WorldWideScience

Sample records for hh-53c helicopter appendix

  1. 14 CFR Appendix F to Part 91 - Helicopter Flight Recorder Specifications

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Helicopter Flight Recorder Specifications F Appendix F to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Appendix F to Part 91—Helicopter Flight Recorder Specifications Parameters Range Installed system 1...

  2. 14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Helicopter Flight Recorder Specifications E Appendix E to Part 135 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION.... E Appendix E to Part 135—Helicopter Flight Recorder Specifications Parameters Range Accuracy...

  3. Condition Monitoring for Helicopter Data. Appendix A

    Science.gov (United States)

    Wen, Fang; Willett, Peter; Deb, Somnath

    2000-01-01

    In this paper the classical "Westland" set of empirical accelerometer helicopter data is analyzed with the aim of condition monitoring for diagnostic purposes. The goal is to determine features for failure events from these data, via a proprietary signal processing toolbox, and to weigh these according to a variety of classification algorithms. As regards signal processing, it appears that the autoregressive (AR) coefficients from a simple linear model encapsulate a great deal of information in a relatively few measurements; it has also been found that augmentation of these by harmonic and other parameters can improve classification significantly. As regards classification, several techniques have been explored, among these restricted Coulomb energy (RCE) networks, learning vector quantization (LVQ), Gaussian mixture classifiers and decision trees. A problem with these approaches, and in common with many classification paradigms, is that augmentation of the feature dimension can degrade classification ability. Thus, we also introduce the Bayesian data reduction algorithm (BDRA), which imposes a Dirichlet prior on training data and is thus able to quantify probability of error in an exact manner, such that features may be discarded or coarsened appropriately.

  4. 14 CFR Appendix G to Part 141 - Flight Instructor Instrument (For an Airplane, Helicopter, or Powered-Lift Instrument Instructor...

    Science.gov (United States)

    2010-01-01

    ... Airplane, Helicopter, or Powered-Lift Instrument Instructor Rating, as Appropriate) Certification Course G Appendix G to Part 141 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SCHOOLS AND OTHER CERTIFICATED AGENCIES PILOT SCHOOLS Pt. 141, App. G Appendix G to Part...

  5. Helicopter

    NARCIS (Netherlands)

    Van Holten, T.

    2004-01-01

    The invention relates to a helicopter provided with a rotor with at least one rotor blade (5), wherein drive means are provided for actively moving the or each rotor blade up and down during rotation of the rotor, in particular about a flapping hinge (8) thereof, so that moments, applied by the roto

  6. 14 CFR Appendix C to Part 60 - Qualification Performance Standards for Helicopter Full Flight Simulators

    Science.gov (United States)

    2010-01-01

    ... graphic scaling or cause difficulties in scale interpretation or resolution. (4) Scaling on graphical... helicopter. The direction of movement of controls and switches must be identical to that in the...

  7. Light Helicopter Family Trade-Off Analysis. Volume 4. Appendix N

    Science.gov (United States)

    1985-05-15

    U) It should be noted that designing a tail pylon folding point into a composite fuselage creates significant structural problema due to...engine operating at this level is 30 minutes. However, after a (short) period of time at a less power setting, V( lRP ) may be used again. The exact...HELICOPTER -so -20 -10 IB +10 +20 ♦ao EFFCCNCYOt) Figure N-VI-25. V( lRP ) speed efficiency sumraary. N-VI-31 LHX

  8. 14 CFR Appendix J to Part 36 - Alternative Noise Certification Procedure for Helicopters Under Subpart H Having a Maximum...

    Science.gov (United States)

    2010-01-01

    ... Pounds J Appendix J to Part 36 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Pt. 36, App. J Appendix...

  9. Helicopter controllability

    OpenAIRE

    Carico, Dean

    1989-01-01

    Approved for public release; distribution is unlimited The concept of helicopter controllability is explained. A background study reviews helicopter development in the U.S. General helicopter configurations, linearized equations of motion, stability, and piloting requirements are discussed. Helicopter flight controls, handling qualities, and associated specification are reviewed. Analytical, simulation and flight test methods for evaluating helicopter automatic flight control systems ar...

  10. Helicopter human factors

    Science.gov (United States)

    Hart, Sandra G.

    1988-01-01

    The state-of-the-art helicopter and its pilot are examined using the tools of human-factors analysis. The significant role of human error in helicopter accidents is discussed; the history of human-factors research on helicopters is briefly traced; the typical flight tasks are described; and the noise, vibration, and temperature conditions typical of modern military helicopters are characterized. Also considered are helicopter controls, cockpit instruments and displays, and the impact of cockpit design on pilot workload. Particular attention is given to possible advanced-technology improvements, such as control stabilization and augmentation, FBW and fly-by-light systems, multifunction displays, night-vision goggles, pilot night-vision systems, night-vision displays with superimposed symbols, target acquisition and designation systems, and aural displays. Diagrams, drawings, and photographs are provided.

  11. 78 FR 65180 - Airworthiness Directives; MD Helicopters, Inc., Helicopters

    Science.gov (United States)

    2013-10-31

    ... condition, vibration, loss of tail rotor pitch control, and loss of directional control of the helicopter...-047-AD; Amendment 39-17606; AD 2013-19-24] RIN 2120-AA64 Airworthiness Directives; MD Helicopters, Inc., Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We...

  12. 78 FR 27867 - Airworthiness Directives; MD Helicopters Inc. Helicopters

    Science.gov (United States)

    2013-05-13

    ..., leading to vibration, loss of tail rotor pitch control, and subsequent loss of tail rotor and helicopter... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; MD Helicopters Inc. Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking...

  13. 14 CFR Appendix A to Part 136 - Special Operating Rules for Air Tour Operators in the State of Hawaii

    Science.gov (United States)

    2010-01-01

    ... Appendix A to Part 136—Special Operating Rules for Air Tour Operators in the State of Hawaii Section 1... compensation or hire. “Air tour operator” means any person who conducts an air tour. Section 3. Helicopter... operator must complete a performance plan before each helicopter air tour flight. The performance plan...

  14. GARTEUR Helicopter Cooperative Research

    OpenAIRE

    Pahlke, Klausdieter

    2010-01-01

    This paper starts with an overview about the general structure of the Group for Aeronautical Research and Technology in EURope (GARTEUR). The focus is on the activities related to rotorcraft which are managed in the GARTEUR Helicopter Group of Responsables (HC GoR). The research activities are carried out in so-called Action Groups. Out of the 5 Action Groups which ended within the last four years results generated in the Helicopter Action Groups HC(AG14) “Methods for Refinement of Structural...

  15. Cost optimizing of large-scale offshore wind farms. Appendix K to Q. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This Volume 4 contains reports prepared by SEAS Distribution A.m.b.A., Risoe National Laboratory, Nellemann, Nielsen and Rauschenberger A/S (NNR), Universidad Politecnica de Madrid, National Wind Power Ltd. and Stadtwerke Rostock AG. Appendix K - Wind and wave measurements; Appendix L - Establishment of design basis (wind, wave and ice loads). Appendix M - Wake effects and wind farm modelling. Appendix N - Functional requirements and optimisation of wind turbines. Appendix O - Operation and maintenance system. Appendix O.1 - Helicopter Service (alternative). Appendix P - Cost optimising of large scale offshore wind farms in UK waters. Appendix Q - Cost optimising of large scale offshore wind farms in German waters. Appendix K, L and N have been prepared by Risoe National Laboratory. Appendix M has been prepared by Universidad Politecnica de Madrid. Appendix 0 has been prepared by SEAS Distribution A.m.b.A.. Appendix O.1 has been prepared by Nellemann, Nielsen and Rauschenberger A/S. Appendix P has been prepared by National Wind Power Ltd.. Appendix Q has been prepared by Stadtwerke Rostock AG. (au)

  16. Helicopter Human Factors

    Science.gov (United States)

    Hart, Sandra G.; Sridhar, Banavar (Technical Monitor)

    1995-01-01

    Even under optimal conditions, helicopter flight is a most demanding form of human-machine interaction, imposing continuous manual, visual, communications, and mental demands on pilots. It is made even more challenging by small margins for error created by the close proximity of terrain in NOE flight and missions flown at night and in low visibility. Although technology advances have satisfied some current and proposed requirements, hardware solutions alone are not sufficient to ensure acceptable system performance and pilot workload. However, human factors data needed to improve the design and use of helicopters lag behind advances in sensor, display, and control technology. Thus, it is difficult for designers to consider human capabilities and limitations when making design decisions. This results in costly accidents, design mistakes, unrealistic mission requirements, excessive training costs, and challenge human adaptability. NASA, in collaboration with DOD, industry, and academia, has initiated a program of research to develop scientific data bases and design principles to improve the pilot/vehicle interface, optimize training time and cost, and maintain pilot workload and system performance at an acceptable level. Work performed at Ames, and by other research laboratories, will be reviewed to summarize the most critical helicopter human factors problems and the results of research that has been performed to: (1) Quantify/model pilots use of visual cues for vehicle control; (2) Improve pilots' performance with helmet displays of thermal imagery and night vision goggles for situation awareness and vehicle control; (3) Model the processes by which pilots encode maps and compare them to the visual scene to develop perceptually and cognitively compatible electronic map formats; (4) Evaluate the use of spatially localized auditory displays for geographical orientation, target localization, radio frequency separation; (5) Develop and flight test control

  17. Helicopter Human Factors

    Science.gov (United States)

    Hart, Sandra G.; Sridhar, Banavar (Technical Monitor)

    1995-01-01

    Even under optimal conditions, helicopter flight is a most demanding form of human-machine interaction, imposing continuous manual, visual, communications, and mental demands on pilots. It is made even more challenging by small margins for error created by the close proximity of terrain in NOE flight and missions flown at night and in low visibility. Although technology advances have satisfied some current and proposed requirements, hardware solutions alone are not sufficient to ensure acceptable system performance and pilot workload. However, human factors data needed to improve the design and use of helicopters lag behind advances in sensor, display, and control technology. Thus, it is difficult for designers to consider human capabilities and limitations when making design decisions. This results in costly accidents, design mistakes, unrealistic mission requirements, excessive training costs, and challenge human adaptability. NASA, in collaboration with DOD, industry, and academia, has initiated a program of research to develop scientific data bases and design principles to improve the pilot/vehicle interface, optimize training time and cost, and maintain pilot workload and system performance at an acceptable level. Work performed at Ames, and by other research laboratories, will be reviewed to summarize the most critical helicopter human factors problems and the results of research that has been performed to: (1) Quantify/model pilots use of visual cues for vehicle control; (2) Improve pilots' performance with helmet displays of thermal imagery and night vision goggles for situation awareness and vehicle control; (3) Model the processes by which pilots encode maps and compare them to the visual scene to develop perceptually and cognitively compatible electronic map formats; (4) Evaluate the use of spatially localized auditory displays for geographical orientation, target localization, radio frequency separation; (5) Develop and flight test control

  18. World helicopter market study

    Science.gov (United States)

    Cleary, B.; Pearson, R. W.; Greenwood, S. W.; Kaplan, L.

    1978-01-01

    The extent of the threat to the US helicopter industry posed by a determined effort by foreign manufacturers, European companies in particular, to supply their own domestic markets and also to penetrate export markets, including the USA is assessed. Available data on US and world markets for civil and military uses are collated and presented in both graphic and tabular form showing the past history of production and markets and, where forecasts are available, anticipated future trends. The data are discussed on an item-by-item basis and inferences are drawn in as much depth as appears justified.

  19. Modeling, Control and Coordination of Helicopter Systems

    CERN Document Server

    Ren, Beibei; Chen, Chang; Fua, Cheng-Heng; Lee, Tong Heng

    2012-01-01

    Modeling, Control and Coordination of Helicopter Systems provides a comprehensive treatment of helicopter systems, ranging from related nonlinear flight dynamic modeling and stability analysis to advanced control design for single helicopter systems, and also covers issues related to the coordination and formation control of multiple helicopter systems to achieve high performance tasks. Ensuring stability in helicopter flight is a challenging problem for nonlinear control design and development. This book is a valuable reference on modeling, control and coordination of helicopter systems,providing readers with practical solutions for the problems that still plague helicopter system design and implementation. Readers will gain a complete picture of helicopters at the systems level, as well as a better understanding of the technical intricacies involved. This book also: Presents a complete picture of modeling, control and coordination for helicopter systems Provides a modeling platform for a general class of ro...

  20. Autonomous Hovering Flight of a Small Helicopter

    Science.gov (United States)

    Ohkura, Akihiro; Tokutake, Hiroshi; Sunada, Shigeru

    During the 20th century, aircraft were only used for transportation. If aircraft can be made small and lightweight, however, they can become tools to assist in everyday life. We developed a small, lightweight co-axial helicopter with a rotor diameter of about 30cm. The mechanisms for varying cyclic pitch of the upper and lower rotors, which are used in the coaxial helicopter for entertainment, are adopted in our develop helicopter. Our developed helicopter is equipped with a flight control system for the attitude and position, which is composed of a micro computer and some sensors. And the helicopter can make autonomous hovering flight just measuring the height and the distances from the walls. The weight of the helicopter is no more than 200g and this helicopter is the lightest helicopter for an autonomous hovering flight among the helicopters where all control systems are onboard, as far as the authors know.

  1. Vertebral pain in helicopter pilots

    Science.gov (United States)

    Auffret, R.; Delahaye, R. P.; Metges, P. J.; VICENS

    1980-01-01

    Pathological forms of spinal pain engendered by piloting helicopters were clinically studied. Lumbalgia and pathology of the dorsal and cervical spine are discussed along with their clinical and radiological signs and origins.

  2. The evolution of helicopters

    Science.gov (United States)

    Chen, R.; Wen, C. Y.; Lorente, S.; Bejan, A.

    2016-07-01

    Here, we show that during their half-century history, helicopters have been evolving into geometrically similar architectures with surprisingly sharp correlations between dimensions, performance, and body size. For example, proportionalities emerge between body size, engine size, and the fuel load. Furthermore, the engine efficiency increases with the engine size, and the propeller radius is roughly the same as the length scale of the whole body. These trends are in accord with the constructal law, which accounts for the engine efficiency trend and the proportionality between "motor" size and body size in animals and vehicles. These body-size effects are qualitatively the same as those uncovered earlier for the evolution of aircraft. The present study adds to this theoretical body of research the evolutionary design of all technologies [A. Bejan, The Physics of Life: The Evolution of Everything (St. Martin's Press, New York, 2016)].

  3. Investigating Flight with a Toy Helicopter

    Science.gov (United States)

    Liebl, Michael

    2010-01-01

    Flight fascinates people of all ages. Recent advances in battery technology have extended the capabilities of model airplanes and toy helicopters. For those who have never outgrown a childhood enthusiasm for the wonders of flight, it is possible to buy inexpensive, remotely controlled planes and helicopters. A toy helicopter offers an opportunity…

  4. Civil helicopter flight research. [for CH-53 helicopter

    Science.gov (United States)

    Snyder, W. J.; Schoultz, M. B.

    1976-01-01

    The paper presents a description of the NASA CH-53 Civil Helicopter Research Aircraft and discusses preliminary results of the aircraft flight research performed to evaluate factors and requirements for future helicopter transport operations. The CH-53 equipped with a 16-seat airline-type cabin and instrumented for flight research studies in noise, vibration, handling qualities, passenger acceptance, fuel utilization, terminal area maneuvers, and gust response. Predicted fuel usage for typical short-haul missions is compared with actual fuel use. Pilot ratings for an IFR handling quality task for three levels of stability augmentation are presented, and the effects of internal noise, vibration, and motion on passenger acceptance are discussed. Future planned CH-53 flight research within the Civil Helicopter Technology Program is discussed.

  5. [Back ache in helicopter pilots].

    Science.gov (United States)

    Colak, S; Jovelić, S; Manojlović, J

    1992-01-01

    Due to low back pain (LBP) and harmful effects of flying, questionnaires were sent to 71 helicopter pilots of the experimental group, 22 mechanics helicopter flyers and to the control group of 28 air-traffic controllers. The prevalence of LBP was the highest in helicopter pilots, then in helicomechanics and air-traffic controllers (53%, 50% and 36%). Effects of exposure to vibration, body posture and working load have not contributed significantly to the occurrence of LBP. LBP has not lead to an important difference in the strength of the back musculature, body mass index and spondylosis, that is, scoliosis. The necessity of further study of LBP and maintaining of specific preventive measures are indicated.

  6. The helicopter - some ergonomic factors.

    Science.gov (United States)

    Lovesey, E J

    1975-09-01

    Helicopter pilots are some of the hardest working human operators, because of the machine's inherant instability and control problems. This article covers some aspects where ergonomists might help to improve the overall system. After considering basic differences between helicopters and fixed wing aircraft, the author examines controls, where there are prospects of using miniature hand levers; cockpit vision and displays with particular reference to night and instrument flying; seating and vibration where the effects of protective clothing and harnesses are considered; and cabin noise from the engine, transmission and intercom systems. Finally, he assesses pilot activity using cine film techniques for different types of flight.

  7. 77 FR 30232 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Science.gov (United States)

    2012-05-22

    ... Textron (BHT) Model 412, 412EP, and 412CF helicopters. This proposed AD is prompted by a reported failure... delay. We may change this proposal in light of the comments we receive. Discussion BHT has received a... develop on other products of the same type design. Related Service Information We reviewed BHT ASB 412-11...

  8. 77 FR 68055 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Science.gov (United States)

    2012-11-15

    ... are adopting a new airworthiness directive (AD) for Bell Helicopter Textron (BHT) Model 412, 412EP... 39 to include an AD that would apply to certain serial-numbered BHT Model 412, 412EP, and 412CF... AD and the Service Information The BHT ASBs require compliance within 100 hours of flight time for...

  9. 78 FR 9793 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Science.gov (United States)

    2013-02-12

    ..., Aerospace Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 2601 Meacham Blvd., Fort... helicopters, are susceptible to the same type of cracking because they are of similar design and manufacture... first. This AD does not require you to report a cracked fitting to the Rotorcraft Certification...

  10. 78 FR 1730 - Airworthiness Directives; Bell Helicopter Textron Inc. Helicopters

    Science.gov (United States)

    2013-01-09

    ...: We are adopting a new airworthiness directive (AD) for the Bell Helicopter Textron Inc. (BHTI) Model... (connector) can deteriorate, causing a short in the connector that may lead to a fire in the starter... short in the connector that may lead to a fire in the starter/generator, smoke in the cockpit...

  11. 78 FR 65195 - Airworthiness Directives; MD Helicopters, Inc. (MDHI) Helicopters

    Science.gov (United States)

    2013-10-31

    ... other helicopters of the same type designs and that air safety and the public interest require adopting... rotor blade (MRB) retention bolts (bolts) installed. This AD requires a daily check of the position of... (ASB SB900-116). ASB SB900-116 specifies a repetitive check of the blade retention bolts, part number...

  12. Smart actuation for helicopter rotorblades

    NARCIS (Netherlands)

    Paternoster, A.R.A.; Loendersloot, R.; Boer, de A.; Akkerman, R.; Berselli, G.; Vertechy, R.; Vassura, G.

    2012-01-01

    Successful rotorcrafts were only achieved when the differences between hovering flight conditions and a stable forward flight were understood. During hovering, the air speed on all helicopter blades is linearly distributed along each blade and is the same for each. However, during forward flight, th

  13. Helicopter Toy and Lift Estimation

    Science.gov (United States)

    Shakerin, Said

    2013-01-01

    A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight. (Contains 1 figure.)

  14. Helicopter Toy and Lift Estimation

    Science.gov (United States)

    Shakerin, Said

    2013-01-01

    A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight. (Contains 1 figure.)

  15. Smart actuation for helicopter rotorblades

    NARCIS (Netherlands)

    Paternoster, Alexandre; Loendersloot, Richard; de Boer, Andries; Akkerman, Remko; Berselli, G.; Vertechy, R.; Vassura, G.

    2012-01-01

    Successful rotorcrafts were only achieved when the differences between hovering flight conditions and a stable forward flight were understood. During hovering, the air speed on all helicopter blades is linearly distributed along each blade and is the same for each. However, during forward flight,

  16. Military display market segment: helicopters

    Science.gov (United States)

    Desjardins, Daniel D.; Hopper, Darrel G.

    2004-09-01

    The military display market is analyzed in terms of one of its segments: helicopter displays. Parameters requiring special consideration, to include luminance ranges, contrast ratio, viewing angles, and chromaticity coordinates, are examined. Performance requirements for rotary-wing displays relative to several premier applications are summarized. Display sizes having aggregate defense applications of 5,000 units or greater and having DoD applications across 10 or more platforms, are tabulated. The issue of size commonality is addressed where distribution of active area sizes across helicopter platforms, individually, in groups of two through nine, and ten or greater, is illustrated. Rotary-wing displays are also analyzed by technology, where total quantities of such displays are broken out into CRT, LCD, AMLCD, EM, LED, Incandescent, Plasma and TFEL percentages. Custom, versus Rugged commercial, versus commercial off-the-shelf designs are contrasted. High and low information content designs are identified. Displays for several high-profile military helicopter programs are discussed, to include both technical specifications and program history. The military display market study is summarized with breakouts for the helicopter market segment. Our defense-wide study as of March 2004 has documented 1,015,494 direct view and virtual image displays distributed across 1,181 display sizes and 503 weapon systems. Helicopter displays account for 67,472 displays (just 6.6% of DoD total) and comprise 83 sizes (7.0% of total DoD) in 76 platforms (15.1% of total DoD). Some 47.6% of these rotary-wing applications involve low information content displays comprising just a few characters in one color; however, as per fixed-wing aircraft, the predominant instantiation involves higher information content units capable of showing changeable graphics, color and video.

  17. Appendix A

    DEFF Research Database (Denmark)

    Henriksen, M. S.; Brincker, Rune; Heshe, Gert

    1999-01-01

    In this appendix a brief summary of experiments on reinforced concrete beams in three-point bending performed at Aalborg University is given. The aim of the investigation is to determine the full load-deflection curves for different beam sizes, different types of concrete and different amounts an...

  18. Appendix C

    DEFF Research Database (Denmark)

    Christensen, F. A.; Henriksen, M. S.; Brincker, Rune

    1999-01-01

    In this appendix a model is formulated for the rotational capacity of reinforced concrete beams assuming rebar tension failure. The model is based on a classical approach and establishes the load-deflection curve of a reinforced concrete beam. The rotational capacity is then obtained as the area ...

  19. 78 FR 34958 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell), Model Helicopters

    Science.gov (United States)

    2013-06-11

    ... 412CF helicopter or on a Model 412 or 412EP helicopter with a (BHT-412-SI-62) slope landing kit, P/N 412... installed on a Model 412 or 412EP helicopter with a (BHT-412-SI-62) slope landing kit, P/N 412-704-012-101...

  20. 78 FR 23688 - Airworthiness Directives; Bell Helicopter Textron Canada Inc. Helicopters

    Science.gov (United States)

    2013-04-22

    ... Bell Helicopter Textron Canada Inc. (BHT) Model 206A, 206B, and 206L helicopters. This proposed AD...-2012-19), to correct an unsafe condition for certain serial numbered BHT Model 206A, 206B, and 206L... Information BHT has issued Alert Service Bulletin (ASB) No. 206-11-127 for Model 206A and 206B helicopters and...

  1. 78 FR 54751 - Airworthiness Directives; Bell Helicopter Textron Canada Inc. Helicopters

    Science.gov (United States)

    2013-09-06

    ... new airworthiness directive (AD) for certain Bell Helicopter Textron Canada Inc. (BHT) Model 206A... 14 CFR part 39 to include an AD that would apply to BHT Model 206A and 206B helicopters, all serial... assembly) part number (P/N) 206-375-017-101 installed and BHT Model 206L helicopters, S/N 45001 through...

  2. Helicopter vibration reduction using robust control

    OpenAIRE

    Mannchen, Thomas

    2003-01-01

    This dissertation presents a control law for helicopters to reduce vibration and to increase damping using individual blade control. H-infinity control synthesis is used to develop a robust controller usable in different operating conditions with different helicopter flight speeds. The control design is applied in simulation to the four-blade BO 105 helicopter rotor, which is equipped with an individual blade control system, where the pitch rod links are replaced by hydraulic actuators, allow...

  3. Lytic spondylolisthesis in helicopter pilots.

    Science.gov (United States)

    Froom, P; Froom, J; Van Dyk, D; Caine, Y; Ribak, J; Margaliot, S; Floman, Y

    1984-06-01

    Trauma to the back from the force of chronic stress is thought to be an etiologic factor in isthmic spondylolisthesis (SLL). The relationship of first degree spondylolisthesis to low back pain (LBP) is controversial. We compare the prevalence of SLL in helicopter pilots who are subject to strong vibrational forces, with other airforce personnel. Helicopter pilots had more than a four times higher prevalence of SLL (4.5%) than did cadets (1.0%) and transport pilots (0.9%). Low back pain was more frequent in pilots with SLL than in those without this lesion but in no case was the pain disabling or the defect progressive. We conclude that SLL may be induced by vibrational forces and although SLL is associated with LBP, the pain was little clinical significance.

  4. When is the helicopter faster? A comparison of helicopter and ground ambulance transport times.

    Science.gov (United States)

    Diaz, Marco A; Hendey, Gregory W; Bivins, Herbert G

    2005-01-01

    A retrospective analysis of 7,854 ground ambulance and 1,075 helicopter transports was conducted. The 911-hospital arrival intervals for three transport methods were compared: ground, helicopter dispatched simultaneously with ground unit, and helicopter dispatched nonsimultaneously after ground unit response. Compared with ground transports, simultaneously dispatched helicopter transports had significantly shorter 911-hospital arrival intervals at all distances greater than 10 miles from the hospital. Nonsimultaneously dispatched helicopter transport was significantly faster than ground at distances greater than 45 miles, and simultaneous helicopter dispatch was faster than nonsimultaneous at virtually all distances. Ground transport was significantly faster than either air transport modality at distances less than 10 miles from the hospital. Ground ambulance transport provided the shortest 911-hospital arrival interval at distances less than 10 miles from the hospital. At distances greater than 10 miles, simultaneously dispatched air transport was faster. Nonsimultaneous dispatched helicopter transport was faster than ground if greater than 45 miles from the hospital.

  5. Study of Helicopter Roll Control Effectiveness Criteria.

    Science.gov (United States)

    1986-04-01

    variety of helicopter configurations and control system types , and a wide range of flight tasks and maneuvers. The basis of the experimental design...represent a wide range of basic helicopter rotor hub and airframe designs and flight control system types . It was intended to generally limit

  6. Pneumatic boot for helicopter rotor deicing

    Science.gov (United States)

    Blaha, B. J.; Evanich, P. L.

    1981-01-01

    Pneumatic deicer boots for helicopter rotor blades were tested. The tests were conducted in the 6 by 9 ft icing research tunnel on a stationary section of a UH-IH helicopter main rotor blade. The boots were effective in removing ice and in reducing aerodynamic drag due to ice.

  7. 78 FR 23692 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-22

    ... in excessive vibration of the helicopter and loss of control of the helicopter. (c) Comments Due Date... Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM... AS350B, BA, B1, B2, B3, and D, and Model AS355E, F, F1, F2, and N helicopters with certain tail rotor...

  8. Helicopter Noise And Noise Abatement Procedures

    Directory of Open Access Journals (Sweden)

    Borivoj Galović

    2004-03-01

    Full Text Available The helicopter generated noise at and around the airports islower than the noise generated by aeroplanes, since their numberof operations, i. e. the number of takeoffs and landings ismuch lower than the takeoffs and landings of the aeroplanes.Out of some hundred operations a day, helicopters participatewith approximately 15%, but the very impact of noise is by nomeans negligible, since the number of helicopter flights aboveurban areas is constantly increasing.This paper attempts to analyse this phenomenon and thetype of helicopter generated noise, its negative impacts, to explainthe flight procedures and the operative procedures duringtakeoff, landing and overflight of helicopters in operations inthe vicinity and outside airports, as well as the methods of measuringand determining the limit of noise [eve~ and the resultingproblems.

  9. Progress in helicopter infrared signature suppression

    Directory of Open Access Journals (Sweden)

    Zhang Jingzhou

    2014-04-01

    Full Text Available Due to their low-attitude and relatively low-speed fight profiles, helicopters are subjected to serious threats from radio, infrared (IR, visual, and aural detection and tracking. Among these threats, infrared detection and tracking are regarded as more crucial for the survivability of helicopters. In order to meet the requirements of infrared stealth, several different types of infrared suppressor (IRS for helicopters have been developed. This paper reviews contemporary developments in this discipline, with particular emphasis on infrared signature suppression, advances in mixer-ejectors and prediction for helicopters. In addition, several remaining challenges, such as advanced IRS, emissivity optimization technique, helicopter infrared characterization, etc., are proposed, as an initial guide and stimulation for future research. In the future, the comprehensive infrared suppression in the 3–5 μm and 8–14 μm bands will doubtfully become the emphasis of helicopter stealth. Multidisciplinary optimization of a complete infrared suppression system deserves further investigation.

  10. Helicopter response to atmospheric turbulence

    Science.gov (United States)

    Riaz, J.; Prasad, J. V. R.; Schrage, D. P.; Gaonkar, G. H.

    1992-01-01

    A new time-domain method for simulating cyclostationary turbulence as seen by a translating and rotating blade element has recently been developed for the case of one-dimensional spectral distribution. This paper extends the simulation method to the cases of two- and three-dimensional spectral distributions and presents validation results for the two-dimensional case. The statistics of an isolated rigid blade flapping response to turbulence are computed using a two-dimensional spectral representation of the von Karman turbulence model, and the results are compared with those obtained using the conventional space-fixed turbulence analysis. The new turbulence simulation method is used for predicting the Black Hawk helicopter response to atmospheric turbulence.

  11. US Helicopter Expands Service to Newark Liberty International Airport

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ US Helicopter Corporation ("US Helicopter") (OTC Bulletin Board: USHP) and Continental Airlines (NYSE: CAL)announced a partnership to provide eight-minute shuttle service between Manhattan and Newark Liberty International Airport beginning Dec.18, 2006.

  12. Helicopter Rotor Blade Monitoring using Autonomous Wireless Sensor Network

    NARCIS (Netherlands)

    Sanchez Ramirez, Andrea; Loendersloot, Richard; Tinga, Tiedo; Basu, B.

    2013-01-01

    The advancement on Wireless Sensor Networks for vibration monitoring presents important possibilities for helicopter rotor health and usage monitoring. While main rotor blades account for the main source of lift for helicopters, rotor induced vibration establishes an important source for

  13. 78 FR 54380 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-04

    ..., AS355F1, and AS355F2 helicopters with an autopilot installed; Model AS350B3 helicopters with an autopilot or modification 073252 installed; and Model AS355N and AS355NP helicopters with an autopilot or..., AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters with either an autopilot...

  14. 77 FR 44434 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2012-07-30

    ... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... Services (previously Erickson Air-Crane Co.); California Department of Forestry; Garlick Helicopters, Inc... (previously Erickson Air-Crane Co.); California Department of Forestry; Garlick Helicopters, Inc.; Global...

  15. 78 FR 47531 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2013-08-06

    ... Component Overhaul Schedule, Revision 11, dated April 30, 2010, of Bell Helicopter Textron, Inc. (BHTI), BHT... Schedule, Revision 11, dated April 30, 2010, of Bell Helicopter Textron, Inc., BHT-212- MM-1, Revision 13... Helicopter Textron, Inc., BHT-212-MM-1, Revision 13, dated September 16, 2010. (3) For BHTI service...

  16. 78 FR 18230 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-03-26

    ... sides of the helicopter. This AD was prompted by a crack and failure of a cabin vibration damper blade... 2007-SW-053-AD. (a) Applicability This AD applies to Model EC130 B4 helicopters with a cabin vibration..., install a vibration damper casing assembly on both sides of the helicopter by following paragraphs...

  17. Helicopter industry - early beginnings to now; an outlook on the helicopter market and its major players in the rotorcraft industry

    NARCIS (Netherlands)

    Spranger, L.

    2013-01-01

    The helicopter is probably the most flexible aircraft that we know today. Although its history dates back to around 1500, the first practical helicopter wasn’t manufactured until the 1940s, roughly three decades after the Wright brothers’ first powered human flight. Today, helicopters fulfil a wide

  18. Helicopter stability during aggressive maneuvers

    Science.gov (United States)

    Mohan, Ranjith

    The dissertation investigates helicopter trim and stability during level bank-angle and diving bank-angle turns. The level turn is moderate in that sufficient power is available to maintain level maneuver, and the diving turn is severe where the power deficit is overcome by the kinetic energy of descent. The investigation basically represents design conditions where the peak loading goes well beyond the steady thrust limit and the rotor experiences appreciable stall. The major objectives are: (1) to assess the sensitivity of the trim and stability predictions to the approximations in modeling stall, (2) to correlate the trim predictions with the UH-60A flight test data, and (3) to demonstrate the feasibility of routinely using the exact fast-Floquet periodic eigenvector method for mode identification in the stability analysis. The UH-60A modeling and analysis are performed using the comprehensive code RCAS (Army's Rotorcraft Comprehensive Analysis System). The trim and damping predictions are based on quasisteady stall, ONERA-Edlin (Equations Differentielles Lineaires) and Leishman-Beddoes dynamic stall models. From the correlation with the test data, the strengths and weaknesses of the trim predictions are presented.

  19. Simulation of Flow around Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Garipov A.O.

    2013-04-01

    Full Text Available Low fuselage drag has always been a key target of helicopter manufacturers. Therefore, this paper focuses on CFD predictions of the drag of several components of a typical helicopter fuselage. In the first section of the paper, validation of the obtained CFD predictions is carried out using wind tunnel measurements. The measurements were carried out at the Kazan National Research Technical University n.a. A. Tupolev. The second section of the paper is devoted to the analysis of drag contributions of several components of the ANSAT helicopter prototype fuselage using the RANS approach. For this purpose, several configurations of fuselages are considered with different levels of complexity including exhausts and skids. Depending on the complexity of the considered configuration and CFD mesh both the multi-block structured HMB solver and the unstructured commercial tool Fluent are used. Finally, the effect of an actuator disk on the predicted drag is addressed.

  20. Neuro-optimal control of helicopter UAVs

    Science.gov (United States)

    Nodland, David; Ghosh, Arpita; Zargarzadeh, H.; Jagannathan, S.

    2011-05-01

    Helicopter UAVs can be extensively used for military missions as well as in civil operations, ranging from multirole combat support and search and rescue, to border surveillance and forest fire monitoring. Helicopter UAVs are underactuated nonlinear mechanical systems with correspondingly challenging controller designs. This paper presents an optimal controller design for the regulation and vertical tracking of an underactuated helicopter using an adaptive critic neural network framework. The online approximator-based controller learns the infinite-horizon continuous-time Hamilton-Jacobi-Bellman (HJB) equation and then calculates the corresponding optimal control input that minimizes the HJB equation forward-in-time. In the proposed technique, optimal regulation and vertical tracking is accomplished by a single neural network (NN) with a second NN necessary for the virtual controller. Both of the NNs are tuned online using novel weight update laws. Simulation results are included to demonstrate the effectiveness of the proposed control design in hovering applications.

  1. Workload and operational fatigue in helicopter pilots.

    Science.gov (United States)

    Rotondo, G

    1978-02-01

    In light of the modern aetiopathogenic views, a brief review was made concerning possible causes of operational fatigue to which flying personnel in general are exposed in the exercise of flying activity. The author then describes and analyzes the meaning and importance of the various stressing factors that constitute the physical and psychic workload to which the helicopter pilot is subjected in performing his professional activities. Also analyzed are the influences exercised, both separately and jointly, on the genesis of flight fatigue in helicopter pilots by stressing and fatiguing effects of vibrations, noise, and psycho-emotional and psycho-sensorial factors related to the variety and danger of utilization of this modern aircraft. Such an analytical investigation enables the author to conclude that one must admit that helicopter piloting involves a psycho-physical workload certainly no less than that required by more powerful and faster aircraft.

  2. Helicopter trajectory planning using optimal control theory

    Science.gov (United States)

    Menon, P. K. A.; Cheng, V. H. L.; Kim, E.

    1988-01-01

    A methodology for optimal trajectory planning, useful in the nap-of-the-earth guidance of helicopters, is presented. This approach uses an adjoint-control transformation along with a one-dimensional search scheme for generating the optimal trajectories. In addition to being useful for helicopter nap-of-the-earth guidance, the trajectory planning solution is of interest in several other contexts, such as robotic vehicle guidance and terrain-following guidance for cruise missiles and aircraft. A distinguishing feature of the present research is that the terrain constraint and the threat envelopes are incorporated in the equations of motion. Second-order necessary conditions are examined.

  3. CMU's autonomous helicopter explores new territory.

    Science.gov (United States)

    Charles, J.

    1998-10-01

    In the summer of 1998, several members of Carnegie Mellon University's (CMUs) Autonomous Helicopter Project team joined NASA on a multidisciplinary expedition to the Canadian Arctic's Haughton Crater. NASA was willing to travel to such a remote corner of the globe because of its similarity to an even more remote locale - Mars. Researchers are studying the 23-million-year-old meteorite impact crater in the hope of learning more about Mars's environment. While there, they also tested a number of technologies that will enable future exploration of Mars, including CMU's autonomous helicopter.

  4. Prehospital airway management on rescue helicopters in the United Kingdom.

    Science.gov (United States)

    Schmid, M; Mang, H; Ey, K; Schüttler, J

    2009-06-01

    Adequate equipment is one prerequisite for advanced, out of hospital, airway management. There are no data on current availability of airway equipment on UK rescue helicopters. An internet search revealed all UK rescue helicopters, and a questionnaire was sent to the bases asking for available airway management items. We identified 27 helicopter bases and 26 (96%) sent the questionnaire back. Twenty-four bases (92%) had at least one supraglottic airway device; 16 (62%) helicopters had material for establishing a surgical airway (e.g. a cricothyroidotomy set); 88% of the helicopters had CO(2) detection; 25 (96%) helicopters carried automatic ventilators; among these, four (15%) had sophisticated ventilators and seven (27%) helicopters carried special face masks suitable for non-invasive ventilation. We found a wide variation in the advanced airway management equipment that was carried routinely on air ambulances. Current guidelines for airway management are not met by all UK air ambulances.

  5. Fuzzy logic mode switching in helicopters

    Science.gov (United States)

    Sherman, Porter D.; Warburton, Frank W.

    1993-01-01

    The application of fuzzy logic to a wide range of control problems has been gaining momentum internationally, fueled by a concentrated Japanese effort. Advanced Research & Development within the Engineering Department at Sikorsky Aircraft undertook a fuzzy logic research effort designed to evaluate how effective fuzzy logic control might be in relation to helicopter operations. The mode switching module in the advanced flight control portion of Sikorsky's motion based simulator was identified as a good candidate problem because it was simple to understand and contained imprecise (fuzzy) decision criteria. The purpose of the switching module is to aid a helicopter pilot in entering and leaving coordinated turns while in flight. The criteria that determine the transitions between modes are imprecise and depend on the varied ranges of three flight conditions (i.e., simulated parameters): Commanded Rate, Duration, and Roll Attitude. The parameters were given fuzzy ranges and used as input variables to a fuzzy rulebase containing the knowledge of mode switching. The fuzzy control program was integrated into a real time interactive helicopter simulation tool. Optimization of the heading hold and turn coordination was accomplished by interactive pilot simulation testing of the handling quality performance of the helicopter dynamic model. The fuzzy logic code satisfied all the requirements of this candidate control problem.

  6. 29 CFR 1910.183 - Helicopters.

    Science.gov (United States)

    2010-07-01

    ... the system with the employees in advance of hoisting the load. This applies to both radio and hand... instruct employees, and shall ensure, that whenever approaching or leaving a helicopter which has its... employer shall ensure its use by employees receiving the load. Personal protective equipment shall...

  7. Neuroevolutionary reinforcement learning for generalized helicopter control

    NARCIS (Netherlands)

    Koppejan, R.; Whiteson, S.

    2009-01-01

    Helicopter hovering is an important challenge problem in the field of reinforcement learning. This paper considers several neuroevolutionary approaches to discovering robust controllers for a generalized version of the problem used in the 2008 Reinforcement Learning Competition, in which wind in the

  8. Multicenter observational prehospital resuscitation on helicopter study.

    Science.gov (United States)

    Holcomb, John B; Swartz, Michael D; DeSantis, Stacia M; Greene, Thomas J; Fox, Erin E; Stein, Deborah M; Bulger, Eileen M; Kerby, Jeffrey D; Goodman, Michael; Schreiber, Martin A; Zielinski, Martin D; O'Keeffe, Terence; Inaba, Kenji; Tomasek, Jeffrey S; Podbielski, Jeanette M; Appana, Savitri N; Yi, Misung; Wade, Charles E

    2017-07-01

    Earlier use of in-hospital plasma, platelets, and red blood cells (RBCs) has improved survival in trauma patients with severe hemorrhage. Retrospective studies have associated improved early survival with prehospital blood product transfusion (PHT). We hypothesized that PHT of plasma and/or RBCs would result in improved survival after injury in patients transported by helicopter. Adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers were prospectively observed from January to November 2015. Five helicopter systems had plasma and/or RBCs, whereas the other four helicopter systems used only crystalloid resuscitation. All patients meeting predetermined high-risk criteria were analyzed. Patients receiving PHT were compared with patients not receiving PHT. Our primary analysis compared mortality at 3 hours, 24 hours, and 30 days, using logistic regression to adjust for confounders and site heterogeneity to model patients who were matched on propensity scores. Twenty-five thousand one hundred eighteen trauma patients were admitted, 2,341 (9%) were transported by helicopter, of which 1,058 (45%) met the highest-risk criteria. Five hundred eighty-five of 1,058 patients were flown on helicopters carrying blood products. In the systems with blood available, prehospital median systolic blood pressure (125 vs 128) and Glasgow Coma Scale (7 vs 14) was significantly lower, whereas median Injury Severity Score was significantly higher (21 vs 14). Unadjusted mortality was significantly higher in the systems with blood products available, at 3 hours (8.4% vs 3.6%), 24 hours (12.6% vs 8.9%), and 30 days (19.3% vs 13.3%). Twenty-four percent of eligible patients received a PHT. A median of 1 unit of RBCs and plasma were transfused prehospital. Of patients receiving PHT, 24% received only plasma, 7% received only RBCs, and 69% received both. In the propensity score matching analysis (n = 109), PHT was not significantly associated with mortality

  9. IMPACT OF AN UNDERSLUNG LOAD ON A HELICOPTER CONTROLLABILITY

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available This article is aimed at finding the causes of controllability variations of a helicopter while transporting sling load.The maximum angular acceleration taken by the helicopter at similar controller displacement at different flight speeds was taken as a quantity characteristic of controllability efficiency to study the load impact on the helicopter cont- rollability.This article offers research results obtained with the use of the НеliСargо software. This software has proven to be a great tool for integrated research of the impact of an underslung load on the parameters of a helicopter controllability, and allows carrying out an analysis of the impact of an underslung load on the parameters of controllability under its dyna- mic behavior.The performed computational experiments have shown that the helicopter maximum angular acceleration with an underslung load significantly rises, as compared to a helicopter without cargo or a helicopter carrying the same load inside the cargo compartment. The data obtained during computational experiments corresponds to the results of analytical computations, and is in line with the literature based on the experience of helicopter flight operations.The cause of the variation in the helicopter controllability parameters during transportation of an underslung load has been found, that is - the underslung load considerably increases the main rotor thrust, due to sling load, as compared to a helicopter without cargo. When compared to a helicopter carrying a load inside the cargo compartment, this increased efficiency is mainly attributed to the fact that a helicopter with an underslung load has lower rotational inertia, since the load is not inside the cargo compartment, but outside.The obtained results can be used to improve flight manuals and flight personnel training publications, which could play a significant part in ensuring flight safety and security, and increasing the operational efficiency of

  10. Input Shaping for Helicopter Slung Load Swing Reduction

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2008-01-01

    dampen swing. Simulations and flight tests show the effectiveness of the input shaping applied to a small scale autonomous helicopter slung load system. Both simulations and flight verifications shows significant slung load swing reduction using the proposed trajectory shaping over over flight without......This chapter presents a feedforward swing reducing control system for augmenting already existing helicopter controllers and enables slung load flight with autonomous helicopters general cargo transport. The feedforward controller is designed to avoid excitation of the lightly damped modes...

  11. 78 FR 16200 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-03-14

    ..., AS355F1, AS355F2, AS355N, and AS355NP helicopters with either an autopilot or certain modifications..., AS350B2, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, and AS355F2 helicopters with an autopilot installed; (2) Model AS350B3 helicopters with an autopilot or modification 073252 installed; and (3)...

  12. Pilot ejection, parachute, and helicopter crash injuries.

    Science.gov (United States)

    McBratney, Colleen M; Rush, Stephen; Kharod, Chetan U

    2014-01-01

    USAF Pararescuemen (PJs) respond to downed aircrew as a fundamental mission for personnel recovery (PR), one of the Air Force's core functions. In addition to responding to these in Military settings, the PJs from the 212 Rescue Squadron routinely respond to small plane crashes in remote regions of Alaska. While there is a paucity of information on the latter, there have been articles detailing injuries sustained from helicopter crashes and while ejecting or parachuting from fixed wing aircraft. The following represents a new chapter added to the Pararescue Medical Operations Handbook, Sixth Edition (2014, editors Matt Wolf, MD, and Stephen Rush, MD, in press). It was designed to be a quick reference for PJs and their Special Operations flight surgeons to help with understanding of mechanism of injury with regard to pilot ejection, parachute, and helicopter accident injuries. It outlines the nature of the injuries sustained in such mishaps and provides an epidemiologic framework from which to approach the problem. 2014.

  13. A cable detection lidar system for helicopters

    Science.gov (United States)

    Grossmann, Benoist; Capbern, Alain; Defour, Martin; Fertala, Remi

    1992-01-01

    Helicopters in low-level flight are endangered by power lines or telephone wires, especially when flying at night and under poor visibility conditions. In order to prevent 'wire strike', Thomson has developed a lidar system consisting of a pulsed diode laser emitting in the near infrared region (lambda = 0.9 microns). The HOWARD (Helicopter Obstacle Warning and Detection) System utilizes a high repetition rate diode laser (PRE = 20 KHz) along with counter-rotating prisms for laser beam deflection with a total field of view of 30 degrees. This system was successfully field tested in 1991. HOWARD can detect one inch wires at ranges up to 200 meters. We are presently in the process of developing a flyable compact lidar system capable of detection ranges in the order of 400 meters.

  14. Helicopter crew/passenger vibration sensitivity -

    Science.gov (United States)

    Gabel, R.; Reed, D. A.

    1972-01-01

    Helicopter crew and passenger vibration sensitivity are presented. Pilot subjective ratings are established for discrete frequencies and the impact of combinations of harmonic frequencies is examined. A passenger long term comfort level and a short term limit are defined for discrete frequencies and compared with pilot ratings. The results show reasonable agreement between pilot and passenger. Subjective comfort levels obtained for mixed frequency environments clearly demonstrate the need for a multi-frequency criterion.

  15. Detection And Avoidance Of Obstacles By Helicopters

    Science.gov (United States)

    Cheng, Victor H. L.; Sridhar, Banavar

    1992-01-01

    Report discusses problems relevant to control subsystems enabling helicopters on nap-of-the-Earth flight paths to detect and avoid obstacles automatically. Indicates similarities between this and obstacle-avoidance problem of industrial mobile robots. Two approaches extend two-dimensional obstacle-avoidance concept to three dimensions. First involves direct search of three-dimensional range-map data for indications of openings between obstacles. Second involves compression of data into two-dimensional map for path search.

  16. Stabilization of Externally Slung Helicopter Loads

    Science.gov (United States)

    1974-08-01

    maximum slir^ Loao weighting and " vertical bounce ." The last question provides information on multi-point suspension of external 1oads. PHASE...an allowable cargo load, and vertical bounce . 110 Maximum Sling Load Weight The maximum sling load lifted by a CH-47B helicopter under...changes were made in their flying technique except for very smooth flight control inputs when lifting an ACL. Vertical Bounce Fifteen of the forty Army

  17. Subjective evaluation of helicopter blade slap noise

    Science.gov (United States)

    Galloway, W. J.

    1978-01-01

    Several methods for adjusting EPNL to account for its underestimate of judged annoyance are applied to eight helicopter flyover noise signatures having various degrees of blade slap. A proposal for an impulsive noise correlation procedure based on a digital analysis of the flyover signal is investigated. When all data are combined, the proposal is little better than simply adding an arbitrary fixed adjustment of 3 decibels to EPNL.

  18. Analysis of muscle fatigue in helicopter pilots.

    Science.gov (United States)

    Balasubramanian, Venkatesh; Dutt, Ashwani; Rai, Shobhit

    2011-11-01

    Helicopter pilots espouse ergonomically unfavourable postures and endure vibration which result in low back pain. The objective of this study was to investigate the effects of a helicopter flight on pilots back and shoulder muscles using surface Electromyography (sEMG) analysis. This study also correlates low back pain symptoms from Rehabilitation Bioengineering Group Pain Scale (RBGPS) questionnaire with muscle fatigue rates obtained. RBGPS was administered on 20 Coast Guard helicopter pilots. sEMG was acquired before and after flight from erector spinae and trapezius muscles in 8 of these 20 pilots. Statistical analysis of time and frequency domain parameters indicated significant fatigue in right trapezius muscle due to flying. Muscle fatigue correlated with average duration of flight (r² = 0.913), total service as pilot (r² = 0.825), pain (r² = 0.463) and total flying hours (r² = 0.507). However, muscle fatigue weakly correlated with Body Mass Index (BMI) (r² = 0.000144) and age (r² = 0.033).

  19. 78 FR 44043 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-07-23

    ... unsafe condition is likely to exist or develop on other products of the same type design. Related Service....3 Flight Envelope, Item 2 Temperature Limits, of the helicopter's Rotorcraft Flight Manual (RFM... Operating Limitations Section of the helicopter's Rotorcraft Flight Manual (RFM) by making pen and...

  20. Power harvesting using piezoelectric materials: applications in helicopter rotors

    NARCIS (Netherlands)

    Jong, de P.H.

    2013-01-01

    The blades of helicopters are heavily loaded and are critical components. Failure of any one blade will lead to loss of the aircraft. Currently, the technical lifespan of helicopter blades is calculated using a worst-case operation scenario. The consequence is that a blade that may be suitable for,

  1. Helicopter Rotor Blade Monitoring using Autonomous Wireless Sensor Network

    NARCIS (Netherlands)

    Sanchez Ramirez, Andrea; Loendersloot, Richard; Tinga, Tiedo; Basu, B.

    2013-01-01

    The advancement on Wireless Sensor Networks for vibration monitoring presents important possibilities for helicopter rotor health and usage monitoring. While main rotor blades account for the main source of lift for helicopters, rotor induced vibration establishes an important source for understandi

  2. Vision Aided State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Bendtsen, Jan Dimon; la Cour-Harbo, Anders

    2007-01-01

    This paper presents the design and verification of a state estimator for a helicopter based slung load system. The estimator is designed to augment the IMU driven estimator found in many helicopter UAV s and uses vision based updates only. The process model used for the estimator is a simple 4 st...

  3. Helicopter Emergency Medical Services: effects, costs and benefits

    NARCIS (Netherlands)

    A.N. Ringburg (Akkie)

    2009-01-01

    textabstractAdvanced prehospital medical care with air transport was introduced in the Netherlands in May 1995. The fi rst helicopter Mobile Medical Team, also called Helicopter Emergency Medical Service (HEMS) was a joint venture initiative of the VU Medical Center in Amsterdam and the Algemene Ned

  4. 77 FR 54796 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-06

    ... 26, 2010, which specifies installing two siliconed glass wool sleeves over both forward main rotor... the continued airworthiness of these helicopters. ] Costs of Compliance We estimate that this AD will.... Required parts cost $212, for a total cost of $297 for each helicopter. Based upon these costs, we...

  5. Model Tests on the Economy and Effectiveness of Helicopter Propellers

    Science.gov (United States)

    Munk, Max M

    1925-01-01

    The average velocity of helicopter blades relative to the air is greater than that of airplane wings. The helicopter may turn out to be more economical than the airplane wing for extreme velocities of horizontal flight, the airplane then requiring a very great speed range.

  6. 78 FR 59298 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-26

    ... pilot of a Eurocopter Model AS350 helicopter felt slight vibrations in the pedal unit in flight. A few minutes later, the vibration level increased and the pilot carried out a precautionary autorotation... neutral position. If the helicopter is fitted with a T/R load compensator, discharge the accumulator...

  7. Small-Scale Helicopter Automatic Autorotation: Modeling, Guidance, and Control

    NARCIS (Netherlands)

    Taamallah, S.

    2015-01-01

    Our research objective consists in developing a, model-based, automatic safety recovery system, for a small-scale helicopter Unmanned Aerial Vehicle (UAV) in autorotation, i.e. an engine OFF flight condition, that safely flies and lands the helicopter to a pre-specified ground location. In pursuit o

  8. 77 FR 58925 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-25

    ... during an inspection of a Model AS- 365 helicopter equipped with a 10-blade TRH. This AD requires... likely to exist or develop on other helicopters of these same type designs. Related Service Information... of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures...

  9. Sleep and Alertness in North Sea Helicopter Operations

    NARCIS (Netherlands)

    Simons, M.; Wilschut, E.S.; Valk, P.J.L.

    2011-01-01

    Introduction : Dutch North Sea helicopter operations are characterized by multiple sector flights to offshore platforms under difficult environmental conditions. In the context of a Ministry of Transport program to improve safety levels of helicopter operations, we assessed effects of pre-duty

  10. A Simplified Mobile Ad Hoc Network Structure for Helicopter Communication

    Directory of Open Access Journals (Sweden)

    Abdeldime Mohamed Salih Abdelgader

    2016-01-01

    Full Text Available There are a number of volunteer and statutory organizations who are capable of conducting an emergency response using helicopters. Rescue operations require a rapidly deployable high bandwidth network to coordinate necessary relief efforts between rescue teams on the ground and helicopters. Due to massive destruction and loss of services, ordinary communication infrastructures may collapse in these situations. Consequently, information exchange becomes one of the major challenges in these circumstances. Helicopters can be also employed for providing many services in rugged environments, military applications, and aerial photography. Ad hoc network can be used to provide alternative communication link between a set of helicopters, particularly in case of significant amount of data required to be shared. This paper addresses the ability of using ad hoc networks to support the communication between a set of helicopters. A simplified network structure model is presented and extensively discussed. Furthermore, a streamlined routing algorithm is proposed. Comprehensive simulations are conducted to evaluate the proposed routing algorithm.

  11. Full State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2007-01-01

    This paper presents the design of a state estimator system for a generic helicopter based slung load system. The estimator is designed to deliver full rigid body state information for both helicopter and load and is based on the unscented Kalman filter. Two different approaches are investigated......: One based on a parameter free kinematic model and one based on a full aerodynamic helicopter and slung load model. The kinematic model approach uses acceleration and rate information from two Inertial Measurement Units, one on the helicopter and one on the load, to drive a simple kinematic model....... A simple and effective virtual sensor method is developed to maintain the constraints imposed by the wires in the system. The full model based approach uses a complex aerodynamical model to describe the helicopter together with a generic rigid body model. This rigid body model is based on a redundant...

  12. Full State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    This paper presents the design of a state estimator system for a generic helicopter based slung load system. The estimator is designed to deliver full rigid body state information for both helicopter and load and is based on the unscented Kalman filter. Two different approaches are investigated......: One based on a parameter free kinematic model and one based on a full aerodynamic helicopter and slung load model. The kinematic model approach uses acceleration and rate information from two Inertial Measurement Units, one on the helicopter and one on the load, to drive a simple kinematic model....... A simple and effective virtual sensor method is developed to maintain the constraints imposed by the wires in the system. The full model based approach uses a complex aerodynamical model to describe the helicopter together with a generic rigid body model. This rigid body model is based on a redundant...

  13. Effectiveness of helicopter versus ground ambulance services for interfacility transport.

    Science.gov (United States)

    Arfken, C L; Shapiro, M J; Bessey, P Q; Littenberg, B

    1998-10-01

    Helicopters provide rapid interfacility transport, but the effect on patients is largely unknown. Patients requested to be transported between facilities by helicopter were followed prospectively to determine survival, disability, health status, and health care utilization. A total of 1,234 patients were transported by the primary aeromedical company; 153 patients were transported by ground and 25 patients were transported by other aeromedical services because of weather or unavailability of aircraft. There were no differences at 30 days for survivors in disability, health status, or health care utilization. Nineteen percent of helicopter-transported patients died compared with 15% of those transported by ground (p=0.21). The patients transported by helicopter did not have improved outcomes compared with patients transported by ground. These data argue against a large advantage of helicopters for interfacility transport. A randomized trial is needed to address these issues conclusively.

  14. 75 FR 5681 - Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205B and 212 Helicopters

    Science.gov (United States)

    2010-02-04

    ..., Rotorcraft Directorate, Rotorcraft Certification Office, 2601 Meacham Blvd., Fort Worth, Texas 76137... condition is likely to exist or develop on other helicopters of the same type design. Therefore, this AD is... 39.19. Contact the Manager, Rotorcraft Certification Office, ATTN: Michael Kohner, Aviation...

  15. 77 FR 64439 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model Helicopters

    Science.gov (United States)

    2012-10-22

    ... warning system. For helicopters with a single or dual Automatic Flight Control System (AFCS) with a Flight... attitude direction indicators airspeed indicators; Leak testing the pilot pitot static system; and Power-up... with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices...

  16. 78 FR 56148 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Science.gov (United States)

    2013-09-12

    ...-2009-32, dated July 24, 2009, issued by Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, to correct an unsafe condition for the specified Bell model ] helicopters. TCCA... operation in the United States. Pursuant to our bilateral agreement with Canada, TCCA has notified us of...

  17. 77 FR 5423 - Airworthiness Directives; Bell Helicopter Textron Canada, Limited (Bell) Helicopters

    Science.gov (United States)

    2012-02-03

    ... turbine outlet temperature (TOT) indicator over-temperature warning light, when illuminated, created glare... while using night vision goggles and to prevent subsequent loss of control of the helicopter. DATES: We.... Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New...

  18. 77 FR 36389 - Airworthiness Directives; Bell Helicopter Textron Canada, Limited, Helicopters

    Science.gov (United States)

    2012-06-19

    ... over-temperature warning light, when illuminated, created glare and reflections that could degrade the... prevent subsequent loss of control of the helicopter. DATES: This AD is effective July 24, 2012. ADDRESSES..., Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Examining the AD Docket: You may...

  19. 75 FR 62639 - Air Ambulance and Commercial Helicopter Operations, Part 91 Helicopter Operations, and Part 135...

    Science.gov (United States)

    2010-10-12

    ...--Nautical mile NTSB--National Transportation Safety Board NVG--Night vision goggles NVIS--Night-vision... ambulances have varying situational- awareness technology (such as night vision goggles, HTAWS, radio... during night conditions as four common factors in helicopter air ambulance accidents. A review...

  20. 76 FR 2607 - Airworthiness Directives; MD Helicopters, Inc. (MDHI) Model MD900 Helicopters

    Science.gov (United States)

    2011-01-14

    ... System (VSCS) switches and turning off the autopilot (AP/SAS) switch; pulling certain AP/SAS circuit... flight to VFR, prohibiting use of the autopilot, and making changes to the RFM. For all helicopters, the...) Turn ON both VSCS switches. (b) If installed, de-energize the autopilot (AP/SAS) as follows:...

  1. Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight

    DEFF Research Database (Denmark)

    Murray, Mike; Lange, Britt; Chreiteh, Shadi Samir

    2016-01-01

    Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB...

  2. Modeling, State Estimation and Control of Unmanned Helicopters

    Science.gov (United States)

    Lau, Tak Kit

    Unmanned helicopters hold both tremendous potential and challenges. Without risking the lives of human pilots, these vehicles exhibit agile movement and the ability to hover and hence open up a wide range of applications in the hazardous situations. Sparing human lives, however, comes at a stiff price for technology. Some of the key difficulties that arise in these challenges are: (i) There are unexplained cross-coupled responses between the control axes on the hingeless helicopters that have puzzled researchers for years. (ii) Most, if not all, navigation on the unmanned helicopters relies on Global Navigation Satellite Systems (GNSSs), which are susceptible to jamming. (iii) It is often necessary to accommodate the re-configurations of the payload or the actuators on the helicopters by repeatedly tuning an autopilot, and that requires intensive human supervision and/or system identification. For the dynamics modeling and analysis, we present a comprehensive review on the helicopter actuation and dynamics, and contributes toward a more complete understanding on the on-axis and off-axis dynamical responses on the helicopter. We focus on a commonly used modeling technique, namely the phase-lag treatment, and employ a first-principles modeling method to justify that (i) why that phase-lag technique is inaccurate, (ii) how we can analyze the helicopter actuation and dynamics more accurately. Moreover, these dynamics modeling and analysis reveal the hard-to-measure but crucial parameters on a helicopter model that require the constant identifications, and hence convey the reasoning of seeking a model-implicit method to solve the state estimation and control problems on the unmanned helicopters. For the state estimation, we present a robust localization method for the unmanned helicopter against the GNSS outage. This method infers position from the acceleration measurement from an inertial measurement unit (IMU). In the core of our method are techniques of the sensor

  3. Is helicopter evacuation effective in rural trauma transport?

    Science.gov (United States)

    Rose, Melanie K; Cummings, G R; Rodning, Charles B; Brevard, Sid B; Gonzalez, Richard P

    2012-07-01

    Helicopter transport for trauma remains controversial because its appropriate utilization and efficacy with regard to improved survival is unproven. The purpose of this study was to assess rural trauma helicopter transport utilization and effect on patient survival. A retrospective chart review over a 2-year period (2007-2008) was performed of all rural helicopter and ground ambulance trauma patient transports to an urban Level I trauma center. Data was collected with regard to patient mortality and Injury Severity Score (ISS). Miles to the Level I trauma center were calculated from the point where helicopter or ground ambulance transport services initiated contact with the patient to the Level I trauma center. During the 2-year period, 1443 rural trauma patients were transported by ground ambulance and 1028 rural trauma patients were transported by helicopter. Of the patients with ISS of 0 to 10, 471 patients were transported by helicopter and 1039 transported by ground. There were 465 (99%) survivors with ISS 0 to 10 transported by helicopter with an average transport distance of 34.6 miles versus 1034 (99.5%) survivors with ISS 0 to 10 who were transported by ground an average of 41.0 miles. Four hundred and twenty-one patients with ISS 11 to 30 were transported by helicopter an average of 33.3 miles with 367 (87%) survivors versus a 95 per cent survival in 352 patients with ISS 11 to 30 who were transported by ground an average of 39.9 miles. One hundred and thirty-six patients with ISS > 30 were transported by helicopter an average of 32.8 miles with 78 (57%) survivors versus a 69 per cent survival in 52 patients with ISS > 30 who were transported by ground an average of 33.0 miles. Helicopter transport does not seem to improve survival in severely injured (ISS > 30) patients. Helicopter transport does not improve survival and is associated with shorter travel distances in less severely injured (ISS < 10) patients in rural areas. This data questions effective

  4. Flight Operations Noise Tests of Eight Helicopters

    Science.gov (United States)

    1985-08-01

    DF -EPENr FLIL3HT ALTITUDES AT VARk10US FIrlE. CI OFTHE L I HE FILOT B LLOON WIND t4H1A, 1 4 .EN- F ER1OLIC"’L~ L)URIN& EACH TESI DtAY, INDLUDES...8217, HELICOPTER: AGUSTi i(,t TEST DATE: --󈧏/84 OFERAT ON : LEVEL FLYOVER (1000 FT. D 145 LY.S (LEFT SIDE) ,RI3HT cIDE ’ EVENT OK’ 1000 50’ 5C0’ 1000’ 2000

  5. General equilibrium characteristics of a dual-lift helicopter system

    Science.gov (United States)

    Cicolani, L. S.; Kanning, G.

    1986-01-01

    The equilibrium characteristics of a dual-lift helicopter system are examined. The system consists of the cargo attached by cables to the endpoints of a spreader bar which is suspended by cables below two helicopters. Results are given for the orientation angles of the suspension system and its internal forces, and for the helicopter thrust vector requirements under general circumstances, including nonidentical helicopters, any accelerating or static equilibrium reference flight condition, any system heading relative to the flight direction, and any distribution of the load to the two helicopters. Optimum tether angles which minimize the sum of the required thrust magnitudes are also determined. The analysis does not consider the attitude degrees of freedom of the load and helicopters in detail, but assumes that these bodies are stable, and that their aerodynamic forces in equilibrium flight can be determined independently as functions of the reference trajectory. The ranges of these forces for sample helicopters and loads are examined and their effects on the equilibrium characteristics are given parametrically in the results.

  6. Performance and Vibration Analyses of Lift-Offset Helicopters

    Directory of Open Access Journals (Sweden)

    Jeong-In Go

    2017-01-01

    Full Text Available A validation study on the performance and vibration analyses of the XH-59A compound helicopter is conducted to establish techniques for the comprehensive analysis of lift-offset compound helicopters. This study considers the XH-59A lift-offset compound helicopter using a rigid coaxial rotor system as a verification model. CAMRAD II (Comprehensive Analytical Method of Rotorcraft Aerodynamics and Dynamics II, a comprehensive analysis code, is used as a tool for the performance, vibration, and loads analyses. A general free wake model, which is a more sophisticated wake model than other wake models, is used to obtain good results for the comprehensive analysis. Performance analyses of the XH-59A helicopter with and without auxiliary propulsion are conducted in various flight conditions. In addition, vibration analyses of the XH-59A compound helicopter configuration are conducted in the forward flight condition. The present comprehensive analysis results are in good agreement with the flight test and previous analyses. Therefore, techniques for the comprehensive analysis of lift-offset compound helicopters are appropriately established. Furthermore, the rotor lifts are calculated for the XH-59A lift-offset compound helicopter in the forward flight condition to investigate the airloads characteristics of the ABC™ (Advancing Blade Concept rotor.

  7. Compound cycle engine for helicopter application

    Science.gov (United States)

    Castor, Jere; Martin, John; Bradley, Curtiss

    1987-01-01

    The compound cycle engine (CCE) is a highly turbocharged, power-compounded, ultra-high-power-density, lightweight diesel engine. The turbomachinery is similar to a moderate-pressure-ratio, free-power-turbine gas turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military helicopter applications. Cycle thermodynamic specific fuel consumption (SFC) and engine weight analyses performed to establish general engine operating parameters and configurations are presented. An extensive performance and weight analysis based on a typical 2-hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a contemporary gas turbine engine. The CCE had a 31 percent lower-fuel consumption and resulted in a 16 percent reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb/hp-hr and installed wet weight is 0.43 lb/hp. The major technology development areas required for the CCE are identified and briefly discussed.

  8. Helicopter pilot back pain: a preliminary study.

    Science.gov (United States)

    Shanahan, D F; Reading, T E

    1984-02-01

    Because of the high prevalence of back pain experienced by U.S. Army helicopter pilots, a study was conducted to ascertain the feasibility of reproducing these symptoms in the laboratory. A mock-up of a UH-1H seat and control configuration was mounted to a multi-axis vibration simulator (MAVS). Eleven subjects were tested on the apparatus for two 120-min periods. During one period, the MAVS was programmed to reproduce vibrations recorded from a UH-1H in cruise flight. The subjects received no vibration during the other test period. All subjects reported back pain which they described as identical to the pain they experience during flight, during one or more of their test periods. There was no statistical difference between the vibration and nonvibration test conditions (p greater than 0.05) in terms of time of onset of pain or intensity of pain as measured by a visual analog scale. It appears the vibration at the frequencies and amplitudes tested plays little or no role in the etiology of the back symptoms reported by these pilots. It is proposed that the primary etiological factor for these symptoms is the poor posture pilots are obliged to assume for extended periods while operating helicopters.

  9. Nonlinear Feedforward Control for Wind Disturbance Rejection on Autonomous Helicopter

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; A. Danapalasingam, Kumeresan

    2010-01-01

    for the purpose. The model is inverted for the calculation of rotor collective and cyclic pitch angles given the wind disturbance. The control strategy is then applied on a small helicopter in a controlled wind environment and flight tests demonstrates the effectiveness and advantage of the feedforward controller.......This paper presents the design and verification of a model based nonlinear feedforward controller for wind disturbance rejection on autonomous helicopters. The feedforward control is based on a helicopter model that is derived using a number of carefully chosen simplifications to make it suitable...

  10. Adaptive Control System for Autonomous Helicopter Slung Load Operations

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2010-01-01

    system on the helicopter that measures the position of the slung load. The controller is a combined feedforward and feedback scheme for simultaneous avoidance of swing excitation and active swing damping. Simulations and laboratory flight tests show the effectiveness of the combined control system......This paper presents design and verification of an estimation and control system for a helicopter slung load system. The estimator provides position and velocity estimates of the slung load and is designed to augment existing navigation in autonomous helicopters. Sensor input is provided by a vision......, yielding significant load swing reduction compared to the baseline controller....

  11. Optimal Tracking Controller Design for a Small Scale Helicopter

    Institute of Scientific and Technical Information of China (English)

    Agus Budiyono; Singgih S. Wibowo

    2007-01-01

    A model helicopter is more difficult to control than its full scale counterpart. This is due to its greater sensitivity to control inputs and disturbances as well as higher bandwidth of dynamics. This work is focused on designing practical tracking controller for a small scale helicopter following predefined trajectories. A tracking controller based on optimal control theory is synthesized as a part of the development of an autonomous helicopter. Some issues with regards to control constraints are addressed.The weighting between state tracking performance and control power expenditure is analyzed. Overall performance of the control design is evaluated based on its time domain histories of trajectories as well as control inputs.

  12. Planning German Army Helicopter Maintenance and Mission Assignment

    Science.gov (United States)

    1994-03-01

    LIMROW - 0, SOLPRINT = OFF ,DECIMALS - 2 RESLIM - 500000, ITERLIM = 150000, OPTCR = 0.15, SEED = 3141 OPTION LP - XA , RMIP = XA . MIP - XA...1; MODEL HELICOPTER /ALL/; SOLVE HELICOPTER USING RMIP MINIMIZING COST; * iterative solving LOOP(CI, LOOP (H. LOOP(E, IF CZ.L(H,E) GT 0.95 ,Z.FX(H,E...Y.FXCH,T) - 0 ); LOOP(E $ S(T,E), IF (Y.L(H.T) EQ 1 , Z.FPC(H,E) - 0 X.FX(H,T) - 0);) ;) SOLVE HELICOPTER USIN4G RMIP MINIMIZI12NG COST; ) SOLVE

  13. A parametric analysis of visual approaches for helicopters

    Science.gov (United States)

    Moen, G. C.; Dicarlo, D. J.; Yenni, K. R.

    1976-01-01

    A flight investigation was conducted to determine the characteristic shapes of the altitude, ground speed, and deceleration profiles of visual approaches for helicopters. Two hundred thirty-six visual approaches were flown from nine sets of initial conditions with four types of helicopters. Mathematical relationships were developed that describe the characteristic visual deceleration profiles. These mathematical relationships were expanded to develop equations which define the corresponding nominal ground speed, pitch attitude, pitch rate, and pitch acceleration profiles. Results are applicable to improved helicopter handling qualities in terminal area operations.

  14. Simulating effectiveness of helicopter evasive manoeuvres to RPG attack

    Science.gov (United States)

    Anderson, D.; Thomson, D. G.

    2010-04-01

    The survivability of helicopters under attack by ground troops using rocket propelled grenades has been amply illustrated over the past decade. Given that an RPG is unguided and it is infeasible to cover helicopters in thick armour, existing optical countermeasures are ineffective - the solution is to compute an evasive manoeuvre. In this paper, an RPG/helicopter engagement model is presented. Manoeuvre profiles are defined in the missile approach warning sensor camera image plane using a local maximum acceleration vector. Required control inputs are then computed using inverse simulation techniques. Assessments of platform survivability to several engagement scenarios are presented.

  15. Study of the helicopter blade running elevation measurement system

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Helicopter blade running elevation measurement is an important measure target in helicopter blade dynamic balance experimentation. The elevation influences the helicopter's security and other performance capabilities. In testing, however, it has been difficult to measure the elevation when the rotor reaches high speeds. To get a simple, fast and highly accurate measurement system, photo electricity technology was applied to measuring the blade running elevation. Discussed is the measurement principle of blade running elevation, the design of the measurement system and analysis of the measurement precision.

  16. 76 FR 66609 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 407 and 427 Helicopters

    Science.gov (United States)

    2011-10-27

    ...) of this AD. Table A Helicopter model Servo P/N Servo prefix ``HR,'' S/N 407 41011300-101 (BHT 206-076-062- Less than 807. 105). 41011400-101 (BHT 206-076-062- Less than 2248. 107). 427 41011300-101 (BHT 206-076-062- Less than 807. 111). 41011700-101 (BHT 206-076-062- Less than 230. 109). (c) Before...

  17. Input Shaping for Helicopter Slung Load Swing Reduction

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2008-01-01

    This chapter presents a feedforward swing reducing control system for augmenting already existing helicopter controllers and enables slung load flight with autonomous helicopters general cargo transport. The feedforward controller is designed to avoid excitation of the lightly damped modes...... of the system by shaping the reference trajectory using robust input shaping. It is developed as part of an integrated adaptive control system consisting of state estimator, feedforward, and feedback controller capable of simultaneously preventing swing in the slung load from helicopter motion and actively...... dampen swing. Simulations and flight tests show the effectiveness of the input shaping applied to a small scale autonomous helicopter slung load system. Both simulations and flight verifications shows significant slung load swing reduction using the proposed trajectory shaping over over flight without...

  18. Swing Damping for Helicopter Slung Load Systems using Delayed Feedback

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2009-01-01

    of swing. The design of the delayed feedback controller is presented as an optimization problem which gives the possibility of an automated design process. Simulations and flight test verifications of the control system on two different autonomous helicopters are presented and it is shown how a significant......This paper presents the design and verification of a swing reducing controller for helicopter slung load systems using intentional delayed feedback. It is intended for augmenting a trajectory tracking helicopter controller and thereby improving the slung load handing capabilities for autonomous...... helicopters. The delayed feedback controller is added to actively reduce oscillations of the slung load by improving the damping of the slung load pendulum modes. Furthermore, it is intended for integration with a feedforward control scheme based on input shaping for concurrent avoidance and dampening...

  19. Dynamics Analysis of Close-coupling Multiple Helicopters System

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhigang; Lu Tiansheng

    2008-01-01

    The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary. Using the model that describes two hovering helicopters carrying one heavy load, an inertia coordinate system and body coordinate systems of each sub-system are established. A nonlinear force model is established too. The equilibrium computation results can be regarded as the reference control inputs of the flight control system under hovering or low-speed flight condition. After the establishment of a translation kinematics model and a posture kinematics model, a coupling dynamics model of the multiple helicopter system is set up. The results can also be regarded as the base to analyze stabilization and design a controller for a close-coupling multiple helicopters harmony operation system.

  20. Helicopter noise exposure curves for use in environmental impact assessment

    Science.gov (United States)

    Newman, J. S.; Rickley, E. J.; Bland, T. L.

    1982-11-01

    This report establishes the current (1982) FAA helicopter noise data base for use in environmental impact assessment. The report sets out assumptions, methodologies, and techniques used in arriving at noise-exposure-versus-distance relationships. Noise data are provided for 15 helicopters, including five flight regimes each: takeoff, approach, level flyover, hover in-ground-effect (HIGE) and hover out-of-ground effect (HOGE). When possible, level flyover data are presented for a variety of airspeeds. Sound exposure level (SEL) is provided for all operational modes except hover. In the case of hover operations (both HOGE and HIGE), the maximum A-Weighted Sound Level (LAM) is identified as a function of distance. The report also includes a discussion of helicopter performance characteristics required for full computer modeling of helicopter/heliport noise exposure.

  1. The Use of Commercial Remote Sensing Predicting Helicopter Brownout Conditions

    Science.gov (United States)

    2007-09-01

    landing. 4 Figure 2. Soil caught in rotor downwash, start of brownout (from Brownout California soil resource lab) . A second issue ...Sensing in Predicting Helicopter Brownout Conditions. September 2006 (Top Secret). Tan, Kim H., First Edition, Enviromental Soil Science Marcel

  2. Helicopter transmission arrangements with split-torque gear trains

    Science.gov (United States)

    White, G.

    1983-01-01

    As an alternative to component development, the case for improved drive-train configuration is argued. In particular, the use of torque-splitting gear trains is proposed as a practicable means of improving the effectiveness of helicopter main gearboxes.

  3. 78 FR 40956 - Airworthiness Directives; Eurocopter Deutschland (Eurocopter) Helicopters

    Science.gov (United States)

    2013-07-09

    ... comments to the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor... helicopters in the air ambulance and offshore operations industries. Since an unsafe condition exists that...

  4. A Computational Tool for Helicopter Rotor Noise Prediction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project proposes to develop a computational tool for helicopter rotor noise prediction based on hybrid Cartesian grid/gridless approach. The uniqueness of...

  5. Vision Aided State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Bendtsen, Jan Dimon; la Cour-Harbo, Anders

    2007-01-01

    This paper presents the design and verification of a state estimator for a helicopter based slung load system. The estimator is designed to augment the IMU driven estimator found in many helicopter UAV s and uses vision based updates only. The process model used for the estimator is a simple 4 st...... the estimator is verified using flight data and it is shown that it is capable of reliably estimating the slung load states....

  6. VH-92A Presidential Helicopter (VH-92A)

    Science.gov (United States)

    2015-12-01

    HMX- 1) and support the President worldwide and the Vice President primarily inside the National Capital Region. Mission tasking encompasses two (2...operations) NCR - National Capital Region NM - Nautical Mile OCONUS - Outside the Continental United States SE - Support Equipment VH-92A December 2015...Factor: 19% of Total Aircraft Inventory (TAI) Squadrons: Marine Helicopter Squadron One (HMX-1) Helicopters per (active) squadron: 16 Monthly Flight

  7. Helicopter Flight Control Research - A Demanding Application of Piloted Simulation.

    Science.gov (United States)

    1986-01-01

    Sigma-8 digital computer (used to run the aircraft mathematical model) and an Applied Dynamics AD-4 analogue computer (used principally as a flexible...interface to cockpit instruments, and for motion and visual systems operation) (Fig 4). The first helicopter simulation to use a digital aircraft...34 Control Technology for helicopters. For fixed-wing aircraft, impresive claims were being made for electrically (and later optically) signalled control

  8. The scope of back pain in Navy helicopter pilots

    OpenAIRE

    Phillips, Andrea S.

    2011-01-01

    Approved for public release; distribution is unlimited. Human Systems Integration Report This thesis investigates issues such as long hours in the cockpit, ineffective seat padding, Night Vision Goggle (NVG) use, and the constant vibrations involved in flying rotary wing aircraft. Pain is subjective and severity is difficult to compare between individuals. Does back pain affect safety of flight? In the military helicopter aviator community, 60-80% of helicopter pilots are estimated ...

  9. Aircrew-aircraft integration issues in future US Army helicopters

    Science.gov (United States)

    Hartzell, E. J.; Aiken, E. W.; Voorhees, J. W.

    1984-01-01

    Some human factors research issues, the resolution of which will be vital to the successful operation of future military helicopters are reviewed. Understanding and reducing the helicopter pilot's workload is examined by a diverse program directed at answering some of the more fundamental questions relating to the transfer displays and interactions between pilot and automated systems. The results of three experimental studies which address the issues of display control compatibility, characteristics of integrated controllers, and voice systems are presented.

  10. Preliminary Analysis of Helicopter Options to Support Tunisian Counterterrorism Operations

    Science.gov (United States)

    2016-04-27

    results of the current analysis and in Mouton et al., 2015, is the relative cost -effectiveness between the CH-47D and the Mi-17v5. In the previous...helicopters from Sikorsky to fulfill a number of roles in counterterrorism operations. Rising costs and delays in delivery raised the question of...whether other cost -effective options exist to meet Tunisia’s helicopter requirement. Approach Our team conducted a preliminary assessment of

  11. Development of adaptive helicopter seat systems for aircrew vibration mitigation

    Science.gov (United States)

    Chen, Yong; Wickramasinghe, Viresh; Zimcik, David G.

    2008-03-01

    Helicopter aircrews are exposed to high levels of whole body vibration during flight. This paper presents the results of an investigation of adaptive seat mount approaches to reduce helicopter aircrew whole body vibration levels. A flight test was conducted on a four-blade helicopter and showed that the currently used passive seat systems were not able to provide satisfactory protection to the helicopter aircrew in both front-back and vertical directions. Long-term exposure to the measured whole body vibration environment may cause occupational health issues such as spine and neck strain injuries for aircrew. In order to address this issue, a novel adaptive seat mount concept was developed to mitigate the vibration levels transmitted to the aircrew body. For proof-of-concept demonstration, a miniature modal shaker was properly aligned between the cabin floor and the seat frame to provide adaptive actuation authority. Adaptive control laws were developed to reduce the vibration transmitted to the aircrew body, especially the helmet location in order to minimize neck and spine injuries. Closed-loop control test have been conducted on a full-scale helicopter seat with a mannequin configuration and a large mechanical shaker was used to provide representative helicopter vibration profiles to the seat frame. Significant vibration reductions to the vertical and front-back vibration modes have been achieved simultaneously, which verified the technical readiness of the adaptive mount approach for full-scale flight test on the vehicle.

  12. Identification of helicopter rotor dynamic models

    Science.gov (United States)

    Molusis, J. A.; Bar-Shalom, Y.; Warmbrodt, W.

    1983-01-01

    A recursive, extended Kalman-filter approach is applied to the identifiction of rotor damping levels of representative helicopter dynamic systems. The general formulation of the approach is presented in the context of a typically posed stochastic estimation problem, and the method is analytically applied to determining the damping levels of a coupled rotor-body system. The identified damping covergence characteristics are studied for sensitivity to both constant-coefficient and periodic-coefficient measurement models, process-noise covariance levels, and specified initial estimates of the rotor-system damping. A second application of the method to identifying the plant model for a highly damped, isolated flapping blade with a constant-coefficient state model (hover) and a periodic-coefficient state model (forward flight) is also investigated. The parameter-identification capability is evaluated for the effect of periodicity on the plant model coefficients and the influence of different measurement noise levels.

  13. Analysis of potential helicopter vibration reduction concepts

    Science.gov (United States)

    Landgrebe, A. J.; Davis, M. W.

    1984-01-01

    Several recent helicopter vibration reduction research programs are described. Results of studies of blade design parameters in rotor vibratory response and of an advanced blade design for reduced vibration are examined. An optimization approach to develop a general automated procedure for rotor blade design is described, and analytical results for an articulated rotor operating at a steady 160 kt flight condition are reported. The use of a self-adaptive controller to implement higher harmonic control in closed-loop fashion is addressed, and a computer simulation used to evaluate and compare the performance of alternative algorithms included in the generic active controller is discussed. Results are presented for steady level flight conditions, short-duration maneuvers, blade stresses and rotor performance, blade-appended aeroelastic devices, vibratory airloads, wake-induced blade airloads, and airloads from blade motions, the interaction of rotor and fuselage, and the interaction of rotor and empennage.

  14. The Appendix on CT

    Energy Technology Data Exchange (ETDEWEB)

    Whitley, S. [Sunnybrook Health Sciences Center, Toronto, Ontario (Canada); Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)], E-mail: siobhanwhitley@yahoo.co.uk; Sookur, P.; McLean, A.; Power, N. [Barts and the Royal London, Royal London Hospital, Whitechapel, London (United Kingdom)

    2009-02-15

    Appendicitis can be a difficult clinical diagnosis to make. A negative appendicectomy rate of 20% has traditionally been accepted as the consequences of appendiceal perforation can be grave. Cross-sectional imaging is increasingly being employed in the investigation of adults with suspected appendicitis. This review will demonstrate the appearance of the normal appendix on computed tomography (CT) and its appearance in a range of inflammatory and neoplastic processes including appendicitis, Crohn's disease, infections, and benign and malignant tumour000.

  15. Simulation validation and flight prediction of UH-60A Black Hawk helicopter/slung load characteristics

    OpenAIRE

    Tyson, Peter H.

    1999-01-01

    Helicopter/slung load systems are two body systems in which the slung load adds its rigid body dynamics, aerodynamics, and sling stretching dynamics to the helicopter. The slung load can degrade helicopter handling qualities and reduce the flight envelope of the helicopter. Confirmation of system stability parameters and envelope is desired, but flight test evaluation is time consuming and costly. A simulation model validated for handling quality assessments would significantly reduce resourc...

  16. A case of a horseshoe appendix

    OpenAIRE

    Takabatake, Kazuya; Ikeda, Jun; Furuke, Hirotaka; Kato, Chikage; Kishimoto, Takuya; Kumano, Tatsuya; Imura, Kenichiro; Shimomura, Katsumi; Kubota, Takeshi; Taniguchi, Fumihiro; Shioaki, Yasuhiro

    2016-01-01

    Anomalies of the appendix are extremely rare, and a horseshoe appendix is even rarer. A literature search has revealed only five reported cases. In this report, we present a case of a horseshoe appendix. A 78-year-old man was referred for further examination following a positive fecal occult blood test. A mass in his ascending colon was detected on colonoscopy, while computed tomography showed that it was connected to the appendix. Tumor invasion derived from the ascending colon or appendix w...

  17. Light Helicopter Family Trade-Off Analysis. Volume 7. Appendix R

    Science.gov (United States)

    1985-05-15

    integracion necessary and to determine the most effective method for information presentation, hot: it should be displayed and when it should be displayed...Memorandum 76-26, US Army Research Institute for the Behavorial and Social Sciences, Alexandria, VA, November 1976. 4. Simmons, Ronald R., and Blackwell...and threat from natural or man made sources. The social environment is created by interactlons among physical- ly present members of a crew or with

  18. 14 CFR Appendix C to Part 135 - Helicopter Flight Recorder Specifications

    Science.gov (United States)

    2010-01-01

    ... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Pt. 135, App... attitude 100% of usable range ±2° 1 0.8°. Roll attitude ±60° or 100% of usable range, whichever is greater... Maximum range +5% 1 1% 2 Engine torque Maximum range ±5% 1 1% 2 Flight Control—Hydraulic Pressure Primary...

  19. 14 CFR Appendix D to Part 60 - Qualification Performance Standards for Helicopter Flight Training Devices

    Science.gov (United States)

    2010-01-01

    ..., evaluation, or experience being conducted in the FTD. End Information 8. FTD Use (§ 60.11). Begin Information..., or bias. Data may be corrected to address known data calibration errors provided that an explanation... experience will have a higher priority for repair or replacement. End Information 19. Automatic Loss...

  20. Corps Helicopter Attack Planning System (CHAPS). Positional Handbook. Appendix C. Database Specification

    Science.gov (United States)

    1989-10-01

    the user. DFIG - LLTR - DG TO X-OFF ON INGRESS 3 Program calculated danger for each generic aircraft type from each transit corridor access point to IFF...REAL 20 -5 NM N/A N/A 230 DFEG REAL 30 -5 DANGER N/A N/A 230 DFIG REAL 30 -5 DANGER N/A N/A 230 DNEG REAL 30 -5 DANGER N/A N/A 230 1 DNIG REAL 30 -5

  1. 14 CFR Appendix H to Part 36 - Noise Requirements For Helicopters Under Subpart H

    Science.gov (United States)

    2010-01-01

    ... on the ground. H36.111Reporting and correcting measured data. H36.113Atmospheric attenuation of sound... line-of-sight obstructions across the flight path that encompasses the 10 dB down points. (c) Takeoff... 20 feet. (4) Each noise measuring station must be surrounded by terrain having no excessive sound...

  2. Helicopter Parenting: The Effect of an Overbearing Caregiving Style on Peer Attachment and Self-Efficacy

    Science.gov (United States)

    van Ingen, Daniel J.; Freiheit, Stacy R.; Steinfeldt, Jesse A.; Moore, Linda L.; Wimer, David J.; Knutt, Adelle D.; Scapinello, Samantha; Roberts, Amber

    2015-01-01

    Helicopter parenting, an observed phenomenon on college campuses, may adversely affect college students. The authors examined how helicopter parenting is related to self-efficacy and peer relationships among 190 undergraduate students ages 16 to 28 years. Helicopter parenting was associated with low self-efficacy, alienation from peers, and a lack…

  3. 78 FR 52410 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-08-23

    ..., separation of tail rotor parts, severe vibration, and subsequent loss of control of the helicopter. DATES... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY..., MBB-BK 117 B-1, MBB-BK-117 B-2, and MBB-BK 117 C-1 helicopters to require inspections for corrosion...

  4. 77 FR 52265 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-08-29

    ... rotor parts, severe vibration, and subsequent loss of control of the helicopter. You may obtain further... vibration, and subsequent loss of control of the helicopter. (c) Compliance You are responsible for... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ] ACTION: Notice of...

  5. 78 FR 12651 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2013-02-25

    ... a crack. Following increased ground vibrations in a Model A 109E helicopter, another crack was... each start of the helicopter engines, allowing an owner/operator (pilot) to check the T/R blade for a.... Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking...

  6. 78 FR 40055 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2013-07-03

    .... We also estimate that it would take about 3 work-hours per helicopter to rework the top cable cutter... helicopter to rework the top cable cutter assembly, $9,085 per helicopter to replace the top cable cutter... WSPS upper installation, P/N 4G9540A00111, either: (i) Rework the top cable cutter assembly, P/N...

  7. 14 CFR 135.271 - Helicopter hospital emergency medical evacuation service (HEMES).

    Science.gov (United States)

    2010-01-01

    ....271 Helicopter hospital emergency medical evacuation service (HEMES). (a) No certificate holder may... assignment, for hospital emergency medical evacuation service helicopter operations unless that assignment... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Helicopter hospital emergency...

  8. Response of Flight Nurses in a Simulated Helicopter Environment.

    Science.gov (United States)

    Kaniecki, David M; Hickman, Ronald L; Alfes, Celeste M; Reimer, Andrew P

    The purpose of this study was to determine if a helicopter flight simulator could provide a useful educational platform by creating experiences similar to those encountered by actual flight nurses. Flight nurse (FN) and non-FN participants completed a simulated emergency scenario in a flight simulator. Physiologic and psychological stress during the simulation was measured using heart rate and perceived stress scores. A questionnaire was then administered to assess the realism of the flight simulator. Subjects reported that the overall experience in the flight simulator was comparable with a real helicopter. Sounds, communications, vibrations, and movements in the simulator most approximated those of a real-life helicopter environment. Perceived stress levels of all participants increased significantly from 27 (on a 0-100 scale) before simulation to 51 at the peak of the simulation and declined thereafter to 28 (P simulation to 54 at the peak of the simulation and declined thereafter to 30 (P simulation to 49 at the peak of the simulation and declined thereafter to 25 (P simulation. FNs' heart rates increased significantly from 77 before simulation to 100 at the peak of the simulation and declined thereafter to 72 (P simulation of a critical care scenario in a high-fidelity helicopter flight simulator can provide a realistic helicopter transport experience and create physiologic and psychological stress for participants. Copyright © 2017 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  9. Square tracking sensor for autonomous helicopter hover stabilization

    Science.gov (United States)

    Oertel, Carl-Henrik

    1995-06-01

    Sensors for synthetic vision are needed to extend the mission profiles of helicopters. A special task for various applications is the autonomous position hold of a helicopter above a ground fixed or moving target. As a proof of concept for a general synthetic vision solution a restricted machine vision system, which is capable of locating and tracking a special target, was developed by the Institute of Flight Mechanics of Deutsche Forschungsanstalt fur Luft- und Raumfahrt e.V. (i.e., German Aerospace Research Establishment). This sensor, which is specialized to detect and track a square, was integrated in the fly-by-wire helicopter ATTHeS (i.e., Advanced Technology Testing Helicopter System). An existing model following controller for the forward flight condition was adapted for the hover and low speed requirements of the flight vehicle. The special target, a black square with a length of one meter, was mounted on top of a car. Flight tests demonstrated the automatic stabilization of the helicopter above the moving car by synthetic vision.

  10. Passive suppression of helicopter ground resonance using nonlinear energy sinks attached on the helicopter blades

    Science.gov (United States)

    Bergeot, B.; Bellizzi, S.; Cochelin, B.

    2017-03-01

    This paper investigates the passive control of a rotor instability named helicopter Ground Resonance (GR). The passive device consists of a set of essential cubic nonlinear absorbers named Nonlinear Energy Sinks (NES) each of them positioned on a blade. A dynamic model reproducing helicopter GR instability is presented and transformed to a time-invariant nonlinear system using a multi-blade coordinate transformation based on Fourier transform mapping the dynamic state variables into a non-rotating reference frame. Combining complexification, slow/fast partition of the dynamics and averaging procedure, a reduced model is obtained which allowed us to use the so-called geometric singular perturbation analysis to characterize the steady state response regimes. As in the case of a NES attached to the fuselage, it is shown that under suitable conditions, GR instability can be completely suppressed, partially suppressed through periodic response or strongly modulated response. Relevant analytical results are compared, for validation purposes, to direct integration of the reference and reduced models.

  11. Dynamics of a split torque helicopter transmission

    Science.gov (United States)

    Rashidi, Majid; Krantz, Timothy

    A high reduction ratio split torque gear train has been proposed as an alternative to a planetary configuration for the final stage of a helicopter transmission. A split torque design allows a high ratio of power-to-weight for the transmission. The design studied in this work includes a pivoting beam that acts to balance thrust loads produced by the helical gear meshes in each of two parallel power paths. When the thrust loads are balanced, the torque is split evenly. A mathematical model was developed to study the dynamics of the system. The effects of time varying gear mesh stiffness, static transmission errors, and flexible bearing supports are included in the model. The model was demonstrated with a test case. Results show that although the gearbox has a symmetric configuration, the simulated dynamic behavior of the first and second compound gears are not the same. Also, results show that shaft location and mesh stiffness tuning are significant design parameters that influence the motions of the system.

  12. Dynamics of a split torque helicopter transmission

    Science.gov (United States)

    Krantz, Timothy L.

    1994-06-01

    Split torque designs, proposed as alternatives to traditional planetary designs for helicopter main rotor transmissions, can save weight and be more reliable than traditional designs. This report presents the results of an analytical study of the system dynamics and performance of a split torque gearbox that uses a balance beam mechanism for load sharing. The Lagrange method was applied to develop a system of equations of motion. The mathematical model includes time-varying gear mesh stiffness, friction, and manufacturing errors. Cornell's method for calculating the stiffness of spur gear teeth was extended and applied to helical gears. The phenomenon of sidebands spaced at shaft frequencies about gear mesh fundamental frequencies was simulated by modeling total composite gear errors as sinusoid functions. Although the gearbox has symmetric geometry, the loads and motions of the two power paths differ. Friction must be considered to properly evaluate the balance beam mechanism. For the design studied, the balance beam is not an effective device for load sharing unless the coefficient of friction is less than 0.003. The complete system stiffness as represented by the stiffness matrix used in this analysis must be considered to precisely determine the optimal tooth indexing position.

  13. A VORTEX MODEL OF A HELICOPTER ROTOR

    Directory of Open Access Journals (Sweden)

    Valentin BUTOESCU

    2009-06-01

    Full Text Available A vortex model of a helicopter rotor is presented. Each blade of the rotor has three degrees of freedom: flapping, lagging and feathering. The motions after each degree of freedom are also known for all blades. The blade is modelled as a thin vortex surface. The wakes are free fluid surfaces. A system of five equations are obtained: the first one is the integral equation of the lifting surface (rotor, the next three describe the wakes motion, and the last one relates the vortex strength on the wakes and the variation of vorticity on the rotor. A numerical solution of this system is presented. To avoid the singularities that can occur due to the complexity of vortex system, a desingularized model of the vortex core was adopted. A Mathcad worksheet containing the method has been written.The original contribution of the work. The calculation method of the motion of the wakes free vortex system, the development of the vortex cores in time and a new method to approximate the aerodynamic influence of remoted wake regions.

  14. Evaluation of ride quality prediction methods for operational military helicopters

    Science.gov (United States)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots' discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  15. Flap motion of helicopter rotors with novel, dynamic stall model

    Directory of Open Access Journals (Sweden)

    Han Wei

    2016-01-01

    Full Text Available In this paper, a nonlinear flapping equation for large inflow angles and flap angles is established by analyzing the aerodynamics of helicopter blade elements. In order to obtain a generalized flap equation, the Snel stall model was first applied to determine the lift coefficient of the helicopter rotor. A simulation experiment for specific airfoils was then conducted to verify the effectiveness of the Snel stall model as it applies to helicopters. Results show that the model requires no extraneous parameters compared to the traditional stall model and is highly accurate and practically applicable. Based on the model, the relationship between the flapping angle and the angle of attack was analyzed, as well as the advance ratio under the dynamic stall state.

  16. A hybrid model of a subminiature helicopter in horizontal turn

    Institute of Scientific and Technical Information of China (English)

    Chen Li; Gong Zhenbang; Liu Liang

    2007-01-01

    A hybrid model of a subminiature helicopter in horizontal turn is presented. This model is based on a mechanism model and its compensated neural network (NN). First, the nonlinear dynamics of a subminiature helicopter is established. Through the linearization of the nonlinear dynamics on a trim point, the linear time-invariant mechanism model in horizontal turn is obtained. Then a diagonal recursive neural network is used to compensate the model error between the mechanism model and the nonlinear model, thus the hybrid model of a subminiature helicopter in horizontal turn is achieved. Simulation results show that the hybrid model has higher accuracy than the mechanism model and the obtained compensated-NN has good generalization capability.

  17. Development and evaluation of a generic active helicopter vibration controller

    Science.gov (United States)

    Davis, M. W.

    1984-01-01

    A computerized generic active controller is developed, which alleviates helicopter vibration by closed-loop implementation of higher harmonic control (HHC). In the system, the higher harmonic blade pitch is input through a standard helicopter swashplate; for a four-blade helicopter rotor the 4/rev vibration in the rotorcraft is minimized by inducing cyclic pitch motions at 3, 4, and 5/rev in the rotating system. The controller employs the deterministic, cautious, and dual control approaches and two linear system models (local and global), as well as several methods of limiting control. Based on model testing, performed at moderate to high values of forward velocity and rotor thrust, reductions in the rotor test apparatus vibration from 75 to 95 percent are predicted, with HHC pitch amplitudes of less than one degree. Good performance is also noted for short-duration maneuvers.

  18. Modelling and Daisy Chaining Control Allocation of a Multirotor Helicopter with a Single Tilting Rotor

    Directory of Open Access Journals (Sweden)

    Robert Porter

    2016-11-01

    Full Text Available This paper presents the development and implementation of a single tilting rotor multirotor helicopter. A single tilting rotor multirotor helicopter is proposed that allows for decoupled lateral acceleration and attitude states. A dynamics model of the proposed multirotor helicopter is established to enable control system development. A control system architecture and daisy chaining-based control allocation scheme is developed and implemented. The control architecture facilitates the control of decoupled lateral accelerations and attitudes. Further, a computational and experimental analysis is undertaken and offers evidence that the proposed multirotor helicopter and control system architecture enables the multirotor helicopter to achieve lateral accelerations without requiring attitude actuation.

  19. Study of operational parameters impacting helicopter fuel consumption. [using computer techniques (computer programs)

    Science.gov (United States)

    Cross, J. L.; Stevens, D. D.

    1976-01-01

    A computerized study of operational parameters affecting helicopter fuel consumption was conducted as an integral part of the NASA Civil Helicopter Technology Program. The study utilized the Helicopter Sizing and Performance Computer Program (HESCOMP) developed by the Boeing-Vertol Company and NASA Ames Research Center. An introduction to HESCOMP is incorporated in this report. The results presented were calculated using the NASA CH-53 civil helicopter research aircraft specifications. Plots from which optimum flight conditions for minimum fuel use that can be obtained are presented for this aircraft. The results of the study are considered to be generally indicative of trends for all helicopters.

  20. Helicopter air resonance modeling and suppression using active control

    Science.gov (United States)

    Takahashi, M. D.; Friedmann, P. P.

    1991-01-01

    A coupled rotor/fuselage helicopter analysis with the important effects of blade torsional flexibility, unsteady aerodynamics, and forward flight is presented. Using this mathematical model, a nominal configuration is selected with an air resonance instability throughout most of its flight envelope. A multivariable compensator is then designed using two swashplate inputs and a single-body roll rate measurement. The controller design is based on the linear quadratic Gaussian technique and the loop transfer recovery method. The controller is shown to suppress the air resonance instability throughout a wide range of helicopter loading conditions and forward flight speeds.

  1. Identification of Helicopter Rigid Body Dynamics from Flight Data.

    Directory of Open Access Journals (Sweden)

    Jatinder Singh

    1998-01-01

    Full Text Available This paper discusses helicopter modelling and identification related aspects. By applying thesystem identification methodology, longitudinal and lateral-directional rigid body helicopter dynamics are identified from flight data. Aerodynamic parameters from single input excitation as wellas multimanoeuver evaluation are estimated utilising output-error approach. The formulatedmathematical models yield adequate fit to measured time histories. Results obtained from the proof-of-match for model validation indicate that the identified derivatives can satisfactorily predictlongitudinal dynamics to a given arbitrary input. It is further demonstrated for the present study thatlateral body dynamics can be adequately predicted by including cross-coupling terms in the estimation model.

  2. Flying control of small-type helicopter by detecting its in-air natural features

    Directory of Open Access Journals (Sweden)

    Chinthaka Premachandra

    2015-05-01

    Full Text Available Control of a small type helicopter is an interesting research area in unmanned aerial vehicle development. This study aims to detect a more typical helicopter unequipped with markers as a means by which to resolve the various issues of the prior studies. Accordingly, we propose a method of detecting the helicopter location and pose through using an infrastructure camera to recognize its in-air natural features such as ellipse traced by the rotation of the helicopter's propellers. A single-rotor system helicopter was used as the controlled airframe in our experiments. Here, helicopter location is measured by detecting the main rotor ellipse center and pose is measured following relationship between the main rotor ellipse and the tail rotor ellipse. Following these detection results we confirmed the hovering control possibility of the helicopter through experiments.

  3. 14 CFR 136.13 - Helicopter performance plan and operations.

    Science.gov (United States)

    2010-01-01

    ... TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS COMMERCIAL AIR TOURS AND NATIONAL PARKS AIR TOUR MANAGEMENT National Air Tour Safety Standards § 136.13 Helicopter performance plan and operations. (a) Each operator must complete a performance plan before...

  4. Designing emergency-medical-service helicopter interiors using virtual manikins.

    Science.gov (United States)

    Michalski, Rafal; Grobelny, Jerzy

    2014-01-01

    Researchers employed digital manikins to determine the space necessary in an emergency-medical-service helicopter to effectively and efficiently conduct life-saving medical procedures. To simulate resuscitation with appropriate digital human models, they used Anthropos ErgoMAX modeling software in the 3D Studio Max environment.

  5. 77 FR 39911 - The New York North Shore Helicopter Route

    Science.gov (United States)

    2012-07-06

    ... consistent with aviation safety. In light of the minimal costs imposed and the substantial number and volume... noted that the helicopter noise interferes with sleep, conversation, and outdoor activities. Still... concerns, at the NPRM stage and now, the action was--and is--not expected to result in more than...

  6. DYNAMICAL VARIABLE STRUCTURE CONTROL OF A HELICOPTER IN VERTICAL FLIGHT

    OpenAIRE

    Sira-Ramirez, Hebertt; Zribi, Mohamed; Ahmad, Shaheen

    1991-01-01

    In this article, a dynamical multivariable discontinuous feedback control strategy of the sliding nlode type is proposed for the altitude stabilization of a nonlinear helicopter model in vertical flight. Vlrhile retaining the basic robustness features associated to sliding mode control policies, the proposed approach also results in smoothed out (i.e., non-chattering) input trajectories and controlled state variable responses.

  7. From Self-Flying Helicopters to Classrooms of the Future

    Science.gov (United States)

    Young, Jeffrey R.

    2012-01-01

    On a summer day four years ago, a Stanford University computer-science professor named Andrew Ng held an unusual air show on a field near the campus. His fleet of small helicopter drones flew under computer control, piloted by artificial-intelligence software that could teach itself to fly after watching a human operator. By the end of the day,…

  8. 77 FR 56581 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Science.gov (United States)

    2012-09-13

    ...) Model S-92A helicopter, which proposed revising the Rotorcraft Flight Manual (RFM), Operating... carrying Class D external loads. This Supplemental NPRM is prompted by a recent design approval, which... PROHIBITED.'' That NPRM was prompted by a mistake in the RFM, which allowed ``Class D'' rotorcraft...

  9. Robust Helicopter Stabilization in the Face of Wind Disturbance

    DEFF Research Database (Denmark)

    A. Danapalasingam, Kumeresan; Leth, John-Josef; la Cour-Harbo, Anders

    2010-01-01

    When a helicopter is required to hover with minimum deviations from a desired position without measurements of an affecting persistent wind disturbance, a robustly stabilizing control action is vital. In this paper, the stabilization of the position and translational velocity of a nonlinear...

  10. 77 FR 58971 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2012-09-25

    ... cargo compartment shelf without reinforcement per Modification 365P081895. Within 110 hours time-in... install a ] shelf reinforcement kit per helicopter at an average labor rate of $85 per work hour. Required... distinction; and 4. Will not have a significant economic impact, positive or negative, on a substantial...

  11. Ground vibration tests of a helicopter structure using OMA techniques

    Science.gov (United States)

    Ameri, N.; Grappasonni, C.; Coppotelli, G.; Ewins, D. J.

    2013-02-01

    This paper is focused on an assessment of the state-of-the-art of operational modal analysis (OMA) methodologies in estimating modal parameters from output responses on helicopter structures. For this purpose, a ground vibration test was performed on a real helicopter airframe. In the following stages, several OMA techniques were applied to the measured data and compared with the results from typical input-output approach. The results presented are part of a more general research activity carried out in the Group of Aeronautical Research and Technology in Europe (GARTEUR) Action Group 19, helicopter technical activity, whose overall objective is the improvement of the structural dynamic finite element models using in-flight test data. The structure considered is a medium-size helicopter, a time-expired Lynx Mk7 (XZ649) airframe. In order to have a comprehensive analysis, the behaviour of both frequency- and time-domain-based OMA techniques are considered for the modal parameter estimates. An accuracy index and the reliability of the OMA methods with respect to the standard EMA procedures, together with the evaluation of the influence of the experimental setup on the estimate of the modal parameters, will be presented in the paper.

  12. Flight vibrations and bleeding in helicoptered patients with pelvic fracture.

    Science.gov (United States)

    Carchietti, Elio; Cecchi, Adriana; Valent, Francesca; Rammer, Raphael

    2013-01-01

    Depending on their amplitude and frequency, vibrations may facilitate bleeding and worsen the prognosis of patients with pelvic fractures transported by helicopter emergency medical services (HEMS). We measured the range of frequencies and amplitudes of forced vibrations produced by the helicopter used by the HEMS of the Italian Friuli Venezia Giulia region on the pelvis of transported persons. We performed 3 flight tests with 3 different volunteers (mass 70, 80, and 90 kg, respectively) loaded on the helicopter's stretcher and recorded the amplitudes and frequencies of vibrations through a triaxis sensor placed on the HEMS stretcher in the pelvis area. The flight profile planned was identical for each of the 3 iterations. Over the whole flight, the frequencies of vibration were between 26.4 and 53.5 Hz, and the greastest amplitude was 0.035 mm. The vibrations recorded in the helicopter may facilitate bleeding in unstable fractures. In the management of patients with pelvic fractures, HEMS crews should provide prehospital care that includes the use of specific splinting devices in addition to the spinal board, which allows an early immobilization of fractures and the limitation of pelvic motion.

  13. Routing helicopters for crew exchanges on off-shore locations

    NARCIS (Netherlands)

    Sierksma, G.; Tijssen, G.A.

    1998-01-01

    This paper deals with a vehicle routing problem with split demands, namely the problem of determining a flight schedule for helicopters to off-shore platform locations for exchanging crew people employed on these platforms. The problem is formulated as an LP model and solved by means of a column-gen

  14. At Issue: Helicopter Parents and Millennial Students, an Annotated Bibliography

    Science.gov (United States)

    Pricer, Wayne F.

    2008-01-01

    Technological advances have made it easy for parents and children--many of them students--to communicate instantaneously. Devices and technologies such as cell phones, laptops, texting, and e-mail all enable various forms of instant communication. "Helicopter parents" are regarded as very overprotective and overly involved in the affairs of their…

  15. Flight Test Guide (Part 61 Revised): Instrument Pilot: Helicopter.

    Science.gov (United States)

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    The guide provides an outline of the skills required to pass the flight test for an Instrument Pilot Helicopter Rating under Part 61 (revised) of Federal Aviation Regulations. General procedures for flight tests are described and the following pilot operations outlined: maneuvering by reference to instruments, IFR navigation, instrument…

  16. 77 FR 42971 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2012-07-23

    ... that is removed with a wire brush or steel wool in the threaded portion of the mast. FAA's.... Costs of Compliance We estimate that this AD will affect 80 helicopters of U.S. Registry, and that... Flexibility Act. We prepared an economic evaluation of the estimated costs to comply with this AD and...

  17. 77 FR 14310 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-03-09

    ... No. 29.00.13, dated July 26, 2010 (ASB 29.00.13), which specifies installing two siliconed glass wool... proposed AD does not, as this model is not type certificated in the U.S. Costs of Compliance We estimate that this proposed AD would affect 695 helicopters of U.S. Registry. We estimate that operators...

  18. Aeromechanical Analysis of a Smart Helicopter Rotor in Forward Flight

    Directory of Open Access Journals (Sweden)

    Jacopo Serafini

    2015-02-01

    Full Text Available This paper deals with a smart system integrated into a helicopter blade aimed at giving an anhedral shape to the blade tip region to alleviate the blade-vortex interaction phenomenon that may cause reduced helicopter performance in terms of noise and vibrations. The blade tip morphing is obtained through the joint action of a magneto-rheological fluid (MRF device, a shape-memory alloy ribbons- based (SMA device and a set of concentrated masses properly distributed spanwise. The presence of this smart actuator (particularly the concentrated masses inside the blades modifies the aeromechanical behaviour of the rotor and may be detrimental in terms of hub vibratory loads, pitch control effectiveness and aeroelastic stability. Following a previous literature work concerning with the effectiveness of the smart actuated rotor in hovering conditions, the present paper focuses on the aeromechanical effects due to the inclusion of the smart device in a four-bladed helicopter rotor in forward flight where blade morphing is not needed. Aim of this work is to investigate on the compatibility of the smart system with the required aeromechanical performance of the rotor, highlighting the feasibility of its application on helicopters.

  19. Evaluation of Dutch Helicopter Emergency Medical Services in transporting children

    NARCIS (Netherlands)

    Peters, J.H.; Beekers, C.; Eijk, R.J.R.; Edwards, M.J.; Hoogerwerf, N.

    2014-01-01

    OBJECTIVE: In the Netherlands, helicopter emergency medical services (HEMS) function as an adjunct to paramedic ambulance service delivering hospital-level medical care to a prehospital location. The main goal of Dutch HEMS is to provide on-scene medical expertise and not primarily to serve as trans

  20. 78 FR 17591 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Science.gov (United States)

    2013-03-22

    ... elements with 10 micron fuel filter elements at the next scheduled inspection or within 150 flight hours... identification plate, cross out the last two digits (``09'') of the ] existing fuel filter P/N 52-2145-009, and... helicopters to require replacing each forward and aft fuel system 40 micron fuel filter element with a...

  1. Acoustic Helicopter and FW Aircraft Detection and Classification

    NARCIS (Netherlands)

    Koersel, A.C. van

    2001-01-01

    The possibility to detect the passage of aircraft (either propeller or jet) with one or more mechanical wave sensors (acoustic or seismic) is investigated. An existing algorithm-sensor demonstator can detect and classify helicopter targets. In its current form it is developed to reject other

  2. 78 FR 24371 - Airworthiness Directives; Robinson Helicopter Company (Robinson)

    Science.gov (United States)

    2013-04-25

    ... AD is prompted by three accidents that occurred because the fuel shut-off valve was inadvertently... review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region.... Discussion Three accidents have occurred with R22 helicopters because the lever-handle fuel valve was...

  3. 78 FR 60185 - Airworthiness Directives; Robinson Helicopter Company (Robinson)

    Science.gov (United States)

    2013-10-01

    ... with a newer design fuel shut-off valve. This AD is prompted by three accidents that occurred because... Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Examining the AD... valve with a newly designed fuel shut-off valve. Three accidents have occurred with R22 helicopters...

  4. 77 FR 58973 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-09-25

    ... helicopter nose to drop and hit the ground while the rotor blades are spinning. DATES: We must receive... designs. Related Service Information We reviewed Eurocopter ASB No. 32.00.18, Revision 2, dated July 12... the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for...

  5. 78 FR 63853 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-10-25

    ... likely to exist or develop on other helicopters of these same type designs. Related Service Information... necessary to modify the log card of the tail rotor blade assembly due to some of the pitch horn part numbers... air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds...

  6. Past applications and future potential of variable stability research helicopters

    Science.gov (United States)

    Hindson, W. S.

    1982-01-01

    The historical development of variable-stability research helicopters and some of their previous applications are presented as a guide for assessing their future potential. The features of three general-purpose rotary-wing flight research aircraft that provide complementary capabilities are described briefly, and a number of future applications are proposed.

  7. 78 FR 24041 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-24

    ... removal and inspection is required. The actions are intended to prevent vibration due to a failed bearing, failure of the T/R, and subsequent loss of control of the helicopter. DATES: This AD becomes effective May... identified in this AD, contact American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 75052...

  8. 78 FR 58256 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-23

    ... proposed actions are intended to prevent vibration due to a failed bearing, failure of the tail rotor, and subsequent loss of control of the helicopter. DATES: We must receive comments on this proposed AD by November..., contact American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641...

  9. Acoustic Helicopter and FW Aircraft Detection and Classification

    NARCIS (Netherlands)

    Koersel, A.C. van

    2001-01-01

    The possibility to detect the passage of aircraft (either propeller or jet) with one or more mechanical wave sensors (acoustic or seismic) is investigated. An existing algorithm-sensor demonstator can detect and classify helicopter targets. In its current form it is developed to reject other targets

  10. 77 FR 16137 - Airworthiness Directives; Eurocopter France Model Helicopters

    Science.gov (United States)

    2012-03-20

    ...-5527) is U.S. Department of Transportation, Docket Operations Office, M-30, West Building Ground Floor... ventilation in the area on the star arm end on ``helicopters operated in hot climatic conditions and/or... a pilot. We omit the phrase ``hot climatic conditions and/or in tropical and damp...

  11. Horseshoe Appendix: An Extremely Rare Appendiceal Anomaly.

    Science.gov (United States)

    Singh, Ch Gyan; Nyuwi, Kuotho T; Rangaswamy, Raju; Ezung, Yibenthung S; Singh, H Manihar

    2016-03-01

    Appendiceal anomalies are extremely rare malformations that are usually found incidentally. Agenesis and duplication of the appendix has been well documented however, the cases of horseshoe appendix reported is very limited, only four cases reported so far. Here, we report a four and half-year-old who underwent interval appendectomy. Intraoperatively both the ends of the appendix were found to be communicating with the cecum with two separate base or stump located at a sagital disposal- the so called "horseshoe appendix".

  12. Helicopter collision avoidance and brown-out recovery with HELLAS

    Science.gov (United States)

    Seidel, Christian; Schwartz, Ingo; Kielhorn, Peter

    2008-10-01

    EADS Germany is the world market leader in commercial and military Helicopter Laser Radar (HELLAS) Obstacle Warning Systems. The HELLAS-Warning System has been introduced into the market in 2000, is in service at German Federal Police and Royal Thai Air Force. HELLAS was also successfully evaluated by the Foreign Comparative Test Program (FCT) of the U.S. Army and other governmental agencies. Currently the successor system for military applications, HELLAS-Awareness, is in qualification phase. It will have extended sensor performance, enhanced real-time data processing capabilities and advanced human machine interface (HMI) features. Flight tests on NH90 helicopter have been successfully performed. Helicopter series integration is scheduled to begin from 2009. We will give an outline of the new sensor unit concerning detection technology and helicopter integration aspects. The system provides a widespread field of view with additional dynamic line of sight steering and a large detection range in combination with a high frame rate. We will show the HMI representations. This HELLAS system is the basis for a 3 dimensional see-and-remember-system for brown-out recovery. When landing in sandy or dusty areas the downwash of the helicopter rotor causes clouds of visually-restrictive material that can completely obstruct the pilot's outside reference, resulting in a complete loss of situational awareness and spatial orientation of the pilot which can end up in total loss of aircraft control and dangerous accidents. The brown-out recovery system presented here creates an augmented enhanced synthetic vision of the landing area with the surrounding which is based on HELLAS range image data as well as altimeter and inertial reference information.

  13. Eye injury risk associated with remote control toy helicopter blades.

    Science.gov (United States)

    Alphonse, Vanessa D; Kemper, Andrew R; Rowson, Steven; Duma, Stefan M

    2012-01-01

    Eye injuries can be caused by a variety of consumer products and toys. Recently, indoor remote controlled (RC) toy helicopters have become very popular. The purpose of this study is to quantify eye injury risk associated with five commercially available RC toy helicopter blades. An experimental matrix of 25 tests was developed to test five different RC toy helicopter blades at full battery power on six postmortem human eyes. A pressure sensor inserted through the optic nerve measured intraocular pressure. Corneal abrasion was assessed post-impact using fluorescein dye. Intraocular pressure was correlated to injury risk for hyphema, lens damage, retinal damage, and globe rupture using published risk functions. All tests resulted in corneal abrasions; however, no other injuries were observed. The 25 tests produced an increase intraocular pressure between 15.2 kPa and 99.3 kPa (114.3 mmHg and 744.7 mmHg). Calculated blade velocities ranged between 16.0 m/s and 25.4 m/s. Injury risk for hyphema was a maximum of 0.2%. Injury risk for lens damage, retinal damage, and globe rupture was 0.0% for all tests. Blade design parameters such as length and mass did not affect the risk of eye injury. This is the first study to quantify the risk of eye injury from RC toy helicopter blades. While corneal abrasions were observed, more serious eye injuries were neither observed nor predicted to have occurred. Results from this study are critical for establishing safe design thresholds for RC toy helicopter blades so that more serious injuries can be prevented.

  14. Waste-Management Education and Research Consortium (WERC) annual progress report, 1991--1992. Appendixes

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-07

    This report contains the following appendices: Appendix A - Requirements for Undergraduate Level; Appendix B - Requirements for Graduate Level; Appendix C - Graduate Degree In Environmental Engineering; Appendix D - Non-degree Certificate Program; Appendix E - Curriculum for Associate Degree Program; Appendix F - Curriculum for NCC Program; Appendix G - Information 1991 Teleconference Series; Appendix H - Information on 1992 Teleconference Series; Appendix I - WERC interactive Television Courses; Appendix J - WERC Research Seminar Series; Appendix K - Sites for Hazardous/Radioactive Waste Management Series; Appendix L- Summary of Technology Development of the Second Year; Appendix M - List of Major Publications Resulting from WERC; Appendix N - Types of Equipment at WERC Laboratories.

  15. Extracting radar micro-Doppler signatures of helicopter rotating rotor blades using K-band radars

    Science.gov (United States)

    Chen, Rachel; Liu, Baokun

    2014-06-01

    Helicopter identification has been an attractive topic. In this paper, we applied radar micro-Doppler signatures to identify helicopter. For identifying the type of a helicopter, besides its shape and size, the number of blades, the length of the blade, and the rotation rate of the rotor are important features, which can be estimated from radar micro-Doppler signatures of the helicopter's rotating rotor blades. In our study, K-band CW/FMCW radars are used for collecting returned signals from helicopters. By analyzing radar micro-Doppler signatures, we can estimate the number of blades, the length of the blade, the angular rotation rate of the rotating blade, and other necessary parameters for identifying the type of a helicopter.

  16. Comparison of Test Stand and Helicopter Oil Cooler Bearing Condition Indicators

    Science.gov (United States)

    Dempsey, Paula J.; Branning, Jeremy; Wade, Damiel R.; Bolander, Nathan

    2010-01-01

    The focus of this paper was to compare the performance of HUMS condition indicators (CI) when detecting a bearing fault in a test stand or on a helicopter. This study compared data from two sources: first, CI data collected from accelerometers installed on two UH-60 Black Hawk helicopters when oil cooler bearing faults occurred, along with data from helicopters with no bearing faults; and second, CI data that was collected from ten cooler bearings, healthy and faulted, that were removed from fielded helicopters and installed in a test stand. A method using Receiver Operating Characteristic (ROC) curves to compare CI performance was demonstrated. Results indicated the bearing energy CI responded differently for the helicopter and the test stand. Future research is required if test stand data is to be used validate condition indicator performance on a helicopter.

  17. Comparison of Test Stand and Helicopter Oil Cooler Bearing Condition Indicators

    Science.gov (United States)

    Dempsey, Paula J.; Branning, Jeremy; Wade, Damiel R.; Bolander, Nathan

    2010-01-01

    The focus of this paper was to compare the performance of HUMS condition indicators (CI) when detecting a bearing fault in a test stand or on a helicopter. This study compared data from two sources: first, CI data collected from accelerometers installed on two UH-60 Black Hawk helicopters when oil cooler bearing faults occurred, along with data from helicopters with no bearing faults; and second, CI data that was collected from ten cooler bearings, healthy and faulted, that were removed from fielded helicopters and installed in a test stand. A method using Receiver Operating Characteristic (ROC) curves to compare CI performance was demonstrated. Results indicated the bearing energy CI responded differently for the helicopter and the test stand. Future research is required if test stand data is to be used validate condition indicator performance on a helicopter.

  18. Hyperspectral and photogrammetric helicopter-based measurements over western Greenland

    Science.gov (United States)

    Tedesco, M.; Mote, T. L.; Smith, L. C.; Rennermalm, A. K.; Lampkin, D. J.

    2015-12-01

    We discuss the setup and results of an experiment aimed at collecting helicopter-based hyperspectral and photogrammetry measurements over the western Greenland ice sheet (GrIS) for studying the evolution of surface albedo and surface hydrological features. Data were collected during three days at the end of July 2015 concurrently with in-situ hydrological measurements of runoff and discharge of a supraglacial stream (Rio Behar) and along the K-transect up to an elevation of ~ 1500 m a.s.l. Hyperspectral measurements of incoming and outgoing radiation collected at a radiometric resolution of 10 nm were acquired in conjunction with geo-located images by means of a digital camera mounted on the same platform. Gyroscopes and 3-D accelerometers were also used to estimate the relative orientation of the sensors collecting the incoming and outgoing solar radiation. To our knowledge, despite their importance, it is the first time that such measurements have been collected over the Greenland ice sheet from an airborne platform. The sensors were installed inside a pod that was specifically modified for our purpose. The impact of the helicopter on the recorded incoming radiation was characterized by collecting measurements in the absence and presence of the helicopter when the rotors were either off or on. Moreover, the effect of the relative position of the helicopter with respect to the sun's position was also quantified by ad-hoc maneuvers during take off and landing with the helicopter spinning around the main rotor axis. The geo-referenced images collected by our instrument provide an unprecedented ground spatial resolution of ~ 6 cm, hence allowing us to study the spatial distribution of surface hydrological features, such as cryoconite holes, small order streams and cracks developing into larger moulins. Such images were also used to evaluate the application of RGB data to estimate streams and lakes surface area and depths. Our helicopter-based hyperspectral and

  19. Contributions to the dynamics of helicopters with active rotor controls

    Science.gov (United States)

    Malpica, Carlos A.

    This dissertation presents an aeromechanical closed loop stability and response analysis of a hingeless rotor helicopter with a Higher Harmonic Control (HHC) system for vibration reduction. The analysis includes the rigid body dynamics of the helicopter and blade flexibility. The gain matrix is assumed to be fixed and computed off-line. The discrete elements of the HHC control loop are rigorously modeled, including the presence of two different time scales in the loop. By also formulating the coupled rotor-fuselage dynamics in discrete form, the entire coupled helicopter-HHC system could be rigorously modeled as a discrete system. The effect of the periodicity of the equations of motion is rigorously taken into account by converting the system into an equivalent system with constant coefficients and identical stability properties using a time lifting technique. The most important conclusion of the present study is that the discrete elements in the HHC loop must be modeled in any HHC analysis. Not doing so is unconservative. For the helicopter configuration and HHC structure used in this study, an approximate continuous modeling of the HHC system indicates that the closed loop, coupled helicopter-HHC system remains stable for optimal feedback control configurations which the more rigorous discrete analysis shows can result in closed loop instabilities. The HHC gains must be reduced to account for the loss of gain margin brought about by the discrete elements. Other conclusions of the study are: (i) the HHC is effective in quickly reducing vibrations, at least at its design condition, although the time constants associated with the closed loop transient response indicate closed loop bandwidth to be 1 rad/sec on average, thus overlapping with FCS or pilot bandwidths, and raising the issue of potential interactions; (ii) a linearized model of helicopter dynamics is adequate for HHC design, as long as the periodicity of the system is correctly taken into account, i

  20. Classification analysis of vibration data from SH-60B Helicopter Transmission Test Facility

    OpenAIRE

    Anderson, Gregory L.

    1997-01-01

    Approved for public release; distribution is unlimited Health and Usage Monitoring Systems (HUMS) is an emerging technology in helicopter aviation. The United States Navy is evaluating its viability for use on its helicopter fleet. HUMS uses sensors placed throughout the helicopter to monitor and record vibration signals and numerous other aircraft operating parameters. This thesis evaluates the vibration signals recorded by a HUMS system using a statistical technique called tree structure...

  1. Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain

    Science.gov (United States)

    2014-01-01

    Annual Forum, Montreal, Canada, 2002. 3. Samuel, P. D.; Pines, D. J. A Review of Vibration Based Techniques for Helicopter Transmission Diagnostics...Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain by Kelsen E. LaBerge, Eric C. Ames, and Brian D. Dykas...5066 ARL-TR-6795 January 2014 Detection of Naturally Occurring Gear and Bearing Faults in a Helicopter Drivetrain Kelsen E. LaBerge

  2. Quadrotor helicopter for surface hydrological measurements

    Science.gov (United States)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  3. [Functional dynamics of the pilots of heavy transport helicopters in the course of a flight shift].

    Science.gov (United States)

    Kamenskiĭ, Iu N

    1982-01-01

    Before and after flights about 300 crewmembers of heavy transport helicopters were examined, using psychophysiological and integral methods that yield professionally important information. During a flight shift the health state of helicopter pilots varies via three stages: habituation, initial decline and distinct lassitude, with the latter developing after 5 h flight load. In order to increase human reliability in the pilot-helicopter system, it is advisable to allow 4 h flight time during a flight shift onboard helicopters of the above type. In this case the pilot exposure to vibration effects will also be limited. The paper describes a maximally permissible spectrum of vibration velocity for a 4 h exposure.

  4. A method for determining internal noise criteria based on practical speech communication applied to helicopters

    Science.gov (United States)

    Sternfeld, H., Jr.; Doyle, L. B.

    1978-01-01

    The relationship between the internal noise environment of helicopters and the ability of personnel to understand commands and instructions was studied. A test program was conducted to relate speech intelligibility to a standard measurement called Articulation Index. An acoustical simulator was used to provide noise environments typical of Army helicopters. Speech material (command sentences and phonetically balanced word lists) were presented at several voice levels in each helicopter environment. Recommended helicopter internal noise criteria, based on speech communication, were derived and the effectiveness of hearing protection devices were evaluated.

  5. Modeling, Estimation, and Control of Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten

    This thesis treats the subject of autonomous helicopter slung load flight and presents the reader with a methodology describing the development path from modeling and system analysis over sensor fusion and state estimation to controller synthesis. The focus is directed along two different....... To enable slung load flight capabilities for general cargo transport, an integrated estimation and control system is developed for use on already autonomous helicopters. The estimator uses vision based updates only and needs little prior knowledge of the slung load system as it estimates the length...... of the suspension system together with the system states. The controller uses a combined feedforward and feedback approach to simultaneously prevent exciting swing and to actively dampen swing in the slung load. For the mine detection application an estimator is developed that provides full system state information...

  6. A new approach to helicopter rotor blade research instrumentation

    Science.gov (United States)

    Knight, V. H., Jr.

    1978-01-01

    A rotor-blade-mounted telemetry instrumentation system developed and used in flight tests by the NASA/Langley Research Center is described. The system uses high-speed digital techniques to acquire research data from miniature pressure transducers on advanced rotor airfoils which are flight tested using an AH-1G helicopter. The system employs microelectronic PCM multiplexer-digitizer stations located remotely on the blade and in a hub-mounted metal canister. The electronics contained in the canister digitizes up to 16 sensors, formats this data with serial PCM data from the remote stations, and transmits the data from the canister which is above the plane of the rotor. Data is transmitted over an RF link to the ground for real-time monitoring and to the helicopter fuselage for tape recording.

  7. Sliding mode tracking control for miniature unmanned helicopters

    Directory of Open Access Journals (Sweden)

    Bin Xian

    2015-02-01

    Full Text Available A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID and linear-quadratic regulator (LQR cascaded controller in the presence of wind gust disturbances.

  8. Sliding mode tracking control for miniature unmanned helicopters

    Institute of Scientific and Technical Information of China (English)

    Xian Bin; Guo Jianchuan; Zhang Yao; Zhao Bo

    2015-01-01

    A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS) of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID) and linear-quadratic regulator (LQR) cascaded controller in the presence of wind gust disturbances.

  9. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  10. A Maneuvering Flight Noise Model for Helicopter Mission Planning

    Science.gov (United States)

    Greenwood, Eric; Rau, Robert; May, Benjamin; Hobbs, Christopher

    2015-01-01

    A new model for estimating the noise radiation during maneuvering flight is developed in this paper. The model applies the Quasi-Static Acoustic Mapping (Q-SAM) method to a database of acoustic spheres generated using the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique. A method is developed to generate a realistic flight trajectory from a limited set of waypoints and is used to calculate the quasi-static operating condition and corresponding acoustic sphere for the vehicle throughout the maneuver. By using a previously computed database of acoustic spheres, the acoustic impact of proposed helicopter operations can be rapidly predicted for use in mission-planning. The resulting FRAME-QS model is applied to near-horizon noise measurements collected for the Bell 430 helicopter undergoing transient pitch up and roll maneuvers, with good agreement between the measured data and the FRAME-QS model.

  11. Lift capability prediction for helicopter rotor blade-numerical evaluation

    Science.gov (United States)

    Rotaru, Constantin; Cîrciu, Ionicǎ; Luculescu, Doru

    2016-06-01

    The main objective of this paper is to describe the key physical features for modelling the unsteady aerodynamic effects found on helicopter rotor blade operating under nominally attached flow conditions away from stall. The unsteady effects were considered as phase differences between the forcing function and the aerodynamic response, being functions of the reduced frequency, the Mach number and the mode forcing. For a helicopter rotor, the reduced frequency at any blade element can't be exactly calculated but a first order approximation for the reduced frequency gives useful information about the degree of unsteadiness. The sources of unsteady effects were decomposed into perturbations to the local angle of attack and velocity field. The numerical calculus and graphics were made in FLUENT and MAPLE soft environments. This mathematical model is applicable for aerodynamic design of wind turbine rotor blades, hybrid energy systems optimization and aeroelastic analysis.

  12. Heli/SITAN: A Terrain Referenced Navigation algorithm for helicopters

    Energy Technology Data Exchange (ETDEWEB)

    Hollowell, J.

    1990-01-01

    Heli/SITAN is a Terrain Referenced Navigation (TRN) algorithm that utilizes radar altimeter ground clearance measurements in combination with a conventional navigation system and a stored digital terrain elevation map to accurately estimate a helicopter's position. Multiple Model Adaptive Estimation (MMAE) techniques are employed using a bank of single state Kalman filters to ensure that reliable position estimates are obtained even in the face of large initial position errors. A real-time implementation of the algorithm was tested aboard a US Army UH-1 helicopter equipped with a Singer-Kearfott Doppler Velocity Sensor (DVS) and a Litton LR-80 strapdown Attitude and Heading Reference System (AHRS). The median radial error of the position fixes provided in real-time by this implementation was less than 50 m for a variety of mission profiles. 6 refs., 7 figs.

  13. Identification and stochastic control of helicopter dynamic modes

    Science.gov (United States)

    Molusis, J. A.; Bar-Shalom, Y.

    1983-01-01

    A general treatment of parameter identification and stochastic control for use on helicopter dynamic systems is presented. Rotor dynamic models, including specific applications to rotor blade flapping and the helicopter ground resonance problem are emphasized. Dynamic systems which are governed by periodic coefficients as well as constant coefficient models are addressed. The dynamic systems are modeled by linear state variable equations which are used in the identification and stochastic control formulation. The pure identification problem as well as the stochastic control problem which includes combined identification and control for dynamic systems is addressed. The stochastic control problem includes the effect of parameter uncertainty on the solution and the concept of learning and how this is affected by the control's duel effect. The identification formulation requires algorithms suitable for on line use and thus recursive identification algorithms are considered. The applications presented use the recursive extended kalman filter for parameter identification which has excellent convergence for systems without process noise.

  14. Noise, vibration and changes in wakefulness during helicopter flight.

    Science.gov (United States)

    Landström, U; Löfstedt, P

    1987-02-01

    The investigation was carried out in cooperation with the helicopter school AF 1 in Boden. Measurements were made in two different types of helicopter, Hkp 3 and Hkp 6. Three different parameters were recorded during the flights: noise, vibrations, and wakefulness. Noise and vibration exposures were mainly correlated to the main rotor energy and frequency. Both types of exposure were dominated by lower frequencies, below 10 Hz. Analyses of wakefulness during long-distance flights, about 4 h, and short-distance flights, less than 2 h, were based on EEG and EKG recordings. As expected the level of wakefulness was influenced by the stress upon the pilots. Take-offs and landings, as well as unexpected events during the flight, were correlated to an increased level of wakefulness. In some cases flying was correlated to a gradual increase of weariness. The correlation between weariness, types of flying, and the external environmental factors of noise and vibration, is also discussed.

  15. Response of the skeletal system to helicopter-unique vibration.

    Science.gov (United States)

    Gearhart, J R

    1978-01-01

    An 18-month prospective skeletal system study was conducted on flying and nonflying personnel relative to chronic low-frequency vibration as experienced in helicopter flight. The aviators were initial entry students in rotary-wing training while the non-flying participants were beginning basic military training. Comparisons were made on the basis of anthropometric measurements, radiological studies, and bone mineral density changes as measured by photon absorption. The bone mineral densitometry showed no significant variation in the aviator group. A short-term 10% demineralization of the distal ulna in the non-flying group was noted immediately following the physical training. The final bone mineral density of basic training subjects returned to the initial level 18 months after the physical training. It was concluded that the helicopter aircrew members under study were exposed to levels of vibration below the threshold of vibration required to produce a measurable change in the skeletal system.

  16. Simulation and Analysis of Crashworthiness of Fuel Tank for Helicopters

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Crashworthiness requirement of fuel tanks is one of the important requirements in helicopter designs. The relations among the protection frame, textile layer and rubber layer of the fuel tank are introduced. Two appropriate FE models are established, one is for an uncovered helicopter fuel tank without protection frame, and the other is for fuel tank with protection frame. The dynamic responses of the two types of fuel tanks impinging on the ground with velocities of 17.3 m/s are numerically simulated for the purpose of analyzing energy-absorbing capabilities of the textile layer and protection frame. The feasibility of the current crashworthiness design of the fuel tank is examined though comparing the dynamic response behaviors of the two fuel tanks.

  17. Application of face-gear drives in helicopter transmissions

    Science.gov (United States)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-05-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  18. Application of Face-Gear Drives in Helicopter Transmissions

    Science.gov (United States)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-01-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  19. Vibration analysis of the SA349/2 helicopter

    Science.gov (United States)

    Heffernan, Ruth; Precetti, Dominique; Johnson, Wayne

    1991-01-01

    Helicopter airframe vibration is examined using calculations and measurements for the SA349/2 research helicopter. The hub loads, which transmit excitations to the fuselage, are predicted using a comprehensive rotorcraft analysis and correlated with measuring hub loads. The predicted and measured hub loads are then coupled with finite element models representing the SA349/2 fuselage. The resulting vertical acceleration at the pilot seat is examined. Adjustments are made to the airframe structural models to examine the sensitivity of predicted vertical acceleration to the model. Changes of a few percent to the damping and frequency of specific models lead to large reductions in predicted vibration, and to major improvements in the correlations with measured pilot-seat vertical acceleration.

  20. Analysis and correlation of SA349/2 helicopter vibration

    Science.gov (United States)

    Heffernan, Ruth; Precetti, Dominique; Johnson, Wayne

    1991-01-01

    Helicopter airframe vibration is examined using calculation and measurements for the SA349/2 research helicopter. The hub loads, which transmit excitation to the fuselage, are predicted using a comprehensive rotorcraft analysis and correlated with measured hub loads. The predicted and measured hub loads are then coupled with finite element models representing the SA349/2 fuselage. The resulting vertical acceleration at the pilot seat is examined. Adjustments are made to the airframe structural models to examine the sensitivity of predicted vertical acceleration to the model. Changes of a few percent to the damping and frequency of specific modes lead to large reductions in predicted vibration and to major improvements in the correlations with measured pilot seat vertical acceleration.

  1. Feasibility study of a superconducting motor for electrical helicopter propulsion

    Science.gov (United States)

    Simons, C. A. B. A. E.; Sanabria-Walter, C.; Polinder, H.

    2014-05-01

    During the past decades, superconducting electrical machines have become more suitable to replace conventional iron based designs, because of their lower weight and higher torque density. These properties make them good candidates for use in More Electric Aircraft (MEA). Especially helicopter propulsion systems could benefit from the increased performance. This paper describes the feasibility study of a superconducting motor to be used for helicopter propulsion as part of a More Electric Aircraft (MEA). For this, the armature, field windings and cryostat are designed, aiming at meeting the difficult specifications. Since superconductors have virtually no electrical resistance when cooled down below a certain critical temperature, they can be used to build high field and low weight coils for electrical machines. Especially the possibility to not use iron can make the superconducting motor lighter with a higher power density compared with conventional Permanent Magnet (PM) motors.

  2. Fluid mechanics mechanisms in the stall process of helicopters

    Science.gov (United States)

    Young, W. H., Jr.

    1981-01-01

    Recent experimental results from airfoils in the Mach number, Reynolds number, or reduced frequency ranges typical of helicopter rotor blades have identified the most influential flow mechanisms in the dynamic stall process. The importance of secondary shed vortices, downstream wake action, and the flow in the separated region is generally acknowledged but poorly understood. By means of surface pressure cross-correlations and flow field measurements in static stall, several new hypotheses have been generated. It is proposed that vortex shedding may be caused by acoustic disturbances propagating forward in the lower (pressure) surface boundary layer, that wake closure is a misnomer, and that the shed vortex leaves a trail of vorticity that forms a turbulent free shear layer. The known dynamic stall flow mechanisms are reviewed and the potential importance of recently proposed and hypothetical flow phenomena with respect to helicopter blade aeroelastic response are assessed.

  3. Streptococcus milleri in the appendix.

    Science.gov (United States)

    Poole, P M; Wilson, G

    1977-10-01

    The appendix was investigated as a possible habitat of Streptococcus milleri. Both normal and inflamed appendices were examined and the isolation rates compared. S. milleri was present in a quarter of the normal appendices and more than half of those associated with apendicitis--a difference that was statistically highly significant. The isolation rates throughout were indepencent of age. There was a pronounced connection between the presence of S. milleri in the appendix and the purulent manifestations of appendicitis. S. milleri was isolated from other abdominal sites associated with appendicitis. The frequency of isolation was increased by culture in an enrichment broth containing nalidixic acid and sulphadimidine.

  4. Detection of Forward Flight Limitations of Unmanned Helicopters

    OpenAIRE

    Voigt, Andreas; Dauer, Johann; Krenik, Alex; Dittrich, Jörg Steffen

    2016-01-01

    In this paper, a method is proposed to determine the flight envelope limitations for steady forward flight with the purpose of performing a flight envelope expansion. First, the rotary wing system is analyzed. In this paper, an intermeshing rotor configuration, a SwissDrones Dragon 50, is used to demonstrate the approach. Next, relevant limitations of the forward flight are reviewed and analyzed with the help of the Helicopter Overall Simulation Tool (HOST). From this analysis, relevant measu...

  5. Detection of small UAV helicopters using micro-Doppler

    Science.gov (United States)

    Tahmoush, David

    2014-05-01

    The detection of small unmanned aerial vehicles (UAVs) using radar can be challenging due to the small radar cross section and the presence of false targets such as birds. We present the initial results of micro-Doppler radar data collected on a small helicopter at G-band and compare the results to previously measured birds. The resulting signature differences can be used to help discriminate small UAVs from naturally occurring moving clutter such as birds.

  6. [Causes of fatigue in civil aviation helicopter crews].

    Science.gov (United States)

    Kamenskiĭ, Iu N

    1981-01-01

    Vibration and noise play an important part in fatiguing crewmembers of helicopters. The exposure to these factors during the flying shift results in an early and marked fatigue of pilots the level of which depends on the vibration effects to a larger extent than on the noise effects. The fatigue is followed by a decline of the psychophysiological parameters characterizing the visual and motor functions as well as the ratio of the basic processes in the central nervous system.

  7. Do Army Helicopter Training Simulators Need Motion Bases?

    OpenAIRE

    McCauley, Michael E.

    2006-01-01

    United States Army Research Institute for the Behavioral and Social Sciences This report reviews the arguments and the evidence regarding the need for simulator motion bases in training helicopter pilots. It discusses flight simulators, perceptual fidelity, history of motion bases, disturbance versus maneuver motion, human motion sensation, and reviews the empirical evidence for the training effectiveness of motion bases. The section on training effectiveness reviews research f...

  8. Classification Trees and the Analysis of Helicopter Vibration Data

    OpenAIRE

    Larson, Harold J.

    1997-01-01

    Health and Usage Monitoring Systems are receiving a great deal of interest, in an attempt to increase the safety and operational readiness of helicopters, and to minimize maintenance costs. These systems monitor (and can record) various flight parameters, pilot conversations, engine exhaust debris, metallic chip detector levels in the lubrication system, rotor track and balance, as well as vibration levels at selected locations throughout the airframe and the power drive system. Vibration lev...

  9. Engineering Design Handbook. Helicopter Engineering. Part One. Preliminary Design

    Science.gov (United States)

    1974-08-30

    by estimation, compound helicopter performance, to think of the air- plots of effective lift and drag areas and pitching mo- craft as a biplane having...stncural design problems but may produce loads that where are critikal locally. A = presented arms ft’ Ca = drag coefficient, dimensionless F• V = wind speed...groups is to be provided in accordance with MIL-STD- 1374, Part I. The useful load condition shall be as I. W. H. Ballhaus, Clear Design Thinking Using

  10. Physical stressors during neonatal transport: helicopter compared with ground ambulance.

    Science.gov (United States)

    Bouchut, Jean-Christophe; Van Lancker, Eric; Chritin, Vincent; Gueugniaud, Pierre-Yves

    2011-01-01

    This study was undertaken to assess concurrent mechanical stresses from shock, vibration, and noise to which a critically ill neonate is exposed during emergency transfer. For neonates transported by a French specialized emergency medical service, we measured and analyzed 27 physical parameters recorded during typical transport by ambulance and by helicopter. The noninvasive sensors were placed to allow better representation of the exposure of the newborn to the physical constraints. Based on 10 hours of transport by ambulance and 2 hours by helicopter, noise, whole body vibration, rate of turn, acceleration, and pitch were extracted as the five most representative dynamic harshness indicators. A helicopter produces a higher-level but more stable (lower relative dispersion) whole body dynamic exposure than an ambulance, with a mean noise level of 86 ± 1 dBA versus 67 ± 3 dBA, mean whole body vibration of 1 ± 0.1 meter per second squared (m/s(2)) versus 0.4 6 0.2 m/s(2), and acceleration of 1 6 0.05 m/s(2) versus 0.4 6 0.1 m/s(2). A ground ambulance has many more dynamic effects in terms of braking, shock, and impulsive noise than a helicopter (1 impulsive event per 2 minutes vs. 1 per 11 minutes). Our results show significant exposure of the sick neonate to both stationary and impulsive dynamic physical stressors during transportation, particularly in a ground ambulance. The study suggests opportunities to reduce physical stressors during neonatal transport. Copyright © 2011 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  11. Design, Test, and Acceptance Criteria for Helicopter Transparent Enclosures

    Science.gov (United States)

    1978-11-01

    polycarbonate materials were superior to glass in resisting impinge- ment abrasion; apparently due to ductility of the coating which minimized spallation ...square. A hole was drilled in the upright section of each "T" block (see Figure 10) to accommodate a metal pin or holding device correlative to the...shock wave. Transparencies that necessarily enclose large portions of the crew-occupied helicopter areas are particularly susceptible to spallation

  12. Development of helicopter attitude axes controlled hover flight without pilot assistance and vehicle crashes

    Science.gov (United States)

    Simon, Miguel

    In this work, we show how to computerize a helicopter to fly attitude axes controlled hover flight without the assistance of a pilot and without ever crashing. We start by developing a helicopter research test bed system including all hardware, software, and means for testing and training the helicopter to fly by computer. We select a Remote Controlled helicopter with a 5 ft. diameter rotor and 2.2 hp engine. We equip the helicopter with a payload of sensors, computers, navigation and telemetry equipment, and batteries. We develop a differential GPS system with cm accuracy and a ground computerized navigation system for six degrees of freedom (6-DoF) free flight while tracking navigation commands. We design feedback control loops with yet-to-be-determined gains for the five control "knobs" available to a flying radio-controlled (RC) miniature helicopter: engine throttle, main rotor collective pitch, longitudinal cyclic pitch, lateral cyclic pitch, and tail rotor collective pitch. We develop helicopter flight equations using fundamental dynamics, helicopter momentum theory and blade element theory. The helicopter flight equations include helicopter rotor equations of motions, helicopter rotor forces and moments, helicopter trim equations, helicopter stability derivatives, and a coupled fuselage-rotor helicopter 6-DoF model. The helicopter simulation also includes helicopter engine control equations, a helicopter aerodynamic model, and finally helicopter stability and control equations. The derivation of a set of non-linear equations of motion for the main rotor is a contribution of this thesis work. We design and build two special test stands for training and testing the helicopter to fly attitude axes controlled hover flight, starting with one axis at a time and progressing to multiple axes. The first test stand is built for teaching and testing controlled flight of elevation and yaw (i.e., directional control). The second test stand is built for teaching and

  13. Dynamic Analysis of a Helicopter Rotor by Dymore Program

    Science.gov (United States)

    Doğan, Vedat; Kırca, Mesut

    The dynamic behavior of hingeless and bearingless blades of a light commercial helicopter which has been under design process at ITU (İstanbul Technical University, Rotorcraft Research and Development Centre) is investigated. Since the helicopter rotor consists of several parts connected to each other by joints and hinges; rotors in general can be considered as an assembly of the rigid and elastic parts. Dynamics of rotor system in rotation is complicated due to coupling of elastic forces (bending, torsion and tension), inertial forces, control and aerodynamic forces on the rotor blades. In this study, the dynamic behavior of the rotor for a real helicopter design project is analyzed by using DYMORE. Blades are modeled as elastic beams, hub as a rigid body, torque tubes as rigid bodies, control links as rigid bodies plus springs and several joints. Geometric and material cross-sectional properties of blades (Stiffness-Matrix and Mass-Matrix) are calculated by using VABS programs on a CATIA model. Natural frequencies and natural modes of the rotating (and non-rotating) blades are obtained by using DYMORE. Fan-Plots which show the variation of the natural frequencies for different modes (Lead-Lag, Flapping, Feathering, etc.) vs. rotor RPM are presented.

  14. The Vibration Impact Determination of the Helicopter Structural Components

    Directory of Open Access Journals (Sweden)

    Khaksar Zeinab

    2017-01-01

    Full Text Available This paper presents the determination of the vibration impact of the helicopter structural components and skin repairs in terms of frequency characteristics. To address this issue, a 3D Finite Element Method (FEM model of 349 Gazelle helicopter has been developed in ABAQUS and the frequency analysis is conducted. The results on the natural frequencies of the full structure reasonably match with the literature giving confidence in the baseline model. The main advantage of this FEM model is that, it can be used to predict the natural frequencies of the full structure, precisely. In addition, the material properties and conditions of the components can be updated based on the applied conditions during the repair and maintenance period. Thus, the model gives a comprehensive design tool for analysing the frequencies of the helicopter with differing components. The effective variations in the frequency changes due to repair are predicted numerically. The discussion of these results helps in developing leads to improved selection of replacement materials and their properties.

  15. Principal Components Analysis of Triaxial Vibration Data From Helicopter Transmissions

    Science.gov (United States)

    Tumer, Irem Y.; Huff, Edward M.

    2001-01-01

    Research on the nature of the vibration data collected from helicopter transmissions during flight experiments has led to several crucial observations believed to be responsible for the high rates of false alarms and missed detections in aircraft vibration monitoring systems. This work focuses on one such finding, namely, the need to consider additional sources of information about system vibrations. In this light, helicopter transmission vibration data, collected using triaxial accelerometers, were explored in three different directions, analyzed for content, and then combined using Principal Components Analysis (PCA) to analyze changes in directionality. In this paper, the PCA transformation is applied to 176 test conditions/data sets collected from an OH58C helicopter to derive the overall experiment-wide covariance matrix and its principal eigenvectors. The experiment-wide eigenvectors. are then projected onto the individual test conditions to evaluate changes and similarities in their directionality based on the various experimental factors. The paper will present the foundations of the proposed approach, addressing the question of whether experiment-wide eigenvectors accurately model the vibration modes in individual test conditions. The results will further determine the value of using directionality and triaxial accelerometers for vibration monitoring and anomaly detection.

  16. The 3600 hp split-torque helicopter transmission

    Science.gov (United States)

    White, G.

    1985-01-01

    Final design details of a helicopter transmission that is powered by GE twin T 700 engines each rated at 1800 hp are presented. It is demonstrated that in comparison with conventional helicopter transmission arrangements the split torque design offers: weight reduction of 15%; reduction in drive train losses of 9%; and improved reliability resulting from redundant drive paths between the two engines and the main shaft. The transmission fits within the NASA LeRC 3000 hp Test Stand and accepts the existing positions for engine inputs, main shaft, connecting drive shafts, and the cradle attachment points. One necessary change to the test stand involved gear trains of different ratio in the tail drive gearbox. Progressive uprating of engine input power from 3600 to 4500 hp twin engine rating is allowed for in the design. In this way the test transmission will provide a base for several years of analytical, research, and component development effort targeted at improving the performance and reliability of helicopter transmission.

  17. Computer Modelling of a Tank Battle with Helicopter Support

    Directory of Open Access Journals (Sweden)

    Chatter Singh

    1986-01-01

    Full Text Available The paper attempts to model a tank versus tank battle scenario in which the defender is provided an armed helicopter unit support, against surprise advance of the attacker towards an important place. The stochastic and dynamic nature of the battle system has been handled by means of Monte Carlo simulation. In that activities like move, search, fire, hit and kill are simulated and their effects generated in the model. The game has been repeated for parameters relating to (i fire power (ii mobility (iii intervisibility (iv blind shooting (v defender/attacker force ratio and (vi helicopter unit support with the defender. Then, average numerical effects in each case have been analysed.Although the results are based on tentative data, the. trend seems to suggest that a battalion of Centurion tanks or 2 coys with a helicopter unit support stand fairly good chance to defeat the attack by M-47/48 tanks equivalent to 4 coys. Neyertheless, the methodology provides an effective basis to systematically approach realistic situations and quantitatively assess weapon systems effectiveness under tactical alternatives and battle field environments.

  18. Selected Problems Of Transmission Wear Of The Mi-24 Helicopter

    Directory of Open Access Journals (Sweden)

    Gębura Andrzej

    2015-12-01

    Full Text Available The hypothesis of mutual, destructive impact of the worn upper bearing of the WR-24 transmission on the Mi-24 helicopter's gearbox was stated. The Mi-24 is the only helicopter operated in Poland, in which the gearbox is mounted outside the main transmission – in the centre of the transmission shaft, between the main gearbox and the tail rotor. Damage to the gears in the gearbox of power generators is equivalent to termination of the tail rotor's drive. Such a termination immediately causes rotation of the body in the direction opposite to the direction of rotation of the main rotor. It is associated with the loss of lift and steering. It may lead to a disaster. Such an incident occurred in January 2011 in Afghanistan – both authors participated in its investigation. The authors, taking into account very good, almost legendary combat properties of the Mi-24, and their research of the specifics of wear and tear of the transmission elements, they think that, first, funds for development and implementation of the drive unit monitoring system should be made available specially for this helicopter. For this purpose, the authors propose to use the FAM-C method. It is characterised with significant ergonomics. Thank to this, multiple kinematic pairs can be observed simultaneously, and, therefore, the relationships between them as well.

  19. Preliminary vibration survey of a suspended full-scale OH-6A helicopter from 0 to 45 HZ

    OpenAIRE

    Harris, John H.

    1996-01-01

    Approved for public release, distribution is unlimited Efforts to establish a helicopter research program in structural dynamics at NPS were greatly enhanced when the U. S. Army donated two OH-6A light observation helicopters. One of the helicopters is reserved for ground vibration testing and dynamics research. Vibration measurements are extremely important in predicting and understanding an aircraft's dynamic behavior and durability. A comparison of a helicopters natural frequencies and ...

  20. A helicopter that flaps its wings: the Ornicopter flaps its wings like a bird to get into the air

    NARCIS (Netherlands)

    Mols, B.

    2003-01-01

    No other type of aircraft is as manoeuvrable as a helicopter. Reverse in full flight, rotate in the air, hover at a standstill, the helicopter can do it all. The police, fire services, medical services, military and civil aviation all use the helicopter for the freedom of flight it offers. However,

  1. 75 FR 48617 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 C-2 Helicopters

    Science.gov (United States)

    2010-08-11

    ... vibration, and subsequent loss of control of the helicopter. Actions and Compliance (e) Before further... Deutschland GmbH (ECD) Model MBB-BK 117 C-2 Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... directive (AD) for ECD Model MBB-BK 117 C-2 helicopters. This proposed AD results from a...

  2. 75 FR 66657 - Airworthiness Directives; Eurocopter Deutschland GmbH Model MBB-BK 117 C-2 Helicopters

    Science.gov (United States)

    2010-10-29

    ... separation of dynamic weights, severe vibration, and subsequent loss of control of the helicopter. Actions... Deutschland GmbH Model MBB- BK 117 C-2 Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Final... Deutschland GmbH (ECD) Model MBB BK 117 C-2 helicopters. This amendment results from a mandatory...

  3. [Pinworm infestation of the appendix].

    Science.gov (United States)

    Di Marco, L; Berghenti, M; Cocuzza, C; Manfredini, A; Sciascia, V; Salmi, R

    2006-01-01

    The Authors present 2 cases of enterobiasis of appendix observed on a total of 186 appendicectomies. Enterobius infestation is an uncommon cause of acute appendicitis. Preoperative diagnosis of pinworm infestation is almost impossible without clinical suspect. Parasites may produce symptoms which resemble acute appendicitis but parasitic infection rarely causes it. It is also important considered in the differential diagnosis cases that mimic Crohn's disease.

  4. 29 CFR Appendix B to Part 1 - Appendix B to Part 1

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Appendix B to Part 1 B Appendix B to Part 1 Labor Office of the Secretary of Labor PROCEDURES FOR PREDETERMINATION OF WAGE RATES Pt. 1, App. B Appendix B to Part... Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah and Wyoming: Regional Administrator, Wage and...

  5. 43 CFR Appendix A to Subpart A of... - Appendix A to Subpart A of Part 17

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Appendix A to Subpart A of Part 17 A Appendix A to Subpart A of Part 17 Public Lands: Interior Office of the Secretary of the Interior... Race, Color, or National Origin Pt. 17, Subpt. A, App. A Appendix A to Subpart A of Part 17...

  6. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Science.gov (United States)

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2 to... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and...

  7. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Science.gov (United States)

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1 to... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and...

  8. The design, construction and operation of the helicopter underwater escape trainer

    Energy Technology Data Exchange (ETDEWEB)

    Urguhart, A.E.

    1983-09-01

    Civil helicopters hopefully are not likely to be subjected to the possibility of being shot from the skies and descending in an uncontrolled manner. Should a civil helicopter have to ditch, due to some mechanical or electrical failure, it is reasonable to predict that it may do so in a controlled manner, with the pilot either taking the positive decision to ditch the helicopter, or being forced to do so. It is for such controlled or nearly controlled ditchings that training of personnel should be considered. The air-crews involved in flying civil helicopters are not dissimilar to military service personnel, in that they are a disciplined group of professionals qualified and experienced in their business of flying and ditching. However, the offshore worker, being ferried to his place of work, is, in essence, the human cargo forced by necessity to be transported by helicopter. Many offshore employees may not wish to be, or particularly enjoy, being transported over the North Sea by helicopter nevertheless, it is the only viable mode of transport and, with the number of helicopter flights which are currently being undertaken to and from the North Sea installations, it is not being over-pessimistic to foresee the likelihood of a civil helicopter with passengers having to ditch in the sea.

  9. FlyTact : A tactile display improves a helicopter pilot's landing performance in degraded visual environments

    NARCIS (Netherlands)

    Jansen, C.; Wennemers, A.S.; Vos, W.K.; Groen, E.L.

    2008-01-01

    Helicopter landings are more challenging in 'brownout' conditions, in which sand and dust is stirred up by the rotary wing aircraft, obscuring visibility. Safe brownout landings require new sensor and display technologies to provide the pilot with information on helicopter motion. In this respect ta

  10. 78 FR 65163 - Airworthiness Directives; Sikorsky Aircraft Corporation-Manufactured (Sikorsky) Model Helicopters...

    Science.gov (United States)

    2013-10-31

    ... Corporation- Manufactured (Sikorsky) Model Helicopters (Type Certificate Currently Held by Erickson Air-Crane... helicopters (type certificate currently held by Erickson Air-Crane Incorporated (Erickson)). AD 97-19-10..., contact Erickson Air-Crane Incorporated, ATTN: Chris Erickson, Director of Regulatory Compliance, 3100...

  11. 78 FR 31863 - Airworthiness Directives; Sikorsky Aircraft Corporation-Manufactured (Sikorsky) Model Helicopters...

    Science.gov (United States)

    2013-05-28

    ... Corporation- Manufactured (Sikorsky) Model Helicopters (type certificate currently held by Erickson Air-Crane... Corporation-manufactured Model S-64E helicopters (type certificate currently held by Erickson Air-Crane Incorporated (Erickson)). That AD currently requires inspecting and reworking the main gearbox (MGB) assembly...

  12. 78 FR 40063 - Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters (Type Certificate...

    Science.gov (United States)

    2013-07-03

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Erickson Air-Crane... helicopter has been transferred to Erickson Air-Crane Incorporated (Erickson), and expand the applicability to include the similar Erickson Model S-64F helicopters. This proposed AD is prompted by a need to...

  13. 78 FR 15599 - Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S-64F Helicopters

    Science.gov (United States)

    2013-03-12

    ... Model S-64F helicopters, now under the Erickson Air-Crane Incorporated (Erickson) Model S-64F type... service information identified in this AD, contact Erickson Air-Crane Incorporated, ATTN: Chris Erickson... Model S-64F helicopters, now under the Erickson Air-Crane Incorporated Model S-64F type certificate...

  14. Merged Vision and GPS Control of a Semi-Autonomous, Small Helicopter

    Science.gov (United States)

    Rock, Stephen M.

    1999-01-01

    This final report documents the activities performed during the research period from April 1, 1996 to September 30, 1997. It contains three papers: Carrier Phase GPS and Computer Vision for Control of an Autonomous Helicopter; A Contestant in the 1997 International Aerospace Robotics Laboratory Stanford University; and Combined CDGPS and Vision-Based Control of a Small Autonomous Helicopter.

  15. World’s smallest helicopter to fly in da Vinci birthplace

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The world’s smallest one-man helicopter will soon take flight in the birthplace of Leonardo da Vinci, who is credited with having first thought of a vertical-flight machine, its developer said.The 75-kilogram helicopter will make a demonstration flight in the city of Vinci, near Florence, on May 25, according to

  16. Development, documentation and correlation of a NASTRAN vibration model of the AH-1G helicopter airframe

    Science.gov (United States)

    Cronkhite, J. D.

    1976-01-01

    NASTRAN was evaluated for vibration analysis of the helicopter airframe. The first effort involved development of a NASTRAN model of the AH-1G helicopter airframe and comprehensive documentation of the model. The next effort was to assess the validity of the NASTRAN model by comparisons with static and vibration tests.

  17. [Physiokinetic therapy in the prevention of cervical disk arthrosis in helicopter personnel].

    Science.gov (United States)

    Lanciani, P; La Verde, R; Losani, F; Guicciardi, M

    1983-08-25

    Helicopter pilots subjected to "chronic microtraumatism" related to the constant vibration present in this type of aircraft are considered. The most suitable physiokinetic treatment in the prevention of cervical spondylodiscarthrosis is discussed. Spondylodiscarthrosis is the most common and debilitating problem affecting helicopter personnel.

  18. Design of a Helicopter Stability and Control Augmentation System Using Optimal Control Theory.

    Science.gov (United States)

    technique is described for the design of multivariable feedback controllers based upon results in optimal control theory . For a specified performance...helicopter flight envelope. The results show that optimal control theory can be used to design a helicopter stability and control augmentation system

  19. 77 FR 52270 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2012-08-29

    ... helicopter to rework the top cable-cutter assembly, one work- hour to replace the top cable-cutter assembly... estimate the cost of the proposed AD on U.S. operators would be $255 per helicopter to rework the top cable... upper installation, P/N 4G9540A00111, either: (i) Rework the top cable cutter assembly, P/N...

  20. 76 FR 35334 - Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A, 205A-1, 205B, 212, 412, 412CF...

    Science.gov (United States)

    2011-06-17

    ... directive (AD) for the specified Bell Helicopter Textron, Inc. (BHT) model helicopters with tail rotor (T R.... SUPPLEMENTARY INFORMATION: This amendment adopts a new AD for the specified BHT model helicopters with an... blade, and subsequent loss of control of the helicopter. We have reviewed the following BHT Alert...

  1. Selected topics on the active control of helicopter aeromechanical and vibration problems

    Science.gov (United States)

    Friedmann, Peretz P.

    1994-01-01

    This paper describes in a concise manner three selected topics on the active control of helicopter aeromechanical and vibration problems. The three topics are as follows: (1) the active control of helicopter air-resonance using an LQG/LTR approach; (2) simulation of higher harmonic control (HHC) applied to a four bladed hingeless helicopter rotor in forward flight; and (3) vibration suppression in forward flight on a hingeless helicopter rotor using an actively controlled, partial span, trailing edge flap, which is mounted on the blade. Only a few selected illustrative results are presented. The results obtained clearly indicate that the partial span, actively controlled flap has considerable potential for vibration reduction in helicopter rotors.

  2. Quad-Rotor Helicopter Autonomous Navigation Based on Vanishing Point Algorithm

    Directory of Open Access Journals (Sweden)

    Jialiang Wang

    2014-01-01

    Full Text Available Quad-rotor helicopter is becoming popular increasingly as they can well implement many flight missions in more challenging environments, with lower risk of damaging itself and its surroundings. They are employed in many applications, from military operations to civilian tasks. Quad-rotor helicopter autonomous navigation based on the vanishing point fast estimation (VPFE algorithm using clustering principle is implemented in this paper. For images collected by the camera of quad-rotor helicopter, the system executes the process of preprocessing of image, deleting noise interference, edge extracting using Canny operator, and extracting straight lines by randomized hough transformation (RHT method. Then system obtains the position of vanishing point and regards it as destination point and finally controls the autonomous navigation of the quad-rotor helicopter by continuous modification according to the calculated navigation error. The experimental results show that the quad-rotor helicopter can implement the destination navigation well in the indoor environment.

  3. Light Observation Helicopter Acquisition, a Historical Case Study

    Science.gov (United States)

    1974-11-01

    ANALiSIS ............................... 14 APPENDIX I: NEGOTIATION .............................. 22 &PPENDIX II: DOD COtd.JENTS...to avoid conflicts of interest, close personal relation- ships between the Army and Industry representatives resulted in departures from established...procurement procedures and placed the Army in a position of having its’ decisions sus- pect. The pertinent message was: Whether a person who accepts

  4. Optimal flight of a helicopter in engine failure

    Science.gov (United States)

    Jhemi, Ali Abdelmajid

    This thesis studies optimal category-A helicopter flight operations in the event of one engine failure. Both Continued Takeoff (CTO) and Rejected Takeoff (RTO) operations are studied. A two-dimensional point mass model has been used to study CTO and RTO from an elevated heliport. In this model, the main rotor and tail rotor dynamics are modeled to better predict the power required during flight. A first order dynamic of the One Engine Inoperative (OEI) contingency power is considered. Flights after engine failure are formulated as nonlinear optimal control problems. For studying optimal strategies, the performance index is selected in a way that reflects the main parameters to be optimized. Problems are formulated to minimize heliport size, subject to helicopter equations. In addition to the equations of motion, state and control constraints, FAA regulations are enforced. FAA regulations are enforced during CTO, while safety considerations are enforced during RTO. These optimal control problems are solved numerically using a direct approach. States, controls, and helicopter constant parameters are parameterized, and a collocation method is employed. The cost function and path constraints are enforced as algebraic equations at the nodes, while the differential constraints are enforced by integrating the equations of motion in between nodes using Simpson's one third rule. The problem is then fed to a nonlinear programming routine to solve for all parameters. Extensive optimization of CTO and RTO problems are conducted, and results are computed, plotted, and interpreted physically. A balanced weight concept is concluded. The balanced weight concept is similar to the balanced field-length concept in field takeoff.

  5. Model Predictive Control for a Small Scale Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Jianfu Du

    2008-11-01

    Full Text Available Kinematical and dynamical equations of a small scale unmanned helicoper are presented in the paper. Based on these equations a model predictive control (MPC method is proposed for controlling the helicopter. This novel method allows the direct accounting for the existing time delays which are used to model the dynamics of actuators and aerodynamics of the main rotor. Also the limits of the actuators are taken into the considerations during the controller design. The proposed control algorithm was verified in real flight experiments where good perfomance was shown in postion control mode.

  6. Reporting Helicopter Emergency Medical Services in Major Incidents

    DEFF Research Database (Denmark)

    Fattah, Sabina; Johnsen, Anne Siri; Sollid, Stephen J M

    2016-01-01

    OBJECTIVE: Research on helicopter emergency medical services (HEMS) in major incidents is predominately based on case descriptions reported in a heterogeneous fashion. Uniform data reported with a consensus-based template could facilitate the collection, analysis, and exchange of experiences...... interacted through e-mail. We asked these experts to define data variables and rank which were most important to report during an immediate prehospital medical response to a major incident. Five rounds were conducted. RESULTS: In the first round, the experts suggested 98 variables. After 5 rounds, 21...

  7. Helicopter rotor loads using matched asymptotic expansions: User's manual

    Science.gov (United States)

    Pierce, G. A.; Vaidyanathan, A. R.

    1983-01-01

    Computer programs were developed to implement the computational scheme arising from Van Holten's asymptotic method for calculating airloads on a helicopter rotor blade in forward flight, and a similar technique which is based on a discretized version of the method. The basic outlines of the two programs are presented, followed by separate descriptions of the input requirements and output format. Two examples illustrating job entry with appropriate input data and corresponding output are included. Appendices contain a sample table of lift coefficient data for the NACA 0012 air foil and listings of the two programs.

  8. Validation of Comprehensive Helicopter Aeroelastic Analysis with Experimental Data

    Directory of Open Access Journals (Sweden)

    Shrinivas R. Bhat

    2004-10-01

    Full Text Available The experimental data for a Cbladed soft-inplane hingeless main rotor is used to validate a comprehensive aeroelastic analysis. A finite element model has been developed for the rotorblade which predicts rotating frequencies quite well, across a range of rotation speeds. The helicopter is trimmed and the predicted trim-control angles are found to be In the range ofmeasured values for a variety of flight speeds. Power predictions over a range of forward speeds also compare well. Finally, the aeroelastlc analysis is used to study the Importance ofaerodynamic models on the vibration predict~onU. nsteady aerodynamics and free-wake models have been investigated.

  9. Prospects for Eulerian CFD analysis of helicopter vortex flows

    Science.gov (United States)

    Drela, Mark; Murman, Earll M.

    1987-01-01

    The applicability of current finite-volume CFD algorithms based on the Euler equations to the vortex flow over a helicopter in forward flight is investigated analytically. The general characteristics of the flow are reviewed; existing Euler, Navier-Stokes, perturbation, high-order, and adaptive methods are briefly characterized; and a novel Eulerian/Lagrangian approach with entropy and vorticity corrections is presented in detail. Numerical results for simple convection of a finite-core Lamb vortex moving downstream with its axis perpendicular to the flow are presented in graphs, and the possibility of extending the method to three-dimensional, viscous, and shock flows is discussed.

  10. Condition Monitoring of Helicopter Gearboxes by Embedded Sensing

    Science.gov (United States)

    Suryavanashi, Abhijit; Wang, Shengda; Gao, Robert; Danai, Kourosh; Lewicki, David G.

    2002-01-01

    Health of helicopter gearboxes is commonly assessed by monitoring the housing vibration, thus it is challenged by poor signal-to-noise ratio of the signal measured away from the source. It is hypothesized that vibration measurements from sensors placed inside the gearbox will be much clearer indicators of faults and will eliminate many of the difficulties faced by present condition monitoring systems. This paper outlines our approach to devising such a monitoring system. Several tasks have been outlined toward this objective and the strategy to address each has been described. Among the tasks are wireless sensor design, antenna design, and selection of sensor locations.

  11. Cost-Effective Helicopter Options for Partner Nations

    Science.gov (United States)

    2015-01-01

    elevation feature MGTOW maximum gross takeoff weight MOB main operating base MoD Ministry of Defense MoI Ministry of Interior nm nautical miles NSRW...we provided a main operat- ing base ( MOB ) or forward operating base (FOB) from which operations would be conducted. In these instances, the...RAND RR141z1-2.2 MOB /FOB MOB /FOB X Y Z LZs Alternate LZs 23 nmPrimary LZ Bor der Bor der 120º 120º 10 Cost-Effective Helicopter Options for Partner

  12. A subjective field study of helicopter blade-slap noise

    Science.gov (United States)

    Powell, C. A.

    1978-01-01

    The effects of impulsiveness on the noisiness of helicopters are examined by varying the main rotor speed while maintaining a constant airspeed. This resulted in other characteristics of the noise being held relatively constant. Other controlled variables included altitude, side line distance, descent operations, and level flyovers. A description is provided of the concept, experimental design and procedures along with results based on partial analyses of acoustic and subjective response data. No significant improvement in the noisiness predictive ability of EPNL was provided by either proposed or an A-weighted crest factor correction for impulsiveness.

  13. Mucinous adenocarcinona of the appendix

    Directory of Open Access Journals (Sweden)

    Milton Roberto Furst Crenitte

    2013-06-01

    Full Text Available Diagnosis of malignancy in the vermiform appendix is quite rare. The most common histological malignant neoplasia found in this tiny portion of the gastrointestinal tract is represented by the mucinous adenocarcinoma. This entity predominates in males around 50 years of age, and clinical presentation usually mimics or occurs along with an acute appendicitis. Early diagnosis is outside the rule since most cases at this stage are symptomless. The authors present the case of a 59-year-old female patient who looked for medical attention complaining of abdominal pain. Physical examination and laboratory workup were poor in diagnostic findings. The computed tomography images were compatible with the diagnosis of appendicitis and/or appendiceal neoplasia. The patient underwent a laparotomy and right hemicolectomy. The histological examination disclosed a moderately differentiated mucinous adenocarcinoma of the appendix stage T4a, N0, M0. The patient outcome was uneventful and was referred to an oncological center.

  14. A case of a horseshoe appendix.

    Science.gov (United States)

    Takabatake, Kazuya; Ikeda, Jun; Furuke, Hirotaka; Kato, Chikage; Kishimoto, Takuya; Kumano, Tatsuya; Imura, Kenichiro; Shimomura, Katsumi; Kubota, Takeshi; Taniguchi, Fumihiro; Shioaki, Yasuhiro

    2016-12-01

    Anomalies of the appendix are extremely rare, and a horseshoe appendix is even rarer. A literature search has revealed only five reported cases. In this report, we present a case of a horseshoe appendix.A 78-year-old man was referred for further examination following a positive fecal occult blood test. A mass in his ascending colon was detected on colonoscopy, while computed tomography showed that it was connected to the appendix. Tumor invasion derived from the ascending colon or appendix was suspected. We diagnosed ascending colon cancer prior to laparoscopic ileocecal resection. Macroscopic findings showed that the appendix connected to the back side of the mass, while microscopic findings showed that the mucosa and submucosa were continuous from the appendiceal orifice in the cecum to the other orifice in the ascending colon, where a type 1 tumor was observed on the orifice. We eventually diagnosed the patient with tubulovillous adenoma and a horseshoe appendix.A horseshoe appendix communicates with the colon at both ends and is supplied by a single fan-shaped mesentery. Cases are classified by the disposal of the mesentery and the location of the orifice. Anatomical anomalies should be considered despite the rarity of horseshoe appendices.

  15. Comparison of induced velocity models for helicopter flight mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.E.; Houston, S.S.

    2002-07-01

    Modeling of rotor-induced velocity receives continued attention in the literature as the rotorcraft community addresses limitations in the fidelity of simulations of helicopter stability, control, and handling qualities. A comparison is presented of results obtained using a rigid-blade rotor-fuselage model configured with two induced velocity models: a conventional, first-order, finite state, dynamic inflow model and a wake model that solves a vorticity transport equation on a computational mesh enclosing the rotorcraft. Differences between the two models are quantified by comparing predictions of trimmed rotor blade flap, lag and feather angles, airframe pitch and roll attitudes, cross-coupling derivatives, response to control inputs, and airframe vibration. Results are presented in the context of measurements taken on a Puma aircraft in steady flight from hover to high speed. More accurate predictions of the cross-coupling derivatives, response to control, and airframe vibration obtained using the vorticity transport model suggest that incorporation of real flowfield effects is important to extending the bandwidth of applicability of helicopter simulation models. Unexpectedly small differences in some of the trim predictions obtained using the two wake models suggest that an overall improvement in simulation fidelity may not be achieved without equivalent attention to the rotor dynamic model. (Author)

  16. Overview: Applications of numerical optimization methods to helicopter design problems

    Science.gov (United States)

    Miura, H.

    1984-01-01

    There are a number of helicopter design problems that are well suited to applications of numerical design optimization techniques. Adequate implementation of this technology will provide high pay-offs. There are a number of numerical optimization programs available, and there are many excellent response/performance analysis programs developed or being developed. But integration of these programs in a form that is usable in the design phase should be recognized as important. It is also necessary to attract the attention of engineers engaged in the development of analysis capabilities and to make them aware that analysis capabilities are much more powerful if integrated into design oriented codes. Frequently, the shortcoming of analysis capabilities are revealed by coupling them with an optimization code. Most of the published work has addressed problems in preliminary system design, rotor system/blade design or airframe design. Very few published results were found in acoustics, aerodynamics and control system design. Currently major efforts are focused on vibration reduction, and aerodynamics/acoustics applications appear to be growing fast. The development of a computer program system to integrate the multiple disciplines required in helicopter design with numerical optimization technique is needed. Activities in Britain, Germany and Poland are identified, but no published results from France, Italy, the USSR or Japan were found.

  17. Numerical Simulation of Helicopter Cockpit Seat subjected to Crash Impact

    Directory of Open Access Journals (Sweden)

    M.N. Sulaiman

    2013-01-01

    Full Text Available Sikorsky S-61 or better known as “Nuri” had served the Malaysian aviation sector for the past four decades. It is mainly used for transportation, combat search and rescue purposes. However, there were Nuri helicopter crashes or accident cases reported during its operation period which involved loss of its occupants. The pilot survivability rate can be improved provided that the vertical impact loading on the helicopter is reduced during the crash accident. Utilization of an energy absorbing pilot seat or cockpit structure maybe one of the approaches to minimize the impact shock exerted to the occupants. However, the shock or maximum acceleration of the cockpit/pilot seat has to be first determined before a thorough design scheme can be undertaken. In this study, a vertical crash event of the Nuri pilot seat from 500 feet altitude was simulated and the maximum acceleration rate was determined using MSC PATRAN/LSDYNA. The pilot survivability was determined by comparing the result with human tolerance criteria data available in other published works. From the result, it was found that the maximum acceleration of the Nuri pilot seat was 584.4g at 19. 63 milliseconds, thus it can be concluded that the survivability aspect of the pilot is fatal when compared to other published works.

  18. Measures for simulator evaluation of a helicopter obstacle avoidance system

    Science.gov (United States)

    Demaio, Joe; Sharkey, Thomas J.; Kennedy, David; Hughes, Micheal; Meade, Perry

    1993-01-01

    The U.S. Army Aeroflightdynamics Directorate (AFDD) has developed a high-fidelity, full-mission simulation facility for the demonstration and evaluation of advanced helicopter mission equipment. The Crew Station Research and Development Facility (CSRDF) provides the capability to conduct one- or two-crew full-mission simulations in a state-of-the-art helicopter simulator. The CSRDF provides a realistic, full field-of-regard visual environment with simulation of state-of-the-art weapons, sensors, and flight control systems. We are using the CSRDF to evaluate the ability of an obstacle avoidance system (OASYS) to support low altitude flight in cluttered terrain using night vision goggles (NVG). The OASYS uses a laser radar to locate obstacles to safe flight in the aircraft's flight path. A major concern is the detection of wires, which can be difficult to see with NVG, but other obstacles--such as trees, poles or the ground--are also a concern. The OASYS symbology is presented to the pilot on a head-up display mounted on the NVG (NVG-HUD). The NVG-HUD presents head-stabilized symbology to the pilot while allowing him to view the image intensified, out-the-window scene through the HUD. Since interference with viewing through the display is a major concern, OASYS symbology must be designed to present usable obstacle clearance information with a minimum of clutter.

  19. An analytically linearized helicopter model with improved modeling accuracy

    Science.gov (United States)

    Jensen, Patrick T.; Curtiss, H. C., Jr.; Mckillip, Robert M., Jr.

    1991-01-01

    An analytically linearized model for helicopter flight response including rotor blade dynamics and dynamic inflow, that was recently developed, was studied with the objective of increasing the understanding, the ease of use, and the accuracy of the model. The mathematical model is described along with a description of the UH-60A Black Hawk helicopter and flight test used to validate the model. To aid in utilization of the model for sensitivity analysis, a new, faster, and more efficient implementation of the model was developed. It is shown that several errors in the mathematical modeling of the system caused a reduction in accuracy. These errors in rotor force resolution, trim force and moment calculation, and rotor inertia terms were corrected along with improvements to the programming style and documentation. Use of a trim input file to drive the model is examined. Trim file errors in blade twist, control input phase angle, coning and lag angles, main and tail rotor pitch, and uniform induced velocity, were corrected. Finally, through direct comparison of the original and corrected model responses to flight test data, the effect of the corrections on overall model output is shown.

  20. Dynamic analysis of multimesh-gear helicopter transmissions

    Science.gov (United States)

    Choy, Fred K.; Townsend, Dennis P.; Oswald, Fred B.

    1988-01-01

    A dynamic analysis of multimesh-gear helicopter transmission systems was performed by correlating analytical simulations with experimental investigations. The two computer programs used in this study, GRDYNMLT and PGT, were developed under NASA/Army sponsorship. Parametric studies of the numerical model with variations on mesh damping ratios, operating speeds, tip-relief tooth modifications, and tooth-spacing errors were performed to investigate the accuracy, application, and limitations of the two computer programs. Although similar levels of dynamic loading were predicted by both programs, the computer code GRDYNMLT was found to be superior and broader in scope. Results from analytical work were also compared with experimental data obtained from the U.S. Army's UH-60A Black Hawk 2240-kW (3000-hp) class, twin-engine helicopter transmission tested at the NASA Lewis Research Center. Good correlation in gear stresses was obtained between the analytical model simulated by GRDYNMLT and the experimental measurements. More realistic mesh damping can be predicted through experimental data correlation.

  1. Helicopter Scene Response for Stroke Patients: A 5-Year Experience.

    Science.gov (United States)

    Hawk, Andrew; Marco, Catherine; Huang, Matt; Chow, Bonnie

    The purpose of this study was to examine the usefulness of an emergency medical service (EMS)-requested air medical helicopter response directly to the scene for a patient with clinical evidence of an ischemic cerebrovascular accident (CVA) and transport to a regional comprehensive CVA center. CareFlight, an air medical critical care transportation service, is based in Dayton, OH. The 3 CareFlight helicopters are geographically located and provided transport to all CVA scene patients in this study. A retrospective chart review was completed for all CareFlight CVA scene flights for 5 years (2011-2015). A total of 136 adult patients were transported. EMS criteria included CVA symptom presence for less than 3 hours or awoke abnormal, nonhypoglycemia, and a significantly positive Cincinnati Prehospital Stroke Scale. The majority of patients (75%) met all 3 EMS CVA scene criteria; 27.5% of these patients received peripheral tissue plasminogen activator, and 9.8% underwent a neurointerventional procedure. Using a 3-step EMS triage for acute CVA, air medical transport from the scene to a comprehensive stroke center allowed for the timely administration of tissue plasminogen activator and/or a neurointerventional procedure in a substantive percentage of patients. Further investigation into air medical scene response for acute stroke is warranted. Copyright © 2016 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  2. Mortality following helicopter versus ground transport of injured children.

    Science.gov (United States)

    Polites, Stephanie F; Zielinski, Martin D; Fahy, Aodhnait S; Wagie, Amy E; Moir, Christopher R; Jenkins, Donald H; Zietlow, Scott P; Habermann, Elizabeth B

    2017-05-01

    Injured children may be transported to trauma centers by helicopter air ambulance (HAA); however, a benefit in outcomes to this expensive resource has not been consistently shown in the literature and there is concern that HAA is over-utilized. A study that adequately controls for selection biases in transport mode is needed to determine which injured children benefit from HAA. The purpose of this study was to determine if HAA impacts mortality differently in minimally and severely injured children and if there are predictors of over-triage of HAA in children that can be identified. Children ≤18 years of age transported by HAA or ground ambulance (GA) from scene to a trauma center were identified from the 2010-2011 National Trauma Data Bank. Analysis was stratified by Injury Severity Score (ISS) into low ISS (≤15) and high ISS (>15) groups. Following propensity score matching of HAA to GA patients, conditional multivariable logistic regression was performed to determine if transport mode independently impacted mortality in each stratum. Rates and predictors of over-triage of HAA were also determined. Transport by HAA occurred in 8218 children (5574 low ISS, 2644 high ISS) and by GA in 35305 (30506 low ISS, 4799 high ISS). Overall mortality was greater in HAA patients (4.0 vs 1.4%, p15. Many children with minor injuries are transported by helicopter despite frequent dismissal within 24h and no mortality benefit. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Some thoughts on the implementation of pilot night vision devices for helicopters

    Science.gov (United States)

    Tucker, G. E.

    1984-01-01

    Night vision enhancement devices greatly expand the range and quality of services by extending night operational capabilities. Evolving military tactical concepts for helicopters survivability and battlefield effectiveness necessitate nap-of-the-earth (NOE) flying under both day and night conditions. From a pilot workload standpoint, flying a helicopter NOE in day VFR conditions with minimum clearance between rotors and obstacles is quite demanding. Doing the same job at night is several times more difficult. There are two general categories of night vision devices in operation in helicopter aviation: the Night Vision Goggles (NVG) and forward looking infrared (FLIR) system. The capabilities and limitations of those two devices are discussed.

  4. Optimization of helicopter airframe structures for vibration reduction considerations, formulations and applications

    Science.gov (United States)

    Murthy, T. Sreekanta

    1988-01-01

    Several key issues involved in the application of formal optimization technique to helicopter airframe structures for vibration reduction are addressed. Considerations which are important in the optimization of real airframe structures are discussed. Considerations necessary to establish relevant set of design variables, constraints and objectives which are appropriate to conceptual, preliminary, detailed design, ground and flight test phases of airframe design are discussed. A methodology is suggested for optimization of airframes in various phases of design. Optimization formulations that are unique to helicopter airframes are described and expressions for vibration related functions are derived. Using a recently developed computer code, the optimization of a Bell AH-1G helicopter airframe is demonstrated.

  5. Helicopter vibration and risk of reversible myopia among military air crews

    OpenAIRE

    Bastaman Basuki; T. Soemardoko

    2002-01-01

    We assessed to what extend the risk of reversible myopia of the different degree of helicopter vibrations and other risk factors among military helicopter pilots and flight engineers. The study was a nested case-control design using medical record at the Institute of Aerospace Medicine of the Indonesian Air Force and Medical Directorate of the Indonesian Army (Flying Wing). Cases and controls were military helicopter pilots and flight engineers who had ametropic visual acuity at the time of e...

  6. Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters

    Science.gov (United States)

    Karmali, M. S.; Phatak, A. V.

    1982-01-01

    Results of a study to investigate, by means of a computer simulation, the performance sensitivity of helicopter IMC DSAL operations as a function of navigation system parameters are presented. A mathematical model representing generically a navigation system is formulated. The scenario simulated consists of a straight in helicopter approach to landing along a 6 deg glideslope. The deceleration magnitude chosen is 03g. The navigation model parameters are varied and the statistics of the total system errors (TSE) computed. These statistics are used to determine the critical navigation system parameters that affect the performance of the closed-loop navigation, guidance and control system of a UH-1H helicopter.

  7. Cost optimizing of large-scale offshore wind farms. Appendix E to J. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This Volume 3 contains reports prepared by SEAS Distribution A.m.b.A. and partly by Risoe National Laboratory. Appendix E: Grid connection. Appendix F: Review of potential offshore sites. Appendix G: Optimisation of wind farm layout. Appendix G.1: Evaluation of Power Production from Three Offshore Wind Farms. Appendix H: Investments, operation and maintenance costs. Appendix I: Authority approvals and environmental investigations. Appendix J: Outline description of demonstration project. Appendix G.1 has been prepared by Risoe National Laboratory. (au)

  8. Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight.

    Science.gov (United States)

    Murray, Mike; Lange, Britt; Chreiteh, Shadi Samir; Olsen, Henrik Baare; Nørnberg, Bo Riebeling; Boyle, Eleanor; Søgaard, Karen; Sjøgaard, Gisela

    2016-04-01

    Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB) and performing search and rescue (SAR). SAR was performed with Night Vision Goggles (NVG), while AB was performed with (AB+NVG) and without NVG (AB-NVG). EMG was recorded for: trapezius (TRA), upper neck extensors (UNE), and sternocleido-mastoid (SCM). Maximal voluntary contractions (MVC) were performed for normalization of EMG (MVE). Neck posture of pilots and crew-members was monitored and pain intensity of neck, shoulder, and back was recorded. Mean muscle activity for UNE was ∼10% MVE and significantly higher than TRA and SCM, and SCM was significantly lower than TRA. There was no significant difference between AB-NVG and AB+NVG. Muscle activity in the UNE was significantly higher during SAR+NVG than AB-NVG. Sortie time (%) with non-neutral neck posture for SAR+NVG and AB-NVG was: 80.4%, 74.5% (flexed), 55.5%, 47.9% (rotated), 4.5%, 3.7% (lateral flexed). Neck pain intensity increased significantly from pre- (0.7±1.3) to post-sortie (1.6±1.9) for pilots (p=0.028). If sustained, UNE activity of ∼10% MVE is high, and implies a risk for neck disorders.

  9. Final assessment of vibro-acoustic source strength descriptors of helicopter gearboxes

    DEFF Research Database (Denmark)

    Ohlrich, Mogens; Rasmussen, Ulrik Møller

    1996-01-01

    Two novel measurement techniques have been developed for quantifying the vibro-aqcoustic source strength of lightweight helicopter gearboxes. The accuracy, robustness and implementation of these methods have been examined by a comprehensive investigation, including theoretical studies of simple...... multi-modal beam systems and extensive experiments with more realistic small scale models and with large, detailed 3/4-scale test structures of a medium-size helicopter. In addition, partial verification tests have been conducted with the Eurocopter BK 117 helicopter and its main rotor gearbox....... The results of this work are essential as input for any prediction code of the internal noise in a helicopter cabin, because the prediction requires knowledge of the major sources, that is, the rotors, engines and gearboxes....

  10. Time domain System Identification of Longitudinal Dynamics of Single Rotor Model Helicopter using SIDPAC

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2015-01-01

    Full Text Available This paper presents a time-domain approach for identification of longitudinal dynamics of single rotor model helicopter. A frequency sweep excitation input signal is applied for hover flying mode widely used for space state linearized model. A fully automated programmed flight test method provides high quality flight data for system identification using the computer controlled flight simulator X-plane©. The flight test data were recorded, analyzed and reduced using the SIDPAC (System Identification Programs for Air Craft toolbox for MATLAB, resulting in an aerodynamic model of single rotor helicopter. Finally, the identified model of single rotor helicopter is validated on Raptor 30-class model helicopter at hover showing the reliability of proposed approach

  11. Maximizing commonality between military and general aviation fly-by-light helicopter system designs

    Science.gov (United States)

    Enns, Russell; Mossman, David C.

    1995-05-01

    In the face of shrinking defense budgets, survival of the United States rotorcraft industry is becoming increasingly dependent on increased sales in a highly competitive civil helicopter market. As a result, only the most competitive rotorcraft manufacturers are likely to survive. A key ingredient in improving our competitive position is the ability to produce more versatile, high performance, high quality, and low cost of ownership helicopters. Fiber optic technology offers a path of achieving these objectives. Also, adopting common components and architectures for different helicopter models (while maintaining each models' uniqueness) will further decrease design and production costs. Funds saved (or generated) by exploiting this commonality can be applied to R&D used to further improve the product. In this paper, we define a fiber optics based avionics architecture which provides the pilot a fly-by-light / digital flight control system which can be implemented in both civilian and military helicopters. We then discuss the advantages of such an architecture.

  12. 58th SOW Low-Dust Helicopter Landing Zone Final Environmental Assessment

    Science.gov (United States)

    2012-11-01

    Gases HLZ Helicopter Landing Zone IICEP Interagency and Intergovernmental Coordination for Environmental Planning IFR Instrument Flight Rule IR...to Instrument Flight Rule ( IFR ) flights and to VFR flights in accordance with the airspace classification (FAA 2008). Controlled airspace is

  13. Maximum acceptable inherent buoyancy limit for aircrew/passenger helicopter immersion suit systems.

    Science.gov (United States)

    Brooks, C J

    1988-12-01

    Helicopter crew and passengers flying over cold water wear immersion suits to provide hypothermic protection in case of ditching in cold water. The suits and linings have trapped air in the material to provide the necessary insulation and are thus very buoyant. By paradox, this buoyancy may be too much for a survivor to overcome in escaping from the cabin of a rapidly sinking inverted helicopter. The Canadian General Standard Board requested that research be conducted to investigate what should be the maximum inherent buoyancy in an immersion suit that would not inhibit escape, yet would provide adequate thermal insulation. This experiment reports on 12 subjects who safely escaped with 146N (33 lbf) of added buoyancy from a helicopter underwater escape trainer. It discusses the logic for and recommendation that the inherent buoyancy in a helicopter crew/passenger immersion suit system should not exceed this figure.

  14. Direct CFD Predictions of Low Frequency Sounds Generated by Helicopter Main Rotors

    Science.gov (United States)

    Sim, Ben W.; Potsdam, Mark; Conner, Dave; Watts, Michael E.

    2010-01-01

    This proposed paper will highlight the application of a CSD/CFD methodology currently inuse by the US Army Aerfolightdynamics Directorate (AFDD) to assess the feasibility and fidelity of directly predicting low frequency sounds of helicopter rotors.

  15. Fully controlled helicopter for 3D-reconstruction of buildings and survey applications

    Science.gov (United States)

    Lehmann, Raimund; Staiger, Stefan; Schröder, Werner

    2011-05-01

    At the Hochschule Offenburg, a fully controlled helicopter has been developed, which is very easy to fly by anybody and can be flown very close to objects. The flight control system consists of an attitude and heading reference system, an inertial navigator augmented by GPS and a flight control computer. The electrically driven helicopter can easily carry payloads of more than 1 kg. With this helicopter high resolution pictures were taken from parts of the Freiburg cathedral. Also pictures with a calibrated camera of terrain have been taken. Pictures were paired and using a commercial software, a 3D-model of a part of the top of the "Hahnenturm" of the Freiburg cathedral has been generated. The terrain pictures have been bundled and used to precisely measure the position of certain objects in the terrain. The first results of these trials are very promising in respect to future applications of the helicopter.

  16. Helicopter parameter extraction using joint Time-Frequency and Tomographic Techniques

    CSIR Research Space (South Africa)

    Cilliers, A

    2008-09-01

    Full Text Available A technique based on time-frequency and tomographic analysis to extract helicopter blade parameters for the purposes of radar non-cooperative target recognition (NCTR) is investigated. The proposed algorithm shows that (under certain conditions...

  17. Materials and structural aspects of advanced gas-turbine helicopter engines

    Science.gov (United States)

    Freche, J. C.; Acurio, J.

    1979-01-01

    The key to improved helicopter gas turbine engine performance lies in the development of advanced materials and advanced structural and design concepts. The modification of the low temperature components of helicopter engines (such as the inlet particle separator), the introduction of composites for use in the engine front frame, the development of advanced materials with increased use-temperature capability for the engine hot section, can result in improved performance and/or decreased engine maintenance cost. A major emphasis in helicopter engine design is the ability to design to meet a required lifetime. This, in turn, requires that the interrelated aspects of higher operating temperatures and pressures, cooling concepts, and environmental protection schemes be integrated into component design. The major material advances, coatings, and design life-prediction techniques pertinent to helicopter engines are reviewed; the current state-of-the-art is identified; and when appropriate, progress, problems, and future directions are assessed.

  18. 78 FR 44042 - Airworthiness Directives; Agusta S.p.A. Helicopters (Type Certificate Currently Held By...

    Science.gov (United States)

    2013-07-23

    ....A. Helicopters (Type Certificate Currently Held By AgustaWestland S.P.A) (AgustaWestland) AGENCY... Certificate Currently Held By Agustawestland S.p.A) (AgustaWestland): Docket No. FAA-2013-0643;...

  19. A Hybrid Flight Control for a Simulated Raptor-30 V2 Helicopter

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2015-04-01

    Full Text Available This paper presents a hybrid flight control system for a single rotor simulated Raptor-30 V2 helicopter. Hybrid intelligent control system, combination of the conventional and intelligent control methodologies, is applied to small model helicopter. The proposed hybrid control used PID as a traditional control and fuzzy as an intelligent control so as to take the maximum advantage of advanced control theory. The helicopter?s model used; comes from X-Plane flight simulator and their hybrid flight control system was simulated using MATLAB/SIMULINK in a simulation platform. X-Plane is also used to visualize the performance of this proposed autopilot design. Through a series of numerous experiments, the operation of hybrid control system was investigated. Results verified that the proposed hybrid control has an excellent performance at hovering flight mode.

  20. A laboratory study of the subjective response to helicopter blade-slap noise

    Science.gov (United States)

    Shepherd, K. P.

    1978-01-01

    The test stimuli recorded during a recent field study consisted of 16 sounds, each presented at 4 peak noise levels. Two helicopters and a fixed-wing aircraft were used. The impulsive characteristics of one helicopter were varied by operating at different rotor speeds, whereas the other helicopter, the noise of which was dominated by the tail rotor, displayed little variation in blade-slap noise. Thirty-two subjects made noisiness judgments on a continuous, 11 point, numerical scale. Preliminary results indicate that proposed impulsiveness corrections provide no significant improvement in the noisiness predictive ability of Effective Perceived Noise Levels (EPNL). For equal EPNL, the two categories of helicopter stimuli, one of which was far more impulsive than the other, showed no difference in judged noisiness. Examination of the physical characteristics of the sounds presented in the laboratory highlighted the difficulty of reproducing acoustical signals with high-crest factors.

  1. Helicopter thermal imaging for detecting insect infested cadavers.

    Science.gov (United States)

    Amendt, Jens; Rodner, Sandra; Schuch, Claus-Peter; Sprenger, Heinz; Weidlich, Lars; Reckel, Frank

    2017-09-01

    One of the most common techniques applied for searching living and even dead persons is the FLIR (Forward Looking Infrared) system fixed on an aircraft like e.g. a helicopter, visualizing the thermal patterns emitted from objects in the long-infrared spectrum. However, as body temperature cools down to ambient values within approximately 24h after death, it is common sense that searching for deceased persons can be just applied the first day post-mortem. We postulated that the insect larval masses on a decomposing body generate a heat which can be considerably higher than ambient temperatures for a period of several weeks and that such heat signatures might be used for locating insect infested human remains. We examined the thermal history of two 70 and 90kg heavy pig cadavers for 21days in May and June 2014 in Germany. Adult and immature insects on the carcasses were sampled daily. Temperatures were measured on and inside the cadavers, in selected maggot masses and at the surroundings. Thermal imaging from a helicopter using the FLIR system was performed at three different altitudes up to 1500ft. during seven day-flights and one night-flight. Insect colonization was dominated by blow flies (Diptera: Calliphoridae) which occurred almost immediately after placement of the cadavers. Larvae were noted first on day 2 and infestation of both cadavers was enormous with several thousand larvae each. After day 14 a first wave of post-feeding larvae left the carcasses for pupation. Body temperature of both cadavers ranged between 15°C and 35°C during the first two weeks of the experiment, while body surface temperatures peaked at about 45°C. Maggot masses temperatures reached values up to almost 25°C above ambient temperature. Detection of both cadavers by thermal imaging was possible on seven of the eight helicopter flights until day 21. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

  2. Helicopter passenger survival suit standards in the UK offshore oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Leese, W.L.; Norman, J.N.

    1979-02-01

    Special protective clothing for helicopter passengers in transit to and from installations in the U.K. offshore oil industry is considered essential. Such clothing is required to increase the survival chances in the unlikely event of a helicopter ditching. This paper discusses the nature of the threat to life in such an event and proposes standards for the specific protective clothing required to meet it. Test criteria are also outlined, to ensure that standards set are maintained.

  3. Applications of numerical optimization methods to helicopter design problems - A survey

    Science.gov (United States)

    Miura, H.

    1985-01-01

    A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

  4. Applications of numerical optimization methods to helicopter design problems: A survey

    Science.gov (United States)

    Miura, H.

    1984-01-01

    A survey of applications of mathematical programming methods is used to improve the design of helicopters and their components. Applications of multivariable search techniques in the finite dimensional space are considered. Five categories of helicopter design problems are considered: (1) conceptual and preliminary design, (2) rotor-system design, (3) airframe structures design, (4) control system design, and (5) flight trajectory planning. Key technical progress in numerical optimization methods relevant to rotorcraft applications are summarized.

  5. Clustering of Parameter Sensitivities: Examples from a Helicopter Airframe Model Updating Exercise

    OpenAIRE

    Shahverdi, H.; C. Mares; W. Wang; J. E. Mottershead

    2009-01-01

    The need for high fidelity models in the aerospace industry has become ever more important as increasingly stringent requirements on noise and vibration levels, reliability, maintenance costs etc. come into effect. In this paper, the results of a finite element model updating exercise on a Westland Lynx XZ649 helicopter are presented. For large and complex structures, such as a helicopter airframe, the finite element model represents the main tool for obtaining accurate models which could pre...

  6. Concepts for the design of a completely active helicopter isolation system using output vector feedback

    Science.gov (United States)

    Schulz, G.

    1977-01-01

    The theory of output vector feedback (a few measured quantities) is used to derive completely active oscillation isolation functions for helicopters. These feedback controller concepts are tested with various versions of the BO 105 helicopter and their performance is demonstrated. A compensation of the vibrational excitations from the rotor and harmonics of the number of blades are considered. There is also a fast and automatic trim function for maneuvers.

  7. Helicopter Parenting and Related Issues: Psychological Well Being, Basic Psychological Needs and Depression on University Students

    OpenAIRE

    Okray, Zihniye

    2016-01-01

    Helicopter parenting is not a new dimension of parenting but it is a parenting that involves hovering parents who are potentially over-involved in the lives of their child. (Padilla-Walker, Nelson, 2012) Helicopter parenting is a unique phenomenon (Odenweller et al, 2014) and unique form of parental control (Willoughby et al., 2013) which can be described as highly involved, intensive, a hands-on method. (Schiffrin et al, 2014) In this study, university students examined about their parental ...

  8. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    OpenAIRE

    Fan Lei; Wang Shaoping; Wang Xingjian; Han Feng; Lyu Huawei

    2016-01-01

    Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effective method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibration of a planetary gear train with a cracked planet carrier plate. The model takes into consideratio...

  9. Helicopter Noise Survey for Selected Cities in the Contiguous United States,

    Science.gov (United States)

    1985-03-20

    ambulance of Chicago space Hospital New Orleans, LA: Pumpkin airport 621 60 85 112 70/61 89 helicopter Helicopters takeoff Chevron Oil airport 450 60 68 86...and 12 are hospital helipads used for emergency ambulance service. Because the frequency of medical emergencies is very irregular, the numbers of...J.19 for station Locations. _ [11 = Noise Lavels mesured with the CNA which is not capabLe of recording measurement duration,Laq, end SL. reading

  10. The Effects of Ambient Conditions on Helicopter Rotor Source Noise Modeling

    Science.gov (United States)

    Schmitz, Frederic H.; Greenwood, Eric

    2011-01-01

    A new physics-based method called Fundamental Rotorcraft Acoustic Modeling from Experiments (FRAME) is used to demonstrate the change in rotor harmonic noise of a helicopter operating at different ambient conditions. FRAME is based upon a non-dimensional representation of the governing acoustic and performance equations of a single rotor helicopter. Measured external noise is used together with parameter identification techniques to develop a model of helicopter external noise that is a hybrid between theory and experiment. The FRAME method is used to evaluate the main rotor harmonic noise of a Bell 206B3 helicopter operating at different altitudes. The variation with altitude of Blade-Vortex Interaction (BVI) noise, known to be a strong function of the helicopter s advance ratio, is dependent upon which definition of airspeed is flown by the pilot. If normal flight procedures are followed and indicated airspeed (IAS) is held constant, the true airspeed (TAS) of the helicopter increases with altitude. This causes an increase in advance ratio and a decrease in the speed of sound which results in large changes to BVI noise levels. Results also show that thickness noise on this helicopter becomes more intense at high altitudes where advancing tip Mach number increases because the speed of sound is decreasing and advance ratio increasing for the same indicated airspeed. These results suggest that existing measurement-based empirically derived helicopter rotor noise source models may give incorrect noise estimates when they are used at conditions where data were not measured and may need to be corrected for mission land-use planning purposes.

  11. Critical Technology Events in the Development of the Apache Helicopter. Project Hindsight Revisited

    Science.gov (United States)

    2006-02-01

    weapons systems also benefited the Apache. Among these advances were a common module approach to FLIR production and a minimum resolvable temperature ( MRT ...determination as a way to measure FLIR performance. Also, it should be noted that for the Apache, with the work on the MRT as a foundation, the U.S...Industry’s creative work on the T700 series of helicopter engines is an example. 3. The Army experiences with helicopters in Vietnam had a strong

  12. Specific exercise training for reducing neck and shoulder pain among military helicopter pilots and crew members

    DEFF Research Database (Denmark)

    Murray, Mike; Lange, Britt; Nørnberg, Bo Riebeling

    2015-01-01

    BACKGROUND: Flight-related neck/shoulder pain is frequent among military helicopter pilots and crew members. With a lifetime prevalence of 81 % for pilots and 84 % for crew members, the prevalence of neck pain is considered high compared to the general population. The aim of this study was to inv......BACKGROUND: Flight-related neck/shoulder pain is frequent among military helicopter pilots and crew members. With a lifetime prevalence of 81 % for pilots and 84 % for crew members, the prevalence of neck pain is considered high compared to the general population. The aim of this study...... was to investigate whether a specifically tailored exercise intervention would reduce the prevalence and incidence rate of neck/shoulder pain among helicopter pilots and crew members. METHOD: This study used a prospective, parallel group, single blinded, randomized controlled design. Participants were military...... helicopter pilots and crew members recruited from the Royal Danish Air Force. Inclusion criteria were: 1) employed within the Royal Danish Air Force as a helicopter pilot or onboard crew member (technician, systems-operator, tactical helicopter observer and/or navigator), 2) maintaining operational flight...

  13. Stable Hovering Flight for a Small Unmanned Helicopter Using Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2014-01-01

    Full Text Available Stable hover flight control for small unmanned helicopter under light air turbulent environment is presented. Intelligent fuzzy logic is chosen because it is a nonlinear control technique based on expert knowledge and is capable of handling sensor created noise and contradictory inputs commonly encountered in flight control. The fuzzy nonlinear control utilizes these distinct qualities for attitude, height, and position control. These multiple controls are developed using two-loop control structure by first designing an inner-loop controller for attitude angles and height and then by establishing outer-loop controller for helicopter position. The nonlinear small unmanned helicopter model used comes from X-Plane simulator. A simulation platform consisting of MATLAB/Simulink and X-Plane© flight simulator was introduced to implement the proposed controls. The main objective of this research is to design computationally intelligent control laws for hovering and to test and analyze this autopilot for small unmanned helicopter model on X-Plane under ideal and mild turbulent condition. Proposed fuzzy flight controls are validated using an X-Plane helicopter model before being embedded on actual helicopter. To show the effectiveness of the proposed fuzzy control method and its ability to cope with the external uncertainties, results are compared with a classical PD controller. Simulated results show that two-loop fuzzy controllers have a good ability to establish stable hovering for a class of unmanned rotorcraft in the presence of light turbulent environment.

  14. Investigation of the flight mechanics simulation of a hovering helicopter

    Science.gov (United States)

    Chaimovich, M.; Rosen, A.; Rand, O.; Mansur, M. H.; Tischler, M. B.

    1992-01-01

    The flight mechanics simulation of a hovering helicopter is investigated by comparing the results of two different numerical models with flight test data for a hovering AH-64 Apache. The two models are the U.S. Army BEMAP and the Technion model. These nonlinear models are linearized by applying a numerical linearization procedure. The results of the linear models are compared with identification results in terms of eigenvalues, stability and control derivatives, and frequency responses. Detailed time histories of the responses of the complete nonlinear models, as a result of various pilots' inputs, are compared with flight test results. In addition the sensitivity of the models to various effects are also investigated. The results are discussed and problematic aspects of the simulation are identified.

  15. Advances in transitional flow modeling applications to helicopter rotors

    CERN Document Server

    Sheng, Chunhua

    2017-01-01

    This book provides a comprehensive description of numerical methods and validation processes for predicting transitional flows based on the Langtry–Menter local correlation-based transition model, integrated with both one-equation Spalart–Allmaras (S–A) and two-equation Shear Stress Transport (SST) turbulence models. A comparative study is presented to combine the respective merits of the two coupling methods in the context of predicting the boundary-layer transition phenomenon from fundamental benchmark flows to realistic helicopter rotors. The book will of interest to industrial practitioners working in aerodynamic design and the analysis of fixed-wing or rotary wing aircraft, while also offering advanced reading material for graduate students in the research areas of Computational Fluid Dynamics (CFD), turbulence modeling and related fields.

  16. Comparison of three controllers applied to helicopter vibration

    Science.gov (United States)

    Leyland, Jane A.

    1992-01-01

    A comparison was made of the applicability and suitability of the deterministic controller, the cautious controller, and the dual controller for the reduction of helicopter vibration by using higher harmonic blade pitch control. A randomly generated linear plant model was assumed and the performance index was defined to be a quadratic output metric of this linear plant. A computer code, designed to check out and evaluate these controllers, was implemented and used to accomplish this comparison. The effects of random measurement noise, the initial estimate of the plant matrix, and the plant matrix propagation rate were determined for each of the controllers. With few exceptions, the deterministic controller yielded the greatest vibration reduction (as characterized by the quadratic output metric) and operated with the greatest reliability. Theoretical limitations of these controllers were defined and appropriate candidate alternative methods, including one method particularly suitable to the cockpit, were identified.

  17. Helicopter vibration isolation: Design approach and test results

    Science.gov (United States)

    Lee, C.-M.; Goverdovskiy, V. N.; Sotenko, A. V.

    2016-03-01

    This paper presents a strategy based on the approach of designing and inserting into helicopter vibration isolation systems mountable mechanisms with springs of adjustable sign-changing stiffness for system stiffness control. A procedure to extend the effective area of stiffness control is presented; a set of parameters for sensitivity analysis and practical mechanism design is formulated. The validity and flexibility of the approach are illustrated by application to crewmen seat suspensions and vibration isolators for equipment protection containers. The strategy provides minimization of vibrations, especially in the infra-low frequency range which is the most important for crewmen efficiency and safety of the equipment. This also would prevent performance degradation of some operating systems. The effectiveness is demonstrated through measured data obtained from development and parallel flight tests of new and operating systems.

  18. Model helicopter performance degradation with simulated ice shapes

    Science.gov (United States)

    Tinetti, Ana F.; Korkan, Kenneth D.

    1987-01-01

    An experimental program using a commercially available model helicopter has been conducted in the Texas A&M University Subsonic Wind Tunnel to investigate main rotor performance degradation due to generic ice. The simulated ice, including both primary and secondary formations, was scaled by chord from previously documented artificial ice accretions. Base and iced performance data were gathered as functions of fuselage incidence, blade collective pitch, main rotor rotational velocity, and freestream velocity. It was observed that the presence of simulated ice tends to decrease the lift to equivalent drag ratio, as well as thrust coefficient for the range of velocity ratios tested. Also, increases in torque coefficient due to the generic ice formations were observed. Evaluation of the data has indicated that the addition of roughness due to secondary ice formations is crucial for proper evaluation of the degradation in main rotor performance.

  19. Recent Ice thickness helicopter borne radar surveys in Patagonia

    Science.gov (United States)

    Rivera, Andres; Zamora, Rodrigo; Andres Uribe, Jose; Oberreuter, Jonathan; Gacitua, Guisella; Rignot, Eric

    2014-05-01

    The Patagonian icefields are the biggest temperate ice bodies in southern hemisphere, which have experienced important areal shrinkage and thinning in recent decades, significantly contributing to sea level rise. The main driving factor behind this retreating condition is recent decade atmospheric warming explaining higher melting rates and equilibrium line altitude upward migration. Ice dynamic is also playing an important role especially in glaciers calving into deep fjords or lakes, type of glaciers that are predominant in the Patagonian icefields. In order to better understand their ice dynamics, several recent works have measured ice velocities using feature tracking and other techniques, however, ice thickness is still barely known. In spite of several on the ground radar measurements successfully detecting several hundred of m of ice thickness at the higher plateaus, this variable remains the great missing part of the equation especially when the thickness is approximately deeper than 600 m or where the glacier surfaces are very crevassed or nearby the Equilibrium line Altitude, where on the ground measurements are logistically constrained. In order to tackle the lack of thickness data, a helicopter borne radar system was used to survey several Patagonian temperate glaciers calving into fjords (Glaciares San Rafael and Jorge Montt) or lakes (Nef, Colonia and Steffen). The radar system is comprised by a hanging bow-tie dipole antenna working at a central frequency of 20 MHz. The antenna is an aluminum structure of 7 x 5 x 1.2 m weighting near 350 kg that is hanging at 20 m below a helicopter, and is connected to the helicopter cabin by an optical fiber cable. At the antenna are installed a 3,200 Volts peak transmitter, a two channel radar receiver, and an integrated GPS registering each trace. The helicopter flying speed was kept at near 40 knots and the antenna was normally hanging at 40 m above the ice. The surveys took place along predefined tracks

  20. Distribution of Acoustic Power Spectra for an Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Kusyumov A.N.

    2016-01-01

    Full Text Available The broadband aerodynamic noise can be studied, assuming isotropic flow, turbulence and decay. Proudman’s approach allows practical calculations of noise based on CFD solutions of RANS or URANS equations at the stage of post processing and analysis of the solution. Another aspect is the broadband acoustic spectrum and the distribution of acoustic power over a range of frequencies. The acoustic energy spectrum distribution in isotropic turbulence is non monotonic and has a maximum at a certain value of Strouhal number. In the present work the value of acoustic power peak frequency is determined using a prescribed form of acoustic energy spectrum distribution presented in papers by S. Sarkar and M. Y. Hussaini and by G. M. Lilley. CFD modelling of the flow around isolated helicopter fuselage model was considered using the HMB CFD code and the RANS equations.

  1. Linear decentralized systems with special structure. [for twin lift helicopters

    Science.gov (United States)

    Martin, C. F.

    1982-01-01

    Certain fundamental structures associated with linear systems having internal symmetries are outlined. It is shown that the theory of finite-dimensional algebras and their representations are closely related to such systems. It is also demonstrated that certain problems in the decentralized control of symmetric systems are equivalent to long-standing problems of linear systems theory. Even though the structure imposed arose in considering the problems of twin-lift helicopters, any large system composed of several identical intercoupled control systems can be modeled by a linear system that satisfies the constraints imposed. Internal symmetry can be exploited to yield new system-theoretic invariants and a better understanding of the way in which the underlying structure affects overall system performance.

  2. Design of an advanced 500-HP helicopter transmission

    Science.gov (United States)

    Braddock, C. E.

    1982-01-01

    A 500-hp Advanced Technology Demonstrator helicopter transmission was designed by an American aerospace company under a NASA contract. The project was mainly concerned with designing a 500-hp version of the OH-58C 317-hp transmission which would have the capabilities for a long, quiet life at a minimum increase in cost, weight, and space, which usually increase along with power increases. This objective was accomplished by implementing advanced technology which has been developed during the last decade and by making improvements dictated by field experience. The improvements are related to bearings made of cleaner gear steels, spiral bevel gears made of cleaner gear steels, high contact ratio spur gear teeth in the planetary which will reduce noise level and increase gear life, and modifications concerning the sun gear.

  3. Integrated cockpit design for the Army helicopter improvement program

    Science.gov (United States)

    Drennen, T.; Bowen, B.

    1984-01-01

    The main Army Helicopter Improvement Program (AHIP) mission is to navigate precisely, locate targets accurately, communicate their position to other battlefield elements, and to designate them for laser guided weapons. The onboard navigation and mast-mounted sight (MMS) avionics enable accurate tracking of current aircraft position and subsequent target location. The AHIP crewstation development was based on extensive mission/task analysis, function allocation, total system design, and test and verification. The avionics requirements to meet the mission was limited by the existing aircraft structural and performance characteristics and resultant space, weight, and power restrictions. These limitations and night operations requirement led to the use of night vision goggles. The combination of these requirements and limitations dictated an integrated control/display approach using multifunction displays and controls.

  4. Pipes's distribution by helicopter in Amazonian forest

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Gilberto R.; Machado, Otto L.M.; Gomes, Antonio E. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-12-19

    The innumerable logistical problems encountered during the implementation of the gas pipeline Urucu - Coari - Manaus, located in the Amazon forest, connecting the Base Operations Geologist Pedro de Moura in Urucu to the refinery Isaac Sabba - Reman, in the city of Manaus, contributed considerably for PETROBRAS to seek non conventional solutions in the construction and assembly of pipelines in our country. Among these solutions, there is the technique of distributing pipes through cargo helicopters. The need for the usage of this technique, innovative in Brazil, comes from the lack and/or insufficiency of land access from Solimoes River to the gas pipeline main route, and the large quantities of flooded areas and/or flood plain, and also the type of soil, that together with the high index of rainfall in the region, makes the soil fully inappropriate to the traffic of heavy equipment. (author)

  5. Data acquisition and processing - helicopter radiometric survey, Krageroe, 1998

    CERN Document Server

    Beard, L P

    2000-01-01

    On 07 October 1998 a helicopter radiometric survey was flown in the vicinity of Krageroe municipality. The purpose of the survey was to provide radiometric information to help assess radon hazard from radioactive rocks in the area. A total of 60 line-kilometres of radiometric data were acquired in a single flight, covering an area of approximately 3 square km with a 50-m line spacing. The data were collected by Geological Survey of Norway (NGU) personnel and processed at NGU. Radiometric data were reduced using the three-channel procedure recommended by the International Atomic Energy Association. All data were gridded using square cells with 30-m sides and geophysical maps were produced at a scale of 1:5000. This report covers aspects of data acquisition and processing (Author)

  6. Model helicopter performance degradation with simulated ice shapes

    Science.gov (United States)

    Tinetti, Ana F.; Korkan, Kenneth D.

    1987-01-01

    An experimental program using a commercially available model helicopter has been conducted in the Texas A&M University Subsonic Wind Tunnel to investigate main rotor performance degradation due to generic ice. The simulated ice, including both primary and secondary formations, was scaled by chord from previously documented artificial ice accretions. Base and iced performance data were gathered as functions of fuselage incidence, blade collective pitch, main rotor rotational velocity, and freestream velocity. It was observed that the presence of simulated ice tends to decrease the lift to equivalent drag ratio, as well as thrust coefficient for the range of velocity ratios tested. Also, increases in torque coefficient due to the generic ice formations were observed. Evaluation of the data has indicated that the addition of roughness due to secondary ice formations is crucial for proper evaluation of the degradation in main rotor performance.

  7. Subjective assessment of simulated helicopter blade-slap noise

    Science.gov (United States)

    Lawton, B. W.

    1976-01-01

    The effects of several characteristics of helicopter blade slap upon human annoyance are examined. Blade slap noise was simulated by using continuous and impulsive noises characterized by five parameters: The number of sine waves in a single impulse; the frequency of the sine waves; the impulse repetition frequency; the sound pressure level (SPL) of the continuous noise; and the idealized crest factor of the impulses. Ten second samples of noise were synthesized with each of the five parameters at representative levels. The annoyance of each noise was judged by 40 human subjects. Analysis of the subjective data indicated that each of the five parameters had a statistically significant effect upon the annoyance judgments. The impulse crest factor and SPL of the continuous noise had very strong positive relationships with annoyance. The other parameters had smaller, but still significant, effects upon the annoyance judgments.

  8. Helicopter individual-blade-control and its applications

    Science.gov (United States)

    Ham, N. D.

    1984-01-01

    A new, advanced type of active control for helicopters and its applications are described. The system, based on previously developed M.I.T. Individual-Blade-Control hardware, employs blade-mounted accelerometers to sense blade motion and feeds back information to control blade pitch in such a manner as to reduce the response of selected blade modes. A linear model of the blade and control system dynamics is used to give guidance in the design process as well as to aid in analysis of experimental results. System performance in wind tunnel tests is described, and evidence is given of the system's ability to provide substantial reduction in blade modal responses, including blade bending vibration.

  9. Smart helicopter rotors optimization and piezoelectric vibration control

    CERN Document Server

    Ganguli, Ranjan; Viswamurthy, Sathyamangalam Ramanarayanan

    2016-01-01

    Exploiting the properties of piezoelectric materials to minimize vibration in rotor-blade actuators, this book demonstrates the potential of smart helicopter rotors to achieve the smoothness of ride associated with jet-engined, fixed-wing aircraft. Vibration control is effected using the concepts of trailing-edge flaps and active-twist. The authors’ optimization-based approach shows the advantage of multiple trailing-edge flaps and algorithms for full-authority control of dual trailing-edge-flap actuators are presented. Hysteresis nonlinearity in piezoelectric stack actuators is highlighted and compensated by use of another algorithm. The idea of response surfaces provides for optimal placement of trailing-edge flaps. The concept of active twist involves the employment of piezoelectrically induced shear actuation in rotating beams. Shear is then demonstrated for a thin-walled aerofoil-section rotor blade under feedback-control vibration minimization. Active twist is shown to be significant in reducing vibra...

  10. Helicopter flights with night-vision goggles: Human factors aspects

    Science.gov (United States)

    Brickner, Michael S.

    1989-01-01

    Night-vision goggles (NVGs) and, in particular, the advanced, helmet-mounted Aviators Night-Vision-Imaging System (ANVIS) allows helicopter pilots to perform low-level flight at night. It consists of light intensifier tubes which amplify low-intensity ambient illumination (star and moon light) and an optical system which together produce a bright image of the scene. However, these NVGs do not turn night into day, and, while they may often provide significant advantages over unaided night flight, they may also result in visual fatigue, high workload, and safety hazards. These problems reflect both system limitations and human-factors issues. A brief description of the technical characteristics of NVGs and of human night-vision capabilities is followed by a description and analysis of specific perceptual problems which occur with the use of NVGs in flight. Some of the issues addressed include: limitations imposed by a restricted field of view; problems related to binocular rivalry; the consequences of inappropriate focusing of the eye; the effects of ambient illumination levels and of various types of terrain on image quality; difficulties in distance and slope estimation; effects of dazzling; and visual fatigue and superimposed symbology. These issues are described and analyzed in terms of their possible consequences on helicopter pilot performance. The additional influence of individual differences among pilots is emphasized. Thermal imaging systems (forward looking infrared (FLIR)) are described briefly and compared to light intensifier systems (NVGs). Many of the phenomena which are described are not readily understood. More research is required to better understand the human-factors problems created by the use of NVGs and other night-vision aids, to enhance system design, and to improve training methods and simulation techniques.

  11. On neck load among helicopter pilots : Effects of head worn equipment, whole body vibration and neck position

    OpenAIRE

    Thuresson, Marcus

    2005-01-01

    Introduction: Helicopter pilots complain of pain originating from the neck region. The causes are still basically unknown, but the ergonomic situation when flying a helicopter, with unfavorable load caused by static neck and body positions, whole-body vibration and heavy head-worn equipment, has been suggested as a risk factor. Aim: The aim of the work reported in this thesis was to quantify the effects of external loads on helicopter pilots necks, and to evaluate diffe...

  12. Plan, formulate, discuss and correlate a NASTRAN finite element vibrations model of the Boeing Model 360 helicopter airframe

    Science.gov (United States)

    Gabel, R.; Lang, P. F.; Smith, L. A.; Reed, D. A.

    1989-01-01

    Boeing Helicopter, together with other United States helicopter manufacturers, participated in a finite element applications program to emplace in the United States a superior capability to utilize finite element analysis models in support of helicopter airframe design. The activities relating to planning and creating a finite element vibrations model of the Boeing Model 36-0 composite airframe are summarized, along with the subsequent analytical correlation with ground shake test data.

  13. A Randomized Controlled Trial of Core Strengthening Exercises in U.S. Air Force Helicopter Crewmembers with Low Back Pain

    Science.gov (United States)

    2014-12-13

    JP, Albert WJ, Veillete DW, McKenzie NP, Croll JC. Helicopter cockpit seat side and trapezius muscle metabolism with night vision goggles . Aviat...ergonomic layout of helicopter controls leads pilots to adopt a posture in which the torso is forward flexed and tilted to the left. This body... helicopter aircrew members is hypothesized to result from the combination of ergonomic strain (i.e., poor posture ) and exposure to vibration (19). The

  14. Villous adenoma of the distal appendix.

    Science.gov (United States)

    Taylor, J V; Thomas, M G; Kelly, S; Sutton, R

    1997-04-01

    Villous adenoma confined to the distal appendix has not been previously reported in conjunction with acute apendicitis. The presence of an adenoma indicates a need for further investigation due to an association with neoplasia elsewhere.

  15. Radiological features of mucocele of the appendix

    Energy Technology Data Exchange (ETDEWEB)

    Skaane, P.

    1988-12-01

    The clinical features of mucocele of the appendix are nonspecific, and a correct preoperative diagnosis based on abdominal pain, a palpable mass in the right lower quadrant, and conventional radiography is rare. The diagnosis of appendiceal mucocele has become easier with the utilisation of the recent imaging techniques ultrasonography and computed tomography. Six patients with mucocele of the appendix are presented, and the characteristic radiological features and differential diagnosis are discussed.

  16. 13 CFR Appendix A to Part 1171 - Appendix A to Part 1171

    Science.gov (United States)

    2010-01-01

    .... International Trade Program Small Business Act, section 22. Technical and Management Assistance Small Business... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Appendix A to Part 1171 A Appendix A to Part 1171 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION NONDISCRIMINATION...

  17. 40 CFR Appendix A to Subpart A of... - Appendix A to Subpart A of Part 750

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Appendix A to Subpart A of Part 750 A Appendix A to Subpart A of Part 750 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... ACT Procedures for Rulemaking Under Section 6 of the Toxic Substances Control Act Pt. 750, Subpt....

  18. 40 CFR Appendix I to Subpart B of... - Appendix I to Subpart B of Part 205

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Appendix I to Subpart B of Part 205 I Appendix I to Subpart B of Part 205 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Medium and Heavy Trucks...

  19. 14 CFR Appendix F to Part 23 - Test Procedure

    Science.gov (United States)

    2010-01-01

    ... prescribed in paragraph (f) of this appendix, the specimen must be mounted in metal frame so that all four...) of this appendix, the specimen must be mounted in a metal frame so that (1) in the vertical tests...

  20. Identification, control and visually-guided behavior for a model helicopter

    Science.gov (United States)

    Saripalli, Srikanth

    Research on unmanned aerial vehicles is motivated by applications where human intervention is impossible, risky or expensive e.g. hazardous material recovery, traffic monitoring, disaster relief support, military operations etc. Due to its vertical take-off, landing and hover capabilities, a helicopter is an attractive platform for such applications. There are significant challenges to building an autonomous robotic helicopter - these span the areas of system identification, low-level control, state estimation, and planning. Towards the goal of fully-autonomous helicopters this thesis makes the following contributions. A continuous-discrete extended Kalman filter has been developed that combines inertial data with GPS and compass data to provide estimates of the 6DOF state of the helicopter. Using this filter a model for the helicopter has been identified based on frequency response techniques. The model has been validated in flight tests on a small helicopter testbed (1.6 m rotor diameter) at speeds upto 5 m/s. Based on evidence from this model a decoupled low-level controller has been developed which is embedded in a control architecture suitable for visually-guided navigation. As a novel application, we show how such a controller can be used to perform trajectory following on the helicopter where the desired trajectories are typical spacecraft landing trajectories, and the only controls available are thrusters. This in effect, produces a low-cost testbed for testing spacecraft landing and hazard avoidance on a planetary surface. Finally, we develop and extensively experimentally characterize algorithms for vision-based autonomous landing, object tracking, and sensor deployment.

  1. Helicopter vibration and risk of reversible myopia among military air crews

    Directory of Open Access Journals (Sweden)

    Bastaman Basuki

    2002-06-01

    Full Text Available We assessed to what extend the risk of reversible myopia of the different degree of helicopter vibrations and other risk factors among military helicopter pilots and flight engineers. The study was a nested case-control design using medical record at the Institute of Aerospace Medicine of the Indonesian Air Force and Medical Directorate of the Indonesian Army (Flying Wing. Cases and controls were military helicopter pilots and flight engineers who had ametropic visual acuity at the time of entry into military service from 1972 until 1992. Reversible myopia means visual acuity corrected of - 0.50 dioptri or less. The final model indicates there was a relationship between vibration level, duration of work and risk of reversible myopia. Helicopter crews exposed to high vibration level had 4.5 times to develop reversible myopia [adjusted odds ratio (OR = 4.47; 95% confidence intervals (CI = 1.48 - 13.55] relative to those who exposed to weak vibration level. There was noted a healthy worker's survivor effect. Those who remain work for a longer peiod had less a chance to be myopia. Those who worked for 10 years or more had a lowered risk of 85% to be myopia compared with those who worked for 14 years (adjusted OR = 0.15; 95% CI = 0.03 - 0.87. Helicopter crews exposed to high helicopter vibration had 4.5 times to develop reversible myopia, and a higher risk occurred during the first four years of employment. (Med J Indones 2002; 11: 93-6Keywords: helicopter vibration, reversible myopia, air crews

  2. A helicopter flight does not induce significant changes in systemic biomarker profiles.

    Science.gov (United States)

    Kåsin, Jan Ivar; Kjekshus, John; Aukrust, Pål; Mollnes, Tom Eirik; Wagstaff, Anthony

    2009-01-01

    Whole-body vibration and noise are inherent characteristics of helicopter operations. The helicopter pilot is affected by vibration from both low-frequency noise and mechanical vibration sources. The way this energy is transmitted to different tissues and organs depends on intensity, frequency and resonance phenomena within the body. Whole-body vibration is known to affect the muscular and skeletal system in the lower part of the spine, but less is known about the response at the cellular level to this stimulation. In some studies, chronic pathological changes have been described in different types of tissue in people exposed to low-frequency noise and vibration. The aim of the present study was to investigate possible cellular reactions to acute exposure to low-frequency noise and vibration in a helicopter. Thirteen healthy males aged 38 (18-69) years were subjected to a 3.5 h helicopter flight in a Westland Sea King Rescue helicopter. Blood tests taken before and after the flight were analysed for more than 40 parameters, including acute phase reactants, markers of leucocyte and platelet activation, complement and hemostasis markers, as well as a broad panel of cytokines, chemokines, growth factors and cell adhesion molecules. The subjects served as their own controls. With the exception of an increase in vascular cell adhesion molecule-1 (VCAM-1) during the flight, no statistically significant changes in the biomarkers were found after controlling for diurnal variation in the control blood tests, which were observed independently of the helicopter flight. In conclusion, one helicopter flight does not induce measurable changes in systemic biomarkers.

  3. Flight test results of the fuzzy logic adaptive controller-helicopter (FLAC-H)

    Science.gov (United States)

    Wade, Robert L.; Walker, Gregory W.

    1996-05-01

    The fuzzy logic adaptive controller for helicopters (FLAC-H) demonstration is a cooperative effort between the US Army Simulation, Training, and Instrumentation Command (STRICOM), the US Army Aviation and Troop Command, and the US Army Missile Command to demonstrate a low-cost drone control system for both full-scale and sub-scale helicopters. FLAC-H was demonstrated on one of STRICOM's fleet of full-scale rotary-winged target drones. FLAC-H exploits fuzzy logic in its flight control system to provide a robust solution to the control of the helicopter's dynamic, nonlinear system. Straight forward, common sense fuzzy rules governing helicopter flight are processed instead of complex mathematical models. This has resulted in a simplified solution to the complexities of helicopter flight. Incorporation of fuzzy logic reduced the cost of development and should also reduce the cost of maintenance of the system. An adaptive algorithm allows the FLAC-H to 'learn' how to fly the helicopter, enabling the control system to adjust to varying helicopter configurations. The adaptive algorithm, based on genetic algorithms, alters the fuzzy rules and their related sets to improve the performance characteristics of the system. This learning allows FLAC-H to automatically be integrated into a new airframe, reducing the development costs associated with altering a control system for a new or heavily modified aircraft. Successful flight tests of the FLAC-H on a UH-1H target drone were completed in September 1994 at the White Sands Missile Range in New Mexico. This paper discuses the objective of the system, its design, and performance.

  4. Primary marginal zone B-cell lymphoma of appendix

    Directory of Open Access Journals (Sweden)

    Radha S

    2008-07-01

    Full Text Available Primary lymphomas of appendix are extremely rare tumors. The first case of primary lymphoma of appendix was reported by Warren in the year 1898. Incidence of primary lymphoma of appendix is 0.015% of all gastrointestinal lymphomas. This is a report of primary marginal zone B-cell lymphoma of appendix which presented as appendicular mass. As some cases are incidentally discovered, this case emphasizes that histological examination of all appendicectomy specimens is mandatory.

  5. The noise environment of a school classroom due to the operation of utility helicopters. [acoustic measurements of helicopter noise during flight over building

    Science.gov (United States)

    Hilton, D. A.; Pegg, R. J.

    1974-01-01

    Noise measurements under controlled conditions have been made inside and outside of a school building during flyover operations of four different helicopters. The helicopters were operated at a condition considered typical for a police patrol mission. Flyovers were made at an altitude of 500 ft and an airspeed of 45 miles per hour. During these operations acoustic measurements were made inside and outside of the school building with the windows closed and then open. The outside noise measurements during helicopter flyovers indicate that the outside db(A) levels were approximately the same for all test helicopters. For the windows closed case, significant reductions for the inside measured db(A) values were noted for all overflights. These reductions were approximately 20 db(A); similar reductions were noted in other subjective measuring units. The measured internal db(A) levels with the windows open exceeded published classroom noise criteria values; however, for the windows-closed case they are in general agreement with the criteria values.

  6. 14 CFR Appendix C to Part 147 - Airframe Curriculum Subjects

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airframe Curriculum Subjects C Appendix C... Appendix C to Part 147—Airframe Curriculum Subjects This appendix lists the subjects required in at least 750 hours of each airframe curriculum, in addition to at least 400 hours in general curriculum...

  7. 14 CFR Appendix D to Part 147 - Powerplant Curriculum Subjects

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Powerplant Curriculum Subjects D Appendix D... Appendix D to Part 147—Powerplant Curriculum Subjects This appendix lists the subjects required in at least 750 hours of each powerplant curriculum, in addition to at least 400 hours in general curriculum...

  8. 40 CFR Appendix B to Part 66 - Instruction Manual

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Instruction Manual B Appendix B to Part 66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Manual Note: For text of appendix B see appendix B to part 67....

  9. Integral Twist Actuation of Helicopter Rotor Blades for Vibration Reduction

    Science.gov (United States)

    Shin, SangJoon; Cesnik, Carlos E. S.

    2001-01-01

    Active integral twist control for vibration reduction of helicopter rotors during forward flight is investigated. The twist deformation is obtained using embedded anisotropic piezocomposite actuators. An analytical framework is developed to examine integrally-twisted blades and their aeroelastic response during different flight conditions: frequency domain analysis for hover, and time domain analysis for forward flight. Both stem from the same three-dimensional electroelastic beam formulation with geometrical-exactness, and axe coupled with a finite-state dynamic inflow aerodynamics model. A prototype Active Twist Rotor blade was designed with this framework using Active Fiber Composites as the actuator. The ATR prototype blade was successfully tested under non-rotating conditions. Hover testing was conducted to evaluate structural integrity and dynamic response. In both conditions, a very good correlation was obtained against the analysis. Finally, a four-bladed ATR system is built and tested to demonstrate its concept in forward flight. This experiment was conducted at NASA Langley Tansonic Dynamics Tunnel and represents the first-of-a-kind Mach-scaled fully-active-twist rotor system to undergo forward flight test. In parallel, the impact upon the fixed- and rotating-system loads is estimated by the analysis. While discrepancies are found in the amplitude of the loads under actuation, the predicted trend of load variation with respect to its control phase correlates well. It was also shown, both experimentally and numerically, that the ATR blade design has the potential for hub vibratory load reduction of up to 90% using individual blade control actuation. Using the numerical framework, system identification is performed to estimate the harmonic transfer functions. The linear time-periodic system can be represented by a linear time-invariant system under the three modes of blade actuation: collective, longitudinal cyclic, and lateral cyclic. A vibration

  10. Helicopter gearbox isolation using periodically layered fluidic isolators

    Science.gov (United States)

    Szefi, Joseph Thomas

    2003-07-01

    In rotorcraft transmissions, vibration generation by meshing gear pairs is a significant source of vibration and cabin noise. This high-frequency gearbox noise is primarily transmitted to the fuselage through rigid connections, which do not appreciably attenuate vibratory energy. The high-frequency vibrations typically include discrete gear-meshing frequencies in the range of 500--2000 Hz, and are often considered irritating and can reduce pilot effectiveness and passenger comfort. Periodically-layered isolators were identified as potential passive attenuators of these high frequency vibrations. Layered isolators exhibit transmissibility "stop bands," or frequency ranges in which there is very low transmissibility. An axisymmetric model was developed to accurately predict the location of these stop bands for isolators in compression. A Ritz approximation method was used to model the axisymmetric elastic behavior of layered cylindrical isolators. This model of layered isolators was validated with experiments. The physical design constraints of the proposed helicopter gearbox isolators were then estimated. Namely, constraints associated with isolator mass, axial stiffness, geometry, and elastomeric fatigue were determined. The passive performance limits of layered isolators were then determined using a design optimization methodology employing a simulated annealing algorithm. The results suggest that layered isolators cannot always meet frequency targets given a certain set of design constraints. Many passive and active design enhancements were considered to address this problem, and the use of embedded inertial amplifiers was found to exhibit a combination of advantageous effects. The first benefit was a lowering of the beginning stop band frequency, and thus a widening of the original stop band. The second was a tuned absorber effect, where the elastomer layer stiffness and the amplified tuned mass combined to act as a vibration absorber within the stop band. The

  11. Dynamics Control Approaches to Improve Vibratory Environment of the Helicopter Aircrew

    Science.gov (United States)

    Wickramasinghe, Viresh Kanchana

    Although helicopter has become a versatile mode of aerial transportation, high vibration levels leads to poor ride quality for its passengers and aircrew. Undesired vibration transmitted through the helicopter seats have been known to cause fatigue and discomfort to the aircrew in the short-term as well as neck strain and back pain injuries due to long-term exposure. This research study investigated the use of novel active as well as passive methodologies integrated in helicopter seats to mitigate the aircrew exposure to high vibration levels. Due to significantly less certification effort required to modify the helicopter seat structure, application of novel technologies to the seat is more practical compared to flight critical components such as the main rotor to reduce aircrew vibration. In particular, this research effort developed a novel adaptive seat mount approach based on active vibration control technology. This novel design that incorporated two stacked piezoelectric actuators as active struts increases the bending stiffness to avoid the low frequency resonance while generating forces to counteract higher harmonic vibration peaks. A real-time controller implemented using a feed-forward algorithm based on adaptive notches counteracted the forced vibration peaks while a robust feedback control algorithm suppressed the resonance modes. The effectiveness of the adaptive seat mount system was demonstrated through extensive closed-loop control tests on a full-scale helicopter seat using representative helicopter floor vibration profiles. Test results concluded that the proposed adaptive seat mount approach based on active control technology is a viable solution for the helicopter seat vibration control application. In addition, a unique flight test using a Bell-412 helicopter demonstrated that the aircrew is exposed to high levels of vibration during flight and that the whole body vibration spectrum varied substantially depending on operating conditions as

  12. Multi-Scale Modeling of an Integrated 3D Braided Composite with Applications to Helicopter Arm

    Science.gov (United States)

    Zhang, Diantang; Chen, Li; Sun, Ying; Zhang, Yifan; Qian, Kun

    2017-01-01

    A study is conducted with the aim of developing multi-scale analytical method for designing the composite helicopter arm with three-dimensional (3D) five-directional braided structure. Based on the analysis of 3D braided microstructure, the multi-scale finite element modeling is developed. Finite element analysis on the load capacity of 3D five-directional braided composites helicopter arm is carried out using the software ABAQUS/Standard. The influences of the braiding angle and loading condition on the stress and strain distribution of the helicopter arm are simulated. The results show that the proposed multi-scale method is capable of accurately predicting the mechanical properties of 3D braided composites, validated by the comparison the stress-strain curves of meso-scale RVCs. Furthermore, it is found that the braiding angle is an important factor affecting the mechanical properties of 3D five-directional braided composite helicopter arm. Based on the optimized structure parameters, the nearly net-shaped composite helicopter arm is fabricated using a novel resin transfer mould (RTM) process.

  13. The Effects of Ambient Conditions on Helicopter Harmonic Noise Radiation: Theory and Experiment

    Science.gov (United States)

    Greenwood, Eric; Sim, Ben W.; Boyd, D. Douglas, Jr.

    2016-01-01

    The effects of ambient atmospheric conditions, air temperature and density, on rotor harmonic noise radiation are characterized using theoretical models and experimental measurements of helicopter noise collected at three different test sites at elevations ranging from sea level to 7000 ft above sea level. Significant changes in the thickness, loading, and blade-vortex interaction noise levels and radiation directions are observed across the different test sites for an AS350 helicopter flying at the same indicated airspeed and gross weight. However, the radiated noise is shown to scale with ambient pressure when the flight condition of the helicopter is defined in nondimensional terms. Although the effective tip Mach number is identified as the primary governing parameter for thickness noise, the nondimensional weight coefficient also impacts lower harmonic loading noise levels, which contribute strongly to low frequency harmonic noise radiation both in and out of the plane of the horizon. Strategies for maintaining the same nondimensional rotor operating condition under different ambient conditions are developed using an analytical model of single main rotor helicopter trim and confirmed using a CAMRAD II model of the AS350 helicopter. The ability of the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique to generalize noise measurements made under one set of ambient conditions to make accurate noise predictions under other ambient conditions is also validated.

  14. Integrated locating of helicopter stations and helipads for wounded transfer under demand location uncertainty.

    Science.gov (United States)

    Bozorgi-Amiri, Ali; Tavakoli, Shayan; Mirzaeipour, Hossein; Rabbani, Masoud

    2017-03-01

    Health emergency medical service (HEMS) plays an important role in reducing injuries by providing advanced medical care in the shortest time and reducing the transfer time to advanced treatment centers. In the regions without ground relief coverage, it would be faster to transfer emergency patients to the hospital by a helicopter. In this paper, an integer nonlinear programming model is presented for the integrated locating of helicopter stations and helipads by considering uncertainty in demand points. We assume three transfer modes: (1) direct transfer by an ambulance, (2) transfer by an ambulance to a helicopter station and then to the hospital by a helicopter, (3) transfer by an ambulance to a predetermined point and then to the hospital by a helicopter. We also assume that demands occur in a square-shaped area, in which each side follows a uniform distribution. It is also assumed that demands in an area decrease errors in the distances between each two cities. The purpose of this model is to minimize the transfer time from demand points to the hospital by considering different modes. The proposed model is examined in terms of validity and applicability in Lorestan Province and a sensitivity analysis is also conducted on the total allocated budget. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Dynamic surface measurements on a model helicopter rotor during blade slap at high angles of attack

    Science.gov (United States)

    Hubbard, J. E., Jr.; Harris, W. L.

    1982-01-01

    The modern helicopter offers a unique operational capability to both the public and private sectors. However, the use of the helicopter may become severely limited due to the radiated noise generated by the rotor system. A description is presented of some of the experimental results obtained with a model helicopter rotor in an anechoic wind tunnel with regard to blade stall as a source mechanism of blade slap. Attention is given to dynamic rotor blade surface phenomena and the resulting far field impulsive noise from the model helicopter rotor at high angles of attack and low tip speed. The results of the investigation strongly implicates the boundary layer as playing an important role in blade slap due to blade/vortex interaction (BVI) in a highly loaded rotor. Intermittent stall cannot be ruled out as a possible source mechanism for blade slap. This implies that blade surface characteristics, airfoil shape and local Reynolds number may now be used as tools to reduce the resultant far-field sound pressure levels in helicopters.

  16. 12 CFR Appendixes A-H to Subpart A... - Appendixes A-H to Subpart A of Part 702

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Appendixes A-H to Subpart A of Part 702 A Appendixes A-H to Subpart A of Part 702 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS PROMPT CORRECTIVE ACTION Net Worth Classification Pt. 702, Apps. Appendixes A-H...

  17. Black Hawk Down?: Establishing Helicopter Parenting as a Distinct Construct from Other Forms of Parental Control during Emerging Adulthood

    Science.gov (United States)

    Padilla-Walker, Laura M.; Nelson, Larry J.

    2012-01-01

    The purpose of the current study was to establish a measure of helicopter parenting that was distinct from other forms of parental control, and to examine parental and behavioral correlates of helicopter parenting. Participants included 438 undergraduate students from four universities in the United States (M[subscript age] = 19.65, SD = 2.00,…

  18. Presidential Helicopter Acquisition: Program Established Knowledge-Based Business Case and Entered System Development with Plans for Managing Challenges

    Science.gov (United States)

    2015-04-14

    Presidential Helicopter Acquisition: Program Established Knowledge-Based Business Case and Entered System Development with Plans for Managing Challenges ...Acquisition Reform Act of 2009 (WSARA), This report discusses the cost, schedule, and performance status of the program, challenges it will face in...Presidential Helicopter Acquisition: Program Established Knowledge-Based Business Case and Entered System Development with Plans for Managing

  19. Nine Years of Cooperation: The US-German Memorandum of Understanding (MoU) on Helicopter Aeromechanics 2003-2012

    Science.gov (United States)

    2013-12-01

    major source of structural loads of the rotor blades and the pitch links, as well a major source of vibrations and fatigue. Objectives: The...Extreme operation conditions on rotor blades limit the helicopter in many respects, like maximum speed, efficiency, noise emissions, and loading ...individuals contributed to the modern helicopter handling quality requirements with theoretical analysis, piloted simulations, and flight tests. The

  20. Quantifying Airborne Induced Polarization effects in helicopter time domain electromagnetics

    Science.gov (United States)

    Macnae, James

    2016-12-01

    This paper derives the Airborne Induced Polarization (AIP) response of an airborne electromagnetic (AEM) system to a horizontal, thin sheet conductor. A vertical component double-dipole approximates helicopter systems with towed concentric horizontal transmitter and receiver loops in frequency- or time-domain. In time domain, the AIP effect typically shows up as late-time negative data with amplitude 4 to 5 orders of magnitude smaller than the early-time peak of the positive AEM responses. Because of limited bandwidth from the short sample time after the decay of inductive responses, accurate extraction of intrinsic AIP parameters other than a minimum chargeability is almost impossible. Modelling further suggests that AIP effects in double-dipole AEM systems can only be reliably detected from polarizable material in the top few tens of metres. A titanium mineral exploration case history from the Lac Brûlé area, Quebec, Canada illustrates strong spatial coherence of AIP minimum chargeability estimates and their independence from other effects such as conductivity and magnetic susceptibility.

  1. Design and Evaluation of a Low-Noise Helicopter Blade

    Science.gov (United States)

    Kondo, Natsuki; Tsujiuchi, Tomoka; Murashige, Atsushi; Nishimura, Hiroki; Aoki, Makoto; Tsuchihashi, Akihiko; Yamakawa, Eiichi; Aoyama, Takashi; Saito, Shigeru

    A low-noise helicopter blade, AT1, was designed with the concept of reducing noise without the drop of rotor performance. In the concept, High-Speed Impulsive (HSI) noise is reduced by applying a thin airfoil in the tip region and a dog-tooth like extension in the leading-edge of the tip region. Blade-Vortex Interaction (BVI) noise is reduced by applying the extension and a strong taper near the tip end. The stall angle of the blade is increased by the effect of the vortex generated from the leading-edge extension. As a result, the drop of rotor performance caused by the thin airfoil and the reduction of rotor rotational speed is recovered. The low-noise characteristics and the performance of AT1 were evaluated by a model rotor test conducted at Deutsch Niederländischer Windkanal (DNW). It is shown that AT1 reduces HSI noise and BVI noise and has good performance in forward flight conditions. However, the improvement of performance in high-lift conditions still remains as a future problem.

  2. Flight crew fatigue III: North Sea helicopter air transport operations.

    Science.gov (United States)

    Gander, P H; Barnes, R M; Gregory, K B; Graeber, R C; Connell, L J; Rosekind, M R

    1998-09-01

    We studied 32 helicopter pilots before, during, and after 4-5 d trips from Aberdeen, Scotland, to service North Sea oil rigs. On duty days, subjects awoke 1.5 h earlier than pretrip or posttrip, after having slept nearly an hour less. Subjective fatigue was greater posttrip than pretrip. By the end of trip days, fatigue was greater and mood more negative than by the end of pretrip days. During trips, daily caffeine consumption increased 42%, reports of headache doubled, reports of back pain increased 12-fold, and reports of burning eyes quadrupled. In the cockpits studied, thermal discomfort and high vibration levels were common. Subjective workload during preflight, taxi, climb, and cruise was related to the crewmembers' ratings of the quality of the aircraft systems. During descent and approach, workload was affected by weather at the landing site. During landing, it was influenced by the quality of the landing site and air traffic control. Beginning duty later, and greater attention to aircraft comfort and maintenance, should reduce fatigue in these operations.

  3. Helicopter Drop”: Perspectives on Modern Central Banking Challenges

    Directory of Open Access Journals (Sweden)

    Munteanu Bogdan

    2017-03-01

    Full Text Available This paper aims to discuss the idea of Milton Friedman’s “helicopter drop” of money, analyzing the concept. It is an unconventional measure of monetary policy seen as a permanent uplift in the nominal monetary mass with a zero nominal interest rate, to finance budget deficit of fiscal authority from money issued by Central Bank. It could be a fiscal stimulus or purchases by the Central Bank of non-monetary sovereign debt, in both cases without affecting the current public spending from state budget. The paper takes into account the opportunity costs of such measure being deployed by ECB, looking at end-users (consumers and psychology of decisions over money. In the end, the article reviews the opinions of leading economists and the conclusions reflect that it is not the time or necessity for ECB to resort to such measure now, as the previous measures of quantitative easing and negative interest rate are starting to pay-off producing the targeted result of 2% inflation rate.

  4. Efficient sensitivity analysis and optimization of a helicopter rotor

    Science.gov (United States)

    Lim, Joon W.; Chopra, Inderjit

    1989-01-01

    Aeroelastic optimization of a system essentially consists of the determination of the optimum values of design variables which minimize the objective function and satisfy certain aeroelastic and geometric constraints. The process of aeroelastic optimization analysis is illustrated. To carry out aeroelastic optimization effectively, one needs a reliable analysis procedure to determine steady response and stability of a rotor system in forward flight. The rotor dynamic analysis used in the present study developed inhouse at the University of Maryland is based on finite elements in space and time. The analysis consists of two major phases: vehicle trim and rotor steady response (coupled trim analysis), and aeroelastic stability of the blade. For a reduction of helicopter vibration, the optimization process requires the sensitivity derivatives of the objective function and aeroelastic stability constraints. For this, the derivatives of steady response, hub loads and blade stability roots are calculated using a direct analytical approach. An automated optimization procedure is developed by coupling the rotor dynamic analysis, design sensitivity analysis and constrained optimization code CONMIN.

  5. Support of Helicopter 'Free Flight' Operations in the 1996 Olympics

    Science.gov (United States)

    Branstetter, James R.; Cooper, Eric G.

    1996-01-01

    The microcosm of activity surrounding the 1996 Olympic Games provided researchers an opportunity for demonstrating state-of-the art technology in the first large-scale deployment of a prototype digital communication/navigation/surveillance system in a confined environment. At the same time it provided an ideal opportunity for transportation officials to showcase the merits of an integrated transportation system in meeting the operational needs to transport time sensitive goods and provide public safety services under real-world conditions. Five aeronautical CNS functions using a digital datalink system were chosen for operational flight testing onboard 91 aircraft, most of them helicopters, participating in the Atlanta Short-Haul Transportation System. These included: GPS-based Automatic Dependent Surveillance, Cockpit Display of Traffic Information, Controller-Pilot Communications, Graphical Weather Information (uplink), and Automated Electronic Pilot Reporting (downlink). Atlanta provided the first opportunity to demonstrate, in an actual operating environment, key datalink functions which would enhance flight safety and situational awareness for the pilot and supplement conventional air traffic control. The knowledge gained from such a large-scale deployment will help system designers in development of a national infrastructure where aircraft would have the ability to navigate autonomously.

  6. Validation of Helicopter Gear Condition Indicators Using Seeded Fault Tests

    Science.gov (United States)

    Dempsey, Paula; Brandon, E. Bruce

    2013-01-01

    A "seeded fault test" in support of a rotorcraft condition based maintenance program (CBM), is an experiment in which a component is tested with a known fault while health monitoring data is collected. These tests are performed at operating conditions comparable to operating conditions the component would be exposed to while installed on the aircraft. Performance of seeded fault tests is one method used to provide evidence that a Health Usage Monitoring System (HUMS) can replace current maintenance practices required for aircraft airworthiness. Actual in-service experience of the HUMS detecting a component fault is another validation method. This paper will discuss a hybrid validation approach that combines in service-data with seeded fault tests. For this approach, existing in-service HUMS flight data from a naturally occurring component fault will be used to define a component seeded fault test. An example, using spiral bevel gears as the targeted component, will be presented. Since the U.S. Army has begun to develop standards for using seeded fault tests for HUMS validation, the hybrid approach will be mapped to the steps defined within their Aeronautical Design Standard Handbook for CBM. This paper will step through their defined processes, and identify additional steps that may be required when using component test rig fault tests to demonstrate helicopter CI performance. The discussion within this paper will provide the reader with a better appreciation for the challenges faced when defining a seeded fault test for HUMS validation.

  7. Apollo 11 Astronaut Neil Armstrong Approaches Practice Helicopter

    Science.gov (United States)

    1969-01-01

    In preparation of the nation's first lunar landing mission, Apollo 11, crew members underwent training to practice activities they would be performing during the mission. In this photograph Neil Armstrong approaches the helicopter he flew to practice landing the Lunar Module (LM) on the Moon. The Apollo 11 mission launched from the Kennedy Space Center (KSC) in Florida via the Marshall Space Flight Center (MSFC) developed Saturn V launch vehicle on July 16, 1969 and safely returned to Earth on July 24, 1969. Aboard the space craft were astronauts Neil A. Armstrong, commander; Michael Collins, Command Module (CM) pilot; and Edwin E. (Buzz) Aldrin Jr., Lunar Module (LM) pilot. The CM, 'Columbia', piloted by Collins, remained in a parking orbit around the Moon while the LM, 'Eagle'', carrying astronauts Armstrong and Aldrin, landed on the Moon. On July 20, 1969, Armstrong was the first human to ever stand on the lunar surface, followed by Aldrin. During 2½ hours of surface exploration, the crew collected 47 pounds of lunar surface material for analysis back on Earth. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished

  8. Neural network-based optimal adaptive output feedback control of a helicopter UAV.

    Science.gov (United States)

    Nodland, David; Zargarzadeh, Hassan; Jagannathan, Sarangapani

    2013-07-01

    Helicopter unmanned aerial vehicles (UAVs) are widely used for both military and civilian operations. Because the helicopter UAVs are underactuated nonlinear mechanical systems, high-performance controller design for them presents a challenge. This paper introduces an optimal controller design via an output feedback for trajectory tracking of a helicopter UAV, using a neural network (NN). The output-feedback control system utilizes the backstepping methodology, employing kinematic and dynamic controllers and an NN observer. The online approximator-based dynamic controller learns the infinite-horizon Hamilton-Jacobi-Bellman equation in continuous time and calculates the corresponding optimal control input by minimizing a cost function, forward-in-time, without using the value and policy iterations. Optimal tracking is accomplished by using a single NN utilized for the cost function approximation. The overall closed-loop system stability is demonstrated using Lyapunov analysis. Finally, simulation results are provided to demonstrate the effectiveness of the proposed control design for trajectory tracking.

  9. Backstepping Controller with Intelligent Parameters Selection for Stabilization of Quadrotor Helicopter

    Directory of Open Access Journals (Sweden)

    Mohd Ariffanan Mohd Basri

    2016-07-01

    Full Text Available In this paper, the dynamic model of quadrotor helicopter has been mathematically formulated. Then, an intelligent backstepping controller (IBC is designed for the quadrotor altitude and attitude stabilization in the existence of external disturbances and measurement noise. The designed controller consists of a backstepping controller which can automatically select its parameters on-line by a fuzzy supervisory mechanism. The stability criterion for the stabilization of the quadrotor is proven by the Lyapunov theorem. Several numerical simulations using the dynamic model of a four degree of freedom (DOF quadrotor helicopter show the effectiveness of the approach. Besides, the simulation results indicate that the proposed design techniques can stabilize the quadrotor helicopter with better performance than established linear design techniques.

  10. Sliding Mode Implementation of an Attitude Command Flight Control System for a Helicopter in Hover

    Directory of Open Access Journals (Sweden)

    D. J. McGeoch

    2005-01-01

    Full Text Available This paper presents an investigation into the design of a flight control system, using a decoupled non-linear sliding mode control structure, designed using a linearised, 9th order representation of the dynamics of a PUMA helicopter in hover. The controllers are then tested upon a higher order, non-linear helicopter model, called RASCAL. This design approach is used for attitude command flight control implementation and the control performance is assessed in the terms of handling qualities through the Aeronautical Design Standards for Rotorcraft (ADS-33. In this context a linearised approximation of the helicopter system is used to design an SMC control scheme. These controllers have been found to yield a system that satisfies the Level 1 handling qualities set out by ADS-33. 

  11. Design and implementation of a GPS-aided inertial navigation system for a helicopter UAV

    Science.gov (United States)

    Kastelan, David R.

    Helicopter unmanned aerial vehicles (UAVs) benefit from vertical takeoff and landing, hover, low-speed, and cruising flight capabilities. This versatility has the expense of nonlinear, unstable, and underactuated system dynamics. These challenges and numerous potential applications make the helicopter UAV an interesting testbed for nonlinear control. A platform for such development has been established in the Applied Nonlinear Controls Lab (ANCL). A miniature helicopter was augmented with a manual/autonomous takeover system and the ANCL Avionics. This payload contains a global positioning system (GPS) receiver, inertial sensors, and communications and computing hardware. Allan variance analysis of inertial sensor data enabled the derivation of a GPS-aided inertial navigation system that was implemented on the ANCL Avionics. This extended Kalman filter (EKF)-based algorithm estimates vehicle position, velocity, and attitude necessary for system identification tasks and control system feedback. Performance validation of this algorithm was demonstrated in simulation and in experimental ground and flight tests.

  12. Evaluation of ride quality prediction methods for helicopter interior noise and vibration environments

    Science.gov (United States)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  13. Piloted simulator investigation of helicopter control systems effects on handling qualities during instrument flight

    Science.gov (United States)

    Forrest, R. D.; Chen, R. T. N.; Gerdes, R. M.; Alderete, T. S.; Gee, D. R.

    1979-01-01

    An exploratory piloted simulation was conducted to investigate the effects of the characteristics of helicopter flight control systems on instrument flight handling qualities. This joint FAA/NASA study was motivated by the need to improve instrument flight capability. A near-term objective is to assist in updating the airworthiness criteria for helicopter instrument flight. The experiment consisted of variations of single-rotor helicopter types and levels of stability and control augmentation systems (SCAS). These configurations were evaluated during an omnirange approach task under visual and instrument flight conditions. The levels of SCAS design included a simple rate damping system, collective decoupling plus rate damping, and an attitude command system with collective decoupling. A limited evaluation of stick force versus airspeed stability was accomplished. Some problems were experienced with control system mechanization which had a detrimental effect on longitudinal stability. Pilot ratings, pilot commentary, and performance data related to the task are presented.

  14. Numerical Analysis of Helicopter Rotor Hovering in Close Proximity to the Ground with a Wall

    Science.gov (United States)

    Itoga, Noriaki; Iboshi, Naohiro; Horimoto, Mitsumasa; Saito, Shigeru; Tanabe, Yasutada

    In rescue operations and emergency medical services, helicopters are frequently required to operate near the ground with obstacles such as buildings and sidewalls of highway. In this paper, numerical analysis of helicopter rotor hovering in close proximity to the ground with an obstacle is done by solving unsteady 3D compressible Euler equations with an overlapped grid system. The obstacle is simulated by a wall vertically set up on the ground. The parameters for numerical analysis are the rotor height and distance from the rotor-hub-center to the wall. The effects of combinations of these parameters on the flowfields around the rotor, inflow distributions on the rotor disc and behaviors of blade flapping motion are discussed. It is also clarified the cause that the helicopter rotor hovering in close proximity to the ground with a wall does not have the enough ground effect depending on the combinations of these parameters.

  15. Application of the ABC helicopter to the emergency medical service role

    Science.gov (United States)

    Levine, L. S.

    1981-01-01

    Attention is called to the use of helicopters in transporting the sick and injured to medical facilities. It is noted that the helicopter's speed of response and delivery increases patient survival rates and may reduce the cost of medical care and its burden on society. Among the vehicle characteristics desired for this use are a cruising speed of 200 knots, a single engine hover capability at 10,000 ft, and an absence of a tail rotor. Three designs for helicopters incorporating such new technologies as digital/optical control systems, all composite air-frames, and third-generation airfoils are presented. A sensitivity analysis is conducted to show the effect of design speed, mission radius, and single engine hover capability on vehicle weight, fuel consumption, operating costs, and productivity.

  16. The cost of applying current helicopter external noise reduction methods while maintaining realistic vehicle performance

    Science.gov (United States)

    Bowes, M. A.

    1978-01-01

    Analytical methods were developed and/or adopted for calculating helicopter component noise, and these methods were incorporated into a unified total vehicle noise calculation model. Analytical methods were also developed for calculating the effects of noise reduction methodology on helicopter design, performance, and cost. These methods were used to calculate changes in noise, design, performance, and cost due to the incorporation of engine and main rotor noise reduction methods. All noise reduction techniques were evaluated in the context of an established mission performance criterion which included consideration of hovering ceiling, forward flight range/speed/payload, and rotor stall margin. The results indicate that small, but meaningful, reductions in helicopter noise can be obtained by treating the turbine engine exhaust duct. Furthermore, these reductions do not result in excessive life cycle cost penalties. Currently available main rotor noise reduction methodology, however, is shown to be inadequate and excessively costly.

  17. ADAPTIVE FLIGHT CONTROL SYSTEM OF ARMED HELICOPTER USING WAVELET NEURAL NETWORK METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHURong-gang; JIANGChangsheng; FENGBin

    2004-01-01

    A discussion is devoted to the design of an adaptive flight control system of the armed helicopter using wavelet neural network method. Firstly, the control loop of the attitude angle is designed with a dynamic inversion scheme in a quick loop and a slow loop. respectively. Then, in order to compensate the error caused by dynamic inversion, the adaptive flight control system of the armed helicopter using wavelet neural network method is put forward, so the BP wavelet neural network and the Lyapunov stable wavelet neural network are used to design the helicopter flight control system. Finally, the typical maneuver flight is simulated to demonstrate its validity and effectiveness. Result proves that the wavelet neural network has an engineering practical value and the effect of WNN is good.

  18. Appendix

    DEFF Research Database (Denmark)

    Friis, Ib; Thulin, Mats

    2009-01-01

    A taxonomic and floristic account of all the additional or new species in Etyhiopia and/or Eritrea that have been discovered while Vols 2 - 7 of the Flora of Ethiopia and Eritrea were being published....

  19. Comparison of helicopter and ground emergency medical service: a retrospective analysis of a German rescue helicopter base.

    Science.gov (United States)

    Mommsen, Philipp; Bradt, Nikolas; Zeckey, Christian; Andruszkow, Hagen; Petri, Max; Frink, Michael; Hildebrand, Frank; Krettek, Christian; Probst, Christian

    2012-01-01

    In consideration of rising cost pressure in the German health care system, the usefulness of helicopter emergency medical service (HEMS) in terms of time- and cost-effectiveness is controversially discussed. The aim of the present study was to investigate whether HEMS is associated with significantly decreased arrival and transportation times compared to ground EMS. In a retrospective study, we evaluated 1,548 primary emergency missions for time sensitive diagnoses (multiple trauma, traumatic brain and burn injury, heart-attack, stroke, and pediatric emergency) performed by a German HEMS using the medical database, NADIN, of the German Air Rescue Service. Arrival and transportation times were compared to calculated ground EMS times. HEMS showed significantly reduced arrival times at the scene in case of heart-attack, stroke and pediatric emergencies. In contrast, HEMS and ground EMS showed comparable arrival times in patients with multiple trauma, traumatic brain and burn injury due to an increased flight distance. HEMS showed a significantly decreased transportation time to the closest centre capable of specialist care in all diagnosis groups (pambulance services with significantly decreased transportation times.

  20. Development of an Autonomous Flight Control System for Small Size Unmanned Helicopter Based on Dynamical Model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    It is devoted to the development of an autonomous flight control system for small size unmanned helicopter based on dynamical model. At first, the mathematical model of a small size helicopter is described. After that simple but effective MTCV control algorithm was proposed. The whole flight control algorithm is composed of two parts:orientation controller based on the model for rotation dynamics and a robust position controller for a double integrator. The MTCV block is also used to achieve translation velocity control. To demonstrate the performance of the presented algorithm, simulation results and results achieved in real flight experiments were presented.

  1. Attitude angle anti-windup control of small size unmanned helicopter

    Science.gov (United States)

    Shao, Taizhou; Long, Haihui; Zhao, Jiankang; Xia, Xuan; Yang, Guang

    2017-01-01

    This paper researches the small-size unmanned helicopter attitude control problem with actuator saturation limit. Traditional approach for this problem is often based on an accurate dynamic model which is complicated and difficult to achieve in engineering. In this paper, we propose an anti-windup PID approach which does not rely on sophicated helicopter dynamic model. The anti-windup PID controller is established by adding a phase-lead compensator to the conventional PID controller. The performance and merits of this proposed controller are exemplified by the simulations between the conventional PID controller and the anti-windup PID controller.

  2. Transverse vibration of the blade for unmanned micro helicopter using rayleigh-ritz method

    Institute of Scientific and Technical Information of China (English)

    Jungang Lü; Jiadao Wang; Darong Chen

    2003-01-01

    A rotor manipulation mechanism for micro unmanned helicopter utilizing the inertia and the elasticity of the rotor is introduced. The lagging motion equation of the rotor blades is established, and then the natural frequencies and mode shapes of the blade for the helicopter are studied by using beam characteristic orthogonal polynomials by the Rayleigh-Ritz method. The variation of natural frequencies with the speed of rotation and the mode shapes at different rotational speeds are plotted. The using of orthogonal polynomials for the bending shapes enables the computation of higher natural frequencies of any order to be accomplished without facing any difficulties.

  3. Static strain and vibration characteristics of a metal semimonocoque helicopter tail cone of moderate size

    Science.gov (United States)

    Bielawa, Richard L.; Hefner, Rachel E.; Castagna, Andre

    1991-01-01

    The results are presented of an analytic and experimental research program involving a Sikorsky S-55 helicopter tail cone directed ultimately to the improved structural analysis of airframe substructures typical of moderate sized helicopters of metal semimonocoque construction. Experimental static strain and dynamic shake-testing measurements are presented. Correlation studies of each of these tests with a PC-based finite element analysis (COSMOS/M) are described. The tests included static loadings at the end of the tail cone supported in the cantilever configuration as well as vibrational shake-testing in both the cantilever and free-free configurations.

  4. Minor Component Analysis-based Landing Forecast System for Ship-borne Helicopter

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bo,; SHI Ai-guo; WAN Lin; YANG Bao-zhang

    2005-01-01

    The general structure of ship-borne helicopter landing forecast system is presented, and a novel ship motion prediction model based on minor component analysis (MCA) is built up to improve the forecast effectiveness. To validate the feasibility of this landing forecast system, time series for the roll, pitch and heave are generated by simulation and then forecasted based on MCA. Simulation results show that ship-borne helicopters can land safely in higher sea condition while carrying on rescue or replenishment tasks at sea in terms of the landing forecast system.

  5. A helicopter emergency medical service may allow faster access to highly specialised care

    DEFF Research Database (Denmark)

    Afzali, Monika; Hesselfeldt, Rasmus; Steinmetz, Jacob

    2013-01-01

    Centralization of the hospital system entails longer transport for some patients. A physician-staffed helicopter may provide effective triage, advanced management and fast transport to highly specialized treatment for time-critical patients. The aim of this study was to describe activity and poss......Centralization of the hospital system entails longer transport for some patients. A physician-staffed helicopter may provide effective triage, advanced management and fast transport to highly specialized treatment for time-critical patients. The aim of this study was to describe activity...

  6. Fuzzy Control of Yaw and Roll Angles of a Simulated Helicopter Model Includes Articulated Manipulators

    Directory of Open Access Journals (Sweden)

    Hossein Sadegh Lafmejani

    2015-09-01

    Full Text Available Fuzzy logic controller (FLC is a heuristic method by If-Then Rules which resembles human intelligence and it is a good method for designing Non-linear control systems. In this paper, an arbitrary helicopter model includes articulated manipulators has been simulated with Matlab SimMechanics toolbox. Due to the difficulties of modeling this complex system, a fuzzy controller with simple fuzzy rules has been designed for its yaw and roll angles in order to stabilize the helicopter while it is in the presence of disturbances or its manipulators are moving for a task. Results reveal that a simple FLC can appropriately control this system.

  7. Design of a simple active controller to suppress helicopter air resonance

    Science.gov (United States)

    Takahashi, M. D.; Friedmann, P. P.

    1988-01-01

    A coupled rotor/fuselage helicopter analysis with the important effects of blade torsional flexibility, unsteady aerodynamics, and forward flight is presented. Using this mathematical model, a nominal configuration is selected that experiences an air resonance instability throughout most of its flight envelope. A simple multivariable compensator using conventional swashplate inputs and a single body roll rate measurement is then designed. The controller design is based on a linear estimator in conjunction with optimal feedback gains, and the design is done in the frequency domain using the Loop Transfer Recovery method. The controller is shown to suppress the air resonance instability throughout wide range helicopter loading conditions and forward flight speeds.

  8. Failure analysis of a bearing in a helicopter turbine engine due to electrical discharge damage

    Directory of Open Access Journals (Sweden)

    Michael K. Budinski

    2014-10-01

    Full Text Available This article documents the metallurgical evaluation of a rolling element bearing that failed due to electrical discharge damage. This rolling element bearing was used in a helicopter turbine engine that failed in-flight, resulting in a hard landing of the helicopter. Optical and electron microscopy as well as energy dispersive spectroscopy were used to evaluate the bearing. Pitting and material transfer on the external bearing races bearing and mating surfaces revealed that the electrical discharge damage occurred while the engine's components were not rotating.

  9. Research requirements to reduce empty weight of helicopters by use of advanced materials

    Science.gov (United States)

    Hoffstedt, D. J.

    1976-01-01

    Utilization of the new, lightweight, high-strength, aerospace structural-composite (filament/matrix) materials, when specifically designed into a new aircraft, promises reductions in structural empty weight of 12 percent at recurring costs competive with metals. A program of basic and applied research and demonstration is identified with the objective of advancing the state of the art to the point where civil helicopters are confidently designed, produced, certified, and marketed by 1985. A structural empty-weight reduction of 12 percent was shown to significantly reduce energy consumption in modern high-performance helicopters.

  10. Impact of a physician-staffed helicopter on a regional trauma system

    DEFF Research Database (Denmark)

    Hesselfeldt, R; Steinmetz, J; Jans, H

    2013-01-01

    This study aims to compare the trauma system before and after implementing a physician-staffed helicopter emergency medical service (PS-HEMS). Our hypothesis was that PS-HEMS would reduce time from injury to definitive care for severely injured patients.......This study aims to compare the trauma system before and after implementing a physician-staffed helicopter emergency medical service (PS-HEMS). Our hypothesis was that PS-HEMS would reduce time from injury to definitive care for severely injured patients....

  11. A comparison of model helicopter rotor Primary and Secondary blade/vortex interaction blade slap

    Science.gov (United States)

    Hubbard, J. E., Jr.; Leighton, K. P.

    1983-01-01

    A study of the relative importance of blade/vortex interactions which occur on the retreating side of a model helicopter rotor disk is described. Some of the salient characteristics of this phenomenon are presented and discussed. It is shown that the resulting Secondary blade slap may be of equal or greater intensity than the advancing side (Primary) blade slap. Instrumented model helicopter rotor data is presented which reveals the nature of the retreating blade/vortex interaction. The importance of Secondary blade slap as it applies to predictive techniques or approaches is discussed. When Secondary blade slap occurs it acts to enlarge the window of operating conditions for which blade slap exists.

  12. Crohn's disease limited to the vermiform appendix

    DEFF Research Database (Denmark)

    Bak, Martin; Andersen, J C

    1987-01-01

    Thirteen cases of Crohn's disease confined to the vermiform appendix were seen during a 12-year period. They constituted 16.9% of patients with primary resection of the bowel for Crohn's disease in the same period, but only 0.4% of the cases of acute appendicitis. In 10 of the 13 cases...... to approach that of recurrence after resection in other parts of the intestines. Collective review of this and three other relatively large case series gave an estimated recurrence rate of 3.5%. We conclude that in Crohn's disease initially confined to the appendix the course appears to be indolent....

  13. Small cell carcinoma of the appendix

    Directory of Open Access Journals (Sweden)

    Carey Declan P

    2008-01-01

    Full Text Available Abstract Background An extrapulmonary small cell carcinoma is a rare condition. It has similar histological features to pulmonary small cell carcinoma and is equally aggressive. Case presentation We present the case of a 60-year-old woman who presented with right upper quadrant pain. Computerised tomography revealed an appendiceal lesion and multiple liver metastases. Exploratory laparotomy and right hemicolectomy was performed with histopathological analysis confirming a primary small cell carcinoma of her appendix. Conclusion This is the first reported case of a pure extrapulmonary carcinoma arising from the appendix.

  14. Appendix to Power Dissipation in Division

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    This document is an appendix to the paper: Wei Liu and Alberto Nannarelli, ”Power Dissipation in Division”, Proc. of 42nd Asilomar Conference on Signals, Systems, and Computers, October 2008. The purpose of the document is to provide the necessary information for the implementation of the archite......This document is an appendix to the paper: Wei Liu and Alberto Nannarelli, ”Power Dissipation in Division”, Proc. of 42nd Asilomar Conference on Signals, Systems, and Computers, October 2008. The purpose of the document is to provide the necessary information for the implementation...

  15. Evaluation of Standard Gear Metrics in Helicopter Flight Operation

    Science.gov (United States)

    Mosher, M.; Pryor, A. H.; Huff, E. M.

    2002-01-01

    sense that the rpm, torque and forces on the gear have been held steady. For gears used in a dynamic environment such as that occurring in aircraft, the rpm, torque and forces on the gear are constantly changing. The authors have measured significant variation in rpm and torque in the transmissions of helicopters in controlled steady flight conditions flown by highly proficient test pilots. Statistical analyses of the data taken in flight show significant nonstationarity in the vibration measurements. These deviations from stationarity may increase false alarms in gear monitoring during aircraft flight. In the proposed paper, the authors will study vibration measurements made in flight on an AH- 1 Cobra and an OH-58C Kiowa helicopters. The primary focus will be the development of a methodology to assess the impact of nonstationarity on false alarms. Issues to be addressed include how time synchronous averages are constructed from raw data as well as how lack of stationarity effects the behavior of single value metrics. Emphasis will be placed on the occurrence of false alarms with the use of standard metrics. In order to maintain an acceptable level of false alarms in the flight environment, this study will also address the determination of appropriate threshold levels, which may need to be higher than for test rigs.

  16. Proposed Wind Turbine Aeroelasticity Studies Using Helicopter Systems Analysis

    Science.gov (United States)

    Ladkany, Samaan G.

    1998-01-01

    Advanced systems for the analysis of rotary wing aeroelastic structures (helicopters) are being developed at NASA Ames by the Rotorcraft Aeromechanics Branch, ARA. The research has recently been extended to the study of wind turbines, used for electric power generation Wind turbines play an important role in Europe, Japan & many other countries because they are non polluting & use a renewable source of energy. European countries such as Holland, Norway & France have been the world leaders in the design & manufacture of wind turbines due to their historical experience of several centuries, in building complex wind mill structures, which were used in water pumping, grain grinding & for lumbering. Fossil fuel cost in Japan & in Europe is two to three times higher than in the USA due to very high import taxes. High fuel cost combined with substantial governmental subsidies, allow wind generated power to be competitive with the more traditional sources of power generation. In the USA, the use of wind energy has been limited mainly because power production from wind is twice as expensive as from other traditional sources. Studies conducted at the National Renewable Energy Laboratories (NREL) indicate that the main cost in the production of wind turbines is due to the materials & the labor intensive processes used in the construction of turbine structures. Thus, for the US to assume world leadership in wind power generation, new lightweight & consequently very flexible wind turbines, that could be economically mass produced, would have to be developed [4,5]. This effort, if successful, would result in great benefit to the US & the developing nations that suffer from overpopulation & a very high cost of energy.

  17. Prototype of a tilt rotor helicopter: A helicopter comprising a multi-rotor system with individual collective and cyclic pitch control.

    OpenAIRE

    Napsholm, Svein Rivli

    2013-01-01

    The use of drones and remote operated aircrafts has become a useful tool for the oil and mining industry, when searching for new production areas. The remote controlled aircrafts can perform some of the tasks during these operations such as deploy sensors, gather geographical data and perform area inspections. The smaller and cheaper aircrafts are a cost and time effective solution compared to using bigger helicopters and air planes. In this master thesis, it is proposed a new type of remote ...

  18. Adaptation of the Neural Network Recognition System of the Helicopter on Its Acoustic Radiation to the Flight Speed

    Directory of Open Access Journals (Sweden)

    V. K. Hohlov

    2015-01-01

    Full Text Available The article concerns the adaptation of a neural tract that recognizes a helicopter from the aerodynamic and ground objects by its acoustic radiation to the helicopter flight speed. It uses non-centered informative signs-indications of estimating signal spectra, which correspond to the local extremes (maximums and minimums of the power spectrum of input signal and have the greatest information when differentiating the helicopter signals from those of tracked vehicles. The article gives justification to the principle of the neural network (NN adaptation and adaptation block structure, which solves problems of blade passage frequency estimation when capturing the object and track it when tracking a target, as well as forming a signal to control the resonant filter parameters of the selection block of informative signs. To create the discriminatory characteristics of the discriminator are used autoregressive statistical characteristics of the quadrature components of signal, obtained through the discrete Hilbert Converter (DGC that perforMathematical modeling of the tracking meter using the helicopter signals obtained in real conditions is performed. The article gives estimates of the tracking parameter when using a tracking meter with DGC by sequential records of realized acoustic noise of the helicopter. It also shows a block-diagram of the adaptive NN. The scientific novelty of the work is that providing the invariance of used informative sign, the counts of local extremes of power spectral density (PSD to changes in the helicopter flight speed is reached due to adding the NN structure and adaptation block, which is implemented as a meter to track the apparent passage frequency of the helicopter rotor blades using its relationship with a function of the autoregressive acoustic signal of the helicopter.Specialized literature proposes solutions based on the use of training classifiers with different parametric methods of spectral representations

  19. Wind tunnel testing of a full scale helicopter blade section with an upstream active Gurney flap

    NARCIS (Netherlands)

    Loendersloot, R.; Freire Gomez, J.; Booker, J.D.

    2014-01-01

    Wind tunnel tests were performed on an aerofoil section comparable to that of a full scale helicopter blade section with an upstream active Gurney flap in the framework of the European project CleanSky ITD Green RotorCraft. A modified NACA0012 profile was used, with 23 Kulite pressure transducers em

  20. 78 FR 69987 - Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters (Type Certificate...

    Science.gov (United States)

    2013-11-22

    ... handle the indicator glass bulb since the heat of the hand may change the internal reference pressure and... indicator color check will take about 0.1 work-hour at an average labor rate of $85 per work- hour. Based on these figures, each visual BIM pressure indicator color check will cost about $9 per helicopter or...

  1. Method and device for the detection and identification of a helicopter

    Science.gov (United States)

    Siebecker, Hans

    1988-01-01

    The invention presents a method for detecting and identifying a helicopter based on its characteristic emission of energy in the visual and infrared regions as well as acoustic energy by employing a fire control computer with data storage and a device for targeting and observation.

  2. 77 FR 38744 - Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S-64F Helicopters

    Science.gov (United States)

    2012-06-29

    ... the Sikorsky Aircraft Corporation-manufactured Model S-64F helicopters, now under the Erickson Air-Crane Incorporated (Erickson) Model S-64F type certificate. That AD currently requires inspections... docket shortly after receipt. For service information identified in this proposed AD, contact Erickson...

  3. 75 FR 56487 - Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

    Science.gov (United States)

    2010-09-16

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Erickson Air-Crane... rulemaking (NPRM). SUMMARY: This document proposes adopting a new airworthiness directive (AD) for Erickson Air-Crane Incorporated (Erickson Air-Crane) Model S- 64F helicopters. The AD would require, at...

  4. Job Performance Tests for U/AH-1 Helicopter Mechanics. Volume 1: Hands- On Performance Test

    Science.gov (United States)

    1991-11-01

    Hands-on performance tests and job knowledge tests were developed for MOS 6114 (U/AH-1 helicopter mechanic) as part of the Marine Corps Job ... Performance Measurement Project. The purpose of this information memorandum is to disseminate these performance measures to Marine Corps personnel managers

  5. Integrated Flight Path Planning System and Flight Control System for Unmanned Helicopters

    Directory of Open Access Journals (Sweden)

    Yu-Hsiang Lin

    2011-07-01

    Full Text Available This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS and the Flight Control System (FCS. The FPPS finds the shortest flight path by the A-Star (A* algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM.

  6. 77 FR 44116 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-07-27

    ... degraded the annunciator system's redundant power supply, so that pilots could not be warned of a second...-BK117 C-1 helicopter. The actions of this AD are intended to prevent uncommanded cutting of the hoist... uncommanded cutting of the hoist cable and subsequent injury to persons being lifted by the hoist....

  7. Helicopter and aircraft detection and classification using adaptive beamforming and tracking techniques

    NARCIS (Netherlands)

    Koersel, A.C. van; Beerens, S.P.

    2002-01-01

    Measurements of different types of aircraft are performed and used to obtain information on target characteristics and develop an algorithm to perform classification between jet aircraft, propeller aircraft and helicopters. To obtain a larger detection range, reduce background noise and to reduce

  8. Prediction and simulator verification of state-space rotor modelling on helicopter manoeuvring flight

    NARCIS (Netherlands)

    Gori, R.; Gennaretti, M.; Pavel, M.D.; Stroosma, O.; Miletovic, I.

    2015-01-01

    Among the many fundamental components of a flight simulator, the mathematical representation of the vehicle dynamics stands out for complexity and importance. This is especially true for helicopters, for which the complex dynamics involved prevents simple models to be sufficiently accurate without t

  9. Velocity-Aided Attitude Estimation for Helicopter Aircraft Using Microelectromechanical System Inertial-Measurement Units

    Directory of Open Access Journals (Sweden)

    Sang Cheol Lee

    2016-12-01

    Full Text Available This paper presents an algorithm for velocity-aided attitude estimation for helicopter aircraft using a microelectromechanical system inertial-measurement unit. In general, high- performance gyroscopes are used for estimating the attitude of a helicopter, but this type of sensor is very expensive. When designing a cost-effective attitude system, attitude can be estimated by fusing a low cost accelerometer and a gyro, but the disadvantage of this method is its relatively low accuracy. The accelerometer output includes a component that occurs primarily as the aircraft turns, as well as the gravitational acceleration. When estimating attitude, the accelerometer measurement terms other than gravitational ones can be considered as disturbances. Therefore, errors increase in accordance with the flight dynamics. The proposed algorithm is designed for using velocity as an aid for high accuracy at low cost. It effectively eliminates the disturbances of accelerometer measurements using the airspeed. The algorithm was verified using helicopter experimental data. The algorithm performance was confirmed through a comparison with an attitude estimate obtained from an attitude heading reference system based on a high accuracy optic gyro, which was employed as core attitude equipment in the helicopter.

  10. Hummingbird wing efficacy depends on aspect ratio and compares with helicopter rotors

    NARCIS (Netherlands)

    Kruyt, J.W.; Quicazan Rubio, E.M.; Heijst, van G.J.F.; Altshuler, D.L.; Lentink, D.

    2014-01-01

    Hummingbirds are the only birds that can sustain hovering. This unique flight behaviour comes, however, at high energetic cost. Based on helicopter and aeroplane design theory, we expect that hummingbird wing aspect ratio (AR), which ranges from about 3.0 to 4.5, determines aerodynamic efficacy. Pre

  11. Advanced medical life support procedures in vitally compromised children by a helicopter emergency medical service.

    NARCIS (Netherlands)

    Gerritse, B.M.; Schalkwijk, A.; Pelzer, B.J.; Scheffer, G.J.; Draaisma, J.M.T.

    2010-01-01

    BACKGROUND: To determine the advanced life support procedures provided by an Emergency Medical Service (EMS) and a Helicopter Emergency Medical Service (HEMS) for vitally compromised children. Incidence and success rate of several procedures were studied, with a distinction made between procedures

  12. 77 FR 37777 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-06-25

    ... and Malfunction Procedures'' and ``Performance Data'' sections of the Rotorcraft Flight Manual (RFM... Schwab, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, 2601 Meacham Blvd... other helicopters of the same type design. Related Service Information We reviewed ECD ASB MBB BK117...

  13. 78 FR 23696 - Airworthiness Directives; Eurocopter Deutschland GmbH (ECD) Helicopters

    Science.gov (United States)

    2013-04-22

    ... 663, Fort Worth, Texas 76137. FOR FURTHER INFORMATION CONTACT: Jim Grigg, Manager, FAA, Rotorcraft... develop on other helicopters of the same type design. Related Service Information ECD has issued Alert... performance section of the Rotorcraft Flight Manual. Costs of Compliance We estimate that this proposed...

  14. Smart actuation mechanisms for helicopter blades: design case for a mach-scaled model blade

    NARCIS (Netherlands)

    Paternoster, Alexandre

    2013-01-01

    This work is part of the European project “Clean Sky”, which aims at improving the efficiency and the global transport quality of aircraft. The research, in this project, is currently focussing on active flap systems for helicopters to adapt the blade aerodynamic properties to local aerodynamic

  15. Helicopter and aircraft detection and classification using adaptive beamforming and tracking techniques

    NARCIS (Netherlands)

    Koersel, A.C. van; Beerens, S.P.

    2002-01-01

    Measurements of different types of aircraft are performed and used to obtain information on target characteristics and develop an algorithm to perform classification between jet aircraft, propeller aircraft and helicopters. To obtain a larger detection range, reduce background noise and to reduce cl

  16. Wireless sensor network for helicopter rotor blade vibration monitoring: Requirements definition and technological aspects

    NARCIS (Netherlands)

    Sanchez Ramirez, Andrea; Das, Kallol; Loendersloot, Richard; Tinga, Tiedo; Havinga, Paul; Basu, Biswajit

    2013-01-01

    The main rotor accounts for the largest vibration source for a helicopter fuselage and its components. However, accurate blade monitoring has been limited due to the practical restrictions on instrumenting rotating blades. The use of Wireless Sensor Networks (WSNs) for real time vibration monitoring

  17. Lumbar back muscle activity of helicopter pilots and whole-body vibration.

    Science.gov (United States)

    de Oliveira, C G; Simpson, D M; Nadal, J

    2001-10-01

    Several studies have attributed the prevalence of low back pain (LBP) in helicopter pilots mainly to poor posture in-flight and whole-body vibration, with the latter hypothesis particularly related to a cyclic response of the erector spine (ES) muscle to vibration. This work aims to determine if helicopter vibration and the pilot's normal posture during flight have significant effects on the electromyogram (EMG) of the ES muscle. The bilateral surface EMG of the ES muscle at the L3 level was collected in 10 young pilots before and during a short flight in UH-50 helicopters. The vibration was monitored by a triaxial accelerometer fixed to the pilots' seat. Prior to the flight, the EMG was recorded for relaxed seated and standing postures with 0 degrees (P0) and 35 degrees (P35) of trunk flexion. The effect of the posture during the flight was tested by comparing left and right EMG (normalized with respect to P35). The in-flight muscle stress was evaluated by histograms of EMG activity, and compared to P0 values. Only one pilot in ten showed significant (pvibration and the EMG over cycles of vibration, and no consistent causal effect was found. The pilots' posture did not show significant asymmetric muscular activity, and low EMG levels were observed during most of the duration of the flight. The results do not provide evidence that LBP in helicopter pilots is caused by ES muscle stress in the conditions studied.

  18. Smart actuation mechanisms for helicopter blades: design case for a mach-scaled model blade

    NARCIS (Netherlands)

    Paternoster, A.R.A.

    2013-01-01

    This work is part of the European project “Clean Sky”, which aims at improving the efficiency and the global transport quality of aircraft. The research, in this project, is currently focussing on active flap systems for helicopters to adapt the blade aerodynamic properties to local aerodynamic cond

  19. Eliminating Fratricide from Attack Helicopter Fires: An Army Aviator’s Perspective

    Science.gov (United States)

    1994-06-03

    ti-ank Helicopters,, (London: Osprey Publishing, 1986), 4. PIbid . ’ 0Ibid. , 5. "Ilbid., 10. 121bid. , 3. ilIbid., 10. "Ibid., 11. 15Charles R. Shrader...Command and General Staff College on 21 March, 1994. 5kT.S. GAO, Apache Fratricide Incident. 17. ŖIbid., 19. PIbid .. 30. *Task Force Iron consisted of

  20. Analysis of U.S. Military Helicopter Operations in Support of Humanitarian Assistance and Disaster Relief

    Science.gov (United States)

    2011-12-01

    49 VI. ALLOCATION OF HELICOPTERS TO ROUTES .............................................51 A. MODEL 2: HEURISTIC APPROACH... Heuristic Distribution.......................................................................................53 Table 16. Priority Distribution...supplies the villagers needed (JLLIS, 2008d). Aircrew debriefs on safe and acceptable landing zones were critical to the tsunami relief success

  1. Prehospital intraosseus access with the bone injection gun by a helicopter-transported emergency medical team.

    NARCIS (Netherlands)

    Gerritse, B.M.; Scheffer, G.J.; Draaisma, J.M.T.

    2009-01-01

    BACKGROUND: To evaluate the use of the bone injection gun to obtain vascular access in the prehospital setting by an Helicopter-Transported Emergency Medical Team. METHODS: Prospective descriptive study to assess the frequency and success rate of the use of the bone injection gun in prehospital care

  2. Framework of Combined Adaptive and Non-adaptive Attitude Control System for a Helicopter Experimental System

    Institute of Scientific and Technical Information of China (English)

    Akira Inoue; Ming-Cong Deng

    2006-01-01

    This paper presents a framework of a combined adaptive and non-adaptive attitude control system for a helicopter experimental system. The design method is based on a combination of adaptive nonlinear control and non-adaptive nonlinear control. With regard to detailed attitude control system design, two schemes are shown for different application cases.

  3. Survival benefit of physician-staffed Helicopter Emergency Medical Services (HEMS) assistance for severely injured patients

    NARCIS (Netherlands)

    D. den Hartog (Dennis); J. Romeo (Jamie); A.N. Ringburg (Akkie); M.H.J. Verhofstad (Michiel); E.M.M. van Lieshout (Esther)

    2015-01-01

    markdownabstractBackground: Physician-staffed Helicopter Emergency Medical Services (HEMS) provide specialist medical care to the accident scene and aim to improve survival of severely injured patients. Previous studies were often underpowered and showed heterogeneous results, leaving the subject at

  4. Full-Scale Crash Test of a MD-500 Helicopter with Deployable Energy Absorbers

    Science.gov (United States)

    Kellas, Sotiris; Jackson, Karen E.; Littell, Justin D.

    2010-01-01

    A new externally deployable energy absorbing system was demonstrated during a full-scale crash test of an MD-500 helicopter. The deployable system is a honeycomb structure and utilizes composite materials in its construction. A set of two Deployable Energy Absorbers (DEAs) were fitted on the MD-500 helicopter for the full-scale crash demonstration. Four anthropomorphic dummy occupants were also used to assess human survivability. A demonstration test was performed at NASA Langley's Landing and Impact Research Facility (LandIR). The test involved impacting the helicopter on a concrete surface with combined forward and vertical velocity components of 40-ft/s and 26-ft/s, respectively. The objectives of the test were to evaluate the performance of the DEA concept under realistic crash conditions and to generate test data for validation of dynamic finite element simulations. Descriptions of this test as well as other component and full-scale tests leading to the helicopter test are discussed. Acceleration data from the anthropomorphic dummies showed that dynamic loads were successfully attenuated to within non-injurious levels. Moreover, the airframe itself survived the relatively severe impact and was retested to provide baseline data for comparison for cases with and without DEAs.

  5. Advanced medical life support procedures in vitally compromised children by a helicopter emergency medical service.

    NARCIS (Netherlands)

    Gerritse, B.M.; Schalkwijk, A.; Pelzer, B.J.; Scheffer, G.J.; Draaisma, J.M.T.

    2010-01-01

    BACKGROUND: To determine the advanced life support procedures provided by an Emergency Medical Service (EMS) and a Helicopter Emergency Medical Service (HEMS) for vitally compromised children. Incidence and success rate of several procedures were studied, with a distinction made between procedures r

  6. 77 FR 20321 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-04-04

    ... anyone being lifted in the rescue hoist. Related Service Information ECD has issued Emergency Alert... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of...

  7. 78 FR 60186 - Airworthiness Directives; AgustaWestland S.p.A. (Agusta) Helicopters

    Science.gov (United States)

    2013-10-01

    ... (AD) for Agusta Model AB139 and AW139 helicopters. This AD requires deactivating the Full Icing Protection System (FIPS) and installing a placard next to the FIPS controller stating that flight into known... views. We also invite comments relating to the economic, environmental, energy, or federalism...

  8. Identification of a coupled flapping/inflow model for the PUMA helicopter from flight test data

    Science.gov (United States)

    Du Val, Ronald; Bruhis, Ofer; Green, John

    1989-01-01

    A model validation procedure is applied to a coupled flapping/inflow model of a PUMA helicopter blade. The structure of the baseline model is first established. Model structure and flight test data are checked for consistency. Parameters of the model are then identified from the flight test data.

  9. A study of the effects of Rotating Frame Turbulence (RFT) on helicopter flight mechanics

    Science.gov (United States)

    Schrage, D. P.; Prasad, J. V. B.; Gaonkar, G. H.

    1989-01-01

    The turbulence actually experienced by a helicopter blade-element significantly differs from the space-fixed free atmospheric turbulence. The turbulence in the rotor disk requires a rotationally sampled description in a rotating frame of reference. It is referred to as the rotating frame turbulence or RFT which exhibits a striking phenomenon. The RFT spectral density versus frequency shows high peak values at 1P,2P, or 3P, frequencies. The energy increase at these peaks is balanced by an energy decrease primarily at the lower-than-1P frequency range. Particularly for low altitude flight regimes of pure helicopters, such as the nap-of-the-earth maneuvers, the conventional space-fixed description of turbulence is not a good approximation, since the turbulence scale length can have values comparable to the rotor radius. Accordingly the flight mechanics characteristics with RFT description are compared with those based on the conventional space-fixed turbulence description. The results demonstrate that the RFT qualitatively and quantitatively affects the prediction of helicopter flight mechanics characteristics in turbulence. Such comparisons should play an important role in the new development of handling qualities specifications for helicopters.

  10. Cancellations of (helicopter-transported) mobile medical team dispatches in the Netherlands

    NARCIS (Netherlands)

    Giannakopoulos, G.F.; Lubbers, W.D.; Christiaans, H.M.T.; van Exter, P.; Bet, P.; Hugen, P.J.C.; Innemee, G.; Schubert, E.; de Lange-Klerk, E.S.M.; Goslings, J.C.; Jukema, G.N.

    2010-01-01

    The trauma centre of the Trauma Center Region North-West Netherlands (TRNWN) has consensus criteria for Mobile Medical Team (MMT) scene dispatch. The MMT can be dispatched by the EMS-dispatch centre or by the on-scene ambulance crew and is transported by helicopter or ground transport. Although much

  11. Neutron radiography and other NDE tests of main rotor helicopter blades

    CSIR Research Space (South Africa)

    De Beer, FC

    2004-10-01

    Full Text Available leading to aircraft structural failures, are addressed by various NDE techniques. In a combined investigation by means of visual inspection, X-ray radiography and shearography on helicopter main rotor blades, neutron radiography (NRad) at SAFARI-1 research...

  12. 77 FR 75073 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2012-12-19

    ... this proposed AD, contact American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, Texas... erosion protective shell, which could lead to an unbalanced main rotor, high vibration, damage to the tail boom or tail rotor, and loss of control of the helicopter. The European Aviation Safety Agency (EASA...

  13. 76 FR 76068 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2011-12-06

    ... rotor blade erosion protective shell which could lead to an unbalanced main rotor, high vibrations, damage to the tail boom or tail rotor, and loss of control of the helicopter. DATES: Comments must be... AD from American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 75052, telephone (972...

  14. Recovery and well-being among Helicopter Emergency Medical Service (HEMS) pilots

    NARCIS (Netherlands)

    Radstaak, M.; Geurts, S.A.E.; Beckers, D.G.J.; Brosschot, J.F.; Kompier, M.A.J.

    2014-01-01

    This study investigated the effects of a compressed working week with high cognitive and emotional work demands within the population of Dutch Helicopter Emergency Medical Service (HEMS) pilots. Work stressors were measured and levels of well-being were examined before, during and after a series of

  15. 78 FR 31394 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Science.gov (United States)

    2013-05-24

    ... ECD Model MBB-BK 117 C-2 helicopters. EASA advises that the autopilot (AP) of a Model MBB-BK 117 C-2... Bulletin MBB-BK117 C-2-22A-013, dated October 12, 2012 (ASB), which states that the autopilot and caution...) Subject Joint Aircraft Service Component (JASC) Code: 22, Autopilot Dispatch Restriction. Issued in...

  16. 16 CFR Appendix to Part 460 - Exemptions

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Exemptions Appendix to Part 460 Commercial Practices FEDERAL TRADE COMMISSION TRADE REGULATION RULES LABELING AND ADVERTISING OF HOME INSULATION Pt... type and thickness of the insulation when they make a representation in an advertisement or...

  17. Appendix - A small scale research review

    DEFF Research Database (Denmark)

    Larsen, Lea Lund

     training? This will be illustrated by describing a research design in progress at the National Centre of Competence Development, DK, regarding a program where teachers are taught Cooperative Learning as a pedagogical and didactical method. This appendix concerns the first question. In search for empiric results concerning: What do...

  18. Mucocele of the appendix. Radiological findings

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Shingo; Satani, Kenichiro; Ozuki, Taizo [Tokyo Medical Coll. (Japan); Shindou, Hiroaki; Saguchi, Toru; Koizumi, Kiyoshi; Katsumata, Kenji [Tokyo Medical Coll. (Japan). Hachioji Medical Center; Kotake, Fumio [Tokyo Medical Coll., Ami, Ibaraki (Japan). Kasumigaura Hospital

    2002-04-01

    Radiological findings of CT and MRI were evaluated in 11 cases of mucocele of the appendix. Mucocele is a rare disease entity and preoperative diagnosis is very important. The radiological findings were a well defined cystic mass with a wall of variable thickness. Nodular lesion in the wall of the mucocele may be a suggestive finding of malignant case of mucocele. (author)

  19. Energy 21. Preconditions and results. Appendix

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This appendix comprises the following 5 scenarios: Reference scenario for electricity and district heating supply; Action plan scenario for electricity and district heat supply; Energy balances for reference and action plan scenarios; Investments and operating costs for user installations; Projection of CO{sub 2} emissions from the transport sector. (EG)

  20. A New Framework For Helicopter Vibration Suppression; Time-Periodic System Identification and Controller Design

    Science.gov (United States)

    Ulker, Fatma Demet

    In forward flight, helicopter rotor blades function within a highly complex aerodynamic environment that includes both near-blade and far-blade aerodynamic phenomena. These aerodynamic phenomena cause fluctuating aerodynamic loads on the rotor blades. These loads when coupled with the dynamic characteristics and elastic motion of the blade create excessive amount of vibration. These vibrations degrade helicopter performance, passenger comfort and contributes to high cost maintenance problems. In an effort to suppress helicopter vibration, recent studies have developed active control strategies using active pitch links, flaps, twist actuation and higher harmonic control of the swash plate. In active helicopter vibration control, designing a controller in a computationally efficient way requires accurate reduced-order models of complex helicopter aeroelasticity. In previous studies, controllers were designed using aeroelastic models that were obtained by coupling independently reduced aerodynamic and structural dynamic models. Unfortunately, these controllers could not satisfy stability and performance criteria when implemented in high-fidelity computer simulations or real-time experiments. In this thesis, we present a novel approach that provides accurate time-periodic reduced-order models and time-periodic H2 and H infinity controllers that satisfy the stability and performance criteria. Computational efficiency and the necessity of using the approach were validated by implementing an actively controlled flap strategy. In this proposed approach, the reduced-order models were directly identified from high-fidelity coupled aeroelastic analysis by using the time-periodic subspace identification method. Time-periodic H2 and Hinfinity controllers that update the control actuation at every time step were designed. The control synthesis problem was solved using Linear Matrix Inequality and periodic Riccati Equation based formulations, for which an in-house periodic

  1. Hearing loss in civilian airline and helicopter pilots compared to air traffic control personnel.

    Science.gov (United States)

    Wagstaff, Anthony S; Arva, Per

    2009-10-01

    In order to investigate possible hearing loss as a consequence of aviation noise, a comparative analysis of audiometric data from Norwegian Air Traffic Control (ATC) personnel, airline (fixed-wing) pilots, and helicopter pilots was performed. The results may be of use in giving advice regarding preventive measures. Male ATC, airline, and helicopter pilots were selected randomly from the Civil Aviation Authority (CAA) medical files. There were 182 subjects included in the study: 50, 81, and 51 subjects for ATC, helicopter, and airline pilots, respectively. Two audiograms with a 2-3-yr interval were analyzed for each individual. Age correction was performed using data from ISO 7129. Threshold changes per year for the frequencies 3, 4, and 6 kHz were examined in particular after age correction. For all three groups, mean hearing threshold levels were above (worse than) ISO 7129 predictions for most frequencies. As expected, hearing thresholds increased with age in the group as a whole. Looking at the 3-, 4-, and 6-kHz frequencies in particular, all groups had small but highly significant increases in hearing thresholds at 4 kHz between the first and second audiogram. The mean hearing thresholds for this group of aviation personnel are higher than International Standard ISO-7129 would predict according to age. Highly significant changes in hearing threshold after age correction, indicating possible noise-induced hearing loss, were found in all groups at 4 kHz. The fact that helicopter pilots had similar hearing loss to their other aviation colleagues indicates that current hearing protection for these pilots is effective in counteracting the increased noise levels in helicopters.

  2. Design of fault tolerant control system for individual blade control helicopters

    Science.gov (United States)

    Tamayo, Sergio

    This dissertation presents the development of a fault tolerant control scheme for helicopters fitted with individually controlled blades. This novel approach attempts to improve fault tolerant capabilities of helicopter control system by increasing control redundancy using additional actuators for individual blade input and software re-mixing to obtain nominal or close to nominal conditions under failure. An advanced interactive simulation environment has been developed including modeling of sensor failure, swashplate actuator failure, individual blade actuator failure, and blade delamination to support the design, testing, and evaluation of the control laws. This simulation environment is based on the blade element theory for the calculation of forces and moments generated by the main rotor. This discretized model allows for individual blade analysis, which in turn allows measuring the consequences of a stuck blade, or loss of the surface area of the blade itself, with respect to the dynamics of the whole helicopter. The control laws are based on non-linear dynamic inversion and artificial neural network augmentation, which is a mix of linear and nonlinear methods that compensates for model inaccuracies due to linearization or failure. A stability analysis based on the Lyapunov function approach has shown that bounded tracking error is guaranteed, and under specific circumstances, global stability is guaranteed as well. An analysis over the degrees of freedom of the mechanical system and its impact over the helicopter handling qualities is also performed to measure the degree of redundancy achieved with the addition of individual blade actuators as compared to a classic swashplate helicopter configuration. Mathematical analysis and numerical simulation, using reconfiguration of the individual blade control under failure have shown that this control architecture can potentially improve the survivability of the aircraft and reduce pilot workload under failure

  3. Missile Captive Carry Monitoring and Helicopter Identification Using a Capacitive Microelectromechanical Systems Accelerometer

    Energy Technology Data Exchange (ETDEWEB)

    Hatchell, Brian K.; Mauss, Fredrick J.; Amaya, Ivan A.; Skorpik, James R.; Silvers, Kurt L.; Marotta, Steve

    2012-03-27

    Military missiles are exposed to many sources of mechanical vibration that can affect system reliability, safety, and mission effectiveness. The U. S. Army Aviation and Missile Research Development and Engineering Center (AMRDEC) has been developing missile health monitoring systems to assess and improve reliability, reduce life cycle costs, and increase system readiness. One of the most significant exposures to vibration occurs when the missile is being carried by a helicopter or other aviation platform, which is a condition known as captive carry. Recording the duration of captive carry exposure during the missile’s service life can enable the implementation of predictive maintenance and resource management programs. Since the vibration imparted by each class of helicopter varies in frequency and amplitude, tracking the vibration exposure from each helicopter separately can help quantify the severity and harmonic content of the exposure. Under the direction of AMRDEC staff, engineers at the Pacific Northwest National Laboratory have developed a Captive Carry Health Monitor (CCHM) for the Hellfire II missile. The CCHM is an embedded usage monitoring device installed on the outer skin of the Hellfire II missile to record the cumulative hours the host missile has been in captive carry mode. To classify the vibration by class of helicopter, the CCHM analyzes the amplitude and frequency content of the vibration with the Goertzel algorithm to detect the presence of distinctive rotor harmonics. Cumulative usage data are accessible in theater from an external display; monthly usage histograms are accessible through an internal download connector. This paper provides an overview of the CCHM electrical and package design, describes field testing and data analysis techniques used to monitor captive carry identify and the class of helicopter, and discusses the potential application of missile health and usage data for real-time reliability analysis and fleet management.

  4. A New Hybrid Control Scheme for an Integrated Helicopter and Engine System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Haibo; WANG Jiankang; CHEN Guoqiang; YAN Changkai

    2012-01-01

    A new hybrid control scheme is presented with a robust multiple model fusion control (RMMFC) law for a UH-60 helicopter and an active disturbance rejection control (ADRC) controller for its engines.This scheme is a control design method with every subsystem designed separately but fully considering the couplings between them.With three subspaces with respect to forward flight velocity,a RMMFC is proposed to devise a four-loop reference signal tracing control for the helicopter,which escapes the closed-loop system from unstable state due to the extreme complexity of this integrated nonlinear system.The engines are controlled by the proposed ADRC decoupling controller,which fully takes advantage of a good compensation ability for unmodeled dynamics and extra disturbances,so as to compensate torque disturbance in power turbine speed loop.By simulating a forward acceleration flight task,the RMMFC for the helicopter is validated.It is apparent that the integrated helicopter and engine system (IHES) has much better dynamic performance under the new control scheme.Especially in the switching process,the large transient is significantly weakened,and smooth transition among candidate controllers is achieved.Over the entire simulation task,the droop of power turbine speed with the proposed ADRC controller is significantly slighter than with the conventional PID controller,and the response time of the former is much faster than the latter.By simulating a rapid climb and descent flight task,the results also show the feasibility for the application of the proposed multiple model fusion control.Although there is aggressive power demand in this maneuver,the droop of power turbine speed with an ADRC controller is smaller than using a PID controller.The control performance for helicopter and engine is enhanced by adopting this hybrid control scheme,and simulation results in other envelope stale give proofs of robustness for this new scheme.

  5. Active structural acoustic control of helicopter interior multifrequency noise using input-output-based hybrid control

    Science.gov (United States)

    Ma, Xunjun; Lu, Yang; Wang, Fengjiao

    2017-09-01

    This paper presents the recent advances in reduction of multifrequency noise inside helicopter cabin using an active structural acoustic control system, which is based on active gearbox struts technical approach. To attenuate the multifrequency gearbox vibrations and resulting noise, a new scheme of discrete model predictive sliding mode control has been proposed based on controlled auto-regressive moving average model. Its implementation only needs input/output data, hence a broader frequency range of controlled system is modelled and the burden on the state observer design is released. Furthermore, a new iteration form of the algorithm is designed, improving the developing efficiency and run speed. To verify the algorithm's effectiveness and self-adaptability, experiments of real-time active control are performed on a newly developed helicopter model system. The helicopter model can generate gear meshing vibration/noise similar to a real helicopter with specially designed gearbox and active struts. The algorithm's control abilities are sufficiently checked by single-input single-output and multiple-input multiple-output experiments via different feedback strategies progressively: (1) control gear meshing noise through attenuating vibrations at the key points on the transmission path, (2) directly control the gear meshing noise in the cabin using the actuators. Results confirm that the active control system is practical for cancelling multifrequency helicopter interior noise, which also weakens the frequency-modulation of the tones. For many cases, the attenuations of the measured noise exceed the level of 15 dB, with maximum reduction reaching 31 dB. Also, the control process is demonstrated to be smoother and faster.

  6. The Acoustic Signal of a Helicopter can be Used to Track it With Seismic Arrays

    Science.gov (United States)

    Eibl, Eva P. S.; Lokmer, Ivan; Bean, Christopher J.; Akerlie, Eggert

    2016-04-01

    We apply traditional frequency domain methods usually applied to volcanic tremor on seismic recordings of a helicopter. On a volcano the source can be repeating, closely spaced earthquakes whereas for a helicopter the source are repeating pressure pulses from the rotor blades that are converted through acoustic-to-seismic coupling. In both cases the seismic signal is referred to as tremor. As frequency gliding is in this case merely caused by the Doppler effect, not a change in the source, we can use its shape to deduce properties of the helicopter. We show in this analysis that the amount of rotor blades, rotor revolutions per minute (RPM), flight direction, height and location can be deduced. The signal was recorded by a seven station broadband array with an aperture of 1.6 km. Our spacing is close enough to record the signal at all stations and far enough to observe traveltime differences. We perform a detailed spectral and location analysis of the signal, and compare our results with the known information on the helicopter's speed, location, height, the frequency of the blades rotation and the amount of blades. This analysis is based on the characteristic shape of the curve i.e. speed of the gliding, minimum and maximum fundamental frequency, amplitudes at the inflection points at different stations and traveltimes deduced from the inflection points at different stations. The helicopter GPS track gives us a robust way of testing the method. This observation has an educative value, because the same principles can be applied to signals in different disciplines.

  7. TORSION OF THE VERMIFORM APPENDIX: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Dr. Imtiaz Wani

    2009-07-01

    Full Text Available Torsion of the vermiform appendix is a rare condition with few cases reported in the literature. Various factors predispose to torsion. Various factors predispose to torsion. We report a case of primary torsion of the vermiform appendix. The clinical presentation was indistinguishable from acute appendicitis and the diagnosis was made at operation. Appendix was preileal in position and the direction of torsion was anticlockwise. There was intrinsic torsion with no obvious factor for torsion identified. Appendectomy was performed.

  8. Carcinoid of the Appendix During Laparoscopic Cholecystectomy: Unexpected Benefits

    Science.gov (United States)

    Haluck, Randy; Cooney, Robert N.; Minnick, Kathleen E.; Ruggiero, Francesco; Smith, J. Stanley

    1999-01-01

    Carcinoid tumors of the midgut arise from the distal duodenum, jejunum, ileum, appendix, ascending and right transverse colon. The appendix and terminal ileum are the most common location. The majority of carcinoid tumors originate from neuroendocrine cells along the gastrointestinal tract, but they are also found in the lung, ovary, and biliary tracts. We report the first case of elective laparoscopic cholecystectomy in which we found a suspicious lesion at the tip of the appendix and proceeded to perform a laparoscopic appendectomy. The lesion revealed a carcinoid tumor of the appendix. PMID:10323177

  9. The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: McDonnell-Douglas Helicopter Company achievements

    Science.gov (United States)

    Toossi, Mostafa; Weisenburger, Richard; Hashemi-Kia, Mostafa

    1993-01-01

    This paper presents a summary of some of the work performed by McDonnell Douglas Helicopter Company under NASA Langley-sponsored rotorcraft structural dynamics program known as DAMVIBS (Design Analysis Methods for VIBrationS). A set of guidelines which is applicable to dynamic modeling, analysis, testing, and correlation of both helicopter airframes and a large variety of structural finite element models is presented. Utilization of these guidelines and the key features of their applications to vibration modeling of helicopter airframes are discussed. Correlation studies with the test data, together with the development and applications of a set of efficient finite element model checkout procedures, are demonstrated on a large helicopter airframe finite element model. Finally, the lessons learned and the benefits resulting from this program are summarized.

  10. Closed-Loop Behavior of an Autonomous Helicopter Equipped with a Robotic Arm for Aerial Manipulation Tasks

    Directory of Open Access Journals (Sweden)

    Konstantin Kondak

    2013-02-01

    Full Text Available This paper is devoted to the control of aerial robots interacting physically with objects in the environment and with other aerial robots. The paper presents a controller for the particular case of a small-scaled autonomous helicopter equipped with a robotic arm for aerial manipulation. Two types of influences are imposed on the helicopter from a manipulator: coherent and non-coherent influence. In the former case, the forces and torques imposed on the helicopter by the manipulator change with frequencies close to those of the helicopter movement. The paper shows that even small interaction forces imposed on the fuselage periodically in proper phase could yield to low frequency instabilities and oscillations, so-called phase circles.

  11. Combined Effects of Exposure to Noise and Whole-Body Vibration in Dumpers, Helicopters and Railway Engines

    National Research Council Canada - National Science Library

    Landström, U; Kjellberg, A; Lundström, R

    1993-01-01

    Three groups of 24 subjects were exposed to alternated periods of noise, vibration and combined exposures of both stimuli, recorded during working conditions in a dumper, a helicopter and a railway engine, respectively...

  12. 76 FR 27958 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 206A, 206B, and 206B3...

    Science.gov (United States)

    2011-05-13

    ... AD docket shortly after receipt. Discussion Bell reissued RFM Supplement (RFMS) BHT-206A-FMS-8 for the Model 206A, BHT-206B-FMS-8 for the Model 206B, and BHT-206B3-FMS-2 for the Model 206B3 helicopters... RFM as follows: For Model 206A helicopters--inserting RFMS BHT-206A-FMS-8, dated December 30, 2009...

  13. System Research Of Multi-Barrel Machine Guns Installed On Board Of The Helicopter Of Mi-17 Type

    Directory of Open Access Journals (Sweden)

    Bęczkowski Grzegorz

    2015-08-01

    Full Text Available This article presents tests of a multi-barreled machine gun system built on board of a helicopter. The described weapon system consists of three 7.62 mm M-134G multi-barreled machine guns built on the designed frames of shooting positions located in the escape hatch window, the side doors and the rear doors of the transport cabin of the Mi-17-1V helicopter.

  14. Building Partner Capacity: DOD Is Meeting Most Targets for Colombias Regional Helicopter Training Center but Should Track Graduates

    Science.gov (United States)

    2013-07-01

    Student pilots also learn other basic skills, such as instrument flight and use of night - vision goggles . IERW training prepares student pilots for...for training helicopter pilots , while also training as many as 24 third-country student pilots annually, primarily from Mexico, in accordance with...the Mérida Initiative, resulted in DOD agreeing to train Mexican helicopter pilots to support counternarcotics efforts. Since the number of Mexican

  15. New capabilities and recent research programs of the NASA/Army CH-47B variable-stability helicopter

    Science.gov (United States)

    Hindson, W. S.; Hilbert, K. B.; Tucker, G. E.; Chen, R. T. N.; Fry, E. B.

    1986-01-01

    The CH-47B is the third in a series of variable-stability helicopters developed and operated by NASA since 1952 to investigate helicopter and VTOL handling qualities. Recently, several new capabilities were added to this helicopter to enable it to better support new and evolving research requirements. The installation of a programmable force-feel system for the evaluation pilot's conventional cyclic stick, and a four-axis side-stick controller permit a range of in-flight investigations concerning manipulator characteristics and augmentation system features that had not been possible with earlier NASA research helicopters. A recently installed color electronic display system with a programmable symbol generator will permit the investigation of display formats for a variety of VTOL and helicopter missions. Finally, a powerful new general-purpose flight computer is now in operation. It is programmable in high-level languages and will provide more efficient support of research programs. In addition to these new hardware capabilities, flight-control software has been developed to improve the in-flight simulation capability of the aircraft. A brief description of the CH-47B's variable-stability research equipment is provided, recent research programs are summarized, and some remarks concerning the potential of the helicopter are presented.

  16. Lead-Lag Control for Helicopter Vibration and Noise Reduction

    Science.gov (United States)

    Gandhi, Farhan

    1995-01-01

    As a helicopter transitions from hover to forward flight, the main rotor blades experience an asymmetry in flow field around the azimuth, with the blade section tangential velocities increasing on the advancing side and decreasing on the retreating side. To compensate for the reduced dynamic pressure on the retreating side, the blade pitch angles over this part of the rotor disk are increased. Eventually, a high enough forward speed is attained to produce compressibility effects on the advancing side of the rotor disk and stall on the retreating side. The onset of these two phenomena drastically increases the rotor vibratory loads and power requirements, thereby effectively establishing a limit on the maximum achievable forward speed. The alleviation of compressibility and stall (and the associated decrease in vibratory loads and power) would potentially result in an increased maximum forward speed. In the past, several methods have been examined and implemented to reduce the vibratory hub loads. Some of these methods are aimed specifically at alleviating vibration at very high flight speeds and increasing the maximum flight speed, while others focus on vibration reduction within the conventional flight envelope. Among the later are several types passive as well as active schemes. Passive schemes include a variety of vibration absorbers such as mechanical springs, pendulums, and bifilar absorbers. These mechanism are easy to design and maintain, but incur significant weight and drag penalties. Among the popular active control schemes in consideration are Higher Harmonic Control (HHC) and Individual Blade Control (IBC). HHC uses a conventional swash plate to generate a multi-cyclic pitch input to the blade. This requires actuators capable of sufficiently high power and bandwidth, increasing the cost and weight of the aircraft. IBC places actuators in the rotating reference frame, requiring the use of slip rings capable of transferring enough power to the actuators

  17. Appendix - A small scale research review

    DEFF Research Database (Denmark)

    Larsen, Lea Lund

    A small scale research review This appendix provides an analysis of a small scale search for empirical studies regarding the efficacy of adult teacher training. The appendix is a part of a paper delivered at the ASEM conference, June 2009, Bergisch Gladbach, Germany. The paper tries to shed light...... over two questions asked in the abstract concerning workshop C - Effects of teacher training in lifelong learning - at the current ASEM conference. At first it is asked what do we already know about teacher training effects in relation to adult learners? This will be identified by a search...... for systematic reviews in the international This will be identified by a search for systematic reviews in the international clearinghouses and afterwards by a small scale mapping done in the pedagogic databaseERIC. The second question sounds: which methods can be used to measure the effects of teacher...

  18. Goblet cell carcinoid of the appendix

    Directory of Open Access Journals (Sweden)

    Pahlavan Payam S

    2005-06-01

    Full Text Available Abstract Background Goblet cell carcinoid (GCC of the appendix is a rare neoplasm that share histological features of both adenocarcinoma and carcinoid tumor. While its malignant potential remains unclear, GCC's are more aggressive than conventional carcinoid. The clinical presentations of this neoplasm are also varied. This review summarizes the published literature on GCC of the appendix. The focus is on its diagnosis, histopathological aspects, clinical manifestations, and management. Methods Published studies in the English language between 1966 to 2004 were identified through Medline keyword search utilizing terms "goblet cell carcinoid," "adenocarcinoid", "mucinous carcinoid" and "crypt cell carcinoma" of the appendix. Results Based on the review of 57 published papers encompassing nearly 600 diagnosed patients, the mean age of presentation for GCC of the appendix was 58.89 years with equal representation in both males and females. Accurate diagnosis of this neoplasm requires astute observations within an acutely inflamed appendix as this neoplasm has a prominent pattern of submucosal growth and usually lacks the formation of a well-defined tumor mass. The mesoappendix was involved in 21.64% followed by perineural involvement in 2.06%. The most common clinical presentations in order of frequency were acute appendicitis in 22.5%; asymptomatic in 5.4%; non-localized abdominal pain in 5.15% and an appendicular mass in 3.09%. The most common surgical treatment of choice was appendectomy with right hemicolectomy in 34.70% followed by simple appendectomy in 24.57%. Concomitant distant metastasis at diagnosis was present in 11.16% of patients with the ovaries being the most common site in 3.60% followed by disseminated abdominal carcinomatosis in 1.03%. Local lymph node involvement was seen in 8.76% of patients at the time of diagnosis. The reported 5-year survival ranges from 60 % to 84%. GCC's of the appendix remains a neoplasm of unpredictable

  19. Preoperatively diagnosed mucocele of the appendix.

    Science.gov (United States)

    Rojnoveanu, Gh; Ghidirim, Gh; Mishin, I; Vozian, M; Mishina, A

    2014-01-01

    Mucocele of the appendix is an infrequent entity, characterized by distension of the lumen due to accumulation of mucoid substance and is rarely diagnosed preoperatively. If untreated, mucocele may rupture producing a potentially fatal entity known as pseudomyxoma peritonei. The type of surgical treatment is related to the dimensions and the histology of the mucocele. Appendectomy is used for simple mucocele or for cystadenoma. Right hemi-colectomy is recommended for cystadeno carcinoma. In this paper, we report a case of an asymptomatic 37-year-old woman in whom mucocele was found on a routine ultrasound examination and preoperative computed tomography scan. Surgery revealed a big appendix measuring 84 mm in length and 40 mm in diameter. The final pathologic diagnosis was simple mucocele. Celsius.

  20. Incidentally discovered giant mucocele of the appendix.

    Science.gov (United States)

    Harris, Syed Hasan; Khan, Roobina; Ansari, Maulana Mohammad; Maheshwari, Veena

    2014-11-01

    Mucocele of the appendix is a rare but well-recognized entity that can mimic several common clinical conditions or present as an incidental radiological or surgical finding at laparotomy. Mucoceles are characterized by distension of the lumen due to accumulation of mucoid substance. They can result from mucosal hyperplasia, mucinous cystadenoma, or mucinous cystadenocarcinoma. If untreated, they may rupture producing the potentially fatal entity Pseudomyxoma peritonei, which is difficult to treat both surgically or medically. Appendectomy is used for simple mucocele or for cystadenoma. Preoperative diagnosis of a mucocele is helpful at the time of surgical intervention with careful mobilization, particularly of large lesions reducing the possibility of rupture and complications. The authors report a case of a 65-year-old man presenting with peritonitis due to a pre-pyloric gastric perforation also having an incidental giant mucocele of the appendix.

  1. Appendix B - GPRA06 biomass program documentation

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    This appendix discusses the assumptions and methods employed in the biomass benefits analysis that is part of the fiscal year 2006 GPRA benefits analysis for all of the Department of Energy’s Energy Efficiency and Renewable Energy (EERE) research and deployment programs. The biomass benefits analysis focuses on the benefits of future achievements by the program and excludes retrospective benefits and benefits resulting from industry’s own initiative and funding.

  2. 32 CFR Appendix B to Part 247 - CE Publications

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false CE Publications B Appendix B to Part 247... Appendix B to Part 247—CE Publications A. Purpose. CE publications consist of DoD newspapers, magazines... publication. CE publishers sell advertising to cover costs and secure earnings, print the publications, and...

  3. 29 CFR Appendix A to Subpart P of... - Soil Classification

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Soil Classification A Appendix A to Subpart P of Part 1926..., App. A Appendix A to Subpart P of Part 1926—Soil Classification (a) Scope and application—(1) Scope... § 1926.652(c), and the use of the data is predicated on the use of the soil classification system...

  4. 23 CFR Appendix B to Part 1327 - OMB Clearance

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false OMB Clearance B Appendix B to Part 1327 Highways NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURES FOR PARTICIPATING..., App. B Appendix B to Part 1327—OMB Clearance The OMB clearance number of this regulation is OMB...

  5. 50 CFR Appendix A to Part 654 - Figures

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Figures A Appendix A to Part 654 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE STONE CRAB FISHERY OF THE GULF OF MEXICO Pt. 654, App. A Appendix A to Part 654...

  6. 40 CFR Appendix E to Part 300 - Oil Spill Response

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Oil Spill Response E Appendix E to... PLAN Pt. 300, App. E Appendix E to Part 300—Oil Spill Response Table of Contents 1.0 Introduction. 1... response actions under the NCP. Miscellaneous oil spill control agent is any product, other than...

  7. 36 CFR Appendix D to Part 1191 - Technical

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Technical D Appendix D to Part 1191 Parks, Forests, and Public Property ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE...; ARCHITECTURAL BARRIERS ACT (ABA) ACCESSIBILITY GUIDELINES Pt. 1191, App. D Appendix D to Part...

  8. 34 CFR Appendixes A-B to Part 682 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false A Appendixes A-B to Part 682 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM Appendixes A-B to Part 682...

  9. 40 CFR Appendix F to Part 403 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true F Appendix F to Part 403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRE-TREAT-MENT REGULATIONS FOR EXIST-ING AND NEW SOURCES OF POLLUTION Appendix F to Part 403 ...

  10. 40 CFR Appendixes A-C to Part 403 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true A Appendixes A-C to Part 403 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GENERAL PRE-TREAT-MENT REGULATIONS FOR EXIST-ING AND NEW SOURCES OF POLLUTION Appendixes A-C to Part 403 ...

  11. 32 CFR Appendix A to Part 246 - Mission

    Science.gov (United States)

    2010-07-01

    ... STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. A Appendix A to Part 246—Mission... 32 National Defense 2 2010-07-01 2010-07-01 false Mission A Appendix A to Part 246 National...-defense mission overseas by providing news and information for the Armed Forces internal audiences serving...

  12. Pathways for School Finance in California. Technical Appendix

    Science.gov (United States)

    Rose, Heather; Sonstelie, Jon; Weston, Margaret

    2010-01-01

    This is a technical appendix for the report, "Pathways for School Finance in California" (ED515651). "Pathways for School Finance in California" simulates alternatives to California's current school finance system. This appendix provides more information about the revenues used in those simulations. The first section describes…

  13. 40 CFR Appendixes I-Vii to Part 85 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false I Appendixes I-VII to Part 85 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Appendixes I-VII to Part 85...

  14. 29 CFR Appendix A to Part 4011 - Model Participant Notice

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Model Participant Notice A Appendix A to Part 4011 Labor... DISCLOSURE REQUIREMENTS DISCLOSURE TO PARTICIPANTS Pt. 4011, App. A Appendix A to Part 4011—Model Participant..., the Internal Revenue Service may grant a funding waiver that permits the company to...

  15. 14 CFR Appendix to Part 1275 - Research Misconduct

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Research Misconduct Appendix to Part 1275 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION RESEARCH MISCONDUCT Pt. 1275, App. Appendix to Part 1275—Research Misconduct NASA Research Disciplines and Respective Associated Enterprises...

  16. 45 CFR Appendix C to Part 5b... - [Reserved

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false C Appendix C to Part 5b-Delegations of Authority Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PRIVACY ACT REGULATIONS Appendix C to Part 5b—Delegations of Authority...

  17. 14 CFR Appendix C to Part 43 - [Reserved

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false C Appendix C to Part 43 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT MAINTENANCE, PREVENTIVE MAINTENANCE, REBUILDING, AND ALTERATION Appendix C to Part 43...

  18. 40 CFR Appendix to Part 240 - Recommended Bibliography

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended Bibliography Appendix to Part 240 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Pt. 240, App. Appendix to Part 240—Recommended...

  19. 40 CFR Appendix to Part 243 - Recommended Bibliography

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended Bibliography Appendix to Part 243 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES.... Appendix to Part 243—Recommended Bibliography 1. American National Standard Z245.1. Safety standard...

  20. 28 CFR Appendix to Subpart K of... - Unknown Title

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Appendix to Subpart K of Part 0 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE Criminal Division Pt. 0, Subpt. K, App. Appendix to Subpart K of Part 0 Criminal Division Editorial Note: Criminal Division Directive...

  1. 10 CFR Appendix B to Part 436 - Goal Setting Methodology

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Goal Setting Methodology B Appendix B to Part 436 Energy... Appendix B to Part 436—Goal Setting Methodology In establishing and updating agency goals for energy conservation, the following methodology or an equivalent method should be utilized: (a) For overall...

  2. 46 CFR Appendix B to Part 154 - Stress Analyses Definitions

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Stress Analyses Definitions B Appendix B to Part 154... STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Pt. 154, App. B Appendix B to Part 154—Stress Analyses Definitions The following are the standard definitions of stresses for the analysis of an...

  3. 46 CFR Appendix A to Part 154 - Equivalent Stress

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Equivalent Stress A Appendix A to Part 154 Shipping... FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Pt. 154, App. A Appendix A to Part 154—Equivalent Stress I. Equivalent stress (σ c) is calculated by the following formula or another formula...

  4. 7 CFR Appendix B to Part 226 - [Reserved

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false B Appendix B to Part 226 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM Appendix B to Part 226...

  5. 10 CFR Appendix D to Part 835 - Surface Contamination Values

    Science.gov (United States)

    2010-01-01

    ... to radioactive contamination deposited on, but not incorporated into the interior or matrix of, the... 10 Energy 4 2010-01-01 2010-01-01 false Surface Contamination Values D Appendix D to Part 835...—Surface Contamination Values The data presented in appendix D are to be used in identifying the need for...

  6. Pathways for School Finance in California. Technical Appendix

    Science.gov (United States)

    Rose, Heather; Sonstelie, Jon; Weston, Margaret

    2010-01-01

    This is a technical appendix for the report, "Pathways for School Finance in California" (ED515651). "Pathways for School Finance in California" simulates alternatives to California's current school finance system. This appendix provides more information about the revenues used in those simulations. The first section describes…

  7. 49 CFR Appendix A to Part 609 - Elderly and Handicapped

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Elderly and Handicapped A Appendix A to Part 609..., DEPARTMENT OF TRANSPORTATION TRANSPORTATION FOR ELDERLY AND HANDICAPPED PERSONS Pt. 609, App. A Appendix A to Part 609—Elderly and Handicapped The definitions of the term elderly and handicapped as applied...

  8. 10 CFR Appendix A to Part 436... - [Reserved

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false A Appendix A to Part 436-Energy Conservation Standards for General Operations Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION FEDERAL ENERGY MANAGEMENT AND PLANNING PROGRAMS Appendix A to Part 436—Energy Conservation Standards for General Operations...

  9. Primary Adenocarcinoma of Appendix Presenting as Omental Metastasis

    Directory of Open Access Journals (Sweden)

    Arun Gupta, Subhash Bhardwaj, Jyotsna Suri

    2001-07-01

    Full Text Available The adenocarcinoma of appendix is a rare entity The patients present usually with symptoms ofappendicitis, a palpable abdominal mass or rarely as a complication of pseudomyxoma peritonei,We report a case who presented with lump abdomen and ascitis and revealed a tiny infiltrativegrowth at the base of appendix at laparotomy

  10. 32 CFR Appendix B to Part 113 - Standards of Fairness

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Standards of Fairness B Appendix B to Part 113 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN INDEBTEDNESS PROCEDURES OF MILITARY PERSONNEL Pt. 113, App. B Appendix B to Part 113—Standards of Fairness 1...

  11. 12 CFR Appendix A to Part 37 - Short Form Disclosures

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Short Form Disclosures A Appendix A to Part 37... AND DEBT SUSPENSION AGREEMENTS Pt. 37, App. A Appendix A to Part 37—Short Form Disclosures • This... will not receive a refund. • Additional disclosures We will give you additional information before...

  12. 22 CFR Appendix A to Part 138 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certification Regarding Lobbying A Appendix A to Part 138 Foreign Relations DEPARTMENT OF STATE MISCELLANEOUS NEW RESTRICTIONS ON LOBBYING Pt. 138, App. A Appendix A to Part 138—Certification Regarding Lobbying Certification for Contracts,...

  13. 45 CFR Appendix A to Part 93 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Certification Regarding Lobbying A Appendix A to... ON LOBBYING Pt. 93, App. A Appendix A to Part 93—Certification Regarding Lobbying Certification for... Standard Form-LLL, “Disclosure Form to Report Lobbying,” in accordance with its instructions. (3)...

  14. 34 CFR Appendix A to Part 82 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Certification Regarding Lobbying A Appendix A to Part 82 Education Office of the Secretary, Department of Education NEW RESTRICTIONS ON LOBBYING Pt. 82, App. A Appendix A to Part 82—Certification Regarding Lobbying Certification for Contracts,...

  15. 12 CFR Appendix A to Part 411 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Certification Regarding Lobbying A Appendix A to Part 411 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES NEW RESTRICTIONS ON LOBBYING Pt. 411, App. A Appendix A to Part 411—Certification Regarding Lobbying Certification for...

  16. 22 CFR Appendix A to Part 712 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Certification Regarding Lobbying A Appendix A to... RESTRICTIONS ON LOBBYING Pt. 712, App. A Appendix A to Part 712—Certification Regarding Lobbying Certification... and submit Standard Form-LLL, “Disclosure Form to Report Lobbying,” in accordance with...

  17. 38 CFR Appendix A to Part 45 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-07-01

    ... Lobbying A Appendix A to Part 45 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS (CONTINUED) NEW RESTRICTIONS ON LOBBYING Pt. 45, App. A Appendix A to Part 45—Certification Regarding Lobbying Certification for Contracts, Grants, Loans, and Cooperative Agreements The undersigned...

  18. 45 CFR Appendix A to Part 604 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Certification Regarding Lobbying A Appendix A to... NEW RESTRICTIONS ON LOBBYING Pt. 604, App. A Appendix A to Part 604—Certification Regarding Lobbying... and submit Standard Form-LLL, “Disclosure Form to Report Lobbying,” in accordance with...

  19. 29 CFR Appendix A to Part 93 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Certification Regarding Lobbying A Appendix A to Part 93 Labor Office of the Secretary of Labor NEW RESTRICTIONS ON LOBBYING Pt. 93, App. A Appendix A to Part 93—Certification Regarding Lobbying Certification for Contracts, Grants, Loans, and Cooperative Agreements...

  20. 22 CFR Appendix A to Part 227 - Certification Regarding Lobbying

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certification Regarding Lobbying A Appendix A to Part 227 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT NEW RESTRICTIONS ON LOBBYING Pt. 227, App. A Appendix A to Part 227—Certification Regarding Lobbying Certification for...