IAMS. Section 6 describes the application of the architecture to a system identification problem. Finally, Section 7 describes steps necessary for completing the project.

  9. ANALYSES ON SYSTEMATIC CONFRONTATION OF FIGHTER AIRCRAFT

    Institute of Scientific and Technical Information of China (English)

    HuaiJinpeng; WuZhe; HuangJun

    2002-01-01

    Analyses of the systematic confrontation between two military forcfes are the highest hierarchy on opera-tional effectiveness study of weapon systema.The physi-cal model for tactical many-on-many engagements of an aerial warfare with heterogeneous figher aircraft is estab-lished.On the basis of Lanchester multivariate equations of square law,a mathematical model corresponding to the established physical model is given.A superiorityh parame-ter is then derived directly from the mathematical model.With view to the high -tech condition of modern war-fare,the concept of superiority parameter which more well and truly reflects the essential of an air-to-air en-gagement is further formulated.The attrition coeffi-cients,which are key to the differential equations,are de-termined by using tactics of random target assignment and air-to-air capability index of the fighter aircraft.Hereby,taking the mathematical model and superiority parameter as cores,calculations amd analyses of complicate systemic problems such as evaluation of battle superiority,prog-mostication of combat process and optimization of colloca-tions have been accomplished.Results indicate that a clas-sical combat theory with its certain recent development has received newer applications in the military operation research for complicated confrontation analysis issues.

  10. Investigation of damping liquids for aircraft instruments

    Science.gov (United States)

    Keulegan, G H

    1929-01-01

    This report covers the results of an investigation carried on at the Bureau of Standards under a research authorization from, and with the financial assistance of, the National Advisory Committee for Aeronautics. The choice of a damping liquid for aircraft instruments is difficult owing to the range of temperature at which aircraft operate. Temperature changes affect the viscosity tremendously. The investigation was undertaken with the object of finding liquids of various viscosities otherwise suitable which had a minimum change in viscosity with temperature. The new data relate largely to solutions. The effect of temperature on the kinematic viscosity of the following liquids and solutions was determined in the temperature interval -18 degrees to +30 degrees C. (1) solutions of animal and vegetable oils in xylene. These were poppy-seed oil, two samples of neat's-foot oils, castor oil, and linseed oil. (2) solutions of mineral oil in xylene. These were Squibb's petrolatum of naphthene base and transformer oil. (3) glycerine solutions in ethyl alcohol and in mixture of 50-50 ethyl alcohol and water. (4) mixtures of normal butyl alcohol with methyl alcohol. (5) individual liquids, kerosene, mineral spirits, xylene, recoil oil. The apparatus consisted of four capillary-tube viscometers, which were immersed in a liquid bath in order to secure temperature control. The method of calibration and the related experimental data are presented.

  11. Damage tolerance analysis of aircraft reinforced panels

    Directory of Open Access Journals (Sweden)

    A. Pirondi

    2011-04-01

    Full Text Available This work is aimed at reproducing numerically a campaign of experimental tests performed for the development of reinforced panels, typically found in aircraft fuselage. The bonded reinforcements can significantly reduce the rate of fatigue crack growth and increase the residual strength of the skin. The reinforcements are of two types: stringers and doublers. The former provides stiffening to the panel while the latter controls the crack growth between the stringers. The purpose of the study is to validate a numerical method of analysis that can predict the damage tolerance of these reinforced panels. Therefore, using a fracture mechanics approach, several models (different by the geometry and the types of reinforcement constraints were simulated with the finite element solver ABAQUS. The bonding between skin and stiffener was taken either rigid or flexible due to the presence of adhesive. The possible rupture of the reinforcements was also considered. The stress intensity factor trend obtained numerically as a function of crack growth was used to determine the fatigue crack growth rate, obtaining a good approximation of the experimental crack propagation rate in the skin. Therefore, different solutions for improving the damage tolerance of aircraft reinforced panels can be virtually tested in this way before performing experiments.

  12. Trust Control of VTOL Aircraft Part Deux

    Science.gov (United States)

    Dugan, Daniel C.

    2014-01-01

    Thrust control of Vertical Takeoff and Landing (VTOL) aircraft has always been a debatable issue. In most cases, it comes down to the fundamental question of throttle versus collective. Some aircraft used throttle(s), with a fore and aft longitudinal motion, some had collectives, some have used Thrust Levers where the protocol is still "Up is Up and Down is Down," and some have incorporated both throttles and collectives when designers did not want to deal with the Human Factors issues. There have even been combinations of throttles that incorporated an arc that have been met with varying degrees of success. A previous review was made of nineteen designs without attempting to judge the merits of the controller. Included in this paper are twelve designs entered in competition for the 1961 Tri-Service VTOL transport. Entries were from a Bell/Lockheed tiltduct, a North American tiltwing, a Vanguard liftfan, and even a Sikorsky tiltwing. Additional designs were submitted from Boeing Wichita (direct lift), Ling-Temco-Vought with its XC-142 tiltwing, Boeing Vertol's tiltwing, Mcdonnell's compound and tiltwing, and the Douglas turboduct and turboprop designs. A private party submitted a re-design of the Breguet 941 as a VTOL transport. It is important to document these 53 year-old designs to preserve a part of this country's aviation heritage.

  13. Separation of gas mixtures

    International Nuclear Information System (INIS)

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  14. Airborne rotary separator study

    Science.gov (United States)

    Drnevich, R. F.; Nowobilski, J. J.

    1992-01-01

    Several air breathing propulsion concepts for future earth-to-orbit transport vehicles utilize air collection and enrichment, and subsequent storage of liquid oxygen for later use in the vehicle mission. Work performed during the 1960's established the feasibility of substantially reducing weight and volume of a distillation type air separator system by operating the distillation elements in high 'g' fields obtained by rotating the separator assembly. The purpose of this study was to evaluate various fuels and fuel combinations with the objective of minimizing the weight and increase the ready alert capability of the plane. Fuels will be used to provide energy as well as act as heat sinks for the on-board heat rejection system. Fuel energy was used to provide power for air separation as well as to produce refrigeration for liquefaction of oxygen enriched air, besides its primary purpose of vehicle propulsion. The heat generated in the cycle was rejected to the fuel and water which is also carried on board the vehicle.The fuels that were evaluated include JP4, methane, and hydrogen. Hydrogen served as a comparison to the JP4 and methane cases.

  15. Apparatus for electrophoresis separation

    Science.gov (United States)

    Anderson, Norman L.

    1978-01-01

    An apparatus is disclosed for simultaneously performing electrophoresis separations on a plurality of slab gels containing samples of protein, protein subunits or nucleic acids. A reservoir of buffer solution is divided into three compartments by two parallel partitions having vertical slots spaced along their length. A sheet of flexible, electrically insulative material is attached to each partition and is provided with vertical slits aligned with the slots. Slab-gel holders are received within the slots with the flexible material folded outwardly as flaps from the slits to overlay portions of the holder surfaces and thereby act as electrical and liquid seals. An elongated, spaghetti-like gel containing a sample of specimen that was previously separated by isoelectric focusing techniques is vertically positioned along a marginal edge portion of the slab gel. On application of an electrical potential between the two outer chambers of buffer solution, a second dimensional electrophoresis separation in accordance with molecular weight occurs as the specimen molecules migrate across the slab gel.

  16. Separation of sulfur isotopes

    Science.gov (United States)

    DeWitt, Robert; Jepson, Bernhart E.; Schwind, Roger A.

    1976-06-22

    Sulfur isotopes are continuously separated and enriched using a closed loop reflux system wherein sulfur dioxide (SO.sub.2) is reacted with sodium hydroxide (NaOH) or the like to form sodium hydrogen sulfite (NaHSO.sub.3). Heavier sulfur isotopes are preferentially attracted to the NaHSO.sub.3, and subsequently reacted with sulfuric acid (H.sub.2 SO.sub.4) forming sodium hydrogen sulfate (NaHSO.sub.4) and SO.sub.2 gas which contains increased concentrations of the heavier sulfur isotopes. This heavy isotope enriched SO.sub.2 gas is subsequently separated and the NaHSO.sub.4 is reacted with NaOH to form sodium sulfate (Na.sub.2 SO.sub.4) which is subsequently decomposed in an electrodialysis unit to form the NaOH and H.sub.2 SO.sub.4 components which are used in the aforesaid reactions thereby effecting sulfur isotope separation and enrichment without objectionable loss of feed materials.

  17. Innovative Separations Technologies

    Energy Technology Data Exchange (ETDEWEB)

    J. Tripp; N. Soelberg; R. Wigeland

    2011-05-01

    Reprocessing used nuclear fuel (UNF) is a multi-faceted problem involving chemistry, material properties, and engineering. Technology options are available to meet a variety of processing goals. A decision about which reprocessing method is best depends significantly on the process attributes considered to be a priority. New methods of reprocessing that could provide advantages over the aqueous Plutonium Uranium Reduction Extraction (PUREX) and Uranium Extraction + (UREX+) processes, electrochemical, and other approaches are under investigation in the Fuel Cycle Research and Development (FCR&D) Separations Campaign. In an attempt to develop a revolutionary approach to UNF recycle that may have more favorable characteristics than existing technologies, five innovative separations projects have been initiated. These include: (1) Nitrogen Trifluoride for UNF Processing; (2) Reactive Fluoride Gas (SF6) for UNF Processing; (3) Dry Head-end Nitration Processing; (4) Chlorination Processing of UNF; and (5) Enhanced Oxidation/Chlorination Processing of UNF. This report provides a description of the proposed processes, explores how they fit into the Modified Open Cycle (MOC) and Full Recycle (FR) fuel cycles, and identifies performance differences when compared to 'reference' advanced aqueous and fluoride volatility separations cases. To be able to highlight the key changes to the reference case, general background on advanced aqueous solvent extraction, advanced oxidative processes (e.g., volumetric oxidation, or 'voloxidation,' which is high temperature reaction of oxide UNF with oxygen, or modified using other oxidizing and reducing gases), and fluorination and chlorination processes is provided.

  18. Modelling and simulation of flexible aircraft : handling qualities with active load control

    OpenAIRE

    Andrews, Stuart P.

    2011-01-01

    The study of the motion of manoeuvring aircraft has traditionally considered the aircraft to be rigid. This simplifying assumption has been shown to give quite accurate results for the flight dynamics of many aircraft types. As modern transport aircraft have developed however, there has been a marked increase in the size and weight of these aircraft. This trend is likely to continue with the development of future blended-wing-body and supersonic transport aircraft. This increas...

  19. Active control of Boundary Layer Separation & Flow Distortion in Adverse Pressure Gradient Flows via Supersonic Microjets

    Science.gov (United States)

    Alvi, Farrukh S.; Gorton, Susan (Technical Monitor)

    2005-01-01

    Inlets to aircraft propulsion systems must supply flow to the compressor with minimal pressure loss, flow distortion or unsteadiness. Flow separation in internal flows such as inlets and ducts in aircraft propulsion systems and external flows such as over aircraft wings, is undesirable as it reduces the overall system performance. The aim of this research has been to understand the nature of separation and more importantly, to explore techniques to actively control this flow separation. In particular, the use of supersonic microjets as a means of controlling boundary layer separation was explored. The geometry used for the early part of this study was a simple diverging Stratford ramp, equipped with arrays of supersonic microjets. Initial results, based on the mean surface pressure distribution, surface flow visualization and Planar Laser Scattering (PLS) indicated a reverse flow region. We implemented supersonic microjets to control this separation and flow visualization results appeared to suggest that microjets have a favorable effect, at least to a certain extent. However, the details of the separated flow field were difficult to determine based on surface pressure distribution, surface flow patterns and PLS alone. It was also difficult to clearly determine the exact influence of the supersonic microjets on this flow. In the latter part of this study, the properties of this flow-field and the effect of supersonic microjets on its behavior were investigated in further detail using 2-component (planar) Particle Image Velocimetry (PIV). The results clearly show that the activation of microjets eliminated flow separation and resulted in a significant increase in the momentum of the fluid near the ramp surface. Also notable is the fact that the gain in momentum due to the elimination of flow separation is at least an order of magnitude larger (two orders of magnitude larger in most cases) than the momentum injected by the microjets and is accomplished with very

  20. Separated flow past smooth slender bodies

    Science.gov (United States)

    Williams, Ann Louise

    1991-02-01

    This dissertation describes an investigation of the separated flow past slender bodies at high angles of attack. Flows of this type occur on aircraft and missile forebodies and can develop large forces which are important when considering stability and control of the vehicle. The objective of this work is to extend the vortex sheet model, which has previously been implemented for slender wings and circular and elliptic cones, to cones of more general cross-section and to non-conical bodies. The cross-sections of the bodies studied here are basically square or triangular, but with rounded corners. The model is inviscid, so the separation positions must be prescribed. Two distinct families of solutions have been identified. For laterally symmetric configurations with symmetric separation positions and no yaw, the first family solutions are symmetric, whereas the second family solutions are asymmetric. For elliptic cones, it is known that cross-section thickness affects the degree of asymmetry of the flow and this represents a mechanism for the control of side forces. Square or triangular cross-sections with rounded corners are of interest to aerodynamicists and have been investigated to assess the effect on asymmetry of making a circular cross-section 'square' or 'triangular'. For 'square' and 'triangular' cones placed either side, or corner on to the flow, results are obtained which enable the effect of cross-section shape on the degree of asymmetry to be assessed. A non-conical vortex sheet model has been developed for the first time for separation from a smooth body. Previously a non-conical line-vortex model was implemented, however lack of representation of vorticity near the separation line limits the applicability of the results. The solution procedure for the non-conical problem consists of a downstream-marching scheme starting from a known solution at the nose. Starting solutions are available if the flow at the nose is assumed conical. With symmetry

  1. Air Separation Using Hollow Fiber Membranes

    Science.gov (United States)

    Huang, Stephen E.

    2004-01-01

    The NASA Glenn Research Center in partnership with the Ohio Aerospace Institute provides internship programs for high school and college students in the areas of science, engineering, professional administrative, and other technical areas. During the summer of 2004, I worked with Dr. Clarence T. Chang at NASA Glenn Research Center s combustion branch on air separation using hollow fiber membrane technology. . In light of the accident of Trans World Airline s flight 800, FAA has mandated that a suitable solution be created to prevent the ignition of fuel tanks in aircrafts. In order for any type of fuel to ignite, three important things are needed: fuel vapor, oxygen, and an energy source. Two different ways to make fuel tanks less likely to ignite are reformulating the fuel to obtain a lower vapor pressure for the fuel and or using an On Board Inert Gas Generating System (OBIGGS) to inert the Central Wing Tank. goal is to accomplish the mission, which means that the Air Separation Module (ASM) tends to be bulky and heavy. The primary goal for commercial aviation companies is to transport as much as they can with the least amount of cost and fuel per person, therefore the ASM must be compact and light as possible. The plan is to take bleed air from the aircraft s engines to pass air through a filter first to remove particulates and then pass the air through the ASM containing hollow fiber membranes. In the lab, there will be a heating element provided to simulate the temperature of the bleed air that will be entering the ASM and analysis of the separated air will be analyzed by a Gas Chromatograph/Mass Spectrometer (GC/MS). The GUMS will separate the different compounds in the exit streams of the ASM and provide information on the performance of hollow fiber membranes. Hopefully I can develop ways to improve efficiency of the ASM. different types of jet fuel were analyzed and data was well represented on SAE Paper 982485. Data consisted of the concentrations of over

  2. Inertial Force Coupling to Nonlinear Aeroelasticity of Flexible Wing Aircraft

    Science.gov (United States)

    Nguyen, Nhan T.; Ting, Eric

    2016-01-01

    This paper investigates the inertial force effect on nonlinear aeroelasticity of flexible wing aircraft. The geometric are nonlinearity due to rotational and tension stiffening. The effect of large bending deflection will also be investigated. Flutter analysis will be conducted for a truss-braced wing aircraft concept with tension stiffening and inertial force coupling.

  3. 48 CFR 1852.228-71 - Aircraft flight risks.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Aircraft flight risks. 1852.228-71 Section 1852.228-71 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE... the aircraft has returned to the ground and rotors are disengaged. (iv) With respect to vertical...

  4. A DSS for capacity planning of aircraft maintenance personnel

    NARCIS (Netherlands)

    M.C. Dijkstra (Matthijs); L.G. Kroon (Leo); J.A.E.E. van Nunen (Jo); M. Salomon (Marc)

    1991-01-01

    textabstractIn this paper we describe a Decision Support System (DSS) that has been developed for the aircraft maintenance department of the Dutch national airline company at the main airport in the Netherlands. The aircraft maintenance department is responsible for carrying out the regular short in

  5. Optimization of operational aircraft parameters reducing noise emission

    OpenAIRE

    Abdallah, Lina; Khardi, Salah; Haddou, Mounir

    2010-01-01

    The objective of this paper is to develop a model and a minimization method to provide flight path optimums reducing aircraft noise in the vicinity of airports. Optimization algorithm has solved a complex optimal control problem, and generates flight paths minimizing aircraft noise levels. Operational and safety constraints have been considered and their limits satisfied. Results are here presented and discussed.

  6. Optimization of operational aircraft parameters Reducing Noise Emission

    CERN Document Server

    Abdallah, Lina; Khardi, Salah

    2008-01-01

    The objective of this paper is to develop a model and a minimization method to provide flight path optimums reducing aircraft noise in the vicinity of airports. Optimization algorithm has solved a complex optimal control problem, and generates flight paths minimizing aircraft noise levels. Operational and safety constraints have been considered and their limits satisfied. Results are here presented and discussed.

  7. 14 CFR 13.17 - Seizure of aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Seizure of aircraft. 13.17 Section 13.17... INVESTIGATIVE AND ENFORCEMENT PROCEDURES Legal Enforcement Actions § 13.17 Seizure of aircraft. (a) Under... by the Regional Administrator of the region, or by the Chief Counsel, may summarily seize an...

  8. 77 FR 24251 - Consensus Standards, Light-Sport Aircraft

    Science.gov (United States)

    2012-04-23

    ... Federal Aviation Administration Consensus Standards, Light-Sport Aircraft AGENCY: Federal Aviation... availability of three new and three revised consensus standards relating to the provisions of the Sport Pilot and Light-Sport Aircraft rule issued July 16, 2004, and effective September 1, 2004....

  9. 78 FR 35085 - Consensus Standards, Light-Sport Aircraft

    Science.gov (United States)

    2013-06-11

    ... Federal Aviation Administration Consensus Standards, Light-Sport Aircraft AGENCY: Federal Aviation... availability of one new and seven revised consensus standards relating to the provisions of the Sport Pilot and Light-Sport Aircraft rule issued July 16, 2004, and effective September 1, 2004. ASTM...

  10. 76 FR 71081 - Public Aircraft Oversight Safety Forum

    Science.gov (United States)

    2011-11-16

    ... SAFETY BOARD Public Aircraft Oversight Safety Forum The National Transportation Safety Board (NTSB) will convene a Public Aircraft Oversight Safety Forum which will begin at 9 a.m., Wednesday, November 30, 2011. NTSB Chairman Deborah A.P. Hersman will chair the two-day forum and all five Board Members...

  11. 14 CFR 135.419 - Approved aircraft inspection program.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Approved aircraft inspection program. 135.419 Section 135.419 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Maintenance, Preventive Maintenance, and Alterations § 135.419 Approved aircraft inspection program....

  12. 14 CFR 91.1041 - Aircraft proving and validation tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft proving and validation tests. 91... Ownership Operations Program Management § 91.1041 Aircraft proving and validation tests. (a) No program... tests. However, pilot flight training may be conducted during the proving tests. (d) Validation...

  13. How Effective Is Communication Training For Aircraft Crews

    Science.gov (United States)

    Linde, Charlotte; Goguen, Joseph; Devenish, Linda

    1992-01-01

    Report surveys communication training for aircraft crews. Intended to alleviate problems caused or worsened by poor communication and coordination among crewmembers. Focuses on two training methods: assertiveness training and grid-management training. Examines theoretical background of methods and attempts made to validate their effectiveness. Presents criteria for evaluating applicability to aviation environment. Concludes communication training appropriate for aircraft crews.

  14. Aircraft bi-level life cycle cost estimation

    NARCIS (Netherlands)

    Zhao, X.; Verhagen, W.J.C.; Curan, R.

    2015-01-01

    n an integrated aircraft design and analysis practice, Life Cycle Cost (LCC) is essential for decision making. The LCC of an aircraft is ordinarily partially estimated by emphasizing a specific cost type. However, an overview of the LCC including design and development cost, production cost, operati

  15. Vulnerability of fighter–aircraft for new threats

    NARCIS (Netherlands)

    Meerten, E. van

    2002-01-01

    Technical developments in modern fighter aircraft design will contribute to aircraft survivability by influencing either the aircraft’s susceptibility or its vulnerability. On the other hand, technical developments in missile warhead and ammunition design will result in a lethality increase against

  16. 77 FR 64442 - Airworthiness Directives; PILATUS AIRCRAFT LTD. Airplanes

    Science.gov (United States)

    2012-10-22

    ... the same type design. Certain changes described above expand the scope of the original NPRM (77 FR..., PILATUS AIRCRAFT LTD. has issued updated revisions to the Structural and Component Airworthiness...). Johan Kruger of PILATUS AIRCRAFT LTD. requested the FAA to incorporate new revisions of the...

  17. 47 CFR 87.51 - Aircraft earth station commissioning.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Aircraft earth station commissioning. 87.51... SERVICES AVIATION SERVICES Applications and Licenses § 87.51 Aircraft earth station commissioning. (a) (b... license together with the commissioning certificate issued by Inmarsat. Notwithstanding the...

  18. Assessment of aircraft noise sources variability using an acoustic camera

    NARCIS (Netherlands)

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

    2015-01-01

    Noise assessment around airports is hampered due to the observed large variability in noise levels for fly-overs of the same aircraft type, which is not considered by the current models. This paper assumes that the noise variability is due to variations in the aircraft emitted noise, neglecting the

  19. 22 CFR 121.3 - Aircraft and related articles.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aircraft and related articles. 121.3 Section 121.3 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS THE UNITED STATES MUNITIONS LIST Enumeration of Articles § 121.3 Aircraft and related articles. In Category...

  20. External interaction of the nuclear EMP with aircraft and missiles

    International Nuclear Information System (INIS)

    The general problem of external coupling of the nuclear EMP to metal structures is discussed with attention directed toward aircraft and missiles. Theoretical and experimental data are presented fo the skin current and charge densities induced on aircraft. Recommendations for future studies are also given