Science.gov

Sample records for aircraft corporation helicopters

  1. 77 FR 18969 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-76C helicopters. This proposed AD is... Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main...

  2. 77 FR 56581 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ... Directives; Sikorsky Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... revising an earlier proposed airworthiness directive (AD) for the Sikorsky Aircraft Corporation (Sikorsky.... For service information identified in this proposed AD, contact Sikorsky Aircraft Corporation,...

  3. 77 FR 68061 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... Aircraft Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for the Sikorsky Aircraft Corporation... service information identified in this AD, contact Sikorsky Aircraft Corporation, Attn:...

  4. 78 FR 44045 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... Corporation (Sikorsky) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... directive (AD): Sikorsky Aircraft Corporation (Sikorsky): Docket No. FAA-2013-0636; Directorate...

  5. 77 FR 49710 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-17

    ... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S... AD, contact Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support,...

  6. 77 FR 68057 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Sikorsky Aircraft Corporation (Sikorsky... service information identified in this AD, contact Sikorsky Aircraft Corporation, Attn:...

  7. 77 FR 23382 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Sikorsky Aircraft Corporation (Sikorsky) Model S.... ADDRESSES: For service information identified in this AD, contact Sikorsky Aircraft Corporation,...

  8. 77 FR 68058 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... Corporation Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for... Aircraft Corporation (Sikorsky) Model S-70, S-70A, S-70C, S-70C(M), and S-70C(M1) helicopters with a... service information identified in this AD, contact Sikorsky Aircraft Corporation, Attn:...

  9. 78 FR 44048 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ... Corporation (Sikorsky) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900 Main Street, Stratford, CT... Corporation: Docket No. FAA-2013-0637; Directorate Identifier 2013-SW-030-AD. (a) Applicability This...

  10. 78 FR 23698 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... Corporation (Sikorsky) Model S-92A helicopters to require modifying the No. 1 engine forward firewall center... condition as failure of the No. 1 engine forward firewall center fire extinguisher discharge tube to...: (1) Modify the No. 1 engine forward firewall center discharge tube in accordance with...

  11. 78 FR 17591 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... system fuel filters and re-identify the fuel tank fuel filter and fuel control assembly bracket. The... malfunction of an internal valve, power loss at a critical phase of flight, and loss of control of the... helicopters to require replacing each forward and aft fuel system 40 micron fuel filter element with a...

  12. 78 FR 60656 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ...-92A helicopters to require modifying the No. 1 engine forward firewall center fire extinguisher...) Unsafe Condition This AD defines the unsafe condition as failure of the No. 1 engine forward firewall...: (1) Modify the No. 1 engine forward firewall center discharge tube in accordance with...

  13. 76 FR 66207 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... Corporation (Sikorsky) Model S-92A Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of... the Sikorsky Model S-92A helicopters. This proposal would require revising the Operating Limitations section of the Sikorsky Model S-92A Rotorcraft Flight Manual (RFM). This proposal is prompted by...

  14. 75 FR 77524 - Special Conditions: Sikorsky Aircraft Corporation Model S-92A Helicopter; Installation of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-13

    ...) weight. (iii) Maximum demonstrated weight. (d) Flight Characteristics. (1) The basic aircraft must meet... recover the aircraft and transition to the normal (Appendix B) IFR flight profile envelope without... Federal Aviation Administration 14 CFR Part 29 Special Conditions: Sikorsky Aircraft Corporation Model...

  15. 75 FR 27409 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-17

    ... Gustafson, Aviation Safety Engineer, Boston Aircraft Certification Office, Engine and Propeller Directorate...-06-AD; Amendment 39-16282; AD 2010-10-03] RIN 2120-AA64 Airworthiness Directives; Sikorsky Aircraft... Sikorsky Aircraft Corporation, Attn: Manager, Commercial Technical Support, mailstop s581a, 6900...

  16. 75 FR 47197 - Airworthiness Directives; Schweizer Aircraft Corporation (Schweizer) Model 269D Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... Housing Blade Containment Shielding Kit on each helicopter. This amendment is prompted by 21 reports of the blades of the oil cooler impeller separating, one of which punctured the engine and transmission... protect the oil cooler from uncontained oil cooler impeller blades that could damage the oil cooler...

  17. 75 FR 12665 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-17

    ... emergency flotation system squib connector (flotation system connector) to determine if a metallic foil... prevent inadvertent activation of a flotation system during installation was still installed in the left-hand flotation system connector of a Model S-76C helicopter. The actions specified in this AD...

  18. 75 FR 81424 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S76A, B, and C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... directive (EAD) for the specified Sikorsky model helicopters. The EAD requires inspecting the LITEF Attitude..., B, and C helicopters, with LITEF LCR-100, Attitude Heading and Reference System (AHRS) Unit,...

  19. 75 FR 70101 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-70A and S-70C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ...-70A and S-70C helicopters. This AD requires an ultrasonic test (UT) inspection of the tail gearbox... Level II Ultrasonic Testing Technician or equivalent, ultransonic inspect the gear for a crack. Ultrasonic inspect the gear by following paragraphs A.(5)a. through A(5)n. of Special Service Instructions...

  20. 77 FR 36131 - Airworthiness Directives; Enstrom Helicopter Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ...-28, 480, and 480B helicopters to add another trim relay to the applicability and to revise the modification instructions. This AD is prompted by the discovery that another part- numbered trim relay...-28F, 280C, 280F, 280FX, TH-28, 480, and 480B helicopters with a trim relay, part-number (P/N)...

  1. 77 FR 729 - Airworthiness Directives; Enstrom Helicopter Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... certain trim relays to require modifying and testing the lateral and longitudinal cyclic trim actuator..., and 480B helicopters with a trim relay, part-number (P/N) KUP14D55-472, M83536/10-015M, or M83536/10...) and flight tests to determine that the trim relay is working correctly. This AD was prompted...

  2. 78 FR 1253 - Schweizer Aircraft Corporation, a Subsidiary of Sikorsky Aircraft Corporation, a Division of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employment and Training Administration Schweizer Aircraft Corporation, a Subsidiary of Sikorsky Aircraft Corporation, a Division of United Technologies, Inc., DBA Sikorsky Military Completion Center, Including...

  3. Price Determination of General Aviation, Helicopter, and Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Anderson, Joseph L.

    1978-01-01

    The NASA must assess its aeronautical research program with economic as well as performance measures. It thus is interested in what price a new technology aircraft would carry to make it attractive to the buyer. But what price a given airplane or helicopter will carry is largely a reflection of the manufacturer's assessment of the competitive market into which the new aircraft will be introduced. The manufacturer must weigh any new aerodynamic or system technology innovation he would add to an aircraft by the impact of this innovation upon the aircraft's economic attractiveness and price. The intent of this paper is to give price standards against which new technologies and the NASA's research program can be assessed. Using reported prices for general aviation, helicopter, and transport aircraft, price estimating relations in terms of engine and airframe characteristics have been developed. The relations are given in terms of the aircraft type, its manufactured empty weight, engine weight, horsepower or thrust. Factors for the effects of inflation are included to aid in making predictions of future aircraft prices. There are discussions of aircraft price in terms of number of passenger seats, airplane size and research and development costs related to an aircraft model, and indirectly as to how new technologies, aircraft complexity and inflation have affected these.

  4. 36 CFR 222.64 - Use of helicopters, fixed-wing aircraft and motor vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-wing aircraft and motor vehicles. 222.64 Section 222.64 Parks, Forests, and Public Property FOREST... § 222.64 Use of helicopters, fixed-wing aircraft and motor vehicles. The Chief, Forest Service, is authorized to use helicopters, fixed-wing aircraft, and motor vehicles in a manner that will ensure...

  5. 36 CFR 222.64 - Use of helicopters, fixed-wing aircraft and motor vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-wing aircraft and motor vehicles. 222.64 Section 222.64 Parks, Forests, and Public Property FOREST... § 222.64 Use of helicopters, fixed-wing aircraft and motor vehicles. The Chief, Forest Service, is authorized to use helicopters, fixed-wing aircraft, and motor vehicles in a manner that will ensure...

  6. 36 CFR 222.24 - Use of helicopters, fixed-wing aircraft and motor vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-wing aircraft and motor vehicles. 222.24 Section 222.24 Parks, Forests, and Public Property FOREST... § 222.24 Use of helicopters, fixed-wing aircraft and motor vehicles. The Chief, Forest Service, is authorized to use helicopters, fixed-wing aircraft, and motor vehicles in a manner that will ensure...

  7. 36 CFR 222.24 - Use of helicopters, fixed-wing aircraft and motor vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-wing aircraft and motor vehicles. 222.24 Section 222.24 Parks, Forests, and Public Property FOREST... § 222.24 Use of helicopters, fixed-wing aircraft and motor vehicles. The Chief, Forest Service, is authorized to use helicopters, fixed-wing aircraft, and motor vehicles in a manner that will ensure...

  8. 77 FR 33083 - Airworthiness Directives; WACO Classic Aircraft Corporation Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-05

    ... Aircraft Corporation Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule... Aircraft Corporation Models 2T-1A, 2T-1A-1, and 2T-1A-2 airplanes. This AD requires inspection of the front..., contact WACO Classic Aircraft Corporation; 15955 South Airport Rd., Battle Creek, Michigan...

  9. Outcome, transport times, and costs of patients evacuated by helicopter versus fixed-wing aircraft.

    PubMed Central

    Thomas, F.; Wisham, J.; Clemmer, T. P.; Orme, J. F.; Larsen, K. G.

    1990-01-01

    We determined the differences in transport times and costs for patients transported by fixed-wing aircraft versus helicopter at ranges of 101 to 150 radial miles, where fixed-wing and helicopter in-hospital transports commonly overlap. Statistical analysis failed to show a significant difference between the trauma-care patients transported by helicopter (n = 109) and those transported by fixed-wing (n = 86) for age, injury severity score, hospital length of stay, hospital mortality, or discharge disability score. The times in returning patients to the receiving hospital by helicopter (n = 104) versus fixed-wing (n = 509) did not differ significantly. Helicopter transport costs per mile ($24), however, were 400% higher than those of fixed-wing aircraft with its associated ground ambulance transport costs ($6). Thus, helicopter transport is economically unjustified for interhospital transports exceeding 100 radial miles when an efficient fixed-wing service exists. PMID:2389575

  10. 77 FR 52205 - Airworthiness Directives; Univair Aircraft Corporation Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... Corporation Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are superseding an existing airworthiness directive (AD) for certain Univair Aircraft Corporation Models (ERCO... of a Univair Aircraft Corporation Model ERCO 415-D Ercoupe that crashed after an in-flight ]...

  11. 77 FR 67561 - Airworthiness Directives; Univair Aircraft Corporation Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... Corporation Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; correction.... That AD applies to certain Univair Aircraft Corporation Models (ERCO) 415-C, 415-CD, 415-D, E, G..., dated September 1, 2008, is made in several places throughout the AD for Univair Aircraft...

  12. Aircraft

    DTIC Science & Technology

    2002-01-01

    Company, Washington, DC Boeing Commercial Aircraft Division, Seattle, WA and Long Beach, CA Boeing Military Aircraft and Missile Division, St. Louis, MO and... aircraft ; military fixed-wing aircraft ; rotorcraft (helicopters and tiltrotor aircraft ); and aircraft jet engines. Two companies dominate the commercial... aircraft business, Boeing and Airbus. Four companies dominate the military fixed-wing market, Boeing, Lockheed Martin, BAE Systems, and European

  13. Price-Weight Relationships of General Aviation, Helicopters, Transport Aircraft and Engines

    NASA Technical Reports Server (NTRS)

    Anderson, Joseph L.

    1981-01-01

    The NASA must assess its aeronautical research program with economic as well as performance measures. It thus is interested in what price a new technology aircraft would carry to make it attractive to the buyer. But what price a given airplane or helicopter will carry is largely a reflection of the manufacturer's assessment of the competitive market into which the new aircraft will be introduced. The manufacturer must weigh any new aerodynamic or system technology innovation he would add to an aircraft by the impact of this innovation upon the aircraft's cost to manufacture, economic attractiveness and price. The intent of this paper is to give price standards against which new technologies and the NASA's research program can be assessed. Using reported prices for sailplanes, general aviation, agriculture, helicopter, business and transport aircraft, price estimating relations in terms of engine and airframe characteristics have been developed. The relations are given in terms of the aircraft type, its manufactured empty weight, engine weight, horsepower or thrust. Factors for the effects of inflation are included to aid in making predictions of future aircraft prices. There are discussions of aircraft price in terms of number of passenger seats, airplane size and research and development costs related to an aircraft model, and indirectly how new technologies, aircraft complexity and inflation have affected these.

  14. Should helicopter noise be measured differently from other aircraft noise? A review of the psychoacoustic literature

    NASA Technical Reports Server (NTRS)

    Molino, J. A.

    1982-01-01

    A review of 34 studies indicates that several factors or variables might be important in providing a psychoacoustic foundation for measurements of the noise from helicopters. These factors are phase relations, tail rotor noise, repetition rate, crest level, and generic differences between conventional aircraft and helicopters. Particular attention was given to the impulsive noise known as blade slap. Analysis of the evidence for and against each factor reveals that, for the present state of scientific knowledge, none of these factors should be regarded as the basis for a significant noise measurement correction due to impulsive blade slap. The current method of measuring effective perceived noise level for conventional aircraft appears to be adequate for measuring helicopter noise as well.

  15. Artificial Icing Test, Utility Tactical Transport Aircraft System (UTTAS), Boeing Vertol YUH-61A Helicopter

    DTIC Science & Technology

    1977-01-01

    Tactical Transport Aircraft System," 10 November 1975. 2. Letter, AVSCOM, DRSAV-EQI, 25 May 1976, subject: Utility Tactical Tranport Aircraft System...Parts, Helicopter Icing Spray System (HISS). 12 November 1973, with Change 1, 15 July 1976. 8. Technical Report. Environmental Research and Technology ...and static air temperature was obtained from table 3. Relative humidity was then computed using the values obtained from table 2 and equation 1: PS

  16. Assessment of NDE needs for aging corporate and private aircraft

    NASA Astrophysics Data System (ADS)

    Reinhart, Eugene R.

    1998-03-01

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

  17. Parametric study of helicopter aircraft systems costs and weights

    NASA Technical Reports Server (NTRS)

    Beltramo, M. N.

    1980-01-01

    Weight estimating relationships (WERs) and recurring production cost estimating relationships (CERs) were developed for helicopters at the system level. The WERs estimate system level weight based on performance or design characteristics which are available during concept formulation or the preliminary design phase. The CER (or CERs in some cases) for each system utilize weight (either actual or estimated using the appropriate WER) and production quantity as the key parameters.

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

    PubMed Central

    Lee, Sang Cheol; Hong, Sung Kyung

    2016-01-01

    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. PMID:27973429

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

    PubMed

    Lee, Sang Cheol; Hong, Sung Kyung

    2016-12-11

    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.

  20. 78 FR 67009 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... to require certain inspections of each spindle cuff assembly or blade fold cuff assembly for a crack. If there is a crack, this AD requires replacing the cracked part. If there is no crack, this AD... was prompted by discovery of cracks in the spindle cuffs. The actions are intended to prevent...

  1. 77 FR 41889 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-17

    ... gearbox (MGB) for a crack. This AD is prompted by a crack in the cored passage of the MGB housing, which may be indicated by oil on the housing. These actions are intended to detect a crack in the MGB... rulemaking based on those comments. Discussion This AD is prompted by an incident in which a crack in the...

  2. 77 FR 5418 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... malfunction of an internal valve, power loss at a critical phase of flight, and loss of control of the... aft fuel system 40 micron fuel filter element with a 10 micron fuel filter element. This proposed AD... contaminants larger than 10 microns present in the engine fuel control units (FCUs). The proposed actions...

  3. 77 FR 28328 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... loose or missing fastener, a crack, damage, or corrosion and adding an internal doubler to the aft shear... proposed actions are intended to detect a loose or missing fastener, a crack, damage, or corrosion on the T... inspection of the T/R pylon ``components and structure for obvious damage, cracks, corrosion, and...

  4. 77 FR 21402 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ...) manufactured with mislocated aluminum wire mesh, leaving portions of the graphite torque tube (spar) region... mislocated aluminum wire mesh in the blade skin which leaves portions of the graphite torque tube...

  5. NASA rotor system research aircraft flight-test data report: Helicopter and compound configuration

    NASA Technical Reports Server (NTRS)

    Erickson, R. E.; Kufeld, R. M.; Cross, J. L.; Hodge, R. W.; Ericson, W. F.; Carter, R. D. G.

    1984-01-01

    The flight test activities of the Rotor System Research Aircraft (RSRA), NASA 740, from June 30, 1981 to August 5, 1982 are reported. Tests were conducted in both the helicopter and compound configurations. Compound tests reconfirmed the Sikorsky flight envelope except that main rotor blade bending loads reached endurance at a speed about 10 knots lower than previously. Wing incidence changes were made from 0 to 10 deg.

  6. Computer simulation incorporating a helicopter model for evaluation of aircraft avionics systems

    NASA Technical Reports Server (NTRS)

    Ostroff, A. J.; Wood, R. B.

    1977-01-01

    A computer program was developed to integrate avionics research in navigation, guidance, controls, and displays with a realistic aircraft model. A user oriented program is described that allows a flexible combination of user supplied models to perform research in any avionics area. A preprocessor technique for selecting various models without significantly changing the memory storage is included. Also included are mathematical models for several avionics error models and for the CH-47 helicopter used in this program.

  7. A Comparative Analysis of Tilt Rotor Aircraft versus Helicopters Using Simulator Results

    DTIC Science & Technology

    1988-09-01

    Veit, Mr. Monti Callero , and Ms. Barbara Rose, all of the RAND Corporation; Mr. David Few, Mr. George Tucker, and Mr. Laurel "Shorty" Schroers, all of...Hickman, R.N. Armstrong and N. Cleek, Vol. 7, pp. 1-68, 15 May 1985. Veit, C., Callero , M., and Rose, B., "LHX Helicopter and Tilt Rotor Flight...Station Alexandria, Virginia 22304-6145 2. Library, Code 0142 2 Naval Postgraduate School Monterey, California 93943-5002 3. Clairice Veit/Monti Callero 1 c

  8. Sikorsky UH-60 (USA 82-23748 NASA-748) Air-loads research aircraft - Blackhawk helicopter with

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Sikorsky UH-60 (USA 82-23748 NASA-748) Air-loads research aircraft - Blackhawk helicopter with MUX-Bucket in flight Note: Used in publication in Flight Research at Ames; 57 Years of Development and Validation of Aeronautical Technology NASA SP-1998-3300 fig. 135

  9. Criteria for Control and Response Characteristics of Helicopters and VTOL Aircraft in Hovering and Low-Speed Flight

    NASA Technical Reports Server (NTRS)

    Tapscott, Robert J.

    1960-01-01

    Criteria for satisfactory control and response characteristics of low-speed aircraft are presented and discussed. The basis for the discussion is the results of a study of the effects of various control power (angular acceleration per unit control deflection) and angular velocity damping on pilots' opinions and on pilots' ability to perform precision tasks during hovering and low speed. The control response characteristics resulting in large improvements in the capability of the pilot-helicopter combination, particularly during instrument flight are discussed. A variation of the criteria with aircraft size is presented. The applicability of the criteria to aircraft of varying types is illustrated.

  10. Detection probability of cliff-nesting raptors during helicopter and fixed-wing aircraft surveys in western Alaska

    USGS Publications Warehouse

    Booms, T.L.; Schempf, P.F.; McCaffery, B.J.; Lindberg, M.S.; Fuller, M.R.

    2010-01-01

    We conducted repeated aerial surveys for breeding cliff-nesting raptors on the Yukon Delta National Wildlife Refuge (YDNWR) in western Alaska to estimate detection probabilities of Gyrfalcons (Falco rusticolus), Golden Eagles (Aquila chrysaetos), Rough-legged Hawks (Buteo lagopus), and also Common Ravens (Corvus corax). Using the program PRESENCE, we modeled detection histories of each species based on single species occupancy modeling. We used different observers during four helicopter replicate surveys in the Kilbuck Mountains and five fixed-wing replicate surveys in the Ingakslugwat Hills near Bethel, AK. During helicopter surveys, Gyrfalcons had the highest detection probability estimate (p^;p^ 0.79; SE 0.05), followed by Golden Eagles (p^=0.68; SE 0.05), Common Ravens (p^=0.45; SE 0.17), and Rough-legged Hawks (p^=0.10; SE 0.11). Detection probabilities from fixed-wing aircraft in the Ingakslugwat Hills were similar to those from the helicopter in the Kilbuck Mountains for Gyrfalcons and Golden Eagles, but were higher for Common Ravens (p^=0.85; SE 0.06) and Rough-legged Hawks (p^=0.42; SE 0.07). Fixed-wing aircraft provided detection probability estimates and SEs in the Ingakslugwat Hills similar to or better than those from helicopter surveys in the Kilbucks and should be considered for future cliff-nesting raptor surveys where safe, low-altitude flight is possible. Overall, detection probability varied by observer experience and in some cases, by study area/aircraft type.

  11. Operation Corporate: Parallels of the Joint Operational Access Concept

    DTIC Science & Technology

    2013-04-04

    150 helicopters. Fleet Air Arm Squadrons 4 squadrons with-Sea Harrier V/STOL aircraft (aircraft carriers) 1 squadron with Lynx MK 2 helicopters...helicopters Aircraft Lost Aboard Ships Sunk or Damaged: 3 Chinook helicopters 3 Lynx helicopters 1 Wessex 3 helicopter 6 Wessex 5 helicopters

  12. 75 FR 79950 - Airworthiness Directives; Kaman Aerospace Corporation (Kaman) Model K-1200 Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ...-084-AD; Amendment 39-16550; AD 2010-26-11] RIN 2120-AA64 Airworthiness Directives; Kaman Aerospace... rule; request for comments. SUMMARY: We are adopting a new airworthiness directive (AD) for the Kaman Model K-1200 helicopters. This AD requires revising the Limitations section of the Instructions...

  13. 77 FR 38744 - Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S-64F Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ..., failure from static overload, and subsequent loss of control of the helicopter. DATES: We must receive... economic evaluation, any comments received and other information. The street address for the Docket... docket shortly after receipt. For service information identified in this proposed AD, contact...

  14. The practical implementation of fatigue requirements to military aircraft and helicopters in the United Kingdom

    NASA Technical Reports Server (NTRS)

    Maxwell, R. D. J.

    1972-01-01

    The methods adopted in the United Kingdom to ensure the structural integrity of military aeroplanes and helicopters from the fatigue point of view are described. The procedure adopted from the writing of the specification to the monitoring of fatigue life in service are presented along with the requirements to be met and the way in which they are satisfied. Some of the outstanding problems that remain to be solved are indicated.

  15. A Trade-off Study of Tilt Rotor Aircraft versus Helicopters Using VASCOMP 2 and HESCOMP

    DTIC Science & Technology

    1986-03-01

    Accessibility to Alaska’s natural resources (offshore oil , minerals, timber, fish, etc.) could be greatly enhanced using V/SrOL aircraft with the...Offshore oil exploration and production H. EXCESSIVE INITIAL COST Although tilt rotor aircraft have advantaaes which may never be matched bv conventional...objective in conducting this experiment was to aanalyze the differences in aircraft canabi ]it’es for civet! values of mission radius. SP3 D. EXPERIMENT

  16. Calculation of the Longitudinal Stability Derivatives and Modes of Motion for Helicopter Aircraft

    DTIC Science & Technology

    1982-10-01

    progress. Before the details of controlling the aircraft can be fully worked out, some understanding of the aircraft’s inherent stability must be...influences (wind gusts, for instance). Pilot work - loaa is also a function of stability. Since adequate maneuverability is a necessity, the aircraft must...B. STATIC STABILITY The static stability of a system is defined by the initial tendency of the system to return to equilibrium conditions following

  17. Instrumentation requirements for aircraft parameter identification with application to the helicopter

    NASA Technical Reports Server (NTRS)

    Sorensen, J. A.; Mohr, R. L.; Cline, T. B.

    1975-01-01

    The extent to which instrumentation errors cause degradation in the knowledge of stability and control derivatives identified for flight tests was studied along with the resultant degradation of the flight system performance base on these derivatives. The error in measurement and data processing systems used for parameter identification, error analysis techniques, and the effects of instrumentation, errors on the accuracy of parameter estimates are discussed. The analysis programs were used to study instrumentation error effects on the accuracy of the identified stability and control derivatives of the CH-46 helicopter.

  18. Helicopter external noise requirements: FAA perspective

    NASA Technical Reports Server (NTRS)

    Foster, C. R.

    1978-01-01

    Enactment of helicopter noise certification standards for the control of noise impact contributing to community annoyance is considered in terms of the development of helicopters as an environmentally compatible air transportation mode. Increased use of helicopters for commercial applications and public awareness of aircraft noise are cited as factors making development of helicopter noise standards necessary both for the protection of the environmental interest of the community and to ensure the orderly growth of the helicopter industry itself. Noise sources, technology trends in helicopter design, and design concepts to control helicopter noise are discussed along with the regulatory background and specific helicopter regulatory concepts.

  19. 77 FR 71087 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... reducing or establishing life limits for the main rotor blade, tail rotor blade, planetary carrier assembly, tail rotor servo, elastomeric sleeve bearing, main landing gear shock strut piston cylinder, crossfeed... attach bolt, $40,000 for the main rotor hub, $12,000 for the main landing gear shock strut piston...

  20. 75 FR 5684 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-04

    ... corrosion. If you do not find a crack, the AD requires applying a corrosion preventive compound. If you find a crack, the AD requires replacing the MGB before further flight. If you find corrosion, bubbled... assembly mounting foot pad and rib for a crack and corrosion. If you do not find a crack, the AD...

  1. 78 FR 37160 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-20

    ... fold cuff assembly for a crack. If there is a crack, this proposed AD would require replacing the cracked part. If there is no crack, this AD would require applying white paint to the inspection area to enhance the existing inspection procedure. This proposed AD is prompted by the discovery of cracks in...

  2. 76 FR 66615 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ...-lock keys that did not meet the specified minimum hardness requirements. This condition, if not... specified minimum hardness requirements, which could lead to a landing gear collapse following a...

  3. 76 FR 31796 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    ... hours time-in-service (TIS). If there is a crack, this AD requires replacing the MGB upper housing.... If there is a crack, the AD requires replacing the MGB upper housing assembly with an airworthy MGB... Current or FPI, of the left, right, and forward MGB mounting foot ribs for a crack. (f) If there is...

  4. 78 FR 31863 - Airworthiness Directives; Sikorsky Aircraft Corporation-Manufactured (Sikorsky) Model Helicopters...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-28

    ... shaft, P/N 6435-20078-104, for a crack, paying particular attention to the lower spline area. (7) Within..., paying particular attention to the lower spline area. (8) Within 150 hours TIS or before reaching...

  5. 75 FR 70812 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... (MGB) assembly mounting foot pad and rib for a crack and corrosion. If you do not find a crack, the AD requires applying a corrosion preventive compound. If you find a crack, the AD requires replacing the MGB before further flight. If you find corrosion, bubbled paint, or paint discoloration, the AD requires...

  6. 76 FR 66209 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... (blade) for mislocated aluminum wire mesh in the blade skin. This proposal is prompted by the discovery that blades were manufactured with aluminum wire mesh mislocated, leaving portions of the graphite... for mislocated aluminum wire mesh in the blade skin. This proposal is prompted by the discovery...

  7. 75 FR 4308 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... visually inspecting it for damage. If the primary filter element has ``wavy'' pleats, internal buckling, or... filter element has ``wavy'' pleats, internal buckling, or indented dimples, before further...

  8. 76 FR 66205 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... through Friday, except Federal holidays. You may get the service information identified in this proposed... holidays. The Docket Operations office (telephone (800) 647-5527) is located in Room W12-140 on the ground...) 76070-55023- 011; a circuit modification kit, P/N 76070-55033-012; and a manifold, relay box,...

  9. 75 FR 26885 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, B, and C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... inspecting the hydraulic fluid for contamination; removing the requirement to reduce the interval for...: ``When checking servo actuators for contamination and leakage, the inspections must be redundant enough... ``inspection'' that must be performed by a mechanic, not a ``check'' that we sometimes allow a pilot to...

  10. 75 FR 42340 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... section of the Instructions ] for Continued Airworthiness (ICA) to reduce the life limit of the main gearbox housing and replacing any main gearbox housing that exceeds the life limit. This proposal is... beginning of your comments. We specifically invite comments on the overall regulatory,...

  11. 78 FR 65163 - Airworthiness Directives; Sikorsky Aircraft Corporation-Manufactured (Sikorsky) Model Helicopters...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... required inspecting and reworking the main gearbox (MGB) assembly second stage lower planetary plate (plate..., September 12, 1997), which required inspecting and reworking the MGB assembly plate. Since AD 97-19-10 was... gearbox second stage lower planetary plate and second stage planetary plate assembly assuming...

  12. 78 FR 44052 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ..., which proposed establishing new fatigue life limits for certain GE engine gas generator turbine (GGT... limits need to be based on low cycle fatigue (LCF) events instead of hours time-in- service. This action... rotor part. The proposed actions are intended to prevent fatigue failure of a GGT rotor part,...

  13. 77 FR 55166 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-07

    ... determination that these life limits need to be based on low cycle fatigue events instead of hours time-in-service. The proposed actions are intended to establish new fatigue life limits for certain GGT rotor parts to prevent fatigue failure of a GGT rotor part, engine failure, and subsequent loss of control...

  14. Multimission helicopter cockpit displays

    NASA Astrophysics Data System (ADS)

    Terry, William S.; Terry, Jody K.; Lovelace, Nancy D.

    1996-05-01

    A new operator display subsystem is being incorporated as part of the next generation United States Navy (USN) helicopter avionics system to be integrated into the multi-mission helicopter (MMH) that replaces both the SH-60B and the SH-60F in 2001. This subsystem exploits state-of-the-art technology for the display hardware, the display driver hardware, information presentation methodologies, and software architecture. Both of the existing SH-60 helicopter display systems are based on monochrome CRT technology; a key feature of the MMH cockpit is the integration of color AMLCD multifunction displays. The MMH program is one of the first military programs to use modified commercial AMLCD elements in a tactical aircraft. This paper presents the general configuration of the MMH cockpit and multifunction display subsystem and discusses the approach taken for presenting helicopter flight information to the pilots as well as presentation of mission sensor data for use by the copilot.

  15. Laser Illumination of Helicopters: A Comparative Analysis With Fixed-Wing Aircraft for the Period 1980 - 2011

    DTIC Science & Technology

    2013-04-01

    Aircraft for the Period 1980 – 2011 April 2013 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No...Agency Code 15. Supplemental Notes 16. Abstract INTRODUCTION. Laser illuminations of aircraft have resulted in pilots reporting...the level of exposure (4). A sharp rise in the number of laser incidents reported in the mid-1990s resulted in a revision of FAA Order 7400.2

  16. Tests Of Helicopter Control System

    NASA Technical Reports Server (NTRS)

    Hilbert, Kathryn B.; Lebacqz, J. Victor; Hindson, William S.

    1988-01-01

    Advanced control systems being developed for rotorcraft. Report discusses aspects of development of multivariable, explicit-model-following control system for CH-47B fly-by-wire helicopter. Project part of recent trend toward use of highly-augmented, high-gain flight-control systems to assist pilots of military helicopters in performance of demanding tasks and to improve handling qualities of aircraft.

  17. Documenting helicopter operations from an energy standpoint

    NASA Technical Reports Server (NTRS)

    Davis, S. J.; Stepniewski, W. Z.

    1974-01-01

    Results are presented of a study of the relative and absolute energy consumption of helicopters, including limited comparisons with fixed-wing aircraft, and selected surface transportation vehicles. Additional comparisons were made to determine the level of reduction in energy consumption expected from the application of advanced technologies to the helicopter design and sizing process. It was found that improvements in helicopter consumption characteristics can be accomplished through the utilization of advanced technology to reduce drag, structures weight, and powerplant fuel consumption.

  18. Research On The CH-47B Helicopter

    NASA Technical Reports Server (NTRS)

    Hilbert, Kathryn B.; Tucker, George E.; Chen, Robert T. N.; Fry, Emmett B.; Hindson, William S.

    1988-01-01

    Report describes equipment added to, and research capabilities of CH-47B helicopter. Programmable symbol generator provides display formats for variety of missions - those of vertical-takeoff-and-landing aircraft and helicopters. Powerful general-purpose flight computer in operation. Computer programmable in high-level languages and supports research more efficiently. Flight-control software developed to improve capability of helicopter to perform simulations in flight.

  19. MUOS: Application in Naval Helicopter Operations

    DTIC Science & Technology

    2015-03-01

    frequency HSC Helicopter Sea Combat Squadron HSL Helicopter Anti-Submarine Squadron Light HSM Helicopter Strike Maritime Squadron ISAR inverse ...using the AN/APS 147 Inverse Synthetic Aperture Radar (ISAR), which gives the aircraft the ability to identify tracks based solely on radar data. The...footprint of the satellite (see Figure 12). Each beam is like a cell tower that covers approximately 600 square miles of earth (Buck & Russ, 2007). Using a

  20. Analysis of Vibratory Excitation of Gear Systems as a Contributor to Aircraft Interior Noise. [helicopter cabin noise

    NASA Technical Reports Server (NTRS)

    Mark, W. D.

    1979-01-01

    Application of the transfer function approach to predict the resulting interior noise contribution requires gearbox vibration sources and paths to be characterized in the frequency domain. Tooth-face deviations from perfect involute surfaces were represented in terms of Legendre polynomials which may be directly interpreted in terms of tooth-spacing errors, mean and random deviations associated with involute slope and fullness, lead mismatch and crowning, and analogous higher-order components. The contributions of these components to the spectrum of the static transmission error is discussed and illustrated using a set of measurements made on a pair of helicopter spur gears. The general methodology presented is applicable to both spur and helical gears.

  1. Development of automatic and manual flight director landing systems for the XV-15 tilt rotor aircraft in helicopter mode

    NASA Technical Reports Server (NTRS)

    Hofmann, L. G.; Hoh, R. H.; Jewell, W. F.; Teper, G. L.; Patel, P. D.

    1978-01-01

    The objective of this effort is to determine IFR approach path and touchdown dispersions for manual and automatic XV-15 tilt rotor landings, and to develop missed approach criteria. Only helicopter mode XV-15 operation is considered. The analysis and design sections develop the automatic and flight director guidance equations for decelerating curved and straight-in approaches into a typical VTOL landing site equipped with an MLS navigation aid. These system designs satisfy all known pilot-centered, guidance and control requirements for this flying task. Performance data, obtained from nonstationary covariance propagation dispersion analysis for the system, are used to develop the approach monitoring criteria. The autoland and flight director guidance equations are programmed for the VSTOLAND 1819B digital computer. The system design dispersion data developed through analysis and the 1819B digital computer program are verified and refined using the fixed-base, man-in-the-loop XV-15 VSTOLAND simulation.

  2. The Use of Commercial Remote Sensing Systems in Predicting Helicopter Brownout Conditions

    DTIC Science & Technology

    2009-09-01

    REMOTE SENSING IN PREDICTING HELICOPTER BROWNOUT CONDITIONS by Christine Kay Rabaja September 2009 Thesis Advisor: Richard C. Olsen...Master’s Thesis 4. TITLE AND SUBTITLE The Use of Commercial Remote Sensing Systems in Predicting Helicopter Brownout Conditions 6. AUTHOR...soils susceptible to helicopter brownout . Helicopter brownout occurs when downwash disturbs the dust and sand beneath the aircraft during takeoff

  3. 76 FR 65103 - Special Conditions: Gulfstream Aerospace Corporation, Model GIV-X Airplane; Aircraft Electronic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... Federal Aviation Administration 14 CFR Part 25 Special Conditions: Gulfstream Aerospace Corporation, Model... comments. SUMMARY: These special conditions are issued for the Gulfstream Aerospace Corporation Model GIV-X... connectivity capabilities of the airplane's computer systems and networks, which may allow access by...

  4. 76 FR 11174 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ...-41A. Remove the safety pin, P/N ASI-700-80. Remove and discard any ball bearings, and clean all... safety pin. Release the cable from the broom closet. Reinstall the cable to the handle with the clevis... (handle assembly), P/N ASI-700-41A. (h) Remove the safety pin, P/N ASI-700-80. (i) Remove and discard...

  5. 75 FR 55453 - Airworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-13

    ..., which could lead to increased vibrations, a fatigue crack, loss of a portion of the vertical stabilizer... the vibration measurements. Also, proposed was requiring, on or before December 31, 2010, installing a... and correct an unbalanced or out-of-track tail rotor, which could lead to increased vibrations,...

  6. 75 FR 26888 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-70A and S-70C Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... a crack. If you find a crack, replacing the gear with an airworthy gear before further flight would be required. This proposal is prompted by three gear cracking incidents, one of which resulted in the... detect a crack in the gear to prevent a tail rotor separating, loss of tail rotor control, and...

  7. 76 FR 65105 - Special Conditions: Gulfstream Aerospace Corporation, Model GIV-X Airplane; Isolation or Aircraft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... networks and systems, such as passenger entertainment and information services, than previous Gulfstream airplane models. This may allow the exploitation of network security vulnerabilities and increased risks... Federal Aviation Administration 14 CFR Part 25 Special Conditions: Gulfstream Aerospace Corporation,...

  8. Helicopter Strakes

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Langley Research Center has done extensive research into the effectiveness of tail boom strakes on conventional tail rotor helicopters. (A strake is a "spoiler" whose purpose is to alter the airflow around an aerodynamic body.) By placing strakes on a tail boom, the air loading can be changed, thrust and power requirements of the tail rotor can be reduced, and helicopter low speed flight handling qualities are improved. This research led to the incorporation of tail boom strakes on three production-type commercial helicopters manufactured by McDonnell Douglas Helicopter Company.

  9. Aircraft icing instrumentation: Unfilled needs. [rotary wing aircraft

    NASA Technical Reports Server (NTRS)

    Kitchens, P. F.

    1980-01-01

    A list of icing instrumentation requirements are presented. Because of the Army's helicopter orientation, many of the suggestions are specific to rotary wing aircraft; however, some of the instrumentation are also suitable for general aviation aircraft.

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Helicopter In-Flight Tracking System (HITS) for the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Martone, Patrick; Tucker, George; Aiken, Edwin W. (Technical Monitor)

    2001-01-01

    The National Aeronautics and Space Administration (NASA) Ames Research Center (ARC) is sponsoring deployment and testing of the Helicopter In-flight Tracking System (HITS) in a portion of the Gulf of Mexico offshore area. Using multilateration principles, HITS determines the location and altitude of all transponder-equipped aircraft without requiring changes to current Mode A, C or S avionics. HITS tracks both rotary and fixed-wing aircraft operating in the 8,500 sq. mi. coverage region. The minimum coverage altitude of 100 ft. is beneficial for petroleum industry, allowing helicopters to be tracked onto the pad of most derricks. In addition to multilateration, HITS provides surveillance reports for aircraft equipped for Automatic Dependent Surveillance - Broadcast (ADS-B), a new surveillance system under development by the Federal Aviation Administration (FAA). The U.S. Department of Transportation (DOT) Volpe National Transportation Systems Center (Volpe Center) is supporting NASA in managing HITS installation and operation, and in evaluating the system's effectiveness. Senses Corporation is supplying, installing and maintaining the HITS ground system. Project activities are being coordinated with the FAA and local helicopter operators. Flight-testing in the Gulf will begin in early 2002. This paper describes the HITS project - specifically, the system equipment (architecture, remote sensors, central processing system at Intracoastal City, LA, and communications) and its performance (accuracy, coverage, and reliability). The paper also presents preliminary results of flight tests.

  12. Aircraft

    DOEpatents

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  13. Aircraft

    DOEpatents

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

    1998-01-01

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

  14. Helicopter problems

    NASA Technical Reports Server (NTRS)

    Kussner, H G

    1937-01-01

    The present report deals with a number of the main problems requiring solution in the development of helicopters and concerning the lift, flying performance, stability, and drive. A complete solution is given for the stability of the helicopter with rigid blades and control surfaces. With a view to making a direct-lift propeller sufficient without the addition of auxiliary propellers, the "flapping drive" is assessed and its efficiency calculated.

  15. Adaptive structures for fixed and rotary wing aircraft

    NASA Astrophysics Data System (ADS)

    Martin, Willi; Jänker, Peter; Siemetzki, Markus; Lorkowski, Thomas; Grohmann, Boris; Maier, Rudolf; Maucher, Christoph; Klöppel, Valentin; Enenkl, Bernhard; Roth, Dieter; Hansen, Heinz

    2007-07-01

    Since more than 10 years EADS Innovation Works, which is the corporate research centre of EADS (European Aeronautic Defence and Space Company), is investigating smart materials and adaptive structures for aircraft in cooperation with EADS business units. Focus of research efforts are adaptive systems for shape control, noise reduction and vibration control of both fixed and rotary wing aircraft as well as for lift optimisation of fixed wing aircraft. Two outstanding adaptive systems which have been pushed ahead in cooperation with Airbus Germany and Eurocopter Germany are adaptive servo flaps for helicopter rotor blades and innovative high lift devices for fixed wing aircraft which both were tested in flight for the first time representing world premieres. In this paper various examples of adaptive systems are presented which were developed and realized by EADS in recent years.

  16. The helicopter - some ergonomic factors.

    PubMed

    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.

  17. Application of a helicopter mathematical model to the Langley differential maneuvering simulator for use in a helicopter/fighter evasive maneuver study

    NASA Technical Reports Server (NTRS)

    Houck, J. A.; Ashworth, B. R.; Baker, D. R.

    1976-01-01

    A real time simulation study was conducted using a differential maneuvering simulator to determine and evaluate helicopter evasive maneuvers when attacked by fighter aircraft. A general helicopter mathematical model was modified to represent an H-53 helicopter. The helicopter model was compared to H-53 flight test data to determine any differences between the simulated and actual vehicles. The simulated helicopter was also subjectively validated by participating pilots. Two fighter mathematical models validated in previous studies were utilized for the attacking aircraft. The results of this simulation study have been verified in a flight test program conducted by the U. S. Air Force and were found to closely match the flight results.

  18. Helicopter training simulators: Key market factors

    NASA Technical Reports Server (NTRS)

    Mcintosh, John

    1992-01-01

    Simulators will gain an increasingly important role in training helicopter pilots only if the simulators are of sufficient fidelity to provide positive transfer of skills to the aircraft. This must be done within an economic model of return on investment. Although rotor pilot demand is still only a small percentage of overall pilot requirements, it will grow in significance. This presentation described the salient factors influencing the use of helicopter training simulators.

  19. Aircraft

    DTIC Science & Technology

    2003-01-01

    national power. But with the recent events such as the war with Iraq, the Severe Acute Respiratory Syndrome (SARS) outbreak, some major carriers... TITLE AND SUBTITLE 2003 Industry Studies: Aircraft 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER

  20. Finite difference time domain grid generation from AMC helicopter models

    NASA Technical Reports Server (NTRS)

    Cravey, Robin L.

    1992-01-01

    A simple technique is presented which forms a cubic grid model of a helicopter from an Aircraft Modeling Code (AMC) input file. The AMC input file defines the helicopter fuselage as a series of polygonal cross sections. The cubic grid model is used as an input to a Finite Difference Time Domain (FDTD) code to obtain predictions of antenna performance on a generic helicopter model. The predictions compare reasonably well with measured data.

  1. 36 CFR 327.4 - Aircraft.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Aircraft. (a) This section pertains to all aircraft including, but not limited to, airplanes, seaplanes..., material or equipment by parachute, balloon, helicopter or other means onto or from project lands or...

  2. 36 CFR 327.4 - Aircraft.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Aircraft. (a) This section pertains to all aircraft including, but not limited to, airplanes, seaplanes..., material or equipment by parachute, balloon, helicopter or other means onto or from project lands or...

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

    NASA Technical Reports Server (NTRS)

    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.

  4. Scoop attachment makes helicopter recoveries easier and safer

    NASA Technical Reports Server (NTRS)

    Koons, W. E.

    1965-01-01

    Helicopter with rigid boom and net attachment performs rescue or recovery operations easily and safely. The attachment in the front of the helicopter scoops objects from difficult and otherwise inaccessible areas and pivots to the side hatch of the aircraft so that no crew member need leave the craft.

  5. 78 FR 23692 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... proposed AD are intended to prevent loss of a T/R blade tab, which could result in excessive vibration and..., and that the loss of the tab leads to a significant increase in the aircraft's vibration level. As a... in excessive vibration of the helicopter and loss of control of the helicopter. (c) Comments Due...

  6. Astronaut James Lovell hoisted from water by recovery helicopter

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut James A. Lovell Jr., pilot of the Gemini 7 space flight, is hoisted from the water by a recovery helicopter from the Aircraft Carrier U.S.S. Wasp. Astronaut Frank Borman, command pilot, waits in the raft to be hoisted aboard the helicopter.

  7. Control of helicopter rotorblade aerodynamics

    NASA Technical Reports Server (NTRS)

    Fabunmi, James A.

    1991-01-01

    The results of a feasibility study of a method for controlling the aerodynamics of helicopter rotorblades using stacks of piezoelectric ceramic plates are presented. A resonant mechanism is proposed for the amplification of the displacements produced by the stack. This motion is then converted into linear displacement for the actuation of the servoflap of the blades. A design which emulates the actuation of the servoflap on the Kaman SH-2F is used to demonstrate the fact that such a system can be designed to produce the necessary forces and velocities needed to control the aerodynamics of the rotorblades of such a helicopter. Estimates of the electrical power requirements are also presented. A Small Business Innovation Research (SBIR) Phase 2 Program is suggested, whereby a bench-top prototype of the device can be built and tested. A collaborative effort between AEDAR Corporation and Kaman Aerospace Corporation is anticipated for future effort on this project.

  8. 78 FR 24371 - Airworthiness Directives; Robinson Helicopter Company (Robinson)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Robinson Helicopter Company (Robinson) AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed..., Aerospace Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA,...

  9. The role of the helicopter in transportation. [technology assessment for use in civil aviation

    NASA Technical Reports Server (NTRS)

    Dajani, J. S.; Warner, D.; Epstein, D.; Obrien, J.

    1976-01-01

    A general overview is presented of the role that the helicopter plays in the current aviation scene with special emphasis on its use in the airport access function. Technological problems of present-day aircraft are discussed along with some plausible solutions. The economic and regulatory aspects of commercial helicopter operations are presented. Finally six commercial operations utilizing helicopters are reviewed and conditions that enhance the success of the helicopter in the airport access function are proposed.

  10. 76 FR 39254 - Airworthiness Directives; Schweizer Aircraft Corporation (Schweizer) Model 269A, A-1, B, C, C-1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... prompted by a locknut working loose from a bolt attaching the tailboom support strut at the aft cluster... attaching the tailboom support strut at the aft cluster fitting. Further investigation revealed that the... helicopters with an Aft Cluster Fitting Modification Kit, part number (P/N) SA-269K-106,...

  11. Development of a Comprehensive Neck Injury Criterion for Aircraft-Related Incidences

    DTIC Science & Technology

    1995-02-15

    Naval helicopter and fixed- wing aircraft crashes and from U.S. Army helicopter crashes were identified in the literature. Together, these statistics...Cervical Spine 3.7 Adapted from Coltman et al., 1989 (Reference 5) Fixed- wing aircraft mishaps produce the same general injury trends as do...helicopter crashes: head and extremity injuries are the most prevalent. Injuries to the thorax occur less often in fixed- wing aircraft than in helicopter

  12. Evaluation of an Autonetics Stabilization System Installed in a Bell Model 47J Helicopter

    DTIC Science & Technology

    1962-07-09

    in an H-19 Helicopter as Task 17-0001, " Stability Augmentation System for Rotary Wing Aircraft. " d. The equipment was received for evaluation...Stabilization System Installed in a Bell Model 47J Helicopter" b. Plan of Test, USAEPG-SIG 950-48, " Stability Augmentation System for Rotary Wing Aircraft

  13. Helicopter Acoustics

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Exterior and interior noise problems are addressed both from the physics and engineering as well as the human factors point of view. The role of technology in closing the gap between what the customers and regulating agencies would like to have and what is available is explored. Noise regulation concepts, design, operations and testing for noise control, helicopter noise prediction, and research tools and measurements are among the topics covered.

  14. Disorientation phenomena in naval helicopter pilots.

    PubMed

    Tormes, F R; Guedry, F E

    1975-04-01

    The incidence of pilot disorientation in fixed- and rotary-wing aircraft has been previously investigated, but special orientation problems of naval helicopter pilots engaged in operations at sea and landing on moving platforms have not been previously investigated. A questionnaire concerning disorientations was answered anonymously and individually by 104 active naval helicopter pilots. Fifty-six percent indicated one or more espisodes of severe disorientation, and 8.6% indicated having experienced severe disorientation five or more times while piloting helicopters. A number of factors conducive to disorientation were identified. Some precipitating factors appear to be specific to operations over water or over a moving deck, although some of these may well have their counterparts in special operations over land. Other factors are common to fixed-wing as well as rotary-wing aircraft. A number of potential countermeasures for various precipitating factors are discussed.

  15. Workload and operational fatigue in helicopter pilots.

    PubMed

    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.

  16. The evolution of helicopters

    NASA Astrophysics Data System (ADS)

    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)].

  17. Aircraft Design Analysis

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The helicopter pictured is the twin-turbine S-76, produced by Sikorsky Aircraft division of United Technologies, Stratford, Connecticut. It is the first transport helicopter ever dey n e d purely as a commercial vehicle rather than an adaptation of a military design. Being built in large numbers for customers in 16 countries, the S-76 is intended for offshore oil rig support, executive transportation and general utility service. The craft carries 12 passengers plus a crew of two and has a range of more than 450 miles-yet it weighs less than 10,000 pounds. Significant weight reduction was achieved by use of composite materials, which are generally lighter but stronger than conventional aircraft materials. NASA composite technology played a part in development of the S-76. Under contract with NASA's Langley Research Center, Sikorsky Aircraft designed and flight-tested a helicopter airframe of advanced composite materials.

  18. Evolution of civil aeromedical helicopter aviation.

    PubMed

    Meier, D R; Samper, E R

    1989-07-01

    The rapid increase in the use of helicopters for hospital transport during the 1980s is the culmination of several hundred years of military medical innovation. Mass battefield casualties spurred both technologic and medical changes necessary for today's sophisticated helicopter systems in use worldwide, particularly in the United States. The Napoleonic Era and the American Civil War provided the framework for the evolution of today's state-of-the-art emergency medical techniques. The use of airplanes to evacuate the wounded eventually led to using helicopters for rescue missions in World War II. The combat experiences of the United States in Korea, the British in Malaya, and the French in Indochina proved that rotary-wing aircraft were invaluable in reducing battlefield death rates. Any skepticism about the efficacy of helicopter medical evacuation was erased during the Vietnam conflict. As an integral part of the modern battlefield, these specialized aircraft became a necessity. The observations and experience of American servicemen and medical personnel in Vietnam established the foundation for the acceptance of helicopter transport in modern hospital systems.

  19. MH-60R Multi-Mission Helicopter (MH-60R)

    DTIC Science & Technology

    2013-12-01

    Helicopter Concept of Operations that replaces the aging SH -60B and SH - 60F helicopters. The avionics upgrades over the existing SH -60B/F include: a glass...fleet as of March 24, 2014 with 13 of 17 prospective MH- 60R squadrons having been established or transitioned from SH -60Bs. Full Rate Production...Aircraft = 34.5 -- Total Operating Aircraft Years = 4,618 Antecedent Information: The antecedent system is the SH -60B/F aircraft. All costs are from the

  20. Maneuver Acoustic Flight Test of the Bell 430 Helicopter

    NASA Technical Reports Server (NTRS)

    Watts, Michael E.; Snider, Royce; Greenwood, Eric; Baden, Joel

    2012-01-01

    A cooperative flight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July, 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 data points over 10 test days and compiled an extensive data base of dynamic maneuver measurements. Three microphone configurations with up to 31 microphones in each configuration were used to acquire acoustic data. Aircraft data included DGPS, aircraft state and rotor state information. This paper provides an overview of the test.

  1. A review of US Army aircrew-aircraft integration research programs

    NASA Technical Reports Server (NTRS)

    Key, D. C.; Aiken, E. W.

    1984-01-01

    If the U.S. Army's desire to develop a one crew version of the Light Helicopter Family (LHX) helicopter is to be realized, both flightpath management and mission management will have to be performed by one crew. Flightpath management, the helicopter pilot, and the handling qualities of the helicopter were discussed. In addition, mission management, the helicopter pilot, and pilot control/display interface were considered. Aircrew-aircraft integration plans and programs were reviewed.

  2. Helicopter trajectory planning using optimal control theory

    NASA Technical Reports Server (NTRS)

    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. Contingency power concepts for helicopter turboshaft engine

    NASA Technical Reports Server (NTRS)

    Hirschkron, R.; Davis, R. H.; Goldstein, D. N.; Haynes, J. F.; Gauntner, J. W.

    1984-01-01

    Twin helicopter engines are often sized by power requirement of safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 minute Contingency Power rating, permitting an engine size reduction. The merits of water injection, cooling flow modulation, throttle push and an auxiliary power plant were evaluated using military life cycle cost (LCC) and commercial helicopter direct operating cost (DOC) merit factors in a rubber engine/rubber aircraft scenario.

  4. A Comparative Analysis of a CV Helicopter and a JVX (Joint Services Advanced Vertical Lift) Tilt-Rotor Aircraft in an Aircraft Carrier Based ASW (anti-Submarine Warfare)

    DTIC Science & Technology

    1985-03-01

    D. SEARCH AND RESCUE -------------------------- 36 E. SUMMARY ------------------------------------ 45 III . COMPARISON OF THE AIRCRAFT IN A SIMULATED...aircraft may respond to contacts generated by remote sources either from an airborne or an on-deck five minute alert status. Once the dipping sonar...scenarios are modeled. The model and results are described in Chapter III . Conclusions and recommendations for further study are contained in Chapter

  5. A practical approach to helicopter internal noise prediction

    NASA Technical Reports Server (NTRS)

    Levine, L. S.; Defelice, J. J.

    1978-01-01

    A practical and well correlated procedure for predicting helicopter internal noise is presented. It accounts for the propagation of noise along multiple paths on an octave by octave basis. The method is sufficiently general to be applicable to conventional helicopters as well as other aircraft types, when the appropriate structural geometry, noise source strengths, and material acoustic properties are defined. A guide is provided for the prediction of various helicopter noise sources over a wide range of horsepower for use when measured data are not available. The method is applied to the prediction of the interior levels of the Civil Helicopter Research Aircraft (CHRA), both with and without soundproofing installed. Results include good correlation with measured levels and prediction of the speech interference level within 1.5 db at all conditions. A sample problem is also shown illustrating the use of the procedure. This example calculates the engine casing noise observed in the passenger cabin of the CHRA.

  6. Army Attack Helicopters: Can They Survive on the Airland Battlefield?

    DTIC Science & Technology

    1987-06-05

    air-to-ar defense sysstems were studied. Specific anti-helicopter systems and tactics were investigated to determine the level of the threat facing...most notable for its suggestion of the development of the helicopter turbine engine , which promised to be an answer to the acute engine power...Argentine Pucara. The Pucara is a small twin engined , two seat aircraft designed for counterinsurgency duties in Argentina. It is armed with two 20mm or

  7. A comprehensive plan for helicopter drag reduction

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Montana, P. S.

    1975-01-01

    Current helicopters have parasite drag levels 6 to 10 times as great as fixed wing aircraft. The commensurate poor cruise efficiency results in a substantial degradation of potential mission capability. The paper traces the origins of helicopter drag and shows that the problem (primarily due to bluff body flow separation) can be solved by the adoption of a comprehensive research and development plan. This plan, known as the Fuselage Design Methodology, comprises both nonaerodynamic and aerodynamic aspects. The aerodynamics are discussed in detail and experimental and analytical programs are described which will lead to a solution of the bluff body problem. Some recent results of work conducted at the Naval Ship Research and Development Center (NSRDC) are presented to illustrate these programs. It is concluded that a 75-per cent reduction of helicopter drag is possible by the full implementation of the Fuselage Design Methodology.

  8. 77 FR 18970 - Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Directives; Bell Helicopter Textron Canada Helicopters AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for the Bell Helicopter Textron Canada Limited (BHTC) Model 407 helicopters. This proposed AD is... Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone (450)...

  9. Anthropometric Cockpit Compatibility Assessment of US Army Aircraft for Large and Small Personnel Wearing a Training, Warm-Weather Clothing Configuration

    DTIC Science & Technology

    1984-07-01

    Helicopters, Rotary- Wing 4 Aircraft, Fixed- Wing Aircraft, Aerospace Medicine, Human Factors 20. AwTRACT (’Coutfue a .mn eew@ 00,11 Neeu 126POSM wdeud...helicopters (except AAH-64) and fixed- wing aircraft. Subjects were dressed in the warm weather training uniform of US Army aviators and were requested...17 Fixed- Wing Aircraft ... ........ . *. . . .. . . . . . . . 23 Summary ...... ........... .......... ... .. ........ 25 Ref er

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

    PubMed

    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.

  11. Rotary-wing aerodynamics. Volume 2: Performance prediction of helicopters

    NASA Technical Reports Server (NTRS)

    Keys, C. N.; Stephniewski, W. Z. (Editor)

    1979-01-01

    Application of theories, as well as, special methods of procedures applicable to performance prediction are illustrated first, on an example of the conventional helicopter and then, winged and tandem configurations. Performance prediction of conventional helicopters in hover and vertical ascent are investigated. Various approaches to performance prediction in forward translation are presented. Performance problems are discussed only this time, a wing is added to the baseline configuration, and both aircraft are compared with respect to their performance. This comparison is extended to a tandem. Appendices on methods for estimating performance guarantees and growth of aircraft concludes this volume.

  12. Research requirements to improve reliability of civil helicopters

    NASA Technical Reports Server (NTRS)

    Dougherty, J. J., III; Barrett, L. D.

    1978-01-01

    The major reliability problems of the civil helicopter fleet as reported by helicopter operational and maintenance personnel are documented. An assessment of each problem is made to determine if the reliability can be improved by application of present technology or whether additional research and development are required. The reliability impact is measured in three ways: (1) The relative frequency of each problem in the fleet. (2) The relative on-aircraft manhours to repair, associated with each fleet problem. (3) The relative cost of repair materials or replacement parts associated with each fleet problem. The data reviewed covered the period of 1971 through 1976 and covered only turbine engine aircraft.

  13. Helicopter Airborne Laser Positioning System (HALPS)

    NASA Technical Reports Server (NTRS)

    Eppel, Joseph C.; Christiansen, Howard; Cross, Jeffrey; Totah, Joseph

    1990-01-01

    The theory of operation, configuration, laboratory, and ground test results obtained with a helicopter airborne laser positioning system developed by Princeton University is presented. Unfortunately, due to time constraints, flight data could not be completed for presentation at this time. The system measures the relative position between two aircraft in three dimensions using two orthogonal fan-shaped laser beams sweeping across an array of four detectors. Specifically, the system calculates the relative range, elevation, and azimuth between an observation aircraft and a test helicopter with a high degree of accuracy. The detector array provides a wide field of view in the presence of solar interference due to compound parabolic concentrators and spectral filtering of the detector pulses. The detected pulses and their associated time delays are processed by the electronics and are sent as position errors to the helicopter pilot who repositions the aircraft as part of the closed loop system. Accuracies obtained in the laboratory at a range of 80 ft in the absence of sunlight were + or - 1 deg in elevation; +0.5 to -1.5 deg in azimuth; +0.5 to -1.0 ft in range; while elevation varied from 0 to +28 deg and the azimuth varied from 0 to + or - 45 deg. Accuracies in sunlight were approximately 40 deg (+ or - 20 deg) in direct sunlight.

  14. The Computational Electromagnetic Modelling of the CH-146 Griffon Helicopter

    NASA Astrophysics Data System (ADS)

    Rogers, Sarah Alicia

    Selecting the optimal location for a new antenna on an aircraft is a difficult task. Given the limited space that is available on the fuselage, there maybe only a few available locations from which to choose. The performance of a new antenna is often hindered by nearby structures on the aircraft, which may block or diffract the antenna's desired radiation. In addition, given that there are many other antennas and electronic systems onboard aircraft, potential interference produced by the new antenna must also be considered. The choice of the best antenna location must therefore be based on the careful study of the electromagnetic performance of the antenna at each location. Given that it is unlikely that a new antenna can be physically tested in various locations on an operational aircraft, recourse must be made to computer simulation. In this work, the selection of an appropriate location for a new satellite communication antenna is considered for the CH-146 Griffon helicopter. To this end, a new computer electromagnetic model of the CH-146 Griffon helicopter was created, validated, and used to characterize the helicopter's electromagnetic environment. A commercial computational software called FEKO was subsequently used to calculate the radiation patterns, near-fields, and surface current distribution generated on the helicopter model by a broad-patterned antenna installed at three different locations on the aircraft. A subsequent analysis of the calculated results was then used to determine the best of the three possible placements of the proposed satellite communications antenna.

  15. Helicopter Handling Qualities

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Helicopters are used by the military and civilian communities for a variety of tasks and must be capable of operating in poor weather conditions and at night. Accompanying extended helicopter operations is a significant increase in pilot workload and a need for better handling qualities. An overview of the status and problems in the development and specification of helicopter handling-qualities criteria is presented. Topics for future research efforts by government and industry are highlighted.

  16. Operational requirements for helicopter operations low level in degraded visual environment

    NASA Astrophysics Data System (ADS)

    Eger, Thorsten W.

    2013-05-01

    In order to assist the pilot to safely operate helicopters in degraded visual environment (DVE), an integrated system of various technologies that will provide improved situation awareness with minimal interpretation whilst controlling the aircraft appears to be essential. To determine the most effective and affordable solution set to enhance helicopter operations in DVE at low altitudes and to help scope the potential range of solutions, the critical tasks of helicopters with the inherent requirements are to be defined. This paper will provide an overview on the operational environment, today procedures and the resulting general requirements for operating helicopters low level in degraded visual environment.

  17. Small Business Innovations (Helicopters)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The amount of engine power required for a helicopter to hover is an important, but difficult, consideration in helicopter design. The EHPIC program model produces converged, freely distorted wake geometries that generate accurate analysis of wake-induced downwash, allowing good predictions of rotor thrust and power requirements. Continuum Dynamics, Inc., the Small Business Innovation Research (SBIR) company that developed EHPIC, also produces RotorCRAFT, a program for analysis of aerodynamic loading of helicopter blades in forward flight. Both helicopter codes have been licensed to commercial manufacturers.

  18. Helicopter-V/STOL dynamic wind and turbulence design methodology

    NASA Technical Reports Server (NTRS)

    Bailey, J. Earl

    1987-01-01

    Aircraft and helicopter accidents due to severe dynamic wind and turbulence continue to present challenging design problems. The development of the current set of design analysis tools for a aircraft wind and turbulence design began in the 1940's and 1950's. The areas of helicopter dynamic wind and turbulence modeling and vehicle response to severe dynamic wind inputs (microburst type phenomena) during takeoff and landing remain as major unsolved design problems from a lack of both environmental data and computational methodology. The development of helicopter and V/STOL dynamic wind and turbulence response computation methology is reviewed, the current state of the design art in industry is outlined, and comments on design methodology are made which may serve to improve future flight vehicle design.

  19. Helicopter simulator qualification

    NASA Technical Reports Server (NTRS)

    Hampson, Brian

    1992-01-01

    CAE has extensive experience in building helicopter simulators and has participated in group working sessions for fixed-wing advisory circulars. Against this background, issues that should be addressed in establishing helicopter approval criteria were highlighted. Some of these issues are not immediately obvious and may, indeed, be more important than the criteria a themselves.

  20. The RMAX Helicopter UAV

    DTIC Science & Technology

    2007-11-02

    7 SYSTEM CONFIGURATION..................................8 OBSERVATION FLIGHT AT ERUPTING VOLCANO , MT. USU...autonomous flight control system. Because our autonomous, unmanned helicopter has succeeded in observation roles at erupting volcanoes , the Japanese...saving devices. In April 2000, we had our GPS-based autonomous helicopter play an observation role at an erupting volcano . This is the first time in

  1. Helicopter support of North Sea oil exploration.

    PubMed

    Preston, F S

    1978-04-01

    Exploration for oil beneath the North Sea started in the early 1960's with the discovery of natural gas and oil in the southern part between the coasts of East Anglia and the Netherlands. Since then oil exploration has built up considerably, the main effort moving northwards between the Shetland Islands and the Norwegian coasts. The helicopter offered the most direct and rapid contact with off-shore oil rigs and since these early days and immense helicopter operation has been built up round the borders of the North Sea by all the nations involved. Flying conditions in this area, particularly in winter, are at times difficult if not to say hazardous. Nevertheless, a sophisticated helicopter support service has been built up using modern aircraft and equipment which is unique in aviation history. This paper attempts to trace the history of the service, the operational problems involved and the special needs such as survival equipment and clothing. In addition, a co-ordinated air/sea rescue service largely based on helicopters has been built up and provides not only rescue facilities for possible rig disasters but also for shipping emergencies in the area.

  2. Helicopter human factors

    NASA Technical Reports Server (NTRS)

    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.

  3. Astronaut Frank Borman hoisted from water by recovery helicopter

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronaut Frank Borman, command pilot of the Gemini 7 space flight, is hoisted from the water by a recovery helicopter from the Aircraft Carrier U.S.S. Wasp. Below him, Navy divers sit in the life raft next to the Gemini spacecraft.

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

    NASA Technical Reports Server (NTRS)

    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.

  5. Optimum Design of a Compound Helicopter

    NASA Technical Reports Server (NTRS)

    Yeo, Hyeonsoo; Johnson, Wayne

    2006-01-01

    A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained when an increase of drag coefficients in the reverse flow region was implemented. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was conducted. Lower wing loading (larger wing area) and higher blade loading (smaller blade chord) increased aircraft lift-to-drag ratio. However, disk loading has a small influence on aircraft lift-to-drag ratio. A rotor parametric study showed that most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of the advancing blade tip Mach number. No stability issues were observed with the current design. Control derivatives did not change significantly with speed, but the did exhibit significant coupling.

  6. Aircraft Ducting

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Templeman Industries developed the Ultra-Seal Ducting System, an environmental composite air duct with a 50 percent weight savings over current metallic ducting, but could not find a commercial facility with the ability to test it. Marshall Space Flight Center conducted a structural evaluation of the duct, equivalent to 86 years of take-offs and landings in an aircraft. Boeing Commercial Airplane Group and McDonnell Douglas Corporation are currently using the ducts.

  7. Effect of helicopter noise on passenger annoyance

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    The effects of helicopter interior noise on passenger annoyance for both reverie and listening situations was investigated. The relative effectiveness of several metrics for quantifying annoyance response for these situations was also studied. The noise stimuli were based upon recordings of the interior noise of civil helicopter research aircraft. These noises were presented at levels ranging from approximately 70 to 86 d with various tonal components selectively attenuated to give a range of spectra. The listening task required the subjects to listen to and record phonetically-balanced words presented within the various noise environments. Results indicate that annoyance during a listening condition is generally higher than annoyance under a reverie condition for corresponding interior noise environments. Attenuation of the tonal components results in increases in listening performance but has only a small effect upon annoyance for a given noise level.

  8. Stealth Aircraft Technology. (Latest Citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The bibliography contains citations concerning design, manufacture, and history of aircraft incorporating stealth technology. Citations focus on construction materials, testing, aircraft performance, and technology assessment. Fighter aircraft, bombers, missiles, and helicopters represent coverage. (Contains 50-250 citations and includes a subject term index and title list.)

  9. YO-3A acoustics research aircraft systems manual

    NASA Technical Reports Server (NTRS)

    Cross, J. L.

    1984-01-01

    The flight testing techniques, equipment, and procedures employed during air-to-air acoustic testing of helicopters using the NASA YO-3A Acoustic Research Aircraft are discussed. The research aircraft instrumentation system is described as well as hardware installation on the test aircraft and techniques used during the tests. Emphasis is placed on formation flying, position locations, test matrices, and test procedures.

  10. Analysis of Seating and Restraint Limitations Restricting Total Body Weight for Aircrew and Passengers on U.S. Army Helicopters

    DTIC Science & Technology

    1993-07-01

    largest available flight suit (size 48L), SRU-21/P survival vest, and webbing restraints accommodate a 47-inch waist circumference . Aviation Life Support Equipment, Restraint, Aircrew, Helicopters, Aircraft seats, Survival vest

  11. 14 CFR Appendix F to Part 91 - Helicopter Flight Recorder Specifications

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Position 4 Full range ±3% 2 1%2. 1 When data sources are aircraft instruments (except altimeters) of... cent of full range. 3 This column applies to aircraft manufactured after October 11, 1991. 4 For all... Appendix F to Part 91—Helicopter Flight Recorder Specifications Parameters Range Installed system 1...

  12. 14 CFR Appendix F to Part 91 - Helicopter Flight Recorder Specifications

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Position 4 Full range ±3% 2 1%2. 1 When data sources are aircraft instruments (except altimeters) of... cent of full range. 3 This column applies to aircraft manufactured after October 11, 1991. 4 For all... Appendix F to Part 91—Helicopter Flight Recorder Specifications Parameters Range Installed system 1...

  13. Maneuver Acoustic Flight Test of the Bell 430 Helicopter Data Report

    NASA Technical Reports Server (NTRS)

    Watts, Michael E.; Greenwood, Eric; Smith, Charles D.; Snider, Royce; Conner, David A.

    2014-01-01

    A cooperative ight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 test points over 10 test days and compiled an extensive database of dynamic maneuver measurements. Three microphone arrays with up to 31 microphon. es in each were used to acquire acoustic data. Aircraft data included Differential Global Positioning System, aircraft state and rotor state information. This paper provides an overview of the test and documents the data acquired.

  14. Occupational Survey Report. Helicopter Maintenance

    DTIC Science & Technology

    1994-03-01

    helicopters I-D53 Oversee helicopter inspectim or maintance activities during cross-country missions on H- I B15 0014 H-1Maian (Continued) H383 Remove or...Plan maintmeance or inspections of helicopters E95 Comdinate estimated times in commission (ETICs) of maintance jobs with job control A19 Plan work

  15. Automated Power Assessment for Helicopter Turboshaft Engines

    NASA Technical Reports Server (NTRS)

    Simon, Donald L.; Litt, Jonathan S.

    2008-01-01

    An accurate indication of available power is required for helicopter mission planning purposes. Available power is currently estimated on U.S. Army Blackhawk helicopters by performing a Maximum Power Check (MPC), a manual procedure performed by maintenance pilots on a periodic basis. The MPC establishes Engine Torque Factor (ETF), an indication of available power. It is desirable to replace the current manual MPC procedure with an automated approach that will enable continuous real-time assessment of available power utilizing normal mission data. This report presents an automated power assessment approach which processes data currently collected within helicopter Health and Usage Monitoring System (HUMS) units. The overall approach consists of: 1) a steady-state data filter which identifies and extracts steady-state operating points within HUMS data sets; 2) engine performance curve trend monitoring and updating; and 3) automated ETF calculation. The algorithm is coded in MATLAB (The MathWorks, Inc.) and currently runs on a PC. Results from the application of this technique to HUMS mission data collected from UH-60L aircraft equipped with T700-GE-701C engines are presented and compared to manually calculated ETF values. Potential future enhancements are discussed.

  16. Aeromechanics Analysis of a Compound Helicopter

    NASA Technical Reports Server (NTRS)

    Yeo, Hyeonsoo; Johnson, Wayne

    2006-01-01

    A design and aeromechanics investigation was conducted for a 100,000-lb compound helicopter with a single main rotor, which is to cruise at 250 knots at 4000 ft/95 deg F condition. Performance, stability, and control analyses were conducted with the comprehensive rotorcraft analysis CAMRAD II. Wind tunnel test measurements of the performance of the H-34 and UH-1D rotors at high advance ratio were compared with calculations to assess the accuracy of the analysis for the design of a high speed helicopter. In general, good correlation was obtained with the increase of drag coefficients in the reverse flow region. An assessment of various design parameters (disk loading, blade loading, wing loading) on the performance of the compound helicopter was made. Performance optimization was conducted to find the optimum twist, collective, tip speed, and taper using the comprehensive analysis. Blade twist was an important parameter on the aircraft performance and most of the benefit of slowing the rotor occurred at the initial 20 to 30% reduction of rotor tip speed. No stability issues were observed with the current design and the control derivatives did not change much with speed, but did exhibit significant coupling.

  17. Noise Measurement Flight Test: Data/Analyses Aerospatiale SA 365N Dauphin 2 Helicopter

    DTIC Science & Technology

    1984-04-01

    Sound Level ALT - Aircraft altitude above the r.icropolone location APP - Approach operational mode CLC - Centerline Center CPA - Closest point of...located parallel to Runway 12/30 between the runway and tne taxiway. The helicopter hover point for the static operations was located on the southwest...static operations consisted of sites 7H, 5H, 1H, 2, and 4H. These sites were situated around the helicopter hover point which was located on the

  18. Application of an X-ray Fluorescence Instrument to Helicopter Wear Debris Analysis

    DTIC Science & Technology

    2008-04-01

    Application of an X-ray Fluorescence Instrument to Helicopter Wear Debris Analysis Andrew Becker Air Vehicles Division...instrument to determine the composition of wear debris collected from helicopter magnetic chip detectors and oil filters. The Twin-X XRF (assessed in this...report) is a commercially produced bench-top XRF and has not previously been applied to wear debris analysis of Australian Defence Force aircraft

  19. Analysis of U.S. Military Helicopter Operations in Support of Humanitarian Assistance and Disaster Relief

    DTIC Science & Technology

    2011-12-01

    Navy. These helicopters are normally onboard cruisers, frigates, and destroyers. 18 The HH-60H and the SH - 60F are utilized onboard the aircraft...rescue (CSAR) and naval special warfare support. The primary mission of the SH - 60F is to detect, classify, and destroy hostile submarines by using ASW...CSAR and naval special warfare support are the secondary missions of the SH - 60F . Both helicopter types can also perform other missions such as

  20. Defense Acquisitions: Application of Lessons Learned and Best Practices in the Presidential Helicopter Program

    DTIC Science & Technology

    2011-03-25

    GAO-11-380R Presidential Helicopter Program Page 1 United States Government Accountability Office Washington, DC 20548 March...acquisition and has been initiated to develop aircraft to replace the current, aging presidential helicopter fleet. The Ike Skelton National Defense...5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Government Accountability Office,441 G Street NW

  1. Progress through precedent: Going where no helicopter simulator has gone before

    NASA Technical Reports Server (NTRS)

    Adams, Richard J.

    1992-01-01

    Helicopter simulators have been approved by means of special exemption; there are no FAA standards for simulators used in training or airmen Certification checking. The fixed-wing industry provides a precedent which can be used for expediting implementation of helicopter simulators. The analysis in this paper is founded on the experience with that precedent and is driven by a clear definition of helicopter user needs for (1) improved training at lower cost, (2) more comprehensive emergency training at lower risk, (3) increased fidelity of transition and instrument training compared with low-cost aircraft alternatives, and (4) certification credit for improved simulator training.

  2. Autonomous vertical autorotation for unmanned helicopters

    NASA Astrophysics Data System (ADS)

    Dalamagkidis, Konstantinos

    Small Unmanned Aircraft Systems (UAS) are considered the stepping stone for the integration of civil unmanned vehicles in the National Airspace System (NAS) because of their low cost and risk. Such systems are aimed at a variety of applications including search and rescue, surveillance, communications, traffic monitoring and inspection of buildings, power lines and bridges. Amidst these systems, small helicopters play an important role because of their capability to hold a position, to maneuver in tight spaces and to take off and land from virtually anywhere. Nevertheless civil adoption of such systems is minimal, mostly because of regulatory problems that in turn are due to safety concerns. This dissertation examines the risk to safety imposed by UAS in general and small helicopters in particular, focusing on accidents resulting in a ground impact. To improve the performance of small helicopters in this area, the use of autonomous autorotation is proposed. This research goes beyond previous work in the area of autonomous autorotation by developing an on-line, model-based, real-time controller that is capable of handling constraints and different cost functions. The approach selected is based on a non-linear model-predictive controller, that is augmented by a neural network to improve the speed of the non-linear optimization. The immediate benefit of this controller is that a class of failures that would otherwise result in an uncontrolled crash and possible injuries or fatalities can now be accommodated. Furthermore besides simply landing the helicopter, the controller is also capable of minimizing the risk of serious injury to people in the area. This is accomplished by minimizing the kinetic energy during the last phase of the descent. The presented research is designed to benefit the entire UAS community as well as the public, by allowing for safer UAS operations, which in turn also allow faster and less expensive integration of UAS in the NAS.

  3. Census of U.S. Civil Aircraft: Calendar Year 1989

    DTIC Science & Technology

    1989-01-01

    2 3,716 3,718 BOEING V.-COLUMBIA HELICOPTERS 107-11 ............................................................ 20 63 2 0 2 2 CH -21C...registered aircraft by manufacturer and model , and general aviation aircraft by state and county of the owner. ) 17. Key Words 18. Distribution...aviation aircraft by owner’s sttte and county, and registered aircraft by make and model . Reporting period

  4. Helicopter simulator standards

    NASA Technical Reports Server (NTRS)

    Boothe, Edward M.

    1992-01-01

    The initial advisory circular was produced in 1984 (AC 120-XX). It was not finalized, however, because the FAR's for pilot certification did not recognize helicopter simulators and, therefore, permitted no credit for their use. That is being rectified, and, when the new rules are published, standards must be available for qualifying simulators. Because of the lack of a data base to support specification of these standards, the FAA must rely on the knowledge of experts in the simulator/training industry. A major aim of this workshop is to form a working group of these experts to produce a set of standards for helicopter training simulators.

  5. A corporate supersonic transport

    NASA Technical Reports Server (NTRS)

    Greene, Randall; Seebass, Richard

    1996-01-01

    This talk address the market and technology for a corporate supersonic transport. It describes a candidate configuration. There seems to be a sufficient market for such an aircraft, even if restricted to supersonic operation over water. The candidate configuration's sonic boom overpressure may be small enough to allow overland operation as well.

  6. Laboratory studies of scales for measuring helicopter noise

    NASA Technical Reports Server (NTRS)

    Ollerhead, J. B.

    1982-01-01

    The adequacy of the effective perceived noise level (EPNL) procedure for rating helicopter noise annoyance was investigated. Recordings of 89 helicopters and 30 fixed wing aircraft (CTOL) flyover sounds were rated with respect to annoyance by groups of approximately 40 subjects. The average annoyance scores were transformed to annoyance levels defined as the equally annoying sound levels of a fixed reference sound. The sound levels of the test sounds were measured on various scales, with and without corrections for duration, tones, and impulsiveness. On average, the helicopter sounds were judged equally annoying to CTOL sounds when their duration corrected levels are approximately 2 dB higher. Multiple regression analysis indicated that, provided the helicopter/CTOL difference of about 2 dB is taken into account, the particular linear combination of level, duration, and tone corrections inherent in EPNL is close to optimum. The results reveal no general requirement for special EPNL correction terms to penalize helicopter sounds which are particularly impulsive; impulsiveness causes spectral and temporal changes which themselves adequately amplify conventionally measured sound levels.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Tilt rotor aircraft aeroacoustics

    NASA Technical Reports Server (NTRS)

    George, Albert R.; Smith, Charles A.; Maisel, Martin D.; Brieger, John T.

    1989-01-01

    This paper studies the state of knowledge and the needed improvement in noise methodology and measurements for tilt rotor aircraft. Similarities and differences between tilt rotor aeroacoustic conditions and helicopter and propeller experience are identified. A discussion of the possible principal noise mechanisms throughout the flight envelope shows a need for further experimental and analytical investigations to develop an adequate understanding of the important sources and influencing factors. Existing experimental data from flight tests suggest terminal area noise reduction by operating within certain portions of the conversion flight envelope. Prediction methods are found to provide approximate indications only for low frequency harmonic and broadband noise for several of the tilt rotor's operating conditions. The acoustic effects of the hover case 'fountain' flow are pronounced and need further research. Impulsive noise and high frequency harmonic noise remain problems, as on helicopters, pending major improvements in wake, unsteady aerodynamics, and acoustics methodology.

  9. Combat Rescue Helicopter (CRH)

    DTIC Science & Technology

    2015-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-479 Combat Rescue Helicopter (CRH) As of FY 2017 President’s Budget Defense Acquisition...Research, Development, Test, and Evaluation SAR - Selected Acquisition Report SCP - Service Cost Position TBD - To Be Determined TY - Then Year UCR

  10. The Focke Helicopter

    NASA Technical Reports Server (NTRS)

    Focke, H; Kruger, K B

    1938-01-01

    This report presents some of the problems concerning tests of helicopters, such as forced landings, controllability and stability, general safety, piloting maneuvers, performance, servicing, and the production of lift of a propeller. Test flights are described including a 67.67 mph flight by Hanna Reitsch.

  11. A mathematical model of the CH-53 helicopter

    NASA Technical Reports Server (NTRS)

    Sturgeon, W. R.; Phillips, J. D.

    1980-01-01

    A mathematical model suitable for real time simulation of the CH-53 helicopter is presented. This model, which is based on modified nonlinear classical rotor theory and nonlinear fuselage aerodynamics, will be used to support terminal-area guidance and navigation studies on a fixed-base simulator. Validation is achieved by comparing the model response with that of a similar aircraft and by a qualitative comparison of the handling characteristics made by experienced pilots.

  12. Helicopter precision approach capability using the Global Positioning System

    NASA Technical Reports Server (NTRS)

    Kaufmann, David N.

    1992-01-01

    The period between 1 July and 31 December, 1992, was spent developing a research plan as well as a navigation system document and flight test plan to investigate helicopter precision approach capability using the Global Positioning System (GPS). In addition, all hardware and software required for the research was acquired, developed, installed, and verified on both the test aircraft and the ground-based reference station.

  13. 78 FR 24363 - Airworthiness Directives; Various Sikorsky-Manufactured Transport and Restricted Category...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ... 61454), R, and V; Croman Corporation Model SH-3H, Carson Helicopters, Inc., Model S-61L; Glacier... SH-3H, Carson Helicopters, Inc. Model S-61L; Glacier Helicopters, Inc. Model CH-3E; Robinson Air...): Sikorsky Aircraft Corporation; Croman Corporation; Carson Helicopters, Inc.; Glacier Helicopters,...

  14. Anthropometric Cockpit Compatibility Assessment of US Army Aircraft for Large and Small Personnel Wearing A Cold Weather, Armored Vest, Chemical Defense Protective Clothing Configuration

    DTIC Science & Technology

    1984-07-01

    identify by block number) Anthropometry, Aircraft, Cockpit-Compatibility, Chemical Defense, Cold Weather Clothing, Helicopters, Fixed- Wing Aircraft...5th percentiles of the Army male population were placed in the cockpits of all current US ArmY helicopters (except AAH-64) and fixed- wing aircraft, and...Fixed Wing Aircraft .... 0........................ 24 References.o........*..e.......o......o............ 29 LIST OF FIGURES FIGURES 1 . Up pe r B o dy

  15. Utility of Helicopter Rotor Reflections at HF

    DTIC Science & Technology

    1972-12-29

    Vesuvius AE 15 Ammunition Helicopter platform Mount Katmai AE 16 Ammunition Helicopter platform Great Sitkin AE 17 Ammunition Helicopter platform Diamond...carried Mount Whitney LCC 20 Amphibious command Utility helicopter carried Eldorado LCC 11 Amphibious command Utility helicopter carried Iwo Jima LPH...Barbara AE 28 Special minesweeper Mount Hood AE 29 Special minesweeper Suribachi AE 21 Ammunition Helicopter platform Mauna Kea AE 22 Ammunition

  16. Aircraft noise source and computer programs - User's guide

    NASA Technical Reports Server (NTRS)

    Crowley, K. C.; Jaeger, M. A.; Meldrum, D. F.

    1973-01-01

    The application of computer programs for predicting the noise-time histories and noise contours for five types of aircraft is reported. The aircraft considered are: (1) turbojet, (2) turbofan, (3) turboprop, (4) V/STOL, and (5) helicopter. Three principle considerations incorporated in the design of the noise prediction program are core effectiveness, limited input, and variable output reporting.

  17. 14 CFR 47.9 - Corporations not U.S. citizens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Corporations not U.S. citizens. 47.9... AIRCRAFT REGISTRATION General § 47.9 Corporations not U.S. citizens. (a) Each corporation applying for... corporation that registers an aircraft pursuant to 49 U.S.C. 44102 shall maintain, and make available...

  18. Results of the noise measurement program on a standard and modified OH-6A helicopter

    NASA Technical Reports Server (NTRS)

    Henderson, H. R.; Peegg, R. J.; Hilton, D. A.

    1973-01-01

    A field noise measurement program has been conducted on a standard OH-6A helicopter and one that had been modified by reducing the rotor speed, altering rotor tip shape, and treating the engine exhaust and inlet to reduce the external noise levels. The modifications consisted of extensive aircraft design changes resulting in substantial noise reductions following state-of-art noise reduction techniques. The purpose of this study was to document the ground noise characteristics of each helicopter during flyover, hover, landing, and take-off operations. Based on an analysis of the measured results, the average of the overall on-track noise levels of the final modified helicopter was approximately 14 db lower than that for the standard helicopter. Narrow-band-spectra data of the hovering helicopter show a reduction in the overall noise due to the reductions achieved for the lifting main and antitorque tail rotor, engine exhaust, and gear box noise for the modified helicopter. The noise results of the test program are found to correlate generally with noise measurements made previously on this type of aircraft.

  19. Applications of advanced V/STOL aircraft concepts to civil utility missions. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The linear performance definition curves for the lift fan aircraft, tilt rotor aircraft, and advanced helicopter are given. The computer program written to perform the mission analysis for this study is also documented, and examples of its use are shown. Methods used to derive the performance coefficients for use in the mission analysis of the lift fan aircraft are described.

  20. Helicopter blade tips

    NASA Technical Reports Server (NTRS)

    Lyothier, R.

    1983-01-01

    Methods of improving helicopter performance and vibration level by proper shaping of helicopter blade tips are considered. The principle involved consists of reducing the extent of the supersonic zone above the advancing tip and of the turbulent interaction. For stationary and advancing flight, the influence of the rotor and the problems posed by blade tips are reviewed. The theoretical methods of dealing with the two types of flight are briefly stated, and the experimental apparatus is described, including model triple and quadruple rotors. Different blade tip shapes are shown and briefly discussed. The theoretical results include an advancing speed of 309 km/H and a blade tip rotational speed of 215 m/s. The experimental values are advancing speed of 302 km/h and blade tip Mach number 0.86 for both types of rotors.

  1. Helicopter Visual Aid System

    NASA Technical Reports Server (NTRS)

    Baisley, R. L.

    1973-01-01

    The results of an evaluation of police helicopter effectiveness revealed a need for improved visual capability. A JPL program developed a method that would enhance visual observation capability for both day and night usage and demonstrated the feasibility of the adopted approach. This approach made use of remote pointable optics, a display screen, a slaved covert searchlight, and a coupled camera. The approach was proved feasible through field testing and by judgement against evaluation criteria.

  2. Apollo 10 Helicopter Recovery

    NASA Technical Reports Server (NTRS)

    1969-01-01

    A Navy helicopter arrivies to recover the Apollo 10 astronauts, seen entering a life raft, as the Command Module 'Charlie Brown' floats in the South Pacific. U.S. Navy underwater demolition team swimmers assist in the recovery operations. Splashdown occurred at 11:53 a.m., May 26, 1969, about 400 miles east of American Samoa. Note that in this photo the divers have attached a flotation collar to the spacecraft.

  3. Operational Helicopter Aviation Medicine

    DTIC Science & Technology

    1978-12-01

    acoustic stimuli travelling through the system to the inner ear. HEARING PROTECTOR AND VOICE COMMUNICATIONS SYSTEMS EFFECTS The humar auditory system just...equipment, communication noise, aircrew hearing loss, and weapons impulse noise. Helicopter Safety and Crashworthiness covered crash injury analysis...protect visual and auditory performance while performing aircrew duties were also pre- sented. A summ. ry of the excellent work presented supported the

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

    NASA Technical Reports Server (NTRS)

    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.

  5. 77 FR 52264 - Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems (Type Certificate Currently... proposed AD, contact MD Helicopters Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop... Airworthiness Directive (AD): Hughes Helicopters Inc., and McDonnel Douglas Helicopter Systems (Type...

  6. Aircraft noise source and contour estimation

    NASA Technical Reports Server (NTRS)

    Dunn, D. G.; Peart, N. A.

    1973-01-01

    Calculation procedures are presented for predicting the noise-time histories and noise contours (footprints) of five basic types of aircraft; turbojet, turofan, turboprop, V/STOL, and helicopter. The procedures have been computerized to facilitate prediction of the noise characteristics during takeoffs, flyovers, and/or landing operations.

  7. Physical Bases of Aircraft Icing,

    DTIC Science & Technology

    1979-08-31

    conditions, it is changed the sensitivity of aircraft to icing, appear now ta6Ks as, for example, about the icing of helicopters or internal icing in jet ... jet aviation led to the need to specially examine qua~tioas of aircraft icing at high flight speeds. This is made in V cndptwir of present monograph...A. M. Yaglom were reported by it at seminax in tut Geophysical institute of the AS USSR, but they were not puisa in press/ printing . ENOFOOTNOTE. The

  8. Development of Low Cost Satellite Communications System for Helicopters and General Aviation

    NASA Technical Reports Server (NTRS)

    Farazian, K.; Abbe, B.; Divsalar, D.; Raphaeli, D.; Tulintseff, A.; Wu, T.; Hinedi, S.

    1994-01-01

    In this paper, the development of low-cost satellite communications (SATCOM) system for helicopters and General Aviation (GA) aircrafts is described. System design and standards analysis have been conducted to meet the low-cost, light-weight, small-size and low-power system requirements for helicopters and GA aircraft environments. Other specific issues investigated include coding schemes, spatial diversity, and antenna arraying techniques. Coding schemes employing Channel State Information (CSI) and inverleaving have been studied in order to mitigate severe banking angle fading and the periodic RF signal blockage due to the helicopter rotor blades. In addition, space diversity and antenna arraying techniques have been investigated to further reduce the fading effects and increase the link margin.

  9. Helicopter simulation: Making it work

    NASA Technical Reports Server (NTRS)

    Payne, Barry

    1992-01-01

    The opportunities for improved training and checking by using helicopter simulators are greater than they are for airplane pilot training. Simulators permit the safe creation of training environments that are conducive to the development of pilot decision-making, situational awareness, and cockpit management. This paper defines specific attributes required in a simulator to meet a typical helicopter operator's training and checking objectives.

  10. Recent European Developments in Helicopters

    NASA Technical Reports Server (NTRS)

    1921-01-01

    Descriptions are given of two captured helicopters, one driven by electric power, the other by a gasoline engine. An account is given of flight tests of the gasoline powered vehicle. After 15 successful flight tests, the gasoline powered vehicle crashed due to the insufficient thrust. Also discussed here are the applications of helicopters for military observations, for meteorological work, and for carrying radio antennas.

  11. Helicopter Acoustics, part 2. [conferences

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Exterior and interior helicopter noise problems are addressed from the physics and engineering as well as the human factors point of view. Noise regulation concepts, human factors and criteria, rotor noise generation and control, design, operations and testing for noise control, helicopter noise prediction, and research tools and measurements are covered.

  12. Helicopter discrimination apparatus for the murine radar

    DOEpatents

    Webb, Jr., John G.; Gray, Roger M.

    1977-01-01

    A helicopter discrimination apparatus for a radar utilizing doppler filtering to discriminate between a missile and ground clutter. The short duration of the doppler filter pulses which are emitted by helicopter rotor blades are processed to prevent false alarms, thus allowing the radar-protected helicopter to operate in formation with other helicopters while maintaining protection against infra-red-seeking missiles.

  13. Acceptance and control of aircraft interior noise and vibration

    NASA Technical Reports Server (NTRS)

    Stephens, D. G.; Leatherwood, J. D.

    1980-01-01

    Ride quality criteria for noise, vibration, and their combination in the helicopter cabin environment are discussed. Results are presented of laboratory and field studies of passenger responses to interior noise and vibration during the performance of a listening task and during reverie, as well as to the interaction of noise with multi-frequency and multi-axis vibration. A study of means for reducing helicopter interior noise based on analytical, experimental and flight studies of the near-field noise source characteristics of the aircraft, the transmission of noise through aircraft structures and the attenuation of noise by various noise control treatments is then presented which has resulted in a reduction of 3 dB in helicopter cabin noise. Finally, a model under development to evaluate passenger acceptance of a helicopter noise and vibration environment is indicated which incorporates the observed noise and vibration effects on comfort and is expected to provide insights for more effective noise and vibration control.

  14. Ground shake test of the UH-60A helicopter airframe and comparison with NASTRAN finite element model predictions

    NASA Technical Reports Server (NTRS)

    Howland, G. R.; Durno, J. A.; Twomey, W. J.

    1990-01-01

    Sikorsky Aircraft, together with the other major helicopter airframe manufacturers, is engaged in a study to improve the use of finite element analysis to predict the dynamic behavior of helicopter airframes, under a rotorcraft structural dynamics program called DAMVIBS (Design Analysis Methods for VIBrationS), sponsored by the NASA-Langley. The test plan and test results are presented for a shake test of the UH-60A BLACK HAWK helicopter. A comparison is also presented of test results with results obtained from analysis using a NASTRAN finite element model.

  15. Two-Dimensional Fourier Transform Applied to Helicopter Flyover Noise

    NASA Technical Reports Server (NTRS)

    Santa Maria, Odilyn L.

    1999-01-01

    A method to separate main rotor and tail rotor noise from a helicopter in flight is explored. Being the sum of two periodic signals of disproportionate, or incommensurate frequencies, helicopter noise is neither periodic nor stationary, but possibly harmonizable. The single Fourier transform divides signal energy into frequency bins of equal size. Incommensurate frequencies are therefore not adequately represented by any one chosen data block size. A two-dimensional Fourier analysis method is used to show helicopter noise as harmonizable. The two-dimensional spectral analysis method is first applied to simulated signals. This initial analysis gives an idea of the characteristics of the two-dimensional autocorrelations and spectra. Data from a helicopter flight test is analyzed in two dimensions. The test aircraft are a Boeing MD902 Explorer (no tail rotor) and a Sikorsky S-76 (4-bladed tail rotor). The results show that the main rotor and tail rotor signals can indeed be separated in the two-dimensional Fourier transform spectrum. The separation occurs along the diagonals associated with the frequencies of interest. These diagonals are individual spectra containing only information related to one particular frequency.

  16. Helicopter Approach Capability Using the Differential Global Positioning System

    NASA Technical Reports Server (NTRS)

    Kaufmann, David N.

    1994-01-01

    The results of flight tests to determine the feasibility of using the Global Positioning System (GPS) in the Differential mode (DGPS) to provide high accuracy, precision navigation and guidance for helicopter approaches to landing are presented. The airborne DGPS receiver and associated equipment is installed in a NASA UH-60 Black Hawk helicopter. The ground-based DGPS reference receiver is located at a surveyed test site and is equipped with a real-time VHF data link to transmit correction information to the airborne DGPS receiver. The corrected airborne DGPS information, together with the preset approach geometry, is used to calculate guidance commands which are sent to the aircraft's approach guidance instruments. The use of DGPS derived guidance for helicopter approaches to landing is evaluated by comparing the DGPS data with the laser tracker truth data. The errors indicate that the helicopter position based on DGPS guidance satisfies the International Civil Aviation Organization (ICAO) Category 1 (CAT 1) lateral and vertical navigational accuracy requirements.

  17. Automatic target recognition flight prototype for police helicopters

    NASA Astrophysics Data System (ADS)

    Stahl, Christoph; Haisch, Stefan; Wolf, Peter

    2002-07-01

    A cooperation between the European Aeronautic Defence and Space Company AG (EADS) and the Bavarian Ministry of the Interior was started at the beginning of 2001 to develop an application for automatic target recognition technology for police helicopter missions. The Bavarian Police Air Support Unit is the main support partner and first user. Bavarian polic helicopters are equipped with a modern infrared system (FLIR) especially for night missions. EADS has extensive knowledge in the area of sensor image exploitation and automatic target recognition (ATR). The technology has been developed for military aircraft reconnaissance missions. The same software kernel is used for a flight prototype which is integrated in a police helicopter. The integration concept presented in this paper is set up so as not to interfere the existing FLIR system in any way. The flight prototype which will be described in detail consists of standard hardware (COTS) components and has the main functionality of detecting pre-selected object classes. With the flight prototype a comprehensive in-flight testing of the automatic target recognition application is enabled. The test procedure and first results of the flight tests are explained with selected examples. The cooperation will go on to further enhance the operational effectiveness of the Bavarian police helicopters.

  18. Kinematic properties of the helicopter in coordinated turns

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.; Jeske, J. A.

    1981-01-01

    A study on the kinematic relationship of the variables of helicopter motion in steady, coordinated turns involving inherent sideslip is described. A set of exact kinematic equations which govern a steady coordinated helical turn about an Earth referenced vertical axis is developed. A precise definition for the load factor parameter that best characterizes a coordinated turn is proposed. Formulas are developed which relate the aircraft angular rates and pitch and roll attitudes to the turn parameters, angle of attack, and inherent sideslip. A steep, coordinated helical turn at extreme angles of attack with inherent sideslip is of primary interest. The bank angle of the aircraft can differ markedly from the tilt angle of the normal load factor. The normal load factor can also differ substantially from the accelerometer reading along the vertical body axis of the aircraft. Sideslip has a strong influence on the pitch attitude and roll rate of the helicopter. Pitch rate is independent of angle of attack in a coordinated turn and in the absence of sideslip, angular rates about the stability axes are independent of the aerodynamic characteristics of the aircraft.

  19. Aircraft Operations Classification System

    NASA Technical Reports Server (NTRS)

    Harlow, Charles; Zhu, Weihong

    2001-01-01

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

  20. Composite components on commercial aircraft

    NASA Technical Reports Server (NTRS)

    Dexter, H. B.

    1980-01-01

    Commercial aircraft manufacturers are making production commitments to composite structure for future aircraft and modifications to current production aircraft. Flight service programs with advanced composites sponsored by NASA during the past 10 years are described. Approximately 2.5 million total composite component flight hours have been accumulated since 1970 on both commercial transports and helicopters. Design concepts with significant mass savings were developed, appropriate inspection and maintenance procedures were established, and satisfactory service was achieved for the various composite components. A major NASA/U.S. industry technology program to reduce fuel consumption of commercial transport aircraft through the use of advanced composites was undertaken. Ground and flight environmental effects on the composite materials used in the flight service programs supplement the flight service evaluation.

  1. Aircraft icing research at NASA

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Shaw, R. J.; Olsen, W. A., Jr.

    1982-01-01

    Research activity is described for: ice protection systems, icing instrumentation, experimental methods, analytical modeling for the above, and in flight research. The renewed interest in aircraft icing has come about because of the new need for All-Weather Helicopters and General Aviation aircraft. Because of increased fuel costs, tomorrow's Commercial Transport aircraft will also require new types of ice protection systems and better estimates of the aeropenalties caused by ice on unprotected surfaces. The physics of aircraft icing is very similar to the icing that occurs on ground structures and structures at sea; all involve droplets that freeze on the surfaces because of the cold air. Therefore all icing research groups will benefit greatly by sharing their research information.

  2. Future Civil Aircraft and Technologies

    NASA Technical Reports Server (NTRS)

    Albers, J.; Zuk, J.

    1989-01-01

    New aircraft technologies are presented that have the potential to expand the air transportation system and reduce congestion through new operating capabilities while also providing greater levels of safety and environmental compatibility. These new capabilities will result from current and planned civil aeronautics technology at the NASA Ames, Lewis, and Langley Research Centers and will cover the complete spectrum of current aircraft and new vehicle concepts including rotorcraft (helicopters and tilt rotors), vertical and short takeoff and landing (V/STOL), and short takeoff and landing (STOL) aircraft, subsonic transports, high-speed transports, and hypersonic/transatmospheric vehicles. New technologies will improve efficiency, affordability, safety, and environmental compatibility of current aircraft and will enable the development of new transportation system. The new capabilities of vehicles could lead to substantial market opportunities and economic growth and could improve the competitive position of the U.S. aerospace industry.

  3. Study of design constraints on helicopter noise

    NASA Technical Reports Server (NTRS)

    Sternfeld, H., Jr.; Wiedersum, C. W.

    1979-01-01

    A means of estimating the noise generated by a helicopter main rotor using information which is generally available during the preliminary design phase of aircraft development is presented. The method utilizes design charts and tables which do not require an understanding of acoustical theory or computational procedures in order to predict the perceived noise level, a weighted sound pressure level, or C weighted sound pressure level of a single hovering rotor. A method for estimating the effective perceived noise level in forward flight is also included. In order to give the designer an assessment of the relative rotor performance, which may be traded off against noise, an additional chart for estimating the percent of available rotor thrust which must be expended in lifting the rotor and drive system, is included as well as approach for comparing the subjective acceptability of various rotors once the absolute sound pressure levels are predicted.

  4. Summary of ARPA-ASO, TTO Aerial Platform Programs. Volume 2. Remotely Piloted Helicopters

    DTIC Science & Technology

    1975-07-01

    activities. Some operating procedures were streamlined to provide quick reaction funding for equipment and to direct commnication channels with the... Corporation , Santa Monica, CA, November 20, 1969. Confidential. (A-3) "Remotely Piloted Liaxial Helicopter Vehicle (U)", Gyrodyne Company of America, Inc., St

  5. 3D-LZ helicopter ladar imaging system

    NASA Astrophysics Data System (ADS)

    Savage, James; Harrington, Walter; McKinley, R. Andrew; Burns, H. N.; Braddom, Steven; Szoboszlay, Zoltan

    2010-04-01

    A joint-service team led by the Air Force Research Laboratory's Munitions and Sensors Directorates completed a successful flight test demonstration of the 3D-LZ Helicopter LADAR Imaging System. This was a milestone demonstration in the development of technology solutions for a problem known as "helicopter brownout", the loss of situational awareness caused by swirling sand during approach and landing. The 3D-LZ LADAR was developed by H.N. Burns Engineering and integrated with the US Army Aeroflightdynamics Directorate's Brown-Out Symbology System aircraft state symbology aboard a US Army EH-60 Black Hawk helicopter. The combination of these systems provided an integrated degraded visual environment landing solution with landing zone situational awareness as well as aircraft guidance and obstacle avoidance information. Pilots from the U.S. Army, Air Force, Navy, and Marine Corps achieved a 77% landing rate in full brownout conditions at a test range at Yuma Proving Ground, Arizona. This paper will focus on the LADAR technology used in 3D-LZ and the results of this milestone demonstration.

  6. Predesign report for the rotor systems research aircraft

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A conceptual predesign of a compound helicopter for conducting rotor research is presented. The aircraft was selected by the Government as the better of two concepts submitted. The helicopter is a three place vehicle in the 24,000 pound gross weight class. It has been determined that the helicopter satisfies the requirements for the rotor research mission. The model has been predesigned sufficiently to allow an assessment of its performance and stability and control characteristics. A brief treatment of these subjects is included.

  7. Helicopter Human Factors

    NASA Technical Reports Server (NTRS)

    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

  8. World helicopter market study

    NASA Technical Reports Server (NTRS)

    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.

  9. Helicopter high gain control

    NASA Technical Reports Server (NTRS)

    Cunningham, T. B.; Nunn, E. C.

    1979-01-01

    High gain control is explored through a design study of the CH-47B helicopter. The plans are designed to obtain the maximum bandwidth possible given the hardware constraints. Controls are designed with modal control theory to specific bandwidths and closed loop mode shapes. Comparisons are made to an earlier complementary filter approach. Bandwidth improvement by removal of limitations is explored in order to establish hardware and mechanization options. Improvements in the pitch axis control system and in the rate gyro sensor noise characteristics in all axes are discussed. The use of rotor state feedback is assessed.

  10. Materials for helicopter gears

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Some of the power train transmission gears in helicopter drive systems can become critical components as performance requirements are increased; accordingly, increasing attention must be paid to new alloys in order to obtain required performance reliability and survivability. Candidate advanced alloys, with improved high temperature properties, while increasing the resistance to scoring and scuffing, tend to have lower ductility and fracture toughness. An attempt is made to identify design materials, and process problems and requirements. In addition, it is recommended that the characterization of candidate steels be accelerated; preliminary investigation indicates that new alloys may provide improved capability against surface distress.

  11. Tradeoff analysis of technology needs for public service helicopters

    NASA Technical Reports Server (NTRS)

    Bauchspies, J. S.; Bryant, W. R., Jr.; Simpson, W. E.

    1985-01-01

    The design requirements for a family or type of Public Service Helicopter (PSH) is examined which will satisfy the needs of municipal and state governments in the following mission areas: Emergency Medical Service--Airborne Rescue Squad; Law Enforcement; Search and Rescue; and Environmental Control (Fire Fighting, Pollution, Resource Management). The report compares both design and performance requirements as specified by the PSH user's group against current technological capabilities, RTOPS and US Army LHX design requirements. The study explores various design trade-offs and options available to the aircraft designer/manufacturer in order to meet the several criteria specified by the PSH user's group. In addition, the report includes a brief assessment of the feasibility of employing certain advanced rotorcraft designs to meet the stringent combination of operational capabilities desired by the Public Service Helicopter Users.

  12. Helicopter Acoustic Flight Test with Altitude Variation and Maneuvers

    NASA Technical Reports Server (NTRS)

    Watts, Michael E.; Greenwood, Eric; Sim, Ben; Stephenson, James; Smith, Charles D.

    2016-01-01

    A cooperative flight test campaign between NASA and the U.S. Army was performed from September 2014 to February 2015. The purposes of the testing were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. This test was performed at three test sites (0, 4000, and 7000 feet above mean sea level) with two aircraft (AS350 SD1 and EH-60L) tested at each site. This report provides an overview of the test, documents the data acquired and describes the formats of the stored data.

  13. Condition based machinery maintenance (helicopter fault detection), phase 1

    NASA Astrophysics Data System (ADS)

    Brotherton, T. W.; Pollard, T. G.

    1993-01-01

    A problem of current interest to the Navy is the automatic detection and classification of faults in mechanical systems such as the transmissions, gearboxes, and bearings of helicopters. The problem is important for both economic and safety reasons. Using automated fault detection and classification, machinery repair can be undertaken as needed and can prevent catastrophic failure. This condition-based maintenance approach is more efficient and cost-effective than the use of predetermined maintenance schedules. Additionally, automated fault detection and classification systems can alert machinery operators, such as helicopter pilots, of the onset of a mechanical problem, thus allowing the pilot to take precautions, such as landing the aircraft, before a potentially catastrophic failure occurs.

  14. Joint Technical Coordinating Group on Aircraft Survivability (JTCG/AS). Bibliography of Joint Aircraft Survivability Reports

    DTIC Science & Technology

    2000-07-01

    Existing 90 Vulnerability Analysis Methods Steady-Flow Fuel Ingestion Tolerance Predictions for New Turbofan Engines 90 Engine Assessment of...Element Assessment Report (U) 102 Helicopter Signature Prediction Model Validation (U) 102 Software User’s Manual for the Advanced Low Altitude...Advanced Wing Skin Material Evaluation 153 A Survey of Analysis Techniques to Predict Residual Properties of Ballistically 153 Damaged Aircraft

  15. Medical helicopters: carbon monoxide risk?

    PubMed

    Poulton, T J

    1987-02-01

    Carbon monoxide exposure of medical personnel working beneath the turning rotor of a medical helicopter appeared to cause mild clinical illness. We measured the carbon monoxide levels found in various locations beneath the rotor of a jet helicopter under two different conditions. Carbon monoxide levels ranged from 8-76 ppm depending on location of sampling and speed of operation of the engine. This level of carbon monoxide is potentially a problem, as is the inhalation of jet fuel vapor, when working beneath the rotors of an operating helicopter.

  16. Helicopter human factors research

    NASA Technical Reports Server (NTRS)

    Nagel, David C.; Hart, Sandra G.

    1988-01-01

    Helicopter flight is among the most demanding of all human-machine integrations. The inherent manual control complexities of rotorcraft are made even more challenging by the small margin for error created in certain operations, such as nap-of-the-Earth (NOE) flight, by the proximity of the terrain. Accident data recount numerous examples of unintended conflict between helicopters and terrain and attest to the perceptual and control difficulties associated with low altitude flight tasks. Ames Research Center, in cooperation with the U.S. Army Aeroflightdynamics Directorate, has initiated an ambitious research program aimed at increasing safety margins for both civilian and military rotorcraft operations. The program is broad, fundamental, and focused on the development of scientific understandings and technological countermeasures. Research being conducted in several areas is reviewed: workload assessment, prediction, and measure validation; development of advanced displays and effective pilot/automation interfaces; identification of visual cues necessary for low-level, low-visibility flight and modeling of visual flight-path control; and pilot training.

  17. Helicopter noise regulations: An industry perspective

    NASA Technical Reports Server (NTRS)

    Wagner, R. A.

    1978-01-01

    A review of helicopter noise measurement programs and noise reduction/economic studies of FAA is given along with a critique of a study which addresses the economic impact of noise reduction on helicopter noise. Modification of several helicopters to reduce noise and demonstrate the economic impact of the application of the current state-of-the-art technology is discussed. Specific helicopters described include Boeing Vertol 347 Helicopter, Hughes OH-6 Helicopter, and Hughes 269C Helicopter. Other topics covered include: (1) noise trends and possible noise limits; (2) accuracy of helicopter noise prediction techniques; (3) limited change possibilities of derivatives; and (4) rotor impulsive noise. The unique operational capabilities of helicopters and the implications relative to noise regulations and certification are discussed.

  18. Code to Optimize Load Sharing of Split-Torque Transmissions Applied to the Comanche Helicopter

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Most helicopters now in service have a transmission with a planetary design. Studies have shown that some helicopters would be lighter and more reliable if they had a transmission with a split-torque design instead. However, a split-torque design has never been used by a U.S. helicopter manufacturer because there has been no proven method to ensure equal sharing of the load among the multiple load paths. The Sikorsky/Boeing team has chosen to use a split-torque transmission for the U.S. Army's Comanche helicopter, and Sikorsky Aircraft is designing and manufacturing the transmission. To help reduce the technical risk of fielding this helicopter, NASA and the Army have done the research jointly in cooperation with Sikorsky Aircraft. A theory was developed that equal load sharing could be achieved by proper configuration of the geartrain, and a computer code was completed in-house at the NASA Lewis Research Center to calculate this optimal configuration.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Matrix Interconnection System for Aircraft Wiring

    DTIC Science & Technology

    1975-07-01

    Aircraft Wiring, ECOM-0102-1, Feb. I973 mmmmMam "" \\:.-JLl.- *"’" " ’^nf--’--^7 -w .mm-m .mm BSU! (2) obtain due to the classified nature of the...steps 2 and 3 of MODE 2 to operate the intercoms. 2’ TTpe gtpp 1 of MODE 3 tn opprnte the compass. Do not rotate the SITS, MODE 10 This test is to be...TABLE II TABLE III TABLE IV MODES OF OPERATION MATRIX OH- GA HELICOPTER EMC EVALUATION OH- GA HELICOPTER EMC EVALUATION TEST SUMMARY GROUND TEST

  1. Preliminary results of the first static calibration of the RSRA helicopter active-isolator rotor balance system

    NASA Technical Reports Server (NTRS)

    Acree, C. W., Jr.

    1983-01-01

    The helicopter version of the Rotor Systems Research Aircraft (RSRA) is designed to make simultaneous measurements of all rotor forces and moments in flight analogous to a wind tunnel balance. Loads are measured by a combination of load cells, strain gages, and hydropneumatic active isolators which use pressure gages to measure loads. Complete evaluation of system performance required calibration of the rotor force and moment measuring system when installed in the aircraft. Measurement system responses to rotor loads obtained during the first static calibration of the RSRA helicopter are plotted and discussed. Plots of the raw transducer data are included.

  2. Affordable MMW aircraft collision avoidance system

    NASA Astrophysics Data System (ADS)

    Almsted, Larry D.; Becker, Robert C.; Zelenka, Richard E.

    1997-06-01

    Collision avoidance is of concern to all aircraft, requiring the detection and identification of hazardous terrain or obstacles in sufficient time for clearance maneuvers. The collision avoidance requirement is even more demanding for helicopters, as their unique capabilities result in extensive operations at low-altitude, near to terrain and other hazardous obstacles. TO augment the pilot's visual collision avoidance abilities, some aircraft are equipped with 'enhanced-vision' systems or terrain collision warning systems. Enhanced-vision systems are typically very large and costly systems that are not very covert and are also difficult to install in a helicopter. The display is typically raw images from infrared or radar sensors, and can require a high degree of pilot interpretation and attention. Terrain collision warning system that rely on stored terrain maps are often of low resolution and accuracy and do not represent hazards to the aircraft placed after map sampling. Such hazards could include aircraft parked on runway, man- made towers or buildings and hills. In this paper, a low cost dual-function scanning pencil-beam, millimeter-wave radar forward sensor is used to determine whether an aircraft's flight path is clear of obstructions. Due to the limited space and weight budget in helicopters, the system is a dual function system that is substituted in place of the existing radar altimeter. The system combines a 35 GHz forward looking obstacle avoidance radar and a 4.3 GHz radar altimeter. The forward looking 35 GHz 3D radar's returns are used to construct a terrain and obstruction database surrounding an aircraft, which is presented to the pilot as a synthetic perspective display. The 35 GHz forward looking radar and the associated display was evaluated in a joint NASA Honeywell flight test program in 1996. The tests were conducted on a NASA/Army test helicopter. The test program clearly demonstrated the systems potential usefulness for collision avoidance.

  3. Influence of sideslip on the kinematics of the helicopter in steady coordinated turns

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.; Jeske, J. A.

    1981-01-01

    A steep coordinated helical turn at extreme angles of attack with inherent sideslip is of primary interest in this study. Unlike fixed-wing aircraft, the helicopter in a steady coordinated turn will inherently sideslip. A set of exact kinematic equations describing this motion in steady helical turns has been developed, and a rational definition for the load factor that best characterizes a coordinated turn for a helicopter has been proposed. An analysis has also been completed on the effects of sideslip on the kinematic relationships in a coordinated turn which is based on new closed-form solutions which relate the aircraft angular rates and pitch and roll attitudes to the turn parameters, angle of attack, and sideslip. The results show that the bank angle of the aircraft can differ markedly from the tilt angle of the normal load factor and that the normal load factor can also differ substantially from the accelerometer reading along the vertical body axis of the aircraft. Generally, sideslip has a strong influence on the pitch attitude and roll rate of the helicopter. The study also indicates that pitch rate is independent of angle of attack in a coordinated turn and that in the absence of sideslip, angular rates about the stability axes are independent of the aerodynamic characteristics of the aircraft.

  4. Vertebral pain in helicopter pilots

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  6. 77 FR 5425 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... Helicopter Textron Canada Limited Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... the Bell Helicopter Textron Canada Limited (BHTC) Model 427 helicopters. This proposed AD is prompted... Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4, telephone (450) 437-2862 or (800)...

  7. Technical evaluation of the Aerospace Medical Panel Specialists Meeting on Escape Problems and Manoeuvres in Combat Aircraft

    NASA Technical Reports Server (NTRS)

    Jones, W. L.

    1974-01-01

    A technical evaluation of the papers presented at a conference on escape systems for helicopters and V/STOL aircraft was made. The subjects discussed include the following: (1) bioengineering aspects of spinal injury during ejection, (2) aerodynamic forces acting on crewman during escape, (3) operational practicality of fly away ejection seats, (4) helicopter survivability requirements, (5) ejection experience from V/STOL aircraft, and (6) research projects involving escape and retrieval systems.

  8. Hydrogen Fuel Cell on a Helicopter: A System Engineering Approach

    NASA Astrophysics Data System (ADS)

    Nesheiwat, Rod

    Hydrogen fuel cells have been previously investigated as a viable replacement to traditional gas turbine auxiliary power unit onboard fixed wing commercial jets. However, so far no study has attempted to extend their applicability to rotary wing aircrafts. To aid in the advancement of such innovative technologies, a holistic technical approach is required to ensure risk reduction and cost effectiveness throughout the product lifecycle. This paper will evaluate the feasibility of replacing a gas turbine auxiliary power unit on a helicopter with a direct hydrogen, air breathing, proton exchange membrane fuel cell, all while emphasizing a system engineering approach that utilize a specialized set of tools and artifacts.

  9. Gemini 4 astronauts relax aboard Navy helicopter after recovery

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Gemini 4 astronauts, James A. McDivitt (right), command pilot, and Edward H. White II, (left), pilot, relax aboard a U.S. Navy helicopter on their way to the aircraft carrier U.S.S. Wasp after recovery from the Gemini 4 spacecraft. They had been picked up out of the Atlantic Ocean following a successful splashdown (33532); White (left) and McDivitt listen to the voice of President Lyndon B. Johnson as he congratulated them by telephone on the successful mission. They are shown aboard the carrier U.S.S. Wasp just after their recovery (33533).

  10. Simulation evaluation of helicopter Terrain Following/Terrain Avoidance concepts

    NASA Technical Reports Server (NTRS)

    Swenson, Herry N.; Hardy, Gordon H.; Morris, Pat M.

    1988-01-01

    A helicopter Terrain-Following/Terrain-Avoidance (TF/TA) system was developed and evaluated using a real-time piloted simulation. The TF/TA system included a guidance algorithm based upon dynamic programming and a head-up display (HUD) concept which incorporates a pathway in the sky, a phantom aircraft, and flightpath vector/predictor symbology. The simulation was conducted at the NASA Ames Research Center Interchangeable Cab (ICAB) Laboratory using NASA test pilots. The pilots performed the TF/TA task by manually tracking the HUD symbology. The pilots were able to satisfactorily perform the TF/TA tasks with an acceptable level of pilot workload.

  11. Helicopters in Irregular Warfare: Algeria, Vietnam, and Afghanistan

    DTIC Science & Technology

    2013-06-13

    drop smoke to show wind conditions, first assault helicopter lands 100-300 yards behind last rocket pass with successive aircraft as permitted by the...agents on VC tunnel complexes. Later, the 1st Cavalry Division employed a few of their Chinooks as “Go-Go birds ,” armed with twenty millimeter Gatling...cannons, forty-millimeter grenade launchers, fifty caliber machine guns, and rockets.182 Of the three “Go-Go birds ” that flew, the enemy downed two

  12. An introduction to the physical aspects of helicopter stability

    NASA Technical Reports Server (NTRS)

    Gessow, Alfred; Amer, Kenneth B

    1950-01-01

    In order to provide engineers interested in rotating-wing aircraft, but with no specialized training in stability theory, some understanding of the factors that influence the flying qualities of the helicopter, an explanation is made of both the static stability and the stick-fixed oscillation in hovering and forward flight in terms of fundamental physical quantities. Three significant stability factors -- static stability with angle of attack, static stability with speed, and damping due to a pitching or rolling velocity -- are explained in detail.

  13. A new helicostat from SNIAS helicopter division

    NASA Technical Reports Server (NTRS)

    Morisset, J.

    1977-01-01

    The Helicostat was described as a helicopter in which the vehicle weight is nullified by two balloons arranged in a catamaran fashion. Development of such a vehicle is discussed, and various uses for these helicopters are summarized.

  14. 77 FR 64693 - Airworthiness Directives; Hawker Beechcraft Corporation Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-23

    ...-17221; AD 2012-21-05] RIN 2120-AA64 Airworthiness Directives; Hawker Beechcraft Corporation Airplanes... airworthiness directive (AD) for certain Hawker Beechcraft Corporation Model G58 airplanes. This AD was prompted by notification from Hawker Beechcraft Corporation that certain affected aircraft were produced...

  15. Helicopter External Load Acquisition Technology Investigation.

    DTIC Science & Technology

    1980-12-01

    101st Airborne Division, Fort Campbell, Ky. Evergreen Helicopters, McMinnville , Oregon The Army Technical Representative for the program was Mr. Richard...commercial helicopter operator, Evergreen Helicopters, McMinnville , Oregon, to obtain additional data on commercial solutions to external load acquisition

  16. Helicopter Aircrew Training Using Fused Reality

    DTIC Science & Technology

    2006-06-01

    RTO-MP-HFM-136 27 - 1 Helicopter Aircrew Training Using Fused Reality Dr. Ed Bachelder Systems Technology Inc. 13766 Hawthorne Blvd...applied to training helicopter aircrew personnel using a prototype simulator, the Prototype Aircrew Virtual Environment Training (PAVET) System...cabin) pixels using blue screen imaging techniques. This bitmap is overlaid on a virtual environment, and sent Bachelder, E. (2006) Helicopter Aircrew

  17. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  18. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  19. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  20. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  1. 29 CFR 1926.551 - Helicopters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... activating device so designed and installed as to prevent inadvertent operation. In addition, these cargo... allowed to approach within 50 feet of the helicopter when the rotor blades are turning. (p) Approaching helicopter. Whenever approaching or leaving a helicopter with blades rotating, all employees shall remain...

  2. Investigating Flight with a Toy Helicopter

    ERIC Educational Resources Information Center

    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…

  3. Method for Studying Helicopter Longitudinal Maneuver Stability

    NASA Technical Reports Server (NTRS)

    Amer, Kenneth B

    1954-01-01

    A theoretical analysis of helicopter maneuver stability is made and the results are compared with experimental results for both a single and a tandem rotor helicopter. Techniques are described for measuring in flight the significant stability derivatives for use with the theory to aid in design studies of means for achieving marginal maneuver stability for a prototype helicopter.

  4. Two-Dimensional Fourier Transform Analysis of Helicopter Flyover Noise

    NASA Technical Reports Server (NTRS)

    SantaMaria, Odilyn L.; Farassat, F.; Morris, Philip J.

    1999-01-01

    A method to separate main rotor and tail rotor noise from a helicopter in flight is explored. Being the sum of two periodic signals of disproportionate, or incommensurate frequencies, helicopter noise is neither periodic nor stationary. The single Fourier transform divides signal energy into frequency bins of equal size. Incommensurate frequencies are therefore not adequately represented by any one chosen data block size. A two-dimensional Fourier analysis method is used to separate main rotor and tail rotor noise. The two-dimensional spectral analysis method is first applied to simulated signals. This initial analysis gives an idea of the characteristics of the two-dimensional autocorrelations and spectra. Data from a helicopter flight test is analyzed in two dimensions. The test aircraft are a Boeing MD902 Explorer (no tail rotor) and a Sikorsky S-76 (4-bladed tail rotor). The results show that the main rotor and tail rotor signals can indeed be separated in the two-dimensional Fourier transform spectrum. The separation occurs along the diagonals associated with the frequencies of interest. These diagonals are individual spectra containing only information related to one particular frequency.

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

    NASA Technical Reports Server (NTRS)

    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.

  6. Measurement and Characterization of Helicopter Noise at Different Altitudes

    NASA Technical Reports Server (NTRS)

    Watts, Michael E.; Greenwood, Eric; Stephenson, James

    2016-01-01

    This paper presents an overview of a flight test campaign performed at different test sites whose altitudes ranged from 0 to 7000 feet above mean sea level (AMSL) between September 2014 and February 2015. The purposes of this campaign were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. In addition to describing the test campaign, results of the acoustic effects of altitude variation for the AS350 SD1 and EH-60L aircraft are presented. Large changes in acoustic amplitudes were observed in response to changes in ambient conditions when the helicopter was flown at constant indicated airspeed and gross weight at the three test sites. However, acoustic amplitudes were found to scale with ambient pressure when flight conditions were defined in terms of the non-dimensional parameters, such as the weight coefficient and effective hover tip Mach number.

  7. Advanced automatic target recognition for police helicopter missions

    NASA Astrophysics Data System (ADS)

    Stahl, Christoph; Schoppmann, Paul

    2000-08-01

    The results of a case study about the application of an advanced method for automatic target recognition to infrared imagery taken from police helicopter missions are presented. The method consists of the following steps: preprocessing, classification, fusion, postprocessing and tracking, and combines the three paradigms image pyramids, neural networks and bayesian nets. The technology has been developed using a variety of different scenes typical for military aircraft missions. Infrared cameras have been in use for several years at the Bavarian police helicopter forces and are highly valuable for night missions. Several object classes like 'persons' or 'vehicles' are tested and the possible discrimination between persons and animals is shown. The analysis of complex scenes with hidden objects and clutter shows the potentials and limitations of automatic target recognition for real-world tasks. Several display concepts illustrate the achievable improvement of the situation awareness. The similarities and differences between various mission types concerning object variability, time constraints, consequences of false alarms, etc. are discussed. Typical police actions like searching for missing persons or runaway criminals illustrate the advantages of automatic target recognition. The results demonstrate the possible operational benefits for the helicopter crew. Future work will include performance evaluation issues and a system integration concept for the target platform.

  8. Identifying and analyzing methods for reducing the energy consumption of helicopters

    NASA Technical Reports Server (NTRS)

    Davis, S. J.; Rosenstein, H. J.

    1975-01-01

    The results are presented of a study to identify those helicopter technology areas which would result in the largest energy (or fuel) savings when applied to large tandem (100 passenger) civil helicopters in the 1985 time frame. Baseline aircraft using 1975 technology in the areas of powerplant, rotor efficiency, parasite drag and structure were sized to a very short haul mission of 100 N.M. and a short haul mission of 200 N.M. A systematic parametric analysis was then conducted to assess the impact of technology improvements. Projections of the technology levels that could be obtained in the 1985 time frame were made and the resources estimated to achieve them. Based on these data, the highest payoff (lowest energy) helicopter technologies are identified.

  9. Initial Flight Evaluation of the Army/NASA RASCAL Variable Stability Helicopter

    NASA Technical Reports Server (NTRS)

    Moralez, Ernesto, III; Hindson, William S.; Arterburn, David R.

    2000-01-01

    NASA Ames Research Center and the U.S. Army Aeroflightdynamics Directorate (AFDD) [will] have performed initial flight evaluations of the Research Flight Control System (RFCS) that has been integrated into the Army/NASA Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) variable stability helicopter. The RASCAL, a highly modified JUH-60A Black Hawk helicopter, is a variable-stability, in-flight simulator that is designed to support flight research programs that leverage on the flight control and handling qualities design tools developed by the Army and NASA. These tools are used in the flight control design life cycle from initial concept definition, through simulation, and ultimately into flight on-board the RASCAL helicopter. The RASCAL will be used to validate methodologies for reducing design cycle costs for new or modified aircraft, and it will serve as a base for the investigation of new rotorcraft technology.

  10. Operational military helicopter interior noise and vibration measurements with comparisons to ride quality criteria

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    Balka (1981) has identified the attainment of a 'jet-smooth' ride as a primary goal of the helicopter industry for commercial and certain military helicopters. It was noted that criteria accounting for both multiple axis vibration and interior noise are needed. The present investigation has the objective to present a vibration and interior noise data base in a format suitable for direct evaluation of aircraft ride quality. The investigation is also concerned with an assessment of the measured environment against available criteria as an indication of the state-of-the-art for current machines. Interior noise and vibration measurements were obtained on eight military helicopters during routine operational flights. The data are presented in the form of a number of parameters.

  11. Census U.S. Civil Aircraft Calendar Year 1993

    DTIC Science & Technology

    1993-12-31

    Turbojet 1.020 Helicopter 1,977 Total 10,692 2-3 TABLE 2.2 AIRCRAFT REPORTED IN OPERATION BY AIR CARRIERS, BY MANUFACTURER AND MODEL 1984-1993 Aircraft...2 41 1 0 146 146 A-49 U.S. REGISTERED CIVIL AIRCRAFT BY MANUFACTURER AND MODEL -NUMBER OF SEATS PISTON AS OF DECEMBER 31, 1993...AS OF DECEMBER 31, 1993 Total General TotalEngine Make Engine Model Engine Power Engines Air Carrier Aviation Aircraft ROLL-ROYCE ........... GRIFFON

  12. Flight experiment of pilot display for search-and-rescue helicopter

    NASA Astrophysics Data System (ADS)

    Funabiki, Kohei; Tsuda, Hiroka; Iijima, Tomoko; Nojima, Takuya; Tawada, Kazuho; Yoshida, Takashi

    2009-05-01

    JAXA (Japan Aerospace Exploration Agency), together with Shimadzu Corporation and NEC, has initiated a research project named SAVERH (Situation Awareness and Visual Enhancer for Rescue Helicopter) that aims at inventing method of presenting suitable pilot information to support helicopter search and rescue missions. As the initial stage of this research, a series of flight experiments was conducted to investigate the feasibility of operations enhanced by an E/SVS (Enhanced / Synthetic Vision System) and to clarify system issues. An integrated system comprising an HMD (Helmet Mounted Display) and a FLIR (Forward Looking Infrared) sensor were installed in a JAXA research helicopter, and Tunnel-in-the-Sky symbology and a Synthetic Terrain image combined with the FLIR image were presented on the HMD and/or on a Head Down Display (HDD). Through a total of 17 flights including night flights, the potential capability of the system was demonstrated while many issues for further investigation were identified.

  13. Virtual sensor for failure detection, identification and recovery in the transition phase of a morphing aircraft.

    PubMed

    Heredia, Guillermo; Ollero, Aníbal

    2010-01-01

    The Helicopter Adaptive Aircraft (HADA) is a morphing aircraft which is able to take-off as a helicopter and, when in forward flight, unfold the wings that are hidden under the fuselage, and transfer the power from the main rotor to a propeller, thus morphing from a helicopter to an airplane. In this process, the reliable folding and unfolding of the wings is critical, since a failure may determine the ability to perform a mission, and may even be catastrophic. This paper proposes a virtual sensor based Fault Detection, Identification and Recovery (FDIR) system to increase the reliability of the HADA aircraft. The virtual sensor is able to capture the nonlinear interaction between the folding/unfolding wings aerodynamics and the HADA airframe using the navigation sensor measurements. The proposed FDIR system has been validated using a simulation model of the HADA aircraft, which includes real phenomena as sensor noise and sampling characteristics and turbulence and wind perturbations.

  14. Virtual Sensor for Failure Detection, Identification and Recovery in the Transition Phase of a Morphing Aircraft

    PubMed Central

    Heredia, Guillermo; Ollero, Aníbal

    2010-01-01

    The Helicopter Adaptive Aircraft (HADA) is a morphing aircraft which is able to take-off as a helicopter and, when in forward flight, unfold the wings that are hidden under the fuselage, and transfer the power from the main rotor to a propeller, thus morphing from a helicopter to an airplane. In this process, the reliable folding and unfolding of the wings is critical, since a failure may determine the ability to perform a mission, and may even be catastrophic. This paper proposes a virtual sensor based Fault Detection, Identification and Recovery (FDIR) system to increase the reliability of the HADA aircraft. The virtual sensor is able to capture the nonlinear interaction between the folding/unfolding wings aerodynamics and the HADA airframe using the navigation sensor measurements. The proposed FDIR system has been validated using a simulation model of the HADA aircraft, which includes real phenomena as sensor noise and sampling characteristics and turbulence and wind perturbations. PMID:22294922

  15. Integrated cockpit design for the Army helicopter improvement program

    NASA Technical Reports Server (NTRS)

    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.

  16. [Importance of helicopter rescue].

    PubMed

    Hofer, G; Voelckel, W G

    2014-03-01

    Helicopter emergency medical service (HEMS) have become a main part of prehospital emergency medical services over the last 40 years. Recently, an ongoing discussion about financial shortage and personal shortcomings question the role of cost-intensive air rescue. Thus, the value of HEMS must be examined and discussed appropriately. Since the number of physician-staffed ground ambulances may decrease due to the limited availability of qualified physicians, HEMS may fill the gap. In addition patient transfer to specialized hospitals will require an increasing number of air transports in order to minimize prehospital time. The higher risk ratio for HEMS missions when compared with ground rescue requires a rigorous quality management system. When it comes to missions in remote and exposed areas, the scope of medical treatment must be adjusted to the individual situation. Medical competence is key in order to balance guideline compliant or maximal care versus optimal care characterized as a mission-specific, individualized emergency care concept. Although, medical decision making and treatment is typically based on the best scientific evidence, personal skills, competence, and the mission scenario will determine the scope of interventions suitable to improve outcome. Thus, the profile of requirements for the HEMS medical crew is high.

  17. [Back ache in helicopter pilots].

    PubMed

    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.

  18. Trimming an aircraft model for flight simulation

    NASA Technical Reports Server (NTRS)

    Mcfarland, Richard E.

    1987-01-01

    Real-time piloted aircraft simulations with digital computers have been performed at Ames Research Center (ARC) for over two decades. For the simulation of conventional aircraft models, the establishment of initial vehicle and control orientations at various operational flight regimes has been adequately handled by either analog techniques or simple inversion processes. However, exotic helicopter configurations have been introduced recently that require more sophisticated techniques because of their expanded degrees of freedom and environmental vibration levels. At ARC, these techniques are used for the backward solutions to real-time simulation models as required for the generation of trim points. These techniques are presented in this paper with examples from a blade-element helicopter simulation model.

  19. Helicopter approach capability using the differential Global Positioning System

    NASA Technical Reports Server (NTRS)

    Kaufmann, David N.

    1993-01-01

    The results of flight tests to determine the feasibility of using the Global Positioning System (GPS) in the differential mode (DGPS) to provide high accuracy, precision navigation and guidance for helicopter approaches to landing are presented. The airborne DGPS receiver and associated equipment is installed in a NASA UH-60 Black Hawk helicopter. The ground-based DGPS reference receiver is located at a surveyed test site and is equipped with a real-time VHF data link to transmit correction information to the airborne DGPS receiver. The corrected airborne DGPS information, together with the preset approach geometry, is used to calculate guidance commands which are sent to the aircraft's approach guidance instruments. The use of DGPS derived guidance for helicopter approaches to landing is evaluated by comparing the DGPS data with the laser tracker truth data. Both standard (3 degrees) and steep (6 degrees and 9 degrees) glidescope straight-in approaches were flown. DGPS positioning accuracy based on a time history analysis of the entire approach was 0.2 m (mean) +/- 1.8 m (2 sigma) laterally and -2.0 m (mean) +/- 3.5 m (2 sigma) vertically for 3 degree glidescope approaches, -0.1 m (mean) +/- 1.5 m (2 sigma) laterally and -1.1 m (mean) +/- 3.5 m (2 sigma) vertically for 6 degree glidescope approaches, and 0.2 m (mean) +/- 1.3 m (2 sigma) laterally and -1.0 m (mean) +/- 2.8 (2 sigma) vertically for 9 degree glidescope approaches. DGPS positioning accuracy at the 200 ft decision height on a standard 3 degree glidescope approach was 0.3 m (mean) +/- 1.5 m (2 sigma) laterally and -2.3 m (mean) +/- 1.6 m (2 sigma) vertically. These errors indicate that the helicopter position based on DGPS guidance satisfies the International Civil Aviation Organization Category 1 lateral and vertical accuracy requirements.

  20. Annoyance of helicopter impulsive noise

    NASA Technical Reports Server (NTRS)

    Dambra, F.; Damongeot, A.

    1978-01-01

    Psychoacoustic studies of helicopter impulsive noise were conducted in order to qualify additional annoyance due to this feature and to develop physical impulsiveness descriptors to develop impulsivity correction methods. The currently proposed descriptors and methods of impulsiveness correction are compared using a multilinear regression analysis technique. It is shown that the presently recommended descriptor and correction method provides the best correlation with the subjective evaluations of real helicopter impulsive noises. The equipment necessary for data processing in order to apply the correction method is discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Educational Aids in Aircraft Combat Survivability.

    DTIC Science & Technology

    1983-12-01

    calculation . Tn all instances, an attempt was made to provide questions which ranged from simple tc quite challenging in order to provide suitable...D. Electrical E. Launch and recovery 3. Helicopters are very power limited and hence must be very lightly constructed. Thrust, lift, and control...structural limits are being approached as the controls are deflected. 28 A 20. The various control surfaces used by aircraft are: A. Elevators B

  3. Requirements for a Hydrogen Powered All-Electric Manned Helicopter

    NASA Technical Reports Server (NTRS)

    Datta, Anubhav

    2012-01-01

    The objective of this paper is to set propulsion system targets for an all-electric manned helicopter of ultra-light utility class to achieve performance comparable to combustion engines. The approach is to begin with a current two-seat helicopter (Robinson R 22 Beta II-like), design an all-electric power plant as replacement for its existing piston engine, and study performance of the new all-electric aircraft. The new power plant consists of high-pressure Proton Exchange Membrane fuel cells, hydrogen stored in 700 bar type-4 tanks, lithium-ion batteries, and an AC synchronous permanent magnet motor. The aircraft and the transmission are assumed to remain the same. The paper surveys the state of the art in each of these areas, synthesizes a power plant using best available technologies in each, examines the performance achievable by such a power plant, identifies key barriers, and sets future technology targets to achieve performance at par with current internal combustion engines.

  4. Full-scale crash test of a CH-47C helicopter

    NASA Technical Reports Server (NTRS)

    Castle, C. B.

    1976-01-01

    A full-scale crash test of a large troop/cargo carrying CH-47C helicopter was conducted at the Langley impact dynamics research facility. The crash test of this large helicopter was performed as part of a joint U.S. Army-NASA helicopter test program to provide dynamic structural and seat response data. The test, the procedures employed, the instrumentation, a general assessment of the resulting damage, and typical levels of accelerations experienced during the crash are reported. Various energy-absorbing seating systems for crew and troops were installed and instrumented to provide data for use in the development of design criteria for future aircraft. The crash conditions were selected to simulate known crash conditions and are representative of the 95th percentile accident environment for an autorotating helicopter. Visual examination of the crashed test specimen indicated irreparable damage to many of the structural components. The highest accelerations were recorded by the accelerometers located on the cabin floor in the aft section of the helicopter, directly above the primary impact location and on the floor of the cockpit above the secondary impact location(s).

  5. 78 FR 27867 - Airworthiness Directives; MD Helicopters Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-13

    ..., leading to vibration, loss of tail rotor pitch control, and subsequent loss of tail rotor and helicopter... from cracking and separating from the blade, leading to an unbalanced condition, vibration, loss of...) separating from the tail rotor blade, leading to an unbalanced condition, vibration, loss of tail rotor...

  6. 78 FR 65180 - Airworthiness Directives; MD Helicopters, Inc., Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... actions are intended to prevent a pitch horn from cracking, leading to vibration, loss of tail rotor pitch... condition, vibration, loss of tail rotor pitch control, and loss of directional control of the helicopter... (pitch horn) separating from the tail rotor blade, leading to an unbalanced condition, vibration, loss...

  7. 78 FR 65195 - Airworthiness Directives; MD Helicopters, Inc. (MDHI) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

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

  8. 77 FR 23638 - Airworthiness Directives; Bell Helicopter Textron, Incorporated Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ..., and the AD ] applicability needs to be expanded to include additional grips similar in design, as well... rotor blade, and subsequent loss of control of the helicopter. DATES: We must receive comments on this... damage to the blade, blade bolt bore, or buffer pad tang surface were found in the two cracked...

  9. 77 FR 5427 - Airworthiness Directives; Bell Helicopter Textron, Inc., Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... creating a component history card or equivalent record and begin counting and recording the number of... Internet at http://www.regulations.gov or in person at the Docket Operations Office between 9 a.m. and 5 p... for the specified Bell model helicopters. This proposal would require creating a component...

  10. 77 FR 68055 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ..., and 412CF helicopters. This AD requires a repetitive inspection of the collective lever for a crack, and if there is a crack, before further flight, replacing the collective lever with an airworthy... to detect a crack in the collective lever, which could lead to failure of the collective lever...

  11. 78 FR 18224 - Airworthiness Directives; Robinson Helicopter Company Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2012-1088; Directorate Identifier 2012-SW...): 2013-05-15 Robinson Helicopter Company: Amendment 39-17387; Docket No. FAA-2012-1088;...

  12. 78 FR 1730 - Airworthiness Directives; Bell Helicopter Textron Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... 205A, 205A-1, and 205B helicopters with certain starter/generator power cable assemblies (power cable assemblies). This AD requires replacing the power cable assemblies and their associated parts, and performing continuity readings. This AD was prompted by the determination that the power cable assembly...

  13. Interior noise and vibration measurements on operational military helicopters and comparisons with various ride quality criteria

    NASA Astrophysics Data System (ADS)

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

    1983-08-01

    The results of physical measurements of the interior noise and vibration obtained within eight operational military helicopters are presented. The data were extensively analyzed and are presented in the following forms: noise and vibration spectra, overall root-mean-square acceleration levels in three linear axes, peak accelerations at dominant blade passage frequencies, acceleration exceedance data, and overall and ""A'' weighted sound pressure levels. Peak acceleration levels were compared to the ISO 1-hr reduced comfort and fatigue decreased proficiency boundaries and the NASA discomfort criteria. The ""A'' weighted noise levels were compared to the NASA annoyance criteria, and the overall noise spectra were compared to MIL-STD-1294 (""Acoustical Noise Limits in Helicopters''). Specific vibration components at blade passage frequencies for several aircraft exceeded both the ISO reduced comfort boundary and the NASA passenger discomfort criteria. The ""A'' weighted noise levels, corrected for SPH-4 helmet attenuation characteristics, exceeded the NASA annoyance threshold for several aircraft.

  14. Interior noise and vibration measurements on operational military helicopters and comparisons with various ride quality criteria

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    The results of physical measurements of the interior noise and vibration obtained within eight operational military helicopters are presented. The data were extensively analyzed and are presented in the following forms: noise and vibration spectra, overall root-mean-square acceleration levels in three linear axes, peak accelerations at dominant blade passage frequencies, acceleration exceedance data, and overall and ""A'' weighted sound pressure levels. Peak acceleration levels were compared to the ISO 1-hr reduced comfort and fatigue decreased proficiency boundaries and the NASA discomfort criteria. The ""A'' weighted noise levels were compared to the NASA annoyance criteria, and the overall noise spectra were compared to MIL-STD-1294 (""Acoustical Noise Limits in Helicopters''). Specific vibration components at blade passage frequencies for several aircraft exceeded both the ISO reduced comfort boundary and the NASA passenger discomfort criteria. The ""A'' weighted noise levels, corrected for SPH-4 helmet attenuation characteristics, exceeded the NASA annoyance threshold for several aircraft.

  15. Investigation of technology needs for avoiding helicopter pilot error related accidents

    NASA Technical Reports Server (NTRS)

    Chais, R. I.; Simpson, W. E.

    1985-01-01

    Pilot error which is cited as a cause or related factor in most rotorcraft accidents was examined. Pilot error related accidents in helicopters to identify areas in which new technology could reduce or eliminate the underlying causes of these human errors were investigated. The aircraft accident data base at the U.S. Army Safety Center was studied as the source of data on helicopter accidents. A randomly selected sample of 110 aircraft records were analyzed on a case-by-case basis to assess the nature of problems which need to be resolved and applicable technology implications. Six technology areas in which there appears to be a need for new or increased emphasis are identified.

  16. Helicopter Toy and Lift Estimation

    ERIC Educational Resources Information Center

    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.)

  17. Bell Helicopter Advanced Rotocraft Transmission (ART) program

    NASA Astrophysics Data System (ADS)

    Henry, Zachary S.

    1995-06-01

    Future rotorcraft transmissions require key emerging material and component technologies using advanced and innovative design practices in order to meet the requirements for a reduced weight to power ratio, a decreased noise level, and a substantially increased reliability. The specific goals for the future rotorcraft transmission when compared with a current state-of-the-art transmission (SOAT) are: (1) a 25 percent weight reduction; (2) a 10 dB reduction in the transmitted noise level; and (3) a system reliability of 5000 hours mean-time-between-removal (MTBR) for the transmission. This report summarizes the work conducted by Bell Helicopter Textron, Inc. to achieve these goals under the Advanced Rotorcraft Transmission (ART) program from 1988 to 1995. The reference aircraft selected by BHTI for the ART program was the Tactical Tiltrotor which is a 17,000 lb gross weight aircraft. A tradeoff study was conducted comparing the ART with a Selected SOAT. The results showed the ART to be 29 percent lighter and up to 13 dB quieter with a calculated MTBR in excess of 5000 hours. The results of the following high risk component and material tests are also presented: (1) sequential meshing high contact ratio planetary with cantilevered support posts; (2) thin dense chrome plated M50 NiL double row spherical roller planetary bearings; (3) reduced kinematic error and increased bending strength spiral bevel gears; (4) high temperature WE43 magnesium housing evaluation and coupon corrosion tests; (5) flexure fatigue tests of precision forged coupons simulating precision forged gear teeth; and (6) flexure fatigue tests of plasma carburized coupons simulating plasma carburized gear teeth.

  18. Bell Helicopter Advanced Rotocraft Transmission (ART) program

    NASA Technical Reports Server (NTRS)

    Henry, Zachary S.

    1995-01-01

    Future rotorcraft transmissions require key emerging material and component technologies using advanced and innovative design practices in order to meet the requirements for a reduced weight to power ratio, a decreased noise level, and a substantially increased reliability. The specific goals for the future rotorcraft transmission when compared with a current state-of-the-art transmission (SOAT) are: (1) a 25 percent weight reduction; (2) a 10 dB reduction in the transmitted noise level; and (3) a system reliability of 5000 hours mean-time-between-removal (MTBR) for the transmission. This report summarizes the work conducted by Bell Helicopter Textron, Inc. to achieve these goals under the Advanced Rotorcraft Transmission (ART) program from 1988 to 1995. The reference aircraft selected by BHTI for the ART program was the Tactical Tiltrotor which is a 17,000 lb gross weight aircraft. A tradeoff study was conducted comparing the ART with a Selected SOAT. The results showed the ART to be 29 percent lighter and up to 13 dB quieter with a calculated MTBR in excess of 5000 hours. The results of the following high risk component and material tests are also presented: (1) sequential meshing high contact ratio planetary with cantilevered support posts; (2) thin dense chrome plated M50 NiL double row spherical roller planetary bearings; (3) reduced kinematic error and increased bending strength spiral bevel gears; (4) high temperature WE43 magnesium housing evaluation and coupon corrosion tests; (5) flexure fatigue tests of precision forged coupons simulating precision forged gear teeth; and (6) flexure fatigue tests of plasma carburized coupons simulating plasma carburized gear teeth.

  19. 78 FR 47531 - Airworthiness Directives; Various Restricted Category Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-06

    ... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter...

  20. 77 FR 44434 - Airworthiness Directives; Various Restricted Category Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-30

    ... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... apply to Arrow Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter... Arrow Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation Helicopter...

  1. 78 FR 54792 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... (Eurocopter) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Model EC225 LP helicopters. This proposed AD would add a new operating limitation that would require increasing the minimum density altitude flight limitation for helicopters without certain...

  2. McDonnell Douglas Helicopter Company independent research and development: Preparing for the future

    NASA Technical Reports Server (NTRS)

    Haggerty, Allen C.

    1988-01-01

    During the 1970's and 80's, research has produced the technology that is seen in aircraft such as the LHX and future models. The technology is discussed that is reaching maturity and moving into the application stage of future programs. Technology is discussed in six major areas: advanced concepts, analysis techniques, structures, systems, simulation, and research and development facilities. The partnership of McDonnell Douglas Helicopter Co. and the government in developing these technologies is illustrated in several programs.

  3. Wind Tunnel Measurements and Calculations of Aerodynamic Interactions Between Tiltrotor Aircraft

    DTIC Science & Technology

    2003-01-01

    the wake of the upwind aircraft. The aircraft were in helicopter configuration ( nacelle angle 90 deg), with the rotor shafts vertical and the wing at...indicating downward convection of the wake (so the upwind aircraft was higher at the maximum interaction). Similar wake behavior was observed in lidar ...Libby, J.; "Wake Vortex Measurements of the XV-15 Tiltrotor Using a Mobile Ground-Based Lidar System." AHS International 57th Annual Forum Proceedings

  4. Passenger demographics and subjective response to commuter aircraft in the northeast

    NASA Technical Reports Server (NTRS)

    Noskowitz, D.; Jacobson, I. D.

    1974-01-01

    Results are compared for comfort and environmental studies taken in conjunction with a STOL program. Data were taken on flights of four different airlines, each flying different aircraft. Two of the lines are classified as commuter airlines flying between relatively close destinations. The aircraft involved are: the De Havilland Twin Otter, a Canadian aircraft; the French Nord 262; the Beechcraft 99 Airliner and the Sikorsky S-61 helicopter, both American.

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

    NASA Technical Reports Server (NTRS)

    Heldenfels, R. R.

    1975-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

    2012-06-01

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

  7. New capabilities and recent research programs of the NASA/Army CH-47B variable-stability helicopter

    NASA Technical Reports Server (NTRS)

    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.

  8. Installation of C-6533(XE-2)/ARC ICS in UH-1H helicopter

    NASA Astrophysics Data System (ADS)

    Hnat, J. A.

    1980-07-01

    This report documents the results of the installation of the C-6533(XE-2)/ARC ICS in UH-1H helicopter. Installation was performed at the AEL, Inc., Monmouth County Airport facility. Design of each installation was coordinated and approved by the Government. The mechanical and electrical installation drawings for the helicopter are attached as Appendix A of this report. The new ICS system consisted of new cabling, new intercoms and helmets rewired with new microphones. All four crew stations of the helicopter were reconfigured with the new system. Existing cabling for the standard ICS system remained in the aircraft but was securely stowed for later restoration of the aircraft. The helmets (4) were rewired using separate jacks for headphones and microphone lines. Transmit and receive cables were installed in the aircraft with a minimum separation of one inch between cables. A junction box was fabricated and installed on the aft end of the console to house the fan-out terminal strips. Transmit and receive lines' separation was maintained in the junction box. During the test phase the onboard radios were used with the new ICS system.

  9. The Need for the Next Special Operations Forces’ Mobility Aircraft

    DTIC Science & Technology

    2012-03-01

    AFSOC relies on the AC-130 for strike missions, the MC-130P for helicopter /tilt rotor air refueling, the MC-130H and CV-22 for SOF mobility, and a...infiltration and extraction of SOF. A tilt-rotor aircraft allows the CV-22 to fly like a C-130, but land and takeoff like a helicopter . Thus far...designation will be the MC-130J and it will conduct helicopter refueling and SOF mobility needs. The MC-130J will certainly slow the aging of

  10. Crew station research and development facility training for the light helicopter demonstration/validation program

    NASA Technical Reports Server (NTRS)

    Matsumoto, Joy Hamerman; Rogers, Steven; Mccauley, Michael; Salinas, AL

    1992-01-01

    The U.S. Army Crew Station Research and Development Branch (CSRDB) of the Aircraft Simulation Division (AVSCOM) was tasked by the Light Helicopter Program Manager (LH-PM) to provide training to Army personnel in advanced aircraft simulation technology. The purpose of this training was to prepare different groups of pilots to support and evaluate two contractor simulation efforts during the Demonstration/Validation (DEM/VAL) phase of the LH program. The personnel in the CSRDB developed mission oriented training programs to accomplish the objectives, conduct the programs, and provide guidance to army personnel and support personnel throughout the DEM/VAL phase.

  11. Optimal landing of a helicopter in autorotation

    NASA Technical Reports Server (NTRS)

    Lee, A. Y. N.

    1985-01-01

    Gliding descent in autorotation is a maneuver used by helicopter pilots in case of engine failure. The landing of a helicopter in autorotation is formulated as a nonlinear optimal control problem. The OH-58A helicopter was used. Helicopter vertical and horizontal velocities, vertical and horizontal displacement, and the rotor angle speed were modeled. An empirical approximation for the induced veloctiy in the vortex-ring state were provided. The cost function of the optimal control problem is a weighted sum of the squared horizontal and vertical components of the helicopter velocity at touchdown. Optimal trajectories are calculated for entry conditions well within the horizontal-vertical restriction curve, with the helicopter initially in hover or forwared flight. The resultant two-point boundary value problem with path equality constraints was successfully solved using the Sequential Gradient Restoration Technique.

  12. Model predictive formation control of helicopter systems

    NASA Astrophysics Data System (ADS)

    Saffarian, Mehdi

    In this thesis, a robust formation control framework for formation control of a group of helicopters is proposed and designed. The dynamic model of the helicopter has been developed and verified through simulations. The control framework is constructed using two main control schemes for navigation of a helicopter group in three-dimensional (3D) environments. Two schemes are designed to maintain the position of one helicopter with respect to one or two other neighboring members, respectively. The developed parameters can uniquely define the position of the helicopters with respect to each other and can be used for any other aerial and under water vehicles such as airplanes, spacecrafts and submarines. Also, since this approach is modular, it is possible to use it for desired number and form of the group helicopters. Using the defined control parameters, two decentralized controllers are designed based on Nonlinear Model Predictive Control (NMPC) algorithm technique. The framework performance has been tested through simulation of different formation scenarios.

  13. 76 FR 66609 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 407 and 427 Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ... Textron Canada (Bell) Model 407 and 427 Helicopters AGENCY: Federal Aviation Administration, DOT. ACTION... the service information identified in this AD from Bell Helicopter Textron Canada Limited, 12,800 Rue... the helicopter. Transport Canada, the airworthiness authority for Canada, notified the FAA that...

  14. 78 FR 23688 - Airworthiness Directives; Bell Helicopter Textron Canada Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... Textron Canada Inc. Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of... Bell Helicopter Textron Canada Inc. (BHT) Model 206A, 206B, and 206L helicopters. This proposed AD... Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or (800)...

  15. Control equivalent turbulence input model for the UH-60 helicopter

    NASA Astrophysics Data System (ADS)

    Lusardi, Jeff

    Flight test data from a UH-60 Black Hawk helicopter hovering in the atmospheric turbulence downwind of a large cube-shaped hanger on a wind day were collected. An inverse modeling method was used to extract the control inputs that are required to replicate the portion of the aircraft response attributable to atmospheric disturbances from the flight-test data. Based on the extracted control inputs, a parametric Control Equivalent Turbulence Input (CETI) model comprised of white-noise driven filters that have a Dryden-type form and are scalable for varying levels of turbulence were developed. The outputs of the filters are disturbance time histories that sum with the pilot's inputs, to replicate the effects of atmospheric turbulence in calm atmospheric conditions. A ground-based piloted simulation study was conducted in the NASA/Ames Vertical Motion Simulator (VMS) comparing the empirically based CETI model with flight-test data and with a complex Simulation Of Rotor Blade Element Turbulence (SORBET) model. Two test pilots performed precision hover tasks with increasing levels of simulated turbulence from both the CETI and SORBET models. The results of the simulation study showed good pilot acceptance of the CETI model and provided a good level of validation of the more complex rotating frame turbulence model. An in-flight simulation study was conducted on the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) UH-60 helicopter using the CETI model. Two test pilots performed a precision hover task on calm days with simulated CETI turbulence. Aircraft response metrics showed good agreement between a hover task with CETI simulated turbulence and the same task in atmospheric turbulence. Both pilots commented that the RASCAL's response to CETI turbulence was similar to the response hovering downwind of the large cube-shaped hangar on a windy day. The CETI model developed in this dissertation simulates turbulence by generating equivalent disturbance inputs to

  16. Implementation of a Helicopter Flight Simulator with Individual Blade Control

    NASA Astrophysics Data System (ADS)

    Zinchiak, Andrew G.

    2011-12-01

    Nearly all modern helicopters are designed with a swashplate-based system for control of the main rotor blades. However, the swashplate-based approach does not provide the level of redundancy necessary to cope with abnormal actuator conditions. For example, if an actuator fails (becomes locked) on the main rotor, the cyclic inputs are consequently fixed and the helicopter may become stuck in a flight maneuver. This can obviously be seen as a catastrophic failure, and would likely lead to a crash. These types of failures can be overcome with the application of individual blade control (IBC). IBC is achieved using the blade pitch control method, which provides complete authority of the aerodynamic characteristics of each rotor blade at any given time by replacing the normally rigid pitch links between the swashplate and the pitch horn of the blade with hydraulic or electronic actuators. Thus, IBC can provide the redundancy necessary for subsystem failure accommodation. In this research effort, a simulation environment is developed to investigate the potential of the IBC main rotor configuration for fault-tolerant control. To examine the applications of IBC to failure scenarios and fault-tolerant controls, a conventional, swashplate-based linear model is first developed for hover and forward flight scenarios based on the UH-60 Black Hawk helicopter. The linear modeling techniques for the swashplate-based helicopter are then adapted and expanded to include IBC. Using these modified techniques, an IBC based mathematical model of the UH-60 helicopter is developed for the purposes of simulation and analysis. The methodology can be used to model and implement a different aircraft if geometric, gravimetric, and general aerodynamic data are available. Without the kinetic restrictions of the swashplate, the IBC model effectively decouples the cyclic control inputs between different blades. Simulations of the IBC model prove that the primary control functions can be manually

  17. Portable-Beacon Landing System for Helicopters

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Clary, George R.; Chisholm, John P.; Macdonald, Stanley L.

    1987-01-01

    Prototype beacon landing system (BLS) allows helicopters to make precise landings in all weather. BLS easily added to existing helicopter avionic equipment and readily deployed at remote sites. Small and light, system employs X-band radar and digital processing. Variety of beams pulsed sequentially by ground station after initial interrogation by weather radar of approaching helicopter. Airborne microprocessor processes pulses to determine glide slope, course deviation, and range.

  18. Assessment of worm gearing for helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Chaiko, Lev

    1990-01-01

    A high-efficiency hydrostatic worm gear drive for helicopter transmissions is assessed. The example given is for a large cargo helicopter with three 4000-kW engines and transmission reduction ratio of 110. Also contained are: an efficiency calculation, a description of the test stand for evaluating the feasibility of worm gear hydrostatic mesh, a weight calculation, and a comparison with conventional helicopter transmissions of the same power and transmission reduction ratio.

  19. Corporal punishment.

    PubMed

    Zolotor, Adam J

    2014-10-01

    Corporal punishment is used for discipline in most homes in the United States. It is also associated with a long list of adverse developmental, behavioral, and health-related consequences. Primary care providers, as trusted sources for parenting information, have an opportunity to engage parents in discussions about discipline as early as infancy. These discussions should focus on building parents' skills in the use of other behavioral techniques, limiting (or eliminating) the use of corporal punishment and identifying additional resources as needed.

  20. Wind Tunnel Measurements and Calculations of Aerodynamic Interactions Between Tiltrotor Aircraft

    NASA Technical Reports Server (NTRS)

    Johnson, Wayne; Yamauchi, Gloria K.; Derby, Michael R.; Wadcock, Alan J.

    2002-01-01

    Wind tunnel measurements and calculations of the aerodynamic interactions between two tiltrotor aircraft in helicopter mode are presented. The measured results include the roll moment and thrust change on the downwind aircraft, as a function of the upwind aircraft position (longitudinal, lateral, and vertical). Magnitudes and locations of the largest interactions are identified. The calculated interactions generally match the measurements, with discrepancies attributed to the unsteadiness of the wake and aerodynamic forces on the airframe. To interpret the interactions in terms of control and power changes on the aircraft, additional calculations are presented for trimmed aircraft with gimballed rotors.

  1. NASA aeronautics. [fact sheet on NASA programs for aeronautical research and aircraft development

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A fact sheet depicting the NASA programs involving aircraft development and aeronautics is presented. The fact sheet consists of artist concepts of the various aircraft which represent specific programs. Among the subjects discussed in the concise explanatory notes are: (1) the YF-12 aircraft, (2) hypersonic drag tests in wind tunnels, (3) augmentor wing concepts, (4) rotary wing development, (5) fly-by-wire aircraft control, (6) supercritical wings, (7) the quiet engine program for noise and emission abatement, (8) flight capabilities of lifting bodies, (9) tilt rotor concepts for improved helicopter performance, and (10) flight safety improvements for general aviation aircraft.

  2. Advanced Control System Increases Helicopter Safety

    NASA Technical Reports Server (NTRS)

    2008-01-01

    With support and funding from a Phase II NASA SBIR project from Ames Research Center, Hoh Aeronautics Inc. (HAI), of Lomita, California, produced HeliSAS, a low-cost, lightweight, attitude-command-attitude-hold stability augmentation system (SAS) for civil helicopters and unmanned aerial vehicles. HeliSAS proved itself in over 160 hours of flight testing and demonstrations in a Robinson R44 Raven helicopter, a commercial helicopter popular with news broadcasting and police operations. Chelton Flight Systems, of Boise, Idaho, negotiated with HAI to develop, market, and manufacture HeliSAS, now available as the Chelton HeliSAS Digital Helicopter Autopilot.

  3. The tilt rotor research aircraft (XV-15) program

    NASA Technical Reports Server (NTRS)

    Magee, J. P.

    1983-01-01

    The tilt rotor concept is introduced and the performance capabilities and noise characteristics of the XV-15 aircraft are discussed. In hover, the aircraft is lifted by the two wing tip mounted rotors with the nacelles in the vertical position. In this flight mode, the vehicle is a twin rotor helicopter and is controlled by rotor cyclic and collective controls. The aircraft can fly as a helicopter or tilt the nacelle to the propeller mode and operate as a fixed-wing twin turboprop airplane. It is also possible to stop the conversion at any intermediate angle and fly continuously or reconvert. The rotors are powered by two modified T-53 engines and the power train includes a cross shaft located in the wing, to allow for the engine failure case and still retain power to both rotors.

  4. System design requirements for advanced rotary-wing agricultural aircraft

    NASA Technical Reports Server (NTRS)

    Lemont, H. E.

    1979-01-01

    Helicopter aerial dispersal systems were studied to ascertain constraints to the system, the effects of removal of limitations (technical and FAA regulations), and subsystem improvements. Productivity indices for the aircraft and swath effects were examined. Typical missions were formulated through conversations with operators, and differing gross weight aircraft were synthesized to perform these missions. Economic analysis of missions and aircraft indicated a general correlation of small aircraft (3000 lb gross weight) suitability for small fields (25 acres), and low dispersion rates (less than 32 lb/acre), with larger aircraft (12,000 lb gross weight) being more favorable for bigger fields (200 acres) and heavier dispersal rates (100 lb/acre). Operator problems, possible aircraft and system improvements, and selected removal of operating limitations were reviewed into recommendations for future NASA research items.

  5. Simulators for corporate pilot training and evaluation

    NASA Technical Reports Server (NTRS)

    Treichel, Curt

    1992-01-01

    Corporate aviation relies heavily on simulation to meet training and evaluation requirements. It appreciates the savings in fuel, money, noise, and time, and the added safety it provides. Also, simulation provides opportunities to experience many emergencies that cannot be safely practiced in the aircraft. There is a need to focus on the advantages of simulator training over aircraft training and to provide appropriate changes in the regulations to allow the community to make it possible for users to take full advantage of simulation.

  6. Light shaping diffusers{trademark} improve aircraft inspection

    SciTech Connect

    Shagam, R.N.; Shie, R.; Lerner, J.

    1994-11-01

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

  7. Census of U.S. Civil Aircraft, Calendar Year 1986.

    DTIC Science & Technology

    1986-12-31

    1,34 1 I 1,,",-# ROTO TUGSA..4 ROTOR TUiOS44AVr 63 148 2 S89 2 731 TOTAL 146 3 930 4 078 901IWG V -COLUMBIA HELICOPTES . C: - -". 6: * ’ 3 ’’ r 234 3...by manufacturer and model , and general aviation aircraft by state and county of the owner. _-,... .c- erton For 22151 7.. ,,-..-- I P... 17. t o. Usedo...both registered and active, detailed reports for general aviation aircraft by owner’s state and county, and registered aircraft by make and model

  8. Lytic spondylolisthesis in helicopter pilots.

    PubMed

    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.

  9. Blade-Pitch Control for Quieting Tilt-Rotor Aircraft

    NASA Technical Reports Server (NTRS)

    Betzina, Mark D.; Nguyen, Khanh Q.

    2004-01-01

    A method of reducing the noise generated by a tilt-rotor aircraft during descent involves active control of the blade pitch of the rotors. This method is related to prior such noise-reduction methods, of a type denoted generally as higher-harmonic control (HHC), in which the blade pitch is made to oscillate at a harmonic of the frequency of rotation of the rotor. A tilt-rotor aircraft is so named because mounted at its wing tips are motors that can be pivoted to enable the aircraft to take off and land like a helicopter or to fly like a propeller airplane. When the aircraft is operating in its helicopter mode, the rotors generate more thrust per unit rotor-disk area than helicopter rotors do, thus producing more blade-vortex interaction (BVI) noise. BVI is a major source of noise produced by helicopters and tilt-rotor aircraft during descent: When a rotor descends into its own wake, the interaction of each blade with the blade-tip vortices generated previously gives rise to large air-pressure fluctuations. These pressure fluctuations radiate as distinct, impulsive noise. In general, the pitch angle of the rotor blades of a tilt-rotor aircraft is controlled by use of a swash plate connected to the rotor blades by pitch links. In both prior HHC methods and the present method, HHC control signals are fed as input to swash-plate control actuators, causing the rotor-blade pitch to oscillate. The amplitude, frequency, and phase of the control signal can be chosen to minimize BVI noise.

  10. Improving aviation safety with information visualization: Airflow hazard display for helicopter pilots

    NASA Astrophysics Data System (ADS)

    Aragon, Cecilia Rodriguez

    Many aircraft accidents each year are caused by encounters with airflow hazards near the ground, such as vortices or other turbulence. While such hazards frequently pose problems to fixed-wing aircraft, they are especially dangerous to helicopters, whose pilots often have to operate into confined areas or under operationally stressful conditions. Pilots are often unaware of these invisible hazards while simultaneously attending to other aspects of aircraft operation close to the ground. Recent advances in aviation sensor technology offer the potential for aircraft-based sensors that can gather large amounts of airflow velocity data in real time. This development is likely to lead to the production of onboard detection systems that can convey detailed, specific information about imminent airflow hazards to pilots. A user interface is required that can present extensive amounts of data to the pilot in a useful manner in real time, yet not distract from the pilot's primary task of flying the aircraft. In this dissertation, we address the question of how best to present safety-critical visual information to a cognitively overloaded user in real time. We designed an airflow hazard visualization system according to user-centered design principles, implemented the system in a high fidelity, aerodynamically realistic rotorcraft flight simulator, and evaluated it via usability studies with experienced military and civilian helicopter pilots. We gathered both subjective data from the pilots' evaluations of the visualizations, and objective data from the pilots' performance during the landing simulations. Our study demonstrated that information visualization of airflow hazards, when presented to helicopter pilots in the simulator, dramatically improved their ability to land safely under turbulent conditions. Although we focused on one particular aviation application, the results may be relevant to user interfaces and information visualization in other safety

  11. Helicopter tail rotor noise analyses

    NASA Technical Reports Server (NTRS)

    George, A. R.; Chou, S. T.

    1986-01-01

    A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex. The vortex and the geometry information required by the analyses are obtained through a free wake geometry analysis of the main rotor. The acoustic pressure-time histories for the tail rotor blade-vortex interactions are then calculated. These acoustic results are compared to tail rotor loading and thickness noise, and are found to be significant to the overall tail rotor noise generation. Under most helicopter operating conditions, large acoustic pressure fluctuations can be generated due to a series of skewed main rotor tip vortices passing through the tail rotor disk. The noise generation depends strongly upon the helicopter operating conditions and the location of the tail rotor relative to the main rotor.

  12. Flight Test Identification and Simulation of a UH-60A Helicopter and Slung Load

    NASA Technical Reports Server (NTRS)

    Cicolani, Luigi S.; Sahai, Ranjana; Tucker, George E.; McCoy, Allen H.; Tyson, Peter H.; Tischler, Mark B.; Rosen, Aviv

    2001-01-01

    Helicopter slung-load operations are common in both military and civil contexts. Helicopters and loads are often qualified for these operations by means of flight tests, which can be expensive and time consuming. There is significant potential to reduce such costs both through revisions in flight-test methods and by using validated simulation models. To these ends, flight tests were conducted at Moffett Field to demonstrate the identification of key dynamic parameters during flight tests (aircraft stability margins and handling-qualities parameters, and load pendulum stability), and to accumulate a data base for simulation development and validation. The test aircraft was a UH-60A Black Hawk, and the primary test load was an instrumented 8- by 6- by 6-ft cargo container. Tests were focused on the lateral and longitudinal axes, which are the axes most affected by the load pendulum modes in the frequency range of interest for handling qualities; tests were conducted at airspeeds from hover to 80 knots. Using telemetered data, the dynamic parameters were evaluated in near real time after each test airspeed and before clearing the aircraft to the next test point. These computations were completed in under 1 min. A simulation model was implemented by integrating an advanced model of the UH-60A aerodynamics, dynamic equations for the two-body slung-load system, and load static aerodynamics obtained from wind-tunnel measurements. Comparisons with flight data for the helicopter alone and with a slung load showed good overall agreement for all parameters and test points; however, unmodeled secondary dynamic losses around 2 Hz were found in the helicopter model and they resulted in conservative stability margin estimates.

  13. Pneumatic boot for helicopter rotor deicing

    NASA Technical Reports Server (NTRS)

    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.

  14. Study of Helicopter Roll Control Effectiveness Criteria.

    DTIC Science & Technology

    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

  15. Neural Network Based Helicopter Low Airspeed Indicator

    DTIC Science & Technology

    1996-10-24

    This invention relates generally to virtual sensors and, more particularly, to a means and method utilizing a neural network for estimating...helicopter airspeed at speeds below about 50 knots using only fixed system parameters (i.e., parameters measured or determined in a reference frame fixed relative to the helicopter fuselage) as inputs to the neural network .

  16. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  17. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  18. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  19. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  20. 46 CFR 109.577 - Helicopter fueling.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.577 Helicopter fueling. (a) The master or person in charge shall designate persons...

  1. Note on Hovering Turns with Tandem Helicopters

    NASA Technical Reports Server (NTRS)

    Reeder, John P; Tapscott, Robert J

    1955-01-01

    The source of an appreciable pitching-moment difference between left and right hovering turns for a tandem helicopter is described. The difference in pitching moment results from the difference in rotational speed of the counter rotating rotors with respect to the air while the helicopter is turning.

  2. NASA helicopter transmission system technology program

    NASA Technical Reports Server (NTRS)

    Zaretsky, E. V.

    1983-01-01

    The purpose of the NASA Helicopter Transmission System Technology Program is to improve specific mechanical components and the technology for combining these into advanced drive systems to make helicopters more viable and cost competitive for commerical applications. The history, goals, and elements of the program are discussed.

  3. Flight service evaluation of composite components on the Bell Helicopter model 206L: Design, fabrication and testing

    NASA Technical Reports Server (NTRS)

    Zinberg, H.

    1982-01-01

    The design, fabrication, and testing phases of a program to obtain long term flight service experience on representative helicopter airframe structural components operating in typical commercial environments are described. The aircraft chosen is the Bell Helicopter Model 206L. The structural components are the forward fairing, litter door, baggage door, and vertical fin. The advanced composite components were designed to replace the production parts in the field and were certified by the FAA to be operable through the full flight envelope of the 206L. A description of the fabrication process that was used for each of the components is given. Static failing load tests on all components were done. In addition fatigue tests were run on four specimens that simulated the attachment of the vertical fin to the helicopter's tail boom.

  4. Helicopter Operations and Personnel Safety (Helirescue Manual). Fourth Edition.

    ERIC Educational Resources Information Center

    Dalle-Molle, John

    The illustrated manual includes information on various aspects of helicopter rescue missions, including mission management roles for key personnel, safety rules around helicopters, requests for helicopter support, sample military air support forms, selection of landing zones, helicopter evacuations, rescuer delivery, passenger unloading, crash…

  5. Community acceptance of helicopter noise: Criteria and application

    NASA Technical Reports Server (NTRS)

    Munch, C. L.; King, R. J.

    1974-01-01

    A study was conducted to define those criteria necessary for civil helicopter operations to be acoustically acceptable to the communities from which they operate and over which they fly. The study involved surveying existing domestic and foreign Federal regulations and guidelines, state and local noise ordinances, results of community noise annoyance studies, and results of individual aircraft noise annoyance studies, and results of individual aircraft noise annoyance studies in order to establish the criteria. The final criteria selection are based on the Day-Night Level, L sub DN, a measure of total noise exposure. The basic rating unit is the A weighted sound pressure level (dbA) which has accuracy comparable to other units currently used for aircraft. An L sub DN of 60 is recommended as a criterion for areas where the ambient noise is below 58 dbA. An L sub DN value 2 dbA above the local ambient is recommended for areas where the ambient is above 58 dbA.

  6. Full-Scale Crash Test of an MD-500 Helicopter

    NASA Technical Reports Server (NTRS)

    Littell, Justin

    2011-01-01

    A full-scale crash test was successfully conducted in March 2010 of an MD-500 helicopter at NASA Langley Research Center s Landing and Impact Research Facility. The reasons for conducting this test were threefold: 1 To generate data to be used with finite element computer modeling efforts, 2 To study the crashworthiness features typically associated with a small representative helicopter, and 3 To compare aircraft response to data collected from a previously conducted MD-500 crash test, which included an externally deployable energy absorbing (DEA) concept. Instrumentation on the airframe included accelerometers on various structural components of the airframe; and strain gages on keel beams, skid gear and portions of the skin. Three Anthropomorphic Test Devices and a specialized Human Surrogate Torso Model were also onboard to collect occupant loads for evaluation with common injury risk criteria. This paper presents background and results from this crash test conducted without the DEA concept. These results showed accelerations of approximately 30 to 50 g on the airframe at various locations, little energy attenuation through the airframe, and moderate to high probability of occupant injury for a variety of injury criteria.

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

    NASA Technical Reports Server (NTRS)

    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.

  8. Hub and pylon fairing integration for helicopter drag reduction

    NASA Technical Reports Server (NTRS)

    Martin, D. M.; Mort, R. W.; Squires, P. K.; Young, L. A.

    1991-01-01

    The results of testing hub and pylon fairings mounted on a one-fifth scale helicopter with the goal of reducing parasite drag are presented. Lift, drag, and pitching moment, as well as side force and yawing moment, were measured. The primary objective of the test was to validate the drag reduction capability of integrated hub and pylon configurations in the aerodynamic environment produced by a rotating hub in forward flight. In addition to the baseline helicopter without fairings, three hub fairings and three pylon fairings were tested in various combinations. The three hub fairings tested reflect two different conceptual design approaches to implementing an integrated fairing configuration on an actual aircraft. The design philosophy is discussed in detail and comparisons are made between the wind tunnel models and potential full-scale prototypes. The data show that model drag can be reduced by as much as 20.8 percent by combining a small hub fairing with circular arc upper and flat lower surfaces and a nontapered 34-percent thick pylon fairing. Aerodynamic effects caused by the fairings, which may have a significant impact on static longitudinal and directional stability, were observed. The results support previous research which showed that the greatest reduction in model drag is achieved if the hub and pylon fairings are integrated with minimum gap between the two.

  9. Full-Scale Crash Test and Finite Element Simulation of a Composite Prototype Helicopter

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.; Boitnott, Richard L.; Lyle, Karen H.

    2003-01-01

    A full-scale crash test of a prototype composite helicopter was performed at the Impact Dynamics Research Facility at NASA Langley Research Center in 1999 to obtain data for validation of a finite element crash simulation. The helicopter was the flight test article built by Sikorsky Aircraft during the Advanced Composite Airframe Program (ACAP). The composite helicopter was designed to meet the stringent Military Standard (MIL-STD-1290A) crashworthiness criteria and was outfitted with two crew and two troop seats and four anthropomorphic dummies. The test was performed at 38-ft/s vertical and 32.5-ft/s horizontal velocity onto a rigid surface. An existing modal-vibration model of the Sikorsky ACAP helicopter was converted into a model suitable for crash simulation. A two-stage modeling approach was implemented and an external user-defined subroutine was developed to represent the complex landing gear response. The crash simulation was executed with a nonlinear, explicit transient dynamic finite element code. Predictions of structural deformation and failure, the sequence of events, and the dynamic response of the airframe structure were generated and the numerical results were correlated with the experimental data to validate the simulation. The test results, the model development, and the test-analysis correlation are described.

  10. The Helicopter Antenna Radiation Prediction Code (HARP)

    NASA Technical Reports Server (NTRS)

    Klevenow, F. T.; Lynch, B. G.; Newman, E. H.; Rojas, R. G.; Scheick, J. T.; Shamansky, H. T.; Sze, K. Y.

    1990-01-01

    The first nine months effort in the development of a user oriented computer code, referred to as the HARP code, for analyzing the radiation from helicopter antennas is described. The HARP code uses modern computer graphics to aid in the description and display of the helicopter geometry. At low frequencies the helicopter is modeled by polygonal plates, and the method of moments is used to compute the desired patterns. At high frequencies the helicopter is modeled by a composite ellipsoid and flat plates, and computations are made using the geometrical theory of diffraction. The HARP code will provide a user friendly interface, employing modern computer graphics, to aid the user to describe the helicopter geometry, select the method of computation, construct the desired high or low frequency model, and display the results.

  11. 75 FR 56858 - Exclusions From Gross Income of Foreign Corporations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ... foreign corporations from the international operation of ships or aircraft. The final regulations adopt... determine if it is eligible to exclude its income from the international operation of ships or aircraft from... to exclude from gross income certain income from the international operation of ships or...

  12. The Development of the CONDUIT Advanced Control System Design and Evaluation Interface with a Case Study Application to an Advanced Fly by Wire Helicopter Design

    NASA Technical Reports Server (NTRS)

    Colbourne, Jason

    1999-01-01

    This report details the development and use of CONDUIT (Control Designer's Unified Interface). CONDUIT is a design tool created at Ames Research Center for the purpose of evaluating and optimizing aircraft control systems against handling qualities. Three detailed design problems addressing the RASCAL UH-60A Black Hawk are included in this report to show the application of CONDUIT to helicopter control system design.

  13. Effects of aircraft noise on human activities

    NASA Technical Reports Server (NTRS)

    Arnoult, M. D.; Gilfillan, L. G.

    1983-01-01

    The effects of aircrft noise on human activities was investigated by developing a battery of tasks (1) representative of a range of human activities and (2) sensitive to the disruptive effects of noise. The noise used were recordings of jet aircraft and helicopter sounds at three lvels of loudness--60, 70, and 80 dB(A). Experiment 1 investigated 12 different cognitive tasks, along with two intelligibility tasks included to validate that the noises were being effective. Interference with intelligibility was essentially the same as found in the research literature, but only inconsistent effects were found on either accuracy or latency of performance on the cognitive tasks. When the tasks were grouped into four categories (Intelligibility, Matching, Verbal, and Arithmetic), reliable differences in rated annoyingness of the noises were related to the task category and to the type of noise (jet or helicopter).

  14. Gulf of Mexico Helicopter Offshore System Technologies Recommended Development Path

    NASA Technical Reports Server (NTRS)

    Koenke, Edmund J.; Williams, Larry; Calafa, Caesar

    1999-01-01

    The National Aeronautics and Space Administration (NASA) Advanced Air Transportation Technologies (AATT) project in cooperation with the Department of Transportation (DOT) Volpe National Transportation Systems Center (VNTSC) contracted with the System Resources Corporation (SRC) for the evaluation of the existing environment and the identification of user and service provider needs in the Gulf of Mexico low-altitude Offshore Sector. The results of this contractor activity are reported in the Gulf of Mexico Helicopter Offshore System Technologies Engineering Needs Assessment. A recommended system design and transition strategy was then developed to satisfy the identified needs within the constraints of the environment. This work, also performed under contract to NASA, is the subject of this report.

  15. An evaluation of helicopter noise and vibration ride qualities criteria

    NASA Technical Reports Server (NTRS)

    Hammond, C. E.; Hollenbaugh, D. D.; Clevenson, S. A.; Leatherwood, J. D.

    1981-01-01

    Two methods of quantifying helicopter ride quality; absorbed power for vibration only and the NASA ride comfort model for both noise and vibration are discussed. Noise and vibration measurements were obtained on five operational US Army helicopters. The data were converted to both absorbed power and DISC's (discomfort units used in the NASA model) for specific helicopter flight conditions. Both models indicate considerable variation in ride quality between the five helicopters and between flight conditions within each helicopter.

  16. The impact of urban operations on helicopter noise requirements

    NASA Technical Reports Server (NTRS)

    Spector, S. R.

    1978-01-01

    The interrelationship of urban helicopter operations, helicopter noise, and the establishment of urban public-use heliports is discussed. Public resistance to urban helicopter operations due to concern for safety and noise is shown to negatively impact the establishment of public-use heliports in urban centers. It is indicated that increased government and industry effort to reduce helicopter noise is needed to ensure continued growth in the helicopter industry.

  17. Injury in U.S. Army helicopter crashes October 1979-September 1985.

    PubMed

    Shanahan, D F; Shanahan, M O

    1989-04-01

    All U.S. Army class A and B mishaps of four types of helicopters occurring from 1 October 1979 through 30 September 1985 were reviewed. During this 6-year period, there were 298 crashes involving 303 aircraft. There were 1,060 individuals aboard the crashed aircraft and 611 were injured, 136 fatally. The most common cause of injury was the "secondary impact" caused by collapse of structure into occupied areas, by inadequate restraint of the occupants which allowed them to flail into structure, or by a combination of both mechanisms. Injury solely related to acceleration occurred infrequently. The most frequently injured body regions in survivable crashes were the head (28%) and extremities (43%). Injury patterns are compared for different helicopter types and related to differences in design. Basic principles of crash injury protection, including individual protection by helmets, seatbelts, and airbags, and structural modifications to minimize injury potential, as well as crashworthy fuel systems, are reviewed, and recommendations are made to increase the crashworthiness of helicopters, such as adapting designs and standards on the basis of active field investigations.

  18. Helicopter flight control compensator design

    NASA Astrophysics Data System (ADS)

    Yaici, Malika; Hariche, Kamel; Clarke, Tim

    2017-01-01

    In a precedent paper a design process is described to achieve eigenstructure assignment using block poles. Systems described in state space equations are transformed to systems in matrix fractions description (MFD) and its desired eigenstructure is transformed to a desired latent structure, which is used to construct desired block poles. In this paper, the proposed design method is applied for attitude stabilization of a Lynx helicopter in hover. An input-output feedback configuration has been chosen for more generality, and to validate the results the output responses are compared to state and output feedback control responses.

  19. Special opportunities in helicopter aerodynamics

    NASA Technical Reports Server (NTRS)

    Mccroskey, W. J.

    1983-01-01

    Aerodynamic research relating to modern helicopters includes the study of three dimensional, unsteady, nonlinear flow fields. A selective review is made of some of the phenomenon that hamper the development of satisfactory engineering prediction techniques, but which provides a rich source of research opportunities: flow separations, compressibility effects, complex vortical wakes, and aerodynamic interference between components. Several examples of work in progress are given, including dynamic stall alleviation, the development of computational methods for transonic flow, rotor-wake predictions, and blade-vortex interactions.

  20. Advanced helicopter cockpit and control configurations for helicopter combat missions

    NASA Technical Reports Server (NTRS)

    Haworth, Loran A.; Atencio, Adolph, Jr.; Bivens, Courtland; Shively, Robert; Delgado, Daniel

    1987-01-01

    Two piloted simulations were conducted by the U.S. Army Aeroflightdynamics Directorate to evaluate workload and helicopter-handling qualities requirements for single pilot operation in a combat Nap-of-the-Earth environment. The single-pilot advanced cockpit engineering simulation (SPACES) investigations were performed on the NASA Ames Vertical Motion Simulator, using the Advanced Digital Optical Control System control laws and an advanced concepts glass cockpit. The first simulation (SPACES I) compared single pilot to dual crewmember operation for the same flight tasks to determine differences between dual and single ratings, and to discover which control laws enabled adequate single-pilot helicopter operation. The SPACES II simulation concentrated on single-pilot operations and use of control laws thought to be viable candidates for single pilot operations workload. Measures detected significant differences between single-pilot task segments. Control system configurations were task dependent, demonstrating a need for inflight reconfigurable control system to match the optimal control system with the required task.

  1. Wind tunnel investigation of helicopter-rotor wake effects on three helicopter fuselage models

    NASA Technical Reports Server (NTRS)

    Wilson, J. C.; Mineck, R. E.

    1975-01-01

    The effects of rotor wake on helicopter fuselage aerodynamic characteristics were investigated in the Langley V/STOL tunnel. Force, moment, and pressure data were obtained on three fuselage models at various combinations of windspeed, sideslip angle, and pitch angle. The data show that the influence of rotor wake on the helicopter fuselage yawing moment imposes a significant additional thrust requirement on the tail rotor of a single-rotor helicopter at high sideslip angles.

  2. A vibration monitoring acquisition and diagnostic system for helicopter drive train bench tests

    NASA Astrophysics Data System (ADS)

    Dousis, Dimitri A.

    An automated drive train test stand vibration monitoring system called VMADS has been developed by Bell Helicopter Textron, Inc., and has been installed at Bell's transmission bench test facility. VMADS provides the operator with warning and alarm indications for preselected degraded conditions, and acquires vibration data to be used by engineers to improve the diagnostics for better fault detection and fault isolation. VMADS is used as a test bed for new monitoring and diagnostic algorithm evaluation and validation, a necessary step to ensure development of accurate, reliable integrated health usage monitoring systems for the Bell rotorcraft fleet. This paper highlights the VMADS features for helicopter and tiltrotor aircraft drive train bench test monitoring and diagnostics and discusses supportive ongoing health and usage monitoring activities at BHTI, both military and commercial for enhanced safety and reduced maintenance costs. Bell is translating VMADS developed capability to airborne applications, while simultaneously enhancing the original VMADS capabilities.

  3. Flight Control Development for the ARH-70 Armed Reconnaissance Helicopter Program

    NASA Technical Reports Server (NTRS)

    Christensen, Kevin T.; Campbell, Kip G.; Griffith, Carl D.; Ivler, Christina M.; Tischler, Mark B.; Harding, Jeffrey W.

    2008-01-01

    In July 2005, Bell Helicopter won the U.S. Army's Armed Reconnaissance Helicopter competition to produce a replacement for the OH-58 Kiowa Warrior capable of performing the armed reconnaissance mission. To meet the U.S. Army requirement that the ARH-70A have Level 1 handling qualities for the scout rotorcraft mission task elements defined by ADS-33E-PRF, Bell equipped the aircraft with their generic automatic flight control system (AFCS). Under the constraints of the tight ARH-70A schedule, the development team used modem parameter identification and control law optimization techniques to optimize the AFCS gains to simultaneously meet multiple handling qualities design criteria. This paper will show how linear modeling, control law optimization, and simulation have been used to produce a Level 1 scout rotorcraft for the U.S. Army, while minimizing the amount of flight testing required for AFCS development and handling qualities evaluation of the ARH-70A.

  4. Analytical methodology for determination of helicopter IFR precision approach requirements. [pilot workload and acceptance level

    NASA Technical Reports Server (NTRS)

    Phatak, A. V.

    1980-01-01

    A systematic analytical approach to the determination of helicopter IFR precision approach requirements is formulated. The approach is based upon the hypothesis that pilot acceptance level or opinion rating of a given system is inversely related to the degree of pilot involvement in the control task. A nonlinear simulation of the helicopter approach to landing task incorporating appropriate models for UH-1H aircraft, the environmental disturbances and the human pilot was developed as a tool for evaluating the pilot acceptance hypothesis. The simulated pilot model is generic in nature and includes analytical representation of the human information acquisition, processing, and control strategies. Simulation analyses in the flight director mode indicate that the pilot model used is reasonable. Results of the simulation are used to identify candidate pilot workload metrics and to test the well known performance-work-load relationship. A pilot acceptance analytical methodology is formulated as a basis for further investigation, development and validation.

  5. Deflection Shape Reconstructions of a Rotating Five-blade Helicopter Rotor from TLDV Measurements

    NASA Astrophysics Data System (ADS)

    Fioretti, A.; Di Maio, D.; Ewins, D. J.; Castellini, P.; Tomasini, E. P.

    2010-05-01

    Helicopters are aircraft machines which are subjected to high level of vibrations, mainly due to spinning rotors. These are made of two or more blades attached by hinges to a central hub, which can make the dynamic behaviour difficult to study. However, they share some common dynamic properties with the ones expected in bladed discs, thereby the analytical modelling of rotors can be performed using some assumptions as the ones adopted for the bladed discs. This paper presents results of a vibrations study performed on a scaled helicopter rotor model which was rotating at a fix rotational speed and excited by an air jet. A simplified analytical model of that rotor was also produced to help the identifications of the vibration patterns measured using a single point tracking-SLDV measurement method.

  6. Development of circumferential seal for helicopter transmissions: Results of bench and flight tests

    NASA Technical Reports Server (NTRS)

    Strom, T. N.; Ludwig, L. P.

    1975-01-01

    A modified circumferential segmented ring seal was designed for direct replacement of a helicopter transmission elastomeric lip seal operating on a shaft diameter of 13.91 centimeters (5.481 in.) at sliding velocities to 52.48 m/sec (10 330 ft/min). The modifications involved the garter spring tension, shaft roundness, seal housing flatness, and pumping grooves to inhibit leakage. Operation of the seals in bench tests under simulated helicopter transmission conditions revealed that the seal leakage rate was within acceptable limits and that the wear rate was negligible. The low leakage and wear rates were confirmed in flight tests of 600 and 175 hours (sliding speed, 48.11 m/sec (9470 ft/min)). An additional 200 hours of air worthiness qualification testing (aircraft tie down) demonstrated that the seal can operate at the advanced sliding conditions of 52.48 m/sec (10 330 ft/min).

  7. The effect of variations in controls and displays on helicopter instrument approach capability

    NASA Technical Reports Server (NTRS)

    Niessen, F. R.; Kelly, J. R.; Garren, J. F., Jr.; Yenni, K. R.; Person, L. H., Jr.

    1977-01-01

    A flight investigation was conducted with a variable stability helicopter to determine the effects of variations in controls and displays on helicopter instrument approach capabilities. The baseline instrument approach task was a decelerating approach to a hover along a 6 deg glide slope. Pilot evaluations were obtained for both the constant speed part of the task and the deceleration and hover part of the task. The attitude stability augmentation system (SAS) was strongly preferred over the rate SAS because the aircraft had a divergent pitch response. From a display variation standpoint, it was not possible to decelerate to a hover in a consistent manner, regardless of the control system employed, with situation information only. In particular, the deceleration and hover part of the task was unacceptable without flight director command information.

  8. Aircraft Design

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  9. Procedures for the use of aircraft in wildlife biotelemetry studies

    USGS Publications Warehouse

    Gilmer, David S.; Cowardin, Lewis M.; Duval, Renee L.; Mechlin, Larry M.; Shaiffer, Charles W.; Kuechle, V.B.

    1981-01-01

    This is a report on the state of the art methodology and on questions that arise while one is preparing to use aircraft in a biotelemetry study. In general the first step in preparing to mount an antenna on an aircraft is to consult with a certified aircraft mechanic. Aircraft certification is discussed to provide background information concerning the role of the Federal Aviation Administration (FAA) in regulating the use of biotelemetry antennas on aircraft. However, approval of any specific design of antenna mount rests with local FAA authority. Airplane and helicopter antenna attachments are described. Performance of the receiving antenna system is discussed with emphasis on how variables as aircraft type and antenna configuration may influence reception. The side-looking vs. front-looking antenna configuration and the VHF vs. HF frequency band are generally recommended for most aerial tracking studies. Characteristics of receivers, transmitters, and antennas that might influence tracking are discussed. Specific topics such as calibration of receivers and transmitter quality control are considered. Suggestions in preparing for and conducting tracking flights that will improve overall efficiency and safety are presented. Search techniques, including procedures for conducting large and specific area surveys as well as methods to improve and evaluate search efficiency, are discussed. A concluding section considers special topics such as low-level operations and the use of helicopters. Diagrams of antenna mounts, equipment check-off lists, and antenna test procedures are included as appendices.

  10. Flight tests with enhanced/synthetic vision system for rescue helicopter

    NASA Astrophysics Data System (ADS)

    Tsuda, Hiroka; Funabiki, Kohei; Iijima, Tomoko; Tawada, Kazuho; Yoshida, Takashi

    2011-06-01

    JAXA (Japan Aerospace Exploration Agency) has been conducting a research project named SAVERH (Situation Awareness and Visual Enhancer for Rescue Helicopter) with Shimadzu Corporation and NEC from 2008. SAVERH aims at inventing a method of presenting suitable information to the pilot to support search and rescue missions. An integrated system comprising an HMD (Helmet-Mounted Display) and a FLIR (Forward Looking Infrared) sensor were installed in a JAXA research helicopter, and a series of flight tests was conducted to evaluate the benefit of presenting FLIR images on the HMD in night flight. Three pilots evaluated the display system during six night flights, considering terrain and position awareness. The tests showed that use of FLIR gave better route tracking performance, and the effectiveness of head-slaved FLIR on an approach task was shown by subjective pilot rating.

  11. What's Cookin' With Helicopter Microwave Landing Systems?

    NASA Technical Reports Server (NTRS)

    Taylor, Richard L.

    1980-01-01

    This article describes a joint effort of the FAA, NASA and the Helicopter Industry to establish a data base for (Microwave Landing Systems) MLS approaches, and to aid the FAA in developing the MLS Terminal Instrument Procedures (TERPS) criteria for rotary-wing IFR operations. The latter is of particular importance for it appears to signal sincere official interest in filling in the blanks in Chapter 11 of TERPS -- that portion set aside for helicopter IFR operations and recognition of the unique capabilities of the helicopter in the instrument environment. One of the program objectives is to find out what a sample of pilots can do with the MLS in a minimum machine.

  12. The Duke University Helicopter Observation Platform (HOP) for Environmental and Earth Science Studies

    NASA Astrophysics Data System (ADS)

    Avissar, R.; Holder, H. E.; Bolch, A.

    2006-12-01

    Duke University purchased a new Bell 206B3 ("JetRanger") helicopter to perform various atmospheric in situ and remotely-sensed environmental observations (referred to as the Helicopter Observation Platform HOP). As compared to other aircraft, the helicopter has the unequaled flexibility and maneuverability to fly slowly and close to the ground. Furthermore, it can land and refuel at station, which allows performing long-term observations during field campaigns. It can also operate from a ship at sea. This presents significant advantages especially for the observations of aerosols, fluxes of heat, water and other gases important for various environmental and Earth science studies. The Duke HOP is currently equipped with high-frequency sensors that can measure the 3D components of the wind, temperature, moisture and CO2. It is also equipped with an inlet to sample undisturbed air outside of the zone of influence of the main rotor wake and it is designed to support many other remote and in-situ sensors. A computational fluid dynamics (CFD) software was used to simulate the aerodynamical envelope of the HOP in flight at various airspeeds. Together with in- situ observations of turbulence in front of the helicopter nose where all the sensors are attached, the CFD results are used to demonstrate that the HOP can make high-quality observations of the above-mentioned environmental characteristics unaffected by the main-rotor wake at airspeeds as low as 15 m/s and as high as 60 m/s. This emphasizes the strong potential of this platform for environmental observations, especially of aerosols, which are sampled very inefficiently with other aircraft platforms. Flights conducted in the Neuse River Basin in North Carolina where atmospheric variables were collected simultaneously with a tethered sonde, a lidar, and on towers demonstrate the HOP capability and potential.

  13. Design of fault tolerant control system for individual blade control helicopters

    NASA Astrophysics Data System (ADS)

    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

  14. Aircraft Hydraulic Systems Dynamic Analysis

    DTIC Science & Technology

    1977-10-01

    technical report has been reviewed and is approved for publication. Project Engineer 0 Acting Technical Area Manager FOR THE COMMANDER STEPHEN P...by the McDonnell Aircraft Company, Design Engineering Power and Fluid Subsystem Department, McDonnell Douglas Corporation under contract F33615-74-C...34 (Pennsylvania State University Graduate School of Mechanical Engineering , June 1970), gave predicted variation in the fluid velocity at three different

  15. Helicopter vibration reduction using steady fixed-system auxiliary moments and forces

    NASA Astrophysics Data System (ADS)

    Sekula, Martin Krystian

    An aeroelastic analysis was developed to examine the vibration reduction ability of steady auxiliary forces and moments applied to a helicopter fuselage. The blade dynamics were modeled using coupled flap-lag-torsion equations of motion, with elastic blade deformations incorporated into the analysis using finite elements. The quasi-steady stall, post-stall, and compressibility effects were captured using a table lookup routine. The equations of equilibrium were modified to include steady force and moment terms that model auxiliary lifting, propulsive, and moment generating devices. Using this methodology, the effect of lift and thrust compounding on hub vibration was examined for a BO-105 type helicopter flying at an advance ratio of 0.35. Auxiliary lift combined with auxiliary thrust greater than the vehicle drag produced over 90 percent reductions in the 4/rev hub load components, significantly affected trim, and decreased rotor power by placing the rotor in a near autorotative state. Effects of auxiliary moments on rotor vibration were examined for UH-60 and BO-105 type helicopters flying at advance ratios of 0.25 and 0.35, respectively. Roll-right, nose-down auxiliary moments reduced all components of rotor vibration of the UH-60 type helicopter by 15 to 60 percent as well as significantly decreased the rotor power. Roll-left, nose-down auxiliary moments reduced the in-plane vibratory forces of the BO-105 type helicopter by 90 percent, with small increases in the remaining loads. The horizontal tails of both aircraft were modified to generate auxiliary pitching and rolling moments through independently controllable incidence angles of either half of the horizontal tail. Smaller vibration reductions were seen due to limited pitch and roll authority resulting from the onset of stall on the horizontal tail. Both aircraft experienced an 8 to 9 percent reduction in rotor power as well as a decrease in rotor thrust resulting from a horizontal tail upload necessary to

  16. Maintenance cost study of rotary wing aircraft, phase 2

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The Navy's maintenance and materials management data base was used in a study to determine the feasibility of predicting unscheduled maintenance costs for the dynamic systems of military rotary wing aircraft. The major operational and design variables were identified and the direct maintenance man hours per flight hour were obtained by step-wise multiple regression analysis. Five nonmilitary helicopter users were contacted to supply data on which variables were important factors in civil applications. These uses included offshore oil exploration and support, police and fire department rescue and enforcement, logging and heavy equipment movement, and U.S. Army military operations. The equations developed were highly effective in predicting unscheduled direct maintenance man hours per flying hours for military aircraft, but less effective for commercial or public service helicopters, probably because of the longer mission durations and the much higher utilization of civil users.

  17. Census of U.S. Civil Aircraft. Calendar Year 1981.

    DTIC Science & Technology

    1981-12-31

    61 1 0 1 1 8-8MG 1 61 1 0 1 1 ROTOR REC ENGINE 61 0 4 4 TOTAL 0 4 4 BOEING V.-COLUMBIA HELICOPTERS 107-11 20 63 2 0 2 2 CH -21C 21 61 1 0 1 1 107-11 20...11NFACTURER AIR GENERAL TOTAL MODEL PL A/E N/E CARRIER AVIATION AIRCRAFT PITCAIRN ROTOR REC ENGINE 61 0 2 2 TOTAL 0 2 2 ROSINSON HELICOPTER COMPANY R22 2 61...MANUFACTURER AIR GENERAL TOTAL MODEL PL A/E N/E CARRIER AVIATION AIRCRAFT CH 2 41 1 0 1 1 CH -I 2 41 1 0 1 1 CHALLENGE 2 41 1 0 1 1 CHALLIS CHAFFINCH 1

  18. Optimization in fractional aircraft ownership

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

  19. Transonic Aeroelasticity Analysis For Helicopter Rotor Blade

    NASA Technical Reports Server (NTRS)

    Chang, I-Chung; Gea, Lie-Mine; Chow, Chuen-Yen

    1991-01-01

    Numerical-simulation method for aeroelasticity analysis of helicopter rotor blade combines established techniques for analysis of aerodynamics and vibrations of blade. Application of method clearly shows elasticity of blade modifies flow and, consequently, aerodynamic loads on blade.

  20. Small crack test program for helicopter materials

    NASA Technical Reports Server (NTRS)

    Annigeri, Bal; Schneider, George

    1994-01-01

    Crack propagation tests were conducted to determine crack growth behavior in five helicopter materials for surface cracks between 0.005 to 0.020 inches in depth. Constant amplitude tests were conducted at stress ratios R equals 0.1 and 0.5, and emphasis was placed on near threshold data (i.e., 10-8 to 10-6 inches/cycle). Spectrum tests were conducted using a helicopter spectrum. The test specimen was an unnotched tension specimen, and cracks were initiated from a small EDM notch. An optical/video system was used to monitor crack growth. The material for the test specimens was obtained from helicopter part forgings. Testing was conducted at stresses below yield to reflect actual stresses in helicopter parts.

  1. 14 CFR 93.103 - Helicopter operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Orient Point, shall utilize the North Shore Helicopter route and altitude, as published. (b) Pilots may deviate from the route and altitude requirements of paragraph (a) of this section when necessary...

  2. 14 CFR 93.103 - Helicopter operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Orient Point, shall utilize the North Shore Helicopter route and altitude, as published. (b) Pilots may deviate from the route and altitude requirements of paragraph (a) of this section when necessary...

  3. Numerical analysis of the first static calibration of the RSRA helicopter active-isolator rotor balance system

    NASA Technical Reports Server (NTRS)

    Acree, C. W., Jr.

    1985-01-01

    The helicopter version of the Rotor Systems Research Aircraft (RSRA) is designed to make simultaneous measurements of all rotor forces and moments in a manner analogous to a wind-tunnel balance. Loads are measured by a combination of load cells, strain gages, and hydropneumatic active isolators with built-in pressure gages. Complete evaluation of system performance requires calibration of the rotor force- and moment-measurement system when installed in the aircraft. Derivations of calibration corrections for various combinations of calibration data are discussed.

  4. Study of aircraft in intraurban transportation systems, volume 3

    NASA Technical Reports Server (NTRS)

    Stout, E. G.; Kesling, P. H.; Matteson, D. E.; Sherwood, D. E.; Tuck, W. R., Jr.; Vaughn, L. A.

    1971-01-01

    An investigation of three aircraft concepts, deflected slipstream STOL, helicopter VTOL, and fixed wing STOL, is presented. An attempt was made to determine the best concept for the intraurban transportation system. Desirability of the concept was based on ease of maintenance, development timing, reliability, operating costs, and the noise produced. Indications are that the deflected slipstream STOL is best suited for intraurban transportation. Tables and graphs are included.

  5. Civil helicopter design and operational requirement

    NASA Technical Reports Server (NTRS)

    Waters, K. T.

    1978-01-01

    Design and operational requirements and other factors that have a restraining influence on expansion of the helicopter market are discussed. The needs of operators, users, pilots and the community at large are examined. The impact of future technology developments and other trends such as use, energy shortages, and civil and military helicopter requirements and development is assessed. Areas where research and development are needed to provide opportunities for lowering life cycle costs and removing barriers to further expansion of the industry are analyzed.

  6. The effective acoustic environment of helicopter crewmen

    NASA Technical Reports Server (NTRS)

    Camp, R. T., Jr.; Mozo, B. T.

    1978-01-01

    Methods of measuring the composite acoustic environment of helicopters in order to quantify the effective acoustic environment of the crewmen and to assess the real acoustic hazards of the personnel are examined. It is indicated that the attenuation characteristics of the helmets and hearing protectors and the variables of the physiology of the human ear be accounted for in determining the effective acoustic environment of Army helicopter crewmen as well as the acoustic hazards of voice communications systems noise.

  7. Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Founded by former Ames Research Center engineer Jim Van Horn, Van Horn Aviation of Tempe, Arizona, built upon a Langley Research Center airfoil design to create a high performance aftermarket tail rotor for the popular Bell 206 helicopter. The highly durable rotor has a lifetime twice that of the original equipment manufacturer blade, reduces noise by 40 percent, and displays enhanced performance at high altitudes. These improvements benefit helicopter performance for law enforcement, military training, wildfire and pipeline patrols, and emergency medical services.

  8. The Evolution of the Advanced Attack Helicopter

    DTIC Science & Technology

    1975-06-06

    engineering laboratory at McCook Field, Dayton, Ohio. The first helicopter which appears to have been evaluated was th. Peter Cooper Hewitt design...through five decades to an evaluation of the Peter Cooper Hewitt design in 1918. The first helicopter contracted for by the military was the 199 200 de...used counter-rotating rotors, control vanes below, 24-hp Antoinette engine, two 20 foot rotors. On 13 Nov lifted inventor and two passen- gers, a

  9. Helicopter Performance Evaluation (HELPE) Computer Model

    DTIC Science & Technology

    1994-07-01

    questions : * For a given helicopter at given flight conditions and specified mission weight, how fast can the helicopter cruise in level flight...possible level speed its maneuverability in a turn, and its hover and climb capabilities in the in-ground and out-of-ground effects modes. The code... levels , and mappings ..... 2 2. Available engine power output as a function of altitude "h".................... 8 3. Schematic drawing of the thrust

  10. Commercial Aircraft Airframe Fuel Systems Survey and Analysis.

    DTIC Science & Technology

    1982-02-01

    Fairchild Swearingen Corporation Pratt & Whitney Aircraft of Canada Ltd. P.O. Box 894 Box 10 San Antonio, Texas 78284 Longueuil , Quebec J4K 4X9 Mr...Antimisting Fuel Engineering and Development Plan, FAA-ED-18-4. The objective was to study the fuel systems of a representative sample of commercial aircraft

  11. 14 CFR 61.165 - Additional aircraft category and class ratings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: PILOTS, FLIGHT INSTRUCTORS, AND GROUND INSTRUCTORS Airline Transport Pilots § 61.165 Additional aircraft category and class ratings. (a) Rotorcraft category and helicopter class rating. A person applying for an airline transport certificate with a rotorcraft...

  12. NASA/Army Rotorcraft Technology. Volume 3: Systems Integration, Research Aircraft, and Industry

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This is part 3 of the conference proceedings on rotorcraft technology. This volume is divided into areas on systems integration, research aircraft, and industry. Representative titles from each area are: system analysis in rotorcraft design, the past decade; rotorcraft flight research with emphasis on rotor systems; and an overview of key technology thrusts at Bell Helicopter Textron.

  13. Computer aiding for low-altitude helicopter flight

    NASA Technical Reports Server (NTRS)

    Swenson, Harry N.

    1991-01-01

    A computer-aiding concept for low-altitude helicopter flight was developed and evaluated in a real-time piloted simulation. The concept included an optimal control trajectory-generated algorithm based on dynamic programming, and a head-up display (HUD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor symbol. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and advanced navigation information to determine a trajectory between mission waypoints that minimizes threat exposure by seeking valleys. The pilot evaluation was conducted at NASA Ames Research Center's Sim Lab facility in both the fixed-base Interchangeable Cab (ICAB) simulator and the moving-base Vertical Motion Simulator (VMS) by pilots representing NASA, the U.S. Army, and the U.S. Air Force. The pilots manually tracked the trajectory generated by the algorithm utilizing the HUD symbology. They were able to satisfactorily perform the tracking tasks while maintaining a high degree of awareness of the outside world.

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

    PubMed

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  17. Corporate manslaughter.

    PubMed

    Berry, Christopher

    2006-01-01

    The Government published its long-awaited draft Bill on the creation of a new criminal offence of corporate manslaughter shortly before the May 2005 general election. The Bill was included in the Queen's Speech after the general election and, with a Labour government back in power, the new offence could be on to the statute book as early as 2006. The Home Affairs Committee and the Work and Pensions Committee announced ajoint inquiry to consider and report on the Bill. This is expected to be completed by the end of 2005. Pressure for reform of the law relating to manslaughter and corporate killing arose out of a series of high profile fatal accidents, including several rail crashes. There has been said to be an increasing concern amongst the public that companies and organisations are not being held sufficiently accountable for deaths caused by their criminal negligence. The author acted in the first of the major cases, representing the directors accused of manslaughter following the Herald of Free Enterprise capsize disaster in 1987.

  18. 77 FR 23388 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... helicopters with certain main rotor blades installed to reduce the life limit of those blades. This AD is... rotor blade failed because of fatigue cracking. These actions are intended to prevent failure of the main rotor blade and subsequent loss of control of the helicopter. DATES: This AD becomes effective...

  19. 78 FR 56148 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ... Textron Canada Limited (Bell) Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... service information identified in this AD, contact Bell Helicopter Textron Canada Limited, 12,800 Rue de l...-2009-32, dated July 24, 2009, issued by Transport Canada Civil Aviation (TCCA), which is the...

  20. 78 FR 54751 - Airworthiness Directives; Bell Helicopter Textron Canada Inc. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ...-17576; AD 2013-18-03] RIN 2120-AA64 Airworthiness Directives; Bell Helicopter Textron Canada Inc... new airworthiness directive (AD) for certain Bell Helicopter Textron Canada Inc. (BHT) Model 206A... Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J1R4; telephone (450) 437-2862 or...

  1. Analysis of helicopter noise data using international helicopter noise certification procedures

    NASA Astrophysics Data System (ADS)

    Newman, J. S.; Rickley, E. J.; Levanduski, D. A.; Woolridge, S. B.

    1986-03-01

    The results of a Federal Aviation Administration (FAA) noise measurement flight test program involving seven helicopters are documented. Noise levels were established using the basic testing, reduction and analysis techniques specified by the International Civil Aviation Organization (ICAO) for helicopter noise certification, supplemented with some procedural refinements contained in ICAO Working Group II recommendations for incorporation into the standard.

  2. Instrument Approach Aids for Helicopters.

    DTIC Science & Technology

    1982-07-01

    Me 3.9 "HELICOPTER ONLY" CRITERIA 3-27 h3-30 3.9.1 Procedure Limitations 3-30 3.9.2 Point in Space Concept 3-30 3.9.3 Descent Gradients 3-30 3.9.4...601-800 ft 3/4 mile 801 ft and up 1 mile * Point in space procedures HAS Visibility Minimum 250-800 ft 3/4 mile 801 ft and up 1 mile 1.3 ESTABLISHED...procedures. In the analysis of visibility data most procedures were able to achieve 1/2 mile minimums. A few, primarily the RNAV Point in Space

  3. Flight test of a low-altitude helicopter guidance system with obstacle avoidance capability

    NASA Technical Reports Server (NTRS)

    Zelenka, Richard E.; Clark, Raymond F.; Branigan, Robert G.

    1995-01-01

    Military aircraft regularly conduct missions that include low-atltitude, near-terrain flight in order to increase covertness and payload effectiveness. Civilian applications include airborne fire fighting, police surveillance, search and rescue, and helicopter emergency medical service. Several fixed-wing aircraft now employ terrain elevation maps and forward-pointed radars to achieve automated terrain following or terrain avoidance flight. Similar systems specialized to helicopters and their flight regime have not received as much attention. A helicopter guidance system relying on digitized terrain elevation maps has been developed that employs airborne navigation, mission requirements, aircraft performance limits, and radar altimeter returns to generate a valley-seeking, low-altitude trajectory between waypoints. The guidance trajectory is symbolically presented to the pilot on a helmet mounted display. This system has been flight tested to 150 ft (45.7 m) above ground level altitude at 80 kts, and is primarily limited by the ability of the pilot to perform manual detection and avoidance of unmapped hazards. In this study, a wide field of view laser radar sensor has been incorporated into this guidance system to assist the pilot in obstacle detection and avoidance, while expanding the system's operational flight envelope. The results from early flight tests of this system are presented. Low-altitude missions to 100 ft (30.5 m) altitude at 80n kts in the presence of unmapped natural and man-made obstacles were demonstrated while the pilot maintained situational awareness and tracking of the guidance trajectory. Further reductions in altitude are expected with continued flight testing.

  4. Aircraft Steels

    DTIC Science & Technology

    2009-02-19

    NAWCADPAX/TR-2009/ 12 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders 19 February 2009...MARYLAND NAWCADPAX/TR-2009/ 12 19 February 2009 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders...Prescribed by ANSI Std. Z39-18 NAWCADPAX/TR-2009/ 12 ii SUMMARY Five high strength and four stainless steels have been studied, identifying their

  5. Benefits of VTOL aircraft in offshore petroleum logistics support

    NASA Technical Reports Server (NTRS)

    Wilcox, D. E.; Shovlin, M. D.

    1975-01-01

    The mission suitability and potential economic benefits of advanced VTOL aircraft were investigated for logistics support of petroleum operations in the North Sea and the Gulf of Mexico. Concepts such as the tilt rotor and lift/cruise fan are promising for future operations beyond 150 miles offshore, where their high cruise efficiency provides savings in trip time, fuel consumption, and capital investment. Depending upon mission requirements, the aircraft operating costs are reduced by as much as 20 percent to 50 percent from those of current helicopters.

  6. 26 CFR 521.107 - Income from operation of ships or aircraft.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 19 2011-04-01 2010-04-01 true Income from operation of ships or aircraft. 521... of Denmark and of Danish Corporations § 521.107 Income from operation of ships or aircraft. The income derived from the operation of ships or aircraft registered in Denmark by a nonresident alien...

  7. 26 CFR 521.107 - Income from operation of ships or aircraft.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 19 2010-04-01 2010-04-01 false Income from operation of ships or aircraft. 521... of Denmark and of Danish Corporations § 521.107 Income from operation of ships or aircraft. The income derived from the operation of ships or aircraft registered in Denmark by a nonresident alien...

  8. 26 CFR 521.107 - Income from operation of ships or aircraft.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 19 2013-04-01 2010-04-01 true Income from operation of ships or aircraft. 521... of Denmark and of Danish Corporations § 521.107 Income from operation of ships or aircraft. The income derived from the operation of ships or aircraft registered in Denmark by a nonresident alien...

  9. 26 CFR 521.107 - Income from operation of ships or aircraft.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 19 2014-04-01 2010-04-01 true Income from operation of ships or aircraft. 521... of Denmark and of Danish Corporations § 521.107 Income from operation of ships or aircraft. The income derived from the operation of ships or aircraft registered in Denmark by a nonresident alien...

  10. 26 CFR 521.107 - Income from operation of ships or aircraft.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 19 2012-04-01 2010-04-01 true Income from operation of ships or aircraft. 521... of Denmark and of Danish Corporations § 521.107 Income from operation of ships or aircraft. The income derived from the operation of ships or aircraft registered in Denmark by a nonresident alien...

  11. Small Aircraft RF Interference Path Loss

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to better interference risk assessment.

  12. GaAs/Ge Solar Powered Aircraft

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Scheiman, David A.; Brinker, David J.

    1998-01-01

    Unmanned Aerial Vehicles (UAV) are being proposed for many applications for many applications including surveillance, mapping and atmospheric studies. These applications require a lightweight, low speed, medium to long duration aircraft. Due to the weight, speed, and altitude constraints imposed on such an aircraft, solar array generated electric power can be a viable alternative to air-breathing engines for certain missions. Development of such an aircraft is currently being funded under the Environmental Research Aircraft and Sensor Technology (ERAST) program. NASA Lewis Research Center (LeRC) has built a Solar Electric Airplane to demonstrate UAV technology. This aircraft utilizes high efficiency Applied Solar Energy Corporation (ASEC) GaAs/Ge space solar cells. The cells have been provided by the Air Force through the ManTech Office.

  13. Small Aircraft RF Interference Path Loss Measurements

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Szatkowski, George N.; Mielnik, John J.; Salud, Maria Theresa P.

    2007-01-01

    Interference to aircraft radio receivers is an increasing concern as more portable electronic devices are allowed onboard. Interference signals are attenuated as they propagate from inside the cabin to aircraft radio antennas mounted on the outside of the aircraft. The attenuation level is referred to as the interference path loss (IPL) value. Significant published IPL data exists for transport and regional category airplanes. This report fills a void by providing data for small business/corporate and general aviation aircraft. In this effort, IPL measurements are performed on ten small aircraft of different designs and manufacturers. Multiple radio systems are addressed. Along with the typical worst-case coupling values, statistical distributions are also reported that could lead to more meaningful interference risk assessment.

  14. Design, Development, and Evaluation of the Helicopter Sling Load Rapid Aerial Delivery Equipment

    DTIC Science & Technology

    2015-09-01

    is taped to one supplemental suspension sling leg with one turn of paper tape.  After the payload was inspected, the helicopter picked up the payload...i~ ~f L~ad )· ~r ’ ’YVerefuere any problems with hook- up ’ ::, ordrop-offofthe load? ::·-:(If Yes. comment in Comments section...Flight ~haracteristics of Aircraft)_ , - :(FiightGha~act~ri~tics of Load ) ····~---• (were there·;,-;;y· problems with-hook- up

  15. Theory of self-excited mechanical oscillations of helicopter rotors with hinged blades

    NASA Technical Reports Server (NTRS)

    Coleman, Robert P; Feingold, Arnold M

    1958-01-01

    Vibrations of rotary-wing aircraft may derive their energy from the rotation of the rotor rather than from the air forces. A theoretical analysis of these vibrations is described and methods for its application are explained in Chapter one. Chapter two reports the results of an investigation of the mechanical stability of a rotor having two vertically hinged blades mounted upon symmetrical supports, that is, of equal stiffness and mass in all horizontal directions. Chapter three presents the theory of ground vibrations of a two-blade helicopter rotor on anisotropic flexible supports.

  16. Establishment of a Remotely Piloted Helicopter Test Flight Program for Higher Harmonic Control Research

    DTIC Science & Technology

    1990-06-01

    of aircraft grade 7075-T6 acid etched aluminum which has been painted with an anti-corrosion epoxy coating. The forward portion oi the fuselage...to the NiCd battery. 6. Powerplant a. Engine The helicopter is power by the two cylinder, two cycle, air cooled T 77i Super Tartan ® engine seen in...Maximum torque from the engine is 30.35 in. lb. at 7,000 R.P.M. The 27 Installed in RPH Without Propeller Spinner Figure 13. T77i Super Tartan ® Engine

  17. State-of-the-art cockpit design for the HH-65A helicopters

    NASA Technical Reports Server (NTRS)

    Castleberry, D. E.; Mcelreath, M. Y.

    1982-01-01

    In the design of a HH-65A helicopter cockpit, advanced integrated electronics systems technology was employed to achieve several important goals for this multimission aircraft. They were: (1) integrated systems operation with consistent and simplified cockpit procedures; (2) mission-task-related cockpit displays and controls, and (3) reduced pilot instrument scan effort with excellent outside visibility. The integrated avionics system was implemented to depend heavily upon distributed but complementary processing, multiplex digital bus technology, and multifunction CRT controls and displays. This avionics system was completely flight tested and will soon enter operational service with the Coast Guard.

  18. Diagnostic and Condition Monitoring System Assessment for Army Helicopter Modular Turboshaft Engines.

    DTIC Science & Technology

    1980-10-01

    and Condition Monitoring METS Modular Engine Test System MPFI Modular Performance F-4ult Isolation MTBF Mean Time Between Failures MTTR Mean Time to...AO-ACO? 31b GENERAL ELECTRIC CO LYNN MA AIRCRAFT ENGINE GROUP F/G 91/5 DIASNObIC AND CONDITION MONITORING SYSTEM ASSESSMENT FOR ARMY -ETCIU) OCT 80 H...1AIN)Il.A AD A-oft LEV t DIAGNOSTIC £ CONDITION MONITORING SYSTEM ASSESSMENT FOR ARMY HELICOPTER MODULAR TURBOSHAFT ENGINES. Harold J. Jord n General

  19. Civil helicopter wire strike assessment study. Volume 1: Findings and recommendations

    NASA Technical Reports Server (NTRS)

    Tuomela, C. H.; Brennan, M. F.

    1980-01-01

    Approximately 208 civil helicopter wire strike accidents for a ten year period 1970 to 1979 are analyzed. It is found that 83% of the wire strikes occurred during bright clear weather. Analysis of the accidents is organized under pilot, environment, and machine factors. Methods to reduce the wire strike accident rate are discussed, including detection/warning devices, identification of wire locations prior to flight, wire cutting devices, and implementation of training programs. The benefits to be gained by implementing accident avoidance methods are estimated to be fully justified by reduction in injury and death and reduction of aircraft damage and loss.

  20. 77 FR 58973 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-25

    ... ] power supply disruptions while a helicopter is on the ground, causing the landing gear to retract and... power supply disruptions, which caused the landing gear to retract and the helicopter to drop,...

  1. Further Study Of Face Gears For Helicopter Transmissions

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    Document describes theoretical, computational, and experimental studies of feasibility of proposed lightweight, split-torque helicopter transmissions based on face gears. Majority of work also described in prior document "Face Gears for Helicopter Transmissions" (LEW-15840).

  2. Evaluation of an Energy Distribution System for Helicopter Landing Gears During Hard Landing

    DTIC Science & Technology

    1978-11-01

    PlC ATION O F THIS PA6.l.mb Data mIMrOM.1 __p PREFACE This report was prepared by Hughes Helicopters, Division of Summa Corporation, under Contract...one blip on the oscillograph record as 0. 1 inch of drop height. The frequency of blips per unit of time (i. e., 1/ 200 second from 200 cycle AC signal...retrofit quantities of 100, . 200 , and 400 shipsets and with the forward production of 100, 200 , and 500 shipsets. The assumptions used in the analysis are

  3. Aircraft technology opportunities for the 21st Century

    NASA Technical Reports Server (NTRS)

    Albers, James A.; Zuk, John

    1988-01-01

    New aircraft technologies are presented that have the potential to expand the air transportation system and reduce congestion through new operating capabilities, and at the same time provide greater levels of safety and environmental compatibility. Both current and planned civil aeronautics technology at the NASA Ames, Lewis, and Langley Research Centers are addressed. The complete spectrum of current aircraft and new vehicle concepts is considered including rotorcraft (helicopters and tiltrotors), vertical and short takeoff and landing (V/STOL) and short takeoff and landing (STOL) aircraft, subsonic transports, high speed transports, and hypersonic/transatmospheric vehicles. New technologies for current aircraft will improve efficiency, affordability, safety, and environmental compatibility. Research and technology promises to enable development of new vehicles that will revolutionize or greatly change the transportation system. These vehicles will provide new capabilities which will lead to enormous market opportunities and economic growth, as well as improve the competitive position of the U.S. aerospace industry.

  4. A review of the analytical simulation of aircraft crash dynamics

    NASA Technical Reports Server (NTRS)

    Fasanella, Edwin L.; Carden, Huey D.; Boitnott, Richard L.; Hayduk, Robert J.

    1990-01-01

    A large number of full scale tests of general aviation aircraft, helicopters, and one unique air-to-ground controlled impact of a transport aircraft were performed. Additionally, research was also conducted on seat dynamic performance, load-limiting seats, load limiting subfloor designs, and emergency-locator-transmitters (ELTs). Computer programs were developed to provide designers with methods for predicting accelerations, velocities, and displacements of collapsing structure and for estimating the human response to crash loads. The results of full scale aircraft and component tests were used to verify and guide the development of analytical simulation tools and to demonstrate impact load attenuating concepts. Analytical simulation of metal and composite aircraft crash dynamics are addressed. Finite element models are examined to determine their degree of corroboration by experimental data and to reveal deficiencies requiring further development.

  5. Corporate Jet

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Gulfstream Aerospace Corporation, Savannah, GA, used a version of a NASA program called WIBCO to design a wing for the Gulfstream IV (G-IV) which will help to reduce transonic drag (created by shock waves that develop as an airplane approaches the speed of sound). The G-IV cruises at 88 percent of the speed of sound, and holds the international record in its class for round-the-world flight. They also used the STANS5 and Profile programs in the design. They will use the NASA program GASP to help determine the gross weight, range, speed, payload and optimum wing area of an intercontinental supersonic business jet being developed in cooperation with Sukhoi Design Bureau, a Soviet organization.

  6. Lubricant Effects on Efficiency of a Helicopter Transmission.

    DTIC Science & Technology

    1982-01-01

    Research Cen- ter’s 500 hp torque regenerative helicopter transmission test stand. The test transmission was the 01158 helicopter main transmission...cooling systema. This effect adds to increase the payload capacity of the helicopter. The total power loss in a helicopter transmision is a function...friction between Sear teeth . Martin (rof 3) concentrates on the problem of calcmlatiui the losses in the tooth contact. Anderson and Loeventhel (ref 4

  7. MMW radar enhanced vision systems: the Helicopter Autonomous Landing System (HALS) and Radar-Enhanced Vision System (REVS) are rotary and fixed wing enhanced flight vision systems that enable safe flight operations in degraded visual environments

    NASA Astrophysics Data System (ADS)

    Cross, Jack; Schneider, John; Cariani, Pete

    2013-05-01

    Sierra Nevada Corporation (SNC) has developed rotary and fixed wing millimeter wave radar enhanced vision systems. The Helicopter Autonomous Landing System (HALS) is a rotary-wing enhanced vision system that enables multi-ship landing, takeoff, and enroute flight in Degraded Visual Environments (DVE). HALS has been successfully flight tested in a variety of scenarios, from brown-out DVE landings, to enroute flight over mountainous terrain, to wire/cable detection during low-level flight. The Radar Enhanced Vision Systems (REVS) is a fixed-wing Enhanced Flight Vision System (EFVS) undergoing prototype development testing. Both systems are based on a fast-scanning, threedimensional 94 GHz radar that produces real-time terrain and obstacle imagery. The radar imagery is fused with synthetic imagery of the surrounding terrain to form a long-range, wide field-of-view display. A symbology overlay is added to provide aircraft state information and, for HALS, approach and landing command guidance cuing. The combination of see-through imagery and symbology provides the key information a pilot needs to perform safe flight operations in DVE conditions. This paper discusses the HALS and REVS systems and technology, presents imagery, and summarizes the recent flight test results.

  8. Detection of helicopter landing sites in unprepared terrain

    NASA Astrophysics Data System (ADS)

    Peinecke, Niklas

    2014-06-01

    The primary usefulness of helicopters shows in missions where regular aircraft cannot be used, especially HEMS (Helicopter Emergency Medical Services). This might be due to requirements for landing in unprepared areas without dedicated runway structures, and an extended exibility to y to more than one previously unprepared target. One example of such missions are search and rescue operations. An important task of such a mission is to locate a proper landing spot near the mission target. Usually, the pilot would have to evaluate possible landing sites by himself, which can be time-intensive, fuel-costly, and generally impossible when operating in degraded visual environments. We present a method for pre-selecting a list of possible landing sites. After specifying the intended size, orientation and geometry of the site, a choice of possibilities is presented to the pilot that can be ordered by means of wind direction, terrain constraints like maximal slope and roughness, and proximity to a mission target. The possible choices are calculated automatically either from a pre-existing terrain data base, or from sensor data collected during earlier missions, e.g., by collecting data with radar or laser sensors. Additional data like water-body maps and topological information can be taken into account to avoid landing in dangerous areas under adverse view conditions. In case of an emergency turnaround the list can be re-ordered to present alternative sites to the pilot. We outline the principle algorithm for selecting possible landing sites, and we present examples of calculated lists.

  9. 77 FR 57524 - Stage 3 Helicopter Noise Certification Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-18

    ... applications for a new helicopter type design and for a supplemental type certificate for those new type designs. A helicopter type certificated under this standard would be designated as a Stage 3 helicopter... standards of the International Civil Aviation Organization (ICAO). The proposal of these more...

  10. 14 CFR 135.207 - VFR: Helicopter surface reference requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false VFR: Helicopter surface reference... VFR/IFR Operating Limitations and Weather Requirements § 135.207 VFR: Helicopter surface reference requirements. No person may operate a helicopter under VFR unless that person has visual surface reference...

  11. 78 FR 17593 - Airworthiness Directives; Bell Helicopter Textron, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... helicopters. This AD requires establishing a lower life limit on certain swashplate outer ring assemblies... lead to the loss of main rotor (M/R) blade pitch control and subsequent loss of helicopter control..., which could lead to the loss of M/R blade pitch control and subsequent loss of helicopter...

  12. FLIR, NVG and HMS/D systems for helicopter operation: Review

    NASA Astrophysics Data System (ADS)

    Boehm, H. D. V.

    1985-12-01

    In the last decade, electro-optical systems have been used successfully in military and civil applications. They extend the scope of operation of ground vehicles, helicopters and fixed wing aircraft from daytime into nighttime, with a 24 hour readiness covering even bad weather conditions. The visual aids fall into two physical categories: the image intensifiers, which amplify reflected residual light in the near infrared and the thermal imager, which detect the thermal radiation of all bodies mainly in the 8 to 12 micrometer atmospheric window for bodies with T approx. 20 C. During the last five years, the investigator has carried out helicopter flight trials at night using examples of all these visionic aids (FLIR, LLLTV, NVG, HMS/D and Direct View Optics) for piloting and observation tasks. The detection, recognition and identification range of nine different FLIR were tested in ground and laboratory tests. The evaluation of an optical sensor platform location in the helicopter nose-, roof- and mast-mounted versions, the comparison of thermal and intensifier images and the NVG compatible cockpit were topics of the tests. The optical sensors are described with their limitations and some results of the trials are given, with regard to the pilot's stress situation and eye safety.

  13. Unsteady Velocity Measurements Taken Behind a Model Helicopter Rotor Hub in Forward Flight

    NASA Technical Reports Server (NTRS)

    Berry, John D.

    1997-01-01

    Drag caused by separated flow behind the hub of a helicopter has an adverse effect on aerodynamic performance of the aircraft. To determine the effect of separated flow on a configuration used extensively for helicopter aerodynamic investigations, an experiment was conducted using a laser velocimeter to measure velocities in the wake of a model helicopter hub operating at Mach-scaled conditions in forward flight. Velocity measurements were taken using a laser velocimeter with components in the vertical and downstream directions. Measurements were taken at 13 stations downstream from the rotor hub. At each station, measurements were taken in both a horizontal and vertical row of locations. These measurements were analyzed for harmonic content based on the rotor period of revolution. After accounting for these periodic velocities, the remaining unsteady velocities were treated as turbulence. Turbulence intensity distributions are presented. Average turbulent intensities ranged from approximately 2 percent of free stream to over 15 percent of free stream at specific locations and azimuths. The maximum average value of turbulence was located near the rear-facing region of the fuselage.

  14. Degenerative Changes of Spine in Helicopter Pilots

    PubMed Central

    Byeon, Joo Hyeon; Kim, Jung Won; Jeong, Ho Joong; Sim, Young Joo; Kim, Dong Kyu; Choi, Jong Kyoung; Im, Hyoung June

    2013-01-01

    Objective To determine the relationship between whole body vibration (WBV) induced helicopter flights and degenerative changes of the cervical and lumbar spine. Methods We examined 186 helicopter pilots who were exposed to WBV and 94 military clerical workers at a military hospital. Questionnaires and interviews were completed for 164 of the 186 pilots (response rate, 88.2%) and 88 of the 94 clerical workers (response rate, 93.6%). Radiographic examinations of the cervical and the lumbar spines were performed after obtaining informed consent in both groups. Degenerative changes of the cervical and lumbar spines were determined using four radiographs per subject, and diagnosed by two independent, blinded radiologists. Results There was no significant difference in general and work-related characteristics except for flight hours and frequency between helicopter pilots and clerical workers. Degenerative changes in the cervical spine were significantly more prevalent in the helicopter pilots compared with control group. In the cervical spine multivariate model, accumulated flight hours (per 100 hours) was associated with degenerative changes. And in the lumbar spine multivariate model, accumulated flight hours (per 100 hours) and age were associated with degenerative changes. Conclusion Accumulated flight hours were associated with degenerative changes of the cervical and lumbar spines in helicopter pilots. PMID:24236259

  15. All-weather capability for rescue helicopters

    NASA Astrophysics Data System (ADS)

    Kreitmair-Steck, Wolfgang; Haisch, Stefan

    2001-08-01

    In Germany as well as in numerous other countries the air rescue system has been extended significantly since the first operation of the rescue helicopter Christoph 1. The primary target of the air rescue system was to guarantee fast and efficient emergency medical services for victims of accidents. During the years, the scope of the helicopter operations has been extended not only to other types of emergency medical services, but also to secondary medical services like the displacement of patients from hospitals to special service hospitals. While in general the displacement of patients is operated from well known and registered helipads, the primary rescue service currently has to rely on available onboard systems only. Those operations are risky and challenging for the pilots because of time pressure and the danger of obstacles in the environment of the helicopter. In addition, reduced visibility due to fog, rainfall or low light levels can further increase the risks or can make the services unavailable at all. Almost one decade ago, Eurocopter started the investigation of technologies and systems that could help the pilots to perform their tasks with reduced workload and risk, and to allow for a 24 h operation of helicopters irrespective of the weather conditions. After a number of preliminary studies, in 1995 the research program 'All-weather helicopter' has been started as a joint effort of Eurocopter and the supplier industry in Europe. The first phase of the program has been successfully completed in 1999 and the second phase is currently in progress.

  16. Design, manufacture and spin test of high contact ratio helicopter transmission utilizing Self-Aligning Bearingless Planetary (SABP)

    NASA Technical Reports Server (NTRS)

    Folenta, Dezi; Lebo, William

    1988-01-01

    A 450 hp high ratio Self-Aligning Bearingless Planetary (SABP) for a helicopter application was designed, manufactured, and spin tested under NASA contract NAS3-24539. The objective of the program was to conduct research and development work on a high contact ratio helical gear SABP to reduce weight and noise and to improve efficiency. The results accomplished include the design, manufacturing, and no-load spin testing of two prototype helicopter transmissions, rated at 450 hp with an input speed of 35,000 rpm and an output speed of 350 rpm. The weight power density ratio of these gear units is 0.33 lb hp. The measured airborne noise at 35,000 rpm input speed and light load is 94 dB at 5 ft. The high speed, high contact ratio SABP transmission appears to be significantly lighter and quieter than comtemporary helicopter transmissions. The concept of the SABP is applicable not only to high ratio helicopter type transmissions but also to other rotorcraft and aircraft propulsion systems.

  17. Comparison of Janus and field test aircraft detection ranges for the line-of-sight forward heavy system

    NASA Astrophysics Data System (ADS)

    Paulo, Eugene P.

    1991-09-01

    The feasibility of accrediting the Janus combat simulation for use with an Army concept called Model-Test-Model is analyzed. Aircraft detection ranges from an operational field test are compared to similar ranges generated by the Janus combat simulation. Means and distributions of detection ranges for both helicopter and fixed-wing aircraft are studied. Methods of collecting detection data in field tests and representing aircraft in Janus must be improved for Janus to be accredited for aircraft detection range analysis of field tests.

  18. Vision-based aircraft guidance

    NASA Technical Reports Server (NTRS)

    Menon, P. K.

    1993-01-01

    Early research on the development of machine vision algorithms to serve as pilot aids in aircraft flight operations is discussed. The research is useful for synthesizing new cockpit instrumentation that can enhance flight safety and efficiency. With the present work as the basis, future research will produce low-cost instrument by integrating a conventional TV camera together with off-the=shelf digitizing hardware for flight test verification. Initial focus of the research will be on developing pilot aids for clear-night operations. Latter part of the research will examine synthetic vision issues for poor visibility flight operations. Both research efforts will contribute towards the high-speed civil transport aircraft program. It is anticipated that the research reported here will also produce pilot aids for conducting helicopter flight operations during emergency search and rescue. The primary emphasis of the present research effort is on near-term, flight demonstrable technologies. This report discusses pilot aids for night landing and takeoff and synthetic vision as an aid to low visibility landing.

  19. Spinal injury in a U.S. Army light observation helicopter.

    PubMed

    Shanahan, D F; Mastroianni, G R

    1984-01-01

    All accident reports involving U.S. Army OH-58 series helicopters were analyzed to determine vertical and horizontal velocity change at impact and the relationship of this kinematic data to the production of spinal injury. This analysis determined that spinal injury is related primarily to vertical velocity change at impact and is relatively independent of horizontal velocity change. The dramatic increase in the rate of spinal injury occurring just above the design sink speed of the aircraft landing gear (3.7 m/s) suggests that the fuselage and seat provide little additional impact attenuation capability above that of the gear alone. It is concluded that if this aircraft were modified to provide protection to the occupants for impacts up to 9.1 m/s (30 ft/s), approximately 80% of all spinal injury incurred in survivable accidents could be substantially mitigated. The incorporation of energy absorbing seats is recommended.

  20. Neutron radiography and other NDE tests of main rotor helicopter blades.

    PubMed

    de Beer, F C; Coetzer, M; Fendeis, D; Da Costa E Silva, A

    2004-10-01

    A few nondestructive examination (NDE) techniques are extensively being used worldwide to investigate aircraft structures for all types of defects. The detection of corrosion and delaminations, which are believed to be the major initiators of defects 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 reactor operated by Necsa, was performed to introduce this form of NDE testing to the South African aviation industry to be evaluated for applicability. The results of the shearography, visual inspection and NRad techniques are compared in this paper. The main features and advantages of neutron radiography, within the framework of these investigations, will be highlighted.

  1. Identification and simulation evaluation of an AH-64 helicopter hover math model

    NASA Technical Reports Server (NTRS)

    Schroeder, J. A.; Watson, D. C.; Tischler, M. B.; Eshow, M. M.

    1991-01-01

    Frequency-domain parameter-identification techniques were used to develop a hover mathematical model of the AH-64 Apache helicopter from flight data. The unstable AH-64 bare-airframe characteristics without a stability-augmentation system were parameterized in the convectional stability-derivative form. To improve the model's vertical response, a simple transfer-function model approximating the effects of dynamic inflow was developed. Additional subcomponents of the vehicle were also modeled and simulated, such as a basic engine response for hover and the vehicle stick dynamic characteristics. The model, with and without stability augmentation, was then evaluated by AH-64 pilots in a moving-base simulation. It was the opinion of the pilots that the simulation was a satisfactory representation of the aircraft for the tasks of interest. The principal negative comment was that height control was more difficult in the simulation than in the aircraft.

  2. Performance and safety aspects of the XV-15 tilt rotor research aircraft

    NASA Technical Reports Server (NTRS)

    Wernicke, K. G.

    1977-01-01

    Aircraft performance is presented illustrating the flexibility and capability of the XV-15 to conduct its planned proof-of-concept flight research in the areas of dynamics, stability and control, and aerodynamics. Additionally, the aircraft will demonstrate mission-type performance typical of future operational aircraft. The aircraft design is described and discussed with emphasis on the safety and fail-operate features of the aircraft and its systems. Two or more levels of redundancy are provided in the dc and ac electrical systems, hydraulics, conversion, flaps, landing gear extension, SCAS, and force-feel. RPM is maintained by a hydro-electrical blade pitch governor that consists of a primary and standby governor with a cockpit wheel control for manual backup. The two engines are interconnected for operation on a single engine. In the event of total loss of power, the aircraft can enter autorotation starting from the airplane as well as the helicopter mode of flight.

  3. Epidemiology of Helicopter Battle Damage

    DTIC Science & Technology

    2010-05-01

    A through Class C accident data , and consider the data to be representative of the spectrum of damage that must be dealt with by deployed...maintenance units. An analysis of the data by year dating back to 1995 was done to look at the effect of OIF and OEF on overall aircraft incident rate. This...per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and

  4. Helicopter stability during aggressive maneuvers

    NASA Astrophysics Data System (ADS)

    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.

  5. Helicopter emergency medical service in mountainous areas.

    PubMed

    Tomazin, Iztok

    2009-01-01

    The outcome of patient care can be dramatically improved by bringing rapid rescue-medical treatment to the scene and by rapid transport to a medical facility. In mountainous areas this is usually possible only with the use of helicopters. ICAR MEDCOM suggests international standards for competent and safe response to medical problems in mountainous and wilderness areas. Rescue helicopters should work within the existing emergency medical system with appropriate mountain rescue and medically-trained personnel and with medical and rescue equipment on board. Safety is most important issue in mountain rescue. Activation and approach time should be as short as possible. All persons responsible for activation and realization of a helicopter rescue operation should be aware of all specific problems in the mountains and wilderness.

  6. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Mardoian, G. H.; Ezzo, M. B.

    1986-01-01

    This report presents an assessment of composite helicopter tail rotor spars and horizontal stabilizers, exposed to the effects of the environment, after up to five and a half years of commercial service. This evaluation is supported by test results of helicopter components and panels which have been exposed to outdoor environmental effects since September 1979. Full scale static and fatigue tests have been conducted on graphite/epoxy and Kevlar/epoxy composite components obtained from Sikorsky Model S-76 helicopters in commercial operations in the Gulf Coast region of Louisiana. Small scale static and fatigue tests are being conducted on coupons obtained from panels under exposure to outdoor conditions in Stratford, Connecticut and West Palm, Florida. The panel layups are representative of the S-76 components. Additionally, this report discusses the results of moisture absorption evaluations and strength tests on the S-76 components and composite panels with up to five years of outdoor exposure.

  7. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Rich, M. J.; Lowry, D. W.

    1985-01-01

    An assessment of composite helicopter structures, exposed to environmental effects, after four years of commercial service is presented. This assessment is supported by test results of helicopter components and test panels which have been exposed to environmental effects since late 1979. Full scale static and fatigue tests are being conducted on composite components obtained from S-76 helicopters in commercial operations in the Gulf Coast region of Louisiana. Small scale tests are being conducted on coupons obtained from panels being exposed to outdoor conditions in Stratford, Connecticut and West Palm Beach, Florida. The panel layups represent S-76 components. Moisture evaluations and strength tests are being conducted, on the S-76 components and panels, over a period of eight years. Results are discussed for components and panels with up to four years of exposure.

  8. Minimum-complexity helicopter simulation math model

    NASA Technical Reports Server (NTRS)

    Heffley, Robert K.; Mnich, Marc A.

    1988-01-01

    An example of a minimal complexity simulation helicopter math model is presented. Motivating factors are the computational delays, cost, and inflexibility of the very sophisticated math models now in common use. A helicopter model form is given which addresses each of these factors and provides better engineering understanding of the specific handling qualities features which are apparent to the simulator pilot. The technical approach begins with specification of features which are to be modeled, followed by a build up of individual vehicle components and definition of equations. Model matching and estimation procedures are given which enable the modeling of specific helicopters from basic data sources such as flight manuals. Checkout procedures are given which provide for total model validation. A number of possible model extensions and refinement are discussed. Math model computer programs are defined and listed.

  9. Neuro-optimal control of helicopter UAVs

    NASA Astrophysics Data System (ADS)

    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.

  10. Helicopter impulsive noise: Theoretical and experimental status

    NASA Technical Reports Server (NTRS)

    Schmitz, F. H.; Yu, Y. H.

    1983-01-01

    The theoretical and experimental status of helicopter impulsive noise is reviewed. The two major source mechanisms of helicopter impulsive noise are addressed: high-speed impulsive noise and blade-vortex interaction impulsive noise. A thorough physical explanation of both generating mechanism is presented together with model and full-scale measurements of the phenomena. Current theoretical prediction methods are compared with experimental findings of isolated rotor tests. The noise generating mechanism of high speed impulsive noise are fairly well understood - theory and experiment compare nicely over Mach number ranges typical of today's helicopters. For the case of blade-vortex interaction noise, understanding of noise generating mechanisms and theoretical comparison with experiment are less satisfactory. Several methods for improving theory-experiment are suggested.

  11. Validation of helicopter noise prediction techniques

    NASA Technical Reports Server (NTRS)

    Succi, G. P.

    1981-01-01

    The current techniques of helicopter rotor noise prediction attempt to describe the details of the noise field precisely and remove the empiricisms and restrictions inherent in previous methods. These techniques require detailed inputs of the rotor geometry, operating conditions, and blade surface pressure distribution. The purpose of this paper is to review those techniques in general and the Farassat/Nystrom analysis in particular. The predictions of the Farassat/Nystrom noise computer program, using both measured and calculated blade surface pressure data, are compared to measured noise level data. This study is based on a contract from NASA to Bolt Beranek and Newman Inc. with measured data from the AH-1G Helicopter Operational Loads Survey flight test program supplied by Bell Helicopter Textron.

  12. A critical care helicopter system in trauma.

    PubMed Central

    Jacobs, L. M.; Bennett, B.

    1989-01-01

    Civilian helicopters and emergency medical services in the United States have been in existence for approximately 15 years. The rapid growth of this type of health care delivery coupled with an increasing number of accidents has prompted professional and lay scrutiny of these programs. Although they have a demonstrated history of benefit to patients, the type and severity of injuries to patients who are eligible for helicopter transportation need further definition. The composition of the medical crews and the benefits that particular crew members bring to the patients require ongoing evaluation. Significant questions regarding the number of pilots in a helicopter and in a program remain to be answered. This article reviews the role of emergency medical air transport services in providing care to trauma patients, staff training and evaluation, and safety criteria and offers recommendations to minimize risks to patients and crews. PMID:2695653

  13. Validation of helicopter noise prediction techniques

    NASA Astrophysics Data System (ADS)

    Succi, G. P.

    1981-04-01

    The current techniques of helicopter rotor noise prediction attempt to describe the details of the noise field precisely and remove the empiricisms and restrictions inherent in previous methods. These techniques require detailed inputs of the rotor geometry, operating conditions, and blade surface pressure distribution. The purpose of this paper is to review those techniques in general and the Farassat/Nystrom analysis in particular. The predictions of the Farassat/Nystrom noise computer program, using both measured and calculated blade surface pressure data, are compared to measured noise level data. This study is based on a contract from NASA to Bolt Beranek and Newman Inc. with measured data from the AH-1G Helicopter Operational Loads Survey flight test program supplied by Bell Helicopter Textron.

  14. ALLFlight: multisensor data fusion for helicopter operations

    NASA Astrophysics Data System (ADS)

    Doehler, H.-U.; Lueken, T.

    2010-04-01

    The objective of the project ALLFlight (Assisted Low Level Flight and Landing on Unprepared Landing Sites) is to demonstrate and evaluate the characteristics of different sensors for helicopter operations within degraded visual environments, such as brownout or whiteout. The sensor suite, which is mounted onto DLR's research helicopter EC135 consists of standard color or black and white TV cameras, an un-cooled thermal infrared camera (EVS-1000, Max-Viz, USA), an optical radar scanner (HELLAS-W, EADS, Germany; a millimeter wave radar system (AI-130, ICx Radar Systems, Canada). Data processing is designed and realized by a sophisticated, high performance sensor co-computer (SCC) cluster architecture, which is installed into the helicopter's experimental electronic cargo bay. This paper describes applied methods and the software architecture in terms of real time data acquisition, recording, time stamping and sensor data fusion. First concepts for a pilot HMI are presented as well.

  15. Helicopter approach capability using the differential global positioning system. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Kaufmann, David N.

    1993-01-01

    The results of flight tests to determine the feasibility of using the Global Positioning System (GPS) in the differential mode (DGPS) to provide high accuracy, precision navigation, and guidance for helicopter approaches to landing are presented. The airborne DGPS receiver and associated equipment is installed in a NASA UH-60 Black Hawk helicopter. The ground-based DGPS reference receiver is located at a surveyed test site and is equipped with a real-time VHF data link to transmit correction information to the airborne DGPS receiver. The corrected airborne DGPS information, together with the preset approach geometry, is used to calculate guidance commands which are sent to the aircraft's approach guidance instruments. The use of DGPS derived guidance for helicopter approaches to landing is evaluated by comparing the DGPS data with the laser tracker truth data. Both standard (3 deg) and steep (6 deg and 9 deg) glideslope straight-in approaches were flown. DGPS positioning accuracy based on a time history analysis of the entire approach was 0.2 m (mean) +/- 1.8 m (2 sigma) laterally and -2.0 m (mean) +/- 3.5 m (2 sigma) vertically for 3 deg glideslope approaches, -0.1 m (mean) +/- 1.5 m (2 sigma) laterally and -1.1 m (mean) +/- 3.5 m (2 sigma) vertically for 6 deg glideslope approaches and 0.2 m (mean) +/- 1.3 m (2 sigma) laterally and -1.0 m (mean) +/- 2.8 m (2 sigma) vertically for 9 deg glideslope approaches. DGPS positioning accuracy at the 200 ft decision height (DH) on a standard 3 deg slideslope approach was 0.3 m (mean) +/- 1.5 m (2 sigma) laterally and -2.3 m (mean) +/- 1.6 m (2 sigma) vertically. These errors indicate that the helicopter position based on DGPS guidance satisfies the International Civil Aviation Organization (ICAO) Category 1 (CAT 1) lateral and vertical navigational accuracy requirements.

  16. Helicopter Mechanic Career Ladder (AFSC 431X0C/D).

    DTIC Science & Technology

    1986-05-01

    SYSTEMS ON H-i HELICOPTERS 88 G352 LAUNCH H-i HELICOPTERS 88 G415 REMOVE OR INSTALL BATTERIES ON H-i HELICOPTERS 88 G351 JACK H-i HELICOPTERS 88 F165...PREPARE AFTO FORMS 781H (AEROSPACE VEHICLE FLIGHT STATUS AND MAINTENANCE DOCUMENT) 72 G351 JACK H-i HELICOPTERS 72 E122 PREPARE AFTO FORMS 350...H-I HELICOPTERS 97 G308 ATTACH OR DETACH TOW BARS ON H-i HELICOPTERS 96 G351 JACK H-I HELICOPTERS 95 G507 TIE DOWN BLADES ON H-i HELICOPTERS 93 G336

  17. A theoretical analysis of the electromagnetic environment of the AS330 super Puma helicopter external and internal coupling

    NASA Technical Reports Server (NTRS)

    Flourens, F.; Morel, T.; Gauthier, D.; Serafin, D.

    1991-01-01

    Numerical techniques such as Finite Difference Time Domain (FDTD) computer programs, which were first developed to analyze the external electromagnetic environment of an aircraft during a wave illumination, a lightning event, or any kind of current injection, are now very powerful investigative tools. The program called GORFF-VE, was extended to compute the inner electromagnetic fields that are generated by the penetration of the outer fields through large apertures made in the all metallic body. Then, the internal fields can drive the electrical response of a cable network. The coupling between the inside and the outside of the helicopter is implemented using Huygen's principle. Moreover, the spectacular increase of computer resources, as calculations speed and memory capacity, allows the modellization structures as complex as these of helicopters with accuracy. This numerical model was exploited, first, to analyze the electromagnetic environment of an in-flight helicopter for several injection configurations, and second, to design a coaxial return path to simulate the lightning aircraft interaction with a strong current injection. The E field and current mappings are the result of these calculations.

  18. The Apache Longbow-Hellfire Missile Test at Yuma Proving Ground: Ecological Risk Assessment for Helicopter Overflight

    SciTech Connect

    Efroymson, Rebecca Ann; Hargrove, William Walter; Suter, Glenn

    2008-01-01

    A multi-stressor risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework. The focus of the assessment was a testing program at Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, M60-A1 tanks. This paper focuses on the wildlife risk assessment for the helicopter overflight. The primary stressors were sound and the view of the aircraft. Exposure to desert mule deer (Odocoileus hemionus crooki) was quantified using Air Force sound contour programs NOISEMAP and MR_NMAP, which gave very different results. Slant distance from helicopters to deer was also used as a measure of exposure that integrated risk from sound and view of the aircraft. Exposure-response models for the characterization of effects consisted of behavioral thresholds in sound exposure level or maximum sound level units or slant distance. Available sound thresholds were limited for desert mule deer, but a distribution of slant-distance thresholds was available for ungulates. The risk characterization used a weight-of-evidence approach and concluded that risk to mule deer behavior from the Apache overflight is uncertain, but that no risk to mule deer abundance and reproduction is expected.

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

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  20. NASA/Army XV-15 tilt rotor research aircraft familiarization document

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The design features and general characteristics of the NASA/Army XV-15 tilt rotor research aircraft are described. This aircraft was conceived as a proof-of-concept vehicle and a V/STOL research tool for integrated wind tunnel, flight-simulation, and flight-test investigations. Discussions of special design provisions and safety considerations necessary to perform these missions are included in this report. In addition to predictions of aircraft and engine performance for the hover, helicopter, and airplane flight modes, analytical estimates of the structural and dynamic limitations of the XV-15 are provided.

  1. Aircraft cybernetics

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  2. Simulation of Aircraft Landing Gears with a Nonlinear Dynamic Finite Element Code

    NASA Technical Reports Server (NTRS)

    Lyle, Karen H.; Jackson, Karen E.; Fasanella, Edwin L.

    2000-01-01

    Recent advances in computational speed have made aircraft and spacecraft crash simulations using an explicit, nonlinear, transient-dynamic, finite element analysis code more feasible. This paper describes the development of a simple landing gear model, which accurately simulates the energy absorbed by the gear without adding substantial complexity to the model. For a crash model, the landing gear response is approximated with a spring where the force applied to the fuselage is computed in a user-written subroutine. Helicopter crash simulations using this approach are compared with previously acquired experimental data from a full-scale crash test of a composite helicopter.

  3. CMU's autonomous helicopter explores new territory.

    NASA Astrophysics Data System (ADS)

    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. Influence of maneuverability on helicopter combat effectiveness

    NASA Technical Reports Server (NTRS)

    Falco, M.; Smith, R.

    1982-01-01

    A computational procedure employing a stochastic learning method in conjunction with dynamic simulation of helicopter flight and weapon system operation was used to derive helicopter maneuvering strategies. The derived strategies maximize either survival or kill probability and are in the form of a feedback control based upon threat visual or warning system cues. Maneuverability parameters implicit in the strategy development include maximum longitudinal acceleration and deceleration, maximum sustained and transient load factor turn rate at forward speed, and maximum pedal turn rate and lateral acceleration at hover. Results are presented in terms of probability of skill for all combat initial conditions for two threat categories.

  5. Efficient fault diagnosis of helicopter gearboxes

    NASA Technical Reports Server (NTRS)

    Chin, H.; Danai, K.; Lewicki, D. G.

    1993-01-01

    Application of a diagnostic system to a helicopter gearbox is presented. The diagnostic system is a nonparametric pattern classifier that uses a multi-valued influence matrix (MVIM) as its diagnostic model and benefits from a fast learning algorithm that enables it to estimate its diagnostic model from a small number of measurement-fault data. To test this diagnostic system, vibration measurements were collected from a helicopter gearbox test stand during accelerated fatigue tests and at various fault instances. The diagnostic results indicate that the MVIM system can accurately detect and diagnose various gearbox faults so long as they are included in training.

  6. A contrarotative aircraft lifting concept for a future Titan mission

    NASA Astrophysics Data System (ADS)

    Duquesnay, P.; Coustenis, A.; Lebreton, J.-P.; Tavel, J.

    2008-09-01

    Titan has a thick and cold atmosphere (surface pressure 1.5 bar and surface temperature 94 K) and the surface gravity is about 1/7 of Earth's. Surface wind velocities are low. These unique characteristics make Titan's atmosphere an ideal place for an helicopter type of aircraft with vertical lift capability. Here we present a conceptual idea of a Titan helicopter designed as a student project. Two cases have been considered: a 100-kg helicopter and a 2-kg one. The concept is based on a contra-rotating double rotor. The device would be powered by a combination of rechargeable batteries and a low-power radioisotope source. The double rotor and the body of the helicopter would be protected by a mesh structure. It would carry a science payload at its base that would allow surface sampling and analysis each time it would land. During landing, it would also recharge its batteries to allow flying to the next stop. The concept has been inspired by studying modelaircraft- making devices. Various concepts developed for industrial and military applications have also been a source of inspiration. The following web sites were consulted: • www.onera.fr/conferences/drones • www.aurora.aero • www.sikorsky.com/sik/index.asp • www.microdrones.com The poster will present a preliminary design of the device. Its capability to contribute to the exploration of Titan's surface will be illustrated.

  7. Proposed health state awareness of helicopter blades using an artificial neural network strategy

    NASA Astrophysics Data System (ADS)

    Lee, Andrew; Habtour, Ed; Gadsden, S. A.

    2016-05-01

    Structural health prognostics and diagnosis strategies can be classified as either model or signal-based. Artificial neural network strategies are popular signal-based techniques. This paper proposes the use of helicopter blades in order to study the sensitivity of an artificial neural network to structural fatigue. The experimental setup consists of a scale aluminum helicopter blade exposed to transverse vibratory excitation at the hub using single axis electrodynamic shaker. The intent of this study is to optimize an algorithm for processing high-dimensional data while retaining important information content in an effort to select input features and weights, as well as health parameters, for training a neural network. Data from accelerometers and piezoelectric transducers is collected from a known system designated as healthy. Structural damage will be introduced to different blades, which they will be designated as unhealthy. A variety of different tests will be performed to track the evolution and severity of the damage. A number of damage detection and diagnosis strategies will be implemented. A preliminary experiment was performed on aluminum cantilever beams providing a simpler model for implementation and proof of concept. Future work will look at utilizing the detection information as part of a hierarchical control system in order to mitigate structural damage and fatigue. The proposed approach may eliminate massive data storage on board of an aircraft through retaining relevant information only. The control system can then employ the relevant information to intelligently reconfigure adaptive maneuvers to avoid harmful regimes, thus, extending the life of the aircraft.

  8. Laboratory and flight tests of medical equipment for use in U.S. Army Medevac helicopters.

    PubMed

    Bruckart, J E; Licina, J R; Quattlebaum, M

    1993-03-01

    When used in an air medical setting, medical equipment designed for use in hospitals can fail from the stresses of in-flight use, or they interfere with critical rotor-wing aircraft systems. From January 1989 to June 1992, 34 medical devices, including monitor/defibrillators, infusion pumps, vital-signs monitors, ventilators and infant transport incubators, were tested under extreme conditions of temperature, humidity, altitude and vibration (MIL-STD 810D). Electromagnetic emissions and susceptibility were measured (MIL-STD 461C and 462), and human factors were evaluated. The devices were flight tested in a UH-60 MEDEVAC helicopter. Thirty-two percent of the medical devices failed at least one environmental test, and 91% of the devices failed to meet electromagnetic interference standards. Failures included excess conducted and radiated emissions and susceptibility to radiated emissions. Five (15%) of the devices were judged unsuitable for use in the UH-60 MEDEVAC helicopter. Testing is critical to discover the ability of a medical device to perform in the harsh rotor-wing MEDEVAC environment. Failure of a device or interference with aircraft systems can result in loss of a patient or aircrew.

  9. Helicopter-based live-line work. Volume 1, Helicopter platform work between phases: Final report

    SciTech Connect

    Gela, G.

    1993-06-01

    This report presents experimental data on tests of a configuration consisting of a helicopter between two energized phases (for AC and switching surge) or poles (for DC). The configuration is that related to live-line work from a hovering helicopter. The McDonnell Douglas 500 Series helicopter was used for the tests. All tests were performed with phase-to-phase, or pole-to-pole energization. For AC tests, proper relationship between the phase-to-ground voltages and the phase-to-phase voltage was maintained by energizing the experimental setup from a balanced 3-{phi} AC source. For DC tests, one pole was energized with positive DC voltage to ground, while the other pole was energized with negative DC voltage to ground. For switching surge tests, a surge of positive polarity and a specific peak voltage magnitude was applied to one phase while a surge of negative polarity and the same peak voltage Magnitude was simultaneously applied to the other phase, resulting in {alpha} = 0.5 ({alpha} is the ratio between negative and total surge). In the research program, four conditions were investigated, namely helicopter operating versus not operating, and helicopter bonded to one phase or pole versus not bonded. Results from this research show effects of the rotating main rotor blade of the helicopter, effect of the position of the electrically floating helicopter in the phase-to-phase or pole-to-pole gap, effects of the mannequin, importance of the polarity of the DC poles and switching surges, and effects of inclement weather such as rain. The overall conclusion of this research is that the phase-to-phase or pole-to-pole spacings that cause sparkover with the helicopter between phases (poles) were always significantly smaller than the typical spacings on actual existing overhead transmission lines of the corresponding voltage rating.

  10. 78 FR 49729 - Takes of Marine Mammals Incidental to Specified Activities; U.S. Air Force Launches, Aircraft and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ... Specified Activities; U.S. Air Force Launches, Aircraft and Helicopter Operations, and Harbor Activities Related to Launch Vehicles From Vandenberg Air Force Base (VAFB), California AGENCY: National Marine... has received a request from the U.S. Air Force (USAF) for authorization to take marine...

  11. Non-contact measurement of helicopter device position in wind tunnels with the use of optical videogrammetry method

    NASA Astrophysics Data System (ADS)

    Kuruliuk, K. A.; Kulesh, V. P.

    2016-10-01

    An optical videogrammetry method using one digital camera for non-contact measurements of geometric shape parameters, position and motion of models and structural elements of aircraft in experimental aerodynamics was developed. The tests with the use of this method for measurement of six components (three linear and three angular ones) of real position of helicopter device in wind tunnel flow were conducted. The distance between camera and test object was 15 meters. It was shown in practice that, in the conditions of aerodynamic experiment instrumental measurement error (standard deviation) for angular and linear displacements of helicopter device does not exceed 0,02° and 0.3 mm, respectively. Analysis of the results shows that at the minimum rotor thrust deviations are systematic and generally are within ± 0.2 degrees. Deviations of angle values grow with the increase of rotor thrust.

  12. The NASA/Industry Design Analysis Methods for Vibrations (DAMVIBS) Program - Boeing helicopters airframe finite element modeling

    NASA Technical Reports Server (NTRS)

    Gabel, R.; Lang, P.; Reed, D.

    1992-01-01

    Finite-element modeling of the airframe vibration of the Army/Boeing CH-47D helicopter is conducted with comparisons to experimental data in an effort to improve the design process. A NASTRAN FEM is developed that is fully representative of the test configuration and includes the support fixture, shakers, and the aircraft/shaker suspension system. The analysis is conducted with specific attention given to the prediction of reasonable forced amplitudes throughout the airframe. Reasonable correlation is noted between the FEM and experimental results, although improved correlation can be obtained by including more accurate damping values and secondary effects such as stringer shear loading. It is shown that the general stress model does not provide an adequate dynamic analysis on which to base design improvements. A more detailed model is required that emphasizes highly detailed helicopter elements and employs a finer mesh particularly in the description of the mass distribution.

  13. A piloted simulator investigation of augmentation systems to improve helicopter nap-of-the-earth handling qualities

    NASA Technical Reports Server (NTRS)

    Chen, R. T. N.; Talbot, P. D.; Gerdes, R. M.; Dugan, D. C.

    1978-01-01

    A piloted simulation study assessed various levels of stability and control augmentation designed to improve the handling qualities of several helicopters in nap-of-the-earth (NOE) flight. Five basic single rotor helicopters - one teetering, two articulated, and two hingeless - which were found to have a variety of major deficiencies in a previous fixed-based simulator study were selected as baseline configurations. The stability and control augmentation systems (SCAS) include simple control augmentation systems (CAS) to decouple pitch and yaw responses due to collective input and to quicken the pitch and roll control responses; SCAS of rate command type designed to optimize the sensitivity and damping and to decouple the pitch-roll due to aircraft angular rate; and attitude command type SCAS. Pilot ratings and commentary are presented as well as performance data related to the task. SCAS control usage and their gain levels associated with specific rotor type are also discussed.

  14. Helicopter Parents Can Be a Good Thing

    ERIC Educational Resources Information Center

    Hiltz, Julie

    2015-01-01

    Helicopter parents get a bad rap. Teachers and administrators should view them as a resource--not a nuisance. By encouraging open communication, teachers can begin to understand the motivations of these parents and find creative ways to connect them with opportunities to promote their students' academic success and the school's overall…

  15. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... cargo hooks shall have the electrical activating device so designed and installed as to prevent... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  16. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cargo hooks shall have the electrical activating device so designed and installed as to prevent... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  17. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cargo hooks shall have the electrical activating device so designed and installed as to prevent... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  18. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Mardoian, George H.; Ezzo, Maureen B.

    1990-01-01

    An assessment is presented of ten composite tail rotor spars and four horizontal stabilizers exposed to the effects of in-flight commercial service for up to nine years to establish realistic environmental factors for use in future designs. This evaluation is supported by test results of helicopter components and panels which have been exposed to outdoor environmental effects since 1979. Full scale static and fatigue tests were conducted on graphite/epoxy and Kevlar/epoxy composite components removed from Sikorsky Model S-76 helicopters in commercial operations off the Gulf Coast of Louisiana. Small scale static and fatigue tests were conducted on coupons obtained from panels exposed to outdoor conditions in Stratford, CT and West Palm Beach, Florida. The panel materials and ply configurations were representative of the S-76 components. The results are discussed of moisture analyses and strength tests on both the S-76 components and composite panels after up to nine years of outdoor exposure. Full scale tests performed on the helicopter components did not disclose any significant reductions from the baseline strengths. The results increased confidence in the long term durability of advanced composite materials in helicopter structural applications.

  19. Finite element analysis of helicopter structures

    NASA Technical Reports Server (NTRS)

    Rich, M. J.

    1978-01-01

    Application of the finite element analysis is now being expanded to three dimensional analysis of mechanical components. Examples are presented for airframe, mechanical components, and composite structure calculations. Data are detailed on the increase of model size, computer usage, and the effect on reducing stress analysis costs. Future applications for use of finite element analysis for helicopter structures are projected.

  20. HH-60D night hawk helicopter

    NASA Technical Reports Server (NTRS)

    Richardson, C. S.

    1984-01-01

    Fundamental development issues, system requirements and improvements are reported for the HH-60D night hawk helicopter. The HH-60D mission requirements are for combat search and rescue (aerospace rescue and recovery service user based at Scott AFB) and special operations (special operations forces based at Hurlburt AFB). Cockpit design, computer architecture and software are described in detail.

  1. Computer Programs for Helicopter Aerodynamic Stability Evaluation

    DTIC Science & Technology

    1976-08-01

    augmentation system . Two methods of calculating the required stability derivatives and solution of the equations of motion in terms of period and time to damp or time histories for various control motions are shown....The three equations of motion for helicopters are reviewed for both pitch and roll. These include provisions for a simplified second order stability

  2. 29 CFR 1910.183 - Helicopters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the system with the employees in advance of hoisting the load. This applies to both radio and hand... employee shall be permitted to approach within 50 feet of the helicopter when the rotor blades are turning... blades rotating, all employees shall remain in full view of the pilot and keep in a crouched position....

  3. Technical Workshop: Advanced Helicopter Cockpit Design

    NASA Technical Reports Server (NTRS)

    Hemingway, J. C. (Editor); Callas, G. P. (Editor)

    1984-01-01

    Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration.

  4. Computerized Analysis Of Helicopter-Rotor Aeroelasticity

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.

    1988-01-01

    Analysis of aeroelastic stability of helicopter rotor automated. Symbolic-manipulation program, HESL, written in FORTRAN, used to aid in derivation of government equations of motion for elastic-bladed rotor. Operates both on expressions and matrices. By transferring some burden of algebraic manipulations from human analyst to computer, program reduces tedium analysis and conequent opportunity for errors.

  5. Considerations of Methods of Improving Helicopter Efficiency

    NASA Technical Reports Server (NTRS)

    Dingeldein, Richard C.

    1961-01-01

    Recent NASA helicopter research indicates that significant improvements in hovering efficiency, up to 7 percent, are available from the use of a special airfoil section formed by combining an NACA 632A015 thickness distribution with an NACA 230 mean line. This airfoil should be considered for flying-crane-type helicopters. Application of standard leading-edge roughness causes a large drop in efficiency; however, the cambered rotor is shown to retain its superiority over a rotor having a symmetrical airfoil when both rotors have leading-edge roughness. A simple analysis of available rotor static-thrust data indicates a greatly reduced effect of compressibility effects on the rotor profile-drag power than predicted from calculations. Preliminary results of an experimental study of helicopter parasite drag indicate the practicability of achieving an equivalent flat-plate parasite-drag area of less than 4 square feet for a rotor-head-pylon-fuselage configuration (landing gear retracted) in the 2,000-pound minimum-flying-weight class. The large drag penalty of a conventional skid-type landing (3.6 square feet) can be reduced by two-thirds by careful design. Clean, fair, and smooth fuselages that tend to have narrow, deep cross sections are shown to have advantages from the standpoint of drag and download. A ferry range of the order of 1,500 miles is indicated to be practicable for the small helicopter considered.

  6. Aircraft Icing Handbook. Volume 3

    DTIC Science & Technology

    1991-03-01

    Address 10. Work Unit No. (TRAIS) Gates Learjet Corporation 11. Contract or G-1nt N• 8220 W. Harry DTFA03-85-C-00007 Wichita, KS 67277 13. Type of Report...38. Chambers, Harry W. and Adams, John, Y., "Summary of Artificial and Natural Icing Tests Conducted on U.S.Army Aircraft from 1974 to 1985," DOT/FAA...Drop Trajectories To and About Arbitrary Three-Dimensional Lifting and Non lifting Bodies in Poter ,,tial Flow," NASA Contractor Report 3935, Contract

  7. Aircraft Corrosion

    DTIC Science & Technology

    1981-08-01

    chlore mais dans une proportion semblable b cells d’une eau de vil)e ; - lea solides, d’aprbs lea analyses chimique et criatallographique, paraissaiont...IATA member airlines at $100 million based on 1976 operations. Thus the numbers are large, but detailed analyses on specific aircraft types, in known...demonstrate this in any quantitative way with accurate figures. Better information is required on the cost of corrosion, together with analyses of the

  8. Training Presentation for NASA Civil Helicopter Safety Website

    NASA Technical Reports Server (NTRS)

    Iseler, Laura

    2002-01-01

    NASA civil helicopter safety News & Updates include the following: Mar. 2002. The Air Medical Operations Survey has been completed! Check it out! Also accessible via the Mission pages under Air Medical Mission. Air Medical and Law Enforcement Mission pages have been added. They are accessible via the Mission pages. The Public Use, Personal, Offshore, Law Enforcement, External Load, Business and Gyro accident pages (accessable via the Mission page) have been updated. Feb. 2002. A Words of Wisdom section has been added. You can access it by clicking the Library button. A link to a Corporate Accident Response Plan has been added to the Accident page. The AMs, Aerial Application and Instruction accident pages (accessable via the Mission page) have been updated. Jan. 2002. A new searchable safety article database has been added. You can access it by clicking the Library button. The 2001 accident summaries have been updated and the statistics have been compiled - check it out by clicking the accident tab to the left. Dec. 2001. Please read the FAA Administrator's memo regarding the latest FBI warning. 3ee the FAA column - Fall 2001 Read it now!

  9. 75 FR 28506 - Airworthiness Directives; Hawker Beechcraft Corporation (Type Certificate No. A00010WI Previously...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... with deficient armature insulating materials may have been installed on certain airplanes. We are... Corporation (Type Certificate No. A00010WI Previously Held by Raytheon Aircraft Company) Model 390 Airplanes... Hawker Beechcraft Corporation Model 390 airplanes. This proposed AD would require inspecting...

  10. Helicopter emergency medical services (doctor-helicopter) in Fukushima Prefecture: present state and problems.

    PubMed

    Tase, Choichiro; Ohno, Yuko; Hasegawa, Arifumi; Tsukada, Yasuhiro; Shimada, Jiro; Ikegami, Yukihiro

    2010-06-01

    The purpose of this study is to identify the problems in operating an emergency medical service helicopter with an emergency medicine doctor on board (doctor-helicopter) in Fukushima Prefecture, Japan, which covers wide regions and many rural areas. The study looked at the numbers of flights and patients during the 523 days since the start of the doctor-helicopter service at the Fukushima Medical University Hospital. The items investigated were: number of flights, number of helicopter dispatches per month, number of patients, the hospitals where patients were taken to, the fire department dispatch centers that requested the doctor-helicopter, and the number of times each doctor flew on the helicopter. There were 450 flights. When the service was started, there were a few flights, but they gradually increased. The majority of the flights were to emergency scenes (295), while 75 flights were interfacility transports of critically ill patients, 79 flights were cancelled after take-off, and one flight was for a disaster relief operation. The nature of requests differed greatly depending on the fire department dispatch center requesting the service. The majority of patients were trauma patients (62.2%). Stroke (8.5%) and acute coronary syndrome (5.2%) patients requiring emergency treatment were fewer than anticipated. The final destination hospitals were appropriate hospitals in the region. Because the number of flight doctors is small, the burden on individual doctors is large. A system for early on-site diagnosis and helicopter request by emergency rescue team is required to maintain a high quality of emergency care.

  11. Subjective field study of response to impulsive helicopter noise

    NASA Technical Reports Server (NTRS)

    Powell, C. A.

    1981-01-01

    Subjects, located outdoors and indoors, judged the noisiness and other subjective noise characteristics of flyovers of two helicopters and a propeller driven airplane as part of a study of the effects of impulsiveness on the subjective response to helicopter noise. In the first experiment, the impulsive characteristics of one helicopter was controlled by varying the main rotor speed while maintaining a constant airspeed in level flight. The second experiment which utilized only the helicopters, included descent and level flight operations. The more impulsive helicopter was consistently judged less noisy than the less impulsive helicopter at equal effective perceived noise levels (EPNL). The ability of EPNL to predict noisiness was not improved by the addition of either of two proposed impulse corrections. A subjective measure of impulsiveness, however, which was not significantly related to the proposed impulse corrections, was found to improve the predictive ability of EPNL.

  12. Helicopter Control Energy Reduction Using Moving Horizontal Tail

    PubMed Central

    Oktay, Tugrul; Sal, Firat

    2015-01-01

    Helicopter moving horizontal tail (i.e., MHT) strategy is applied in order to save helicopter flight control system (i.e., FCS) energy. For this intention complex, physics-based, control-oriented nonlinear helicopter models are used. Equations of MHT are integrated into these models and they are together linearized around straight level flight condition. A specific variance constrained control strategy, namely, output variance constrained Control (i.e., OVC) is utilized for helicopter FCS. Control energy savings due to this MHT idea with respect to a conventional helicopter are calculated. Parameters of helicopter FCS and dimensions of MHT are simultaneously optimized using a stochastic optimization method, namely, simultaneous perturbation stochastic approximation (i.e., SPSA). In order to observe improvement in behaviors of classical controls closed loop analyses are done. PMID:26180841

  13. Flight evaluation of a computer aided low-altitude helicopter flight guidance system

    NASA Technical Reports Server (NTRS)

    Swenson, Harry N.; Jones, Raymond D.; Clark, Raymond

    1993-01-01

    The Flight Systems Development branch of the U.S. Army's Avionics Research and Development Activity (AVRADA) and NASA Ames Research Center have developed for flight testing a Computer Aided Low-Altitude Helicopter Flight (CALAHF) guidance system. The system includes a trajectory-generation algorithm which uses dynamic programming and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and precision navigation information to determine a trajectory between mission way points that seeks valleys to minimize threat exposure. This system was developed and evaluated through extensive use of piloted simulation and has demonstrated a 'pilot centered' concept of automated and integrated navigation and terrain mission planning flight guidance. This system has shown a significant improvement in pilot situational awareness, and mission effectiveness as well as a decrease in training and proficiency time required for a near terrain, nighttime, adverse weather system. AVRADA's NUH-60A STAR (Systems Testbed for Avionics Research) helicopter was specially modified, in house, for the flight evaluation of the CALAHF system. The near terrain trajectory generation algorithm runs on a multiprocessor flight computer. Global Positioning System (GPS) data are integrated with Inertial Navigation Unit (INU) data in the flight computer to provide a precise navigation solution. The near-terrain trajectory and the aircraft state information are passed to a Silicon Graphics computer to provide the graphical 'pilot centered' guidance, presented on a Honeywell Integrated Helmet And Display Sighting System (IHADSS). The system design, piloted simulation, and initial flight test results are presented.

  14. Educating with Aircraft Models

    ERIC Educational Resources Information Center

    Steele, Hobie

    1976-01-01

    Described is utilization of aircraft models, model aircraft clubs, and model aircraft magazines to promote student interest in aerospace education. The addresses for clubs and magazines are included. (SL)

  15. 25 CFR 227.6 - Corporations and corporate information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Corporations and corporate information. 227.6 Section 227... § 227.6 Corporations and corporate information. (a) If the applicant for a lease is a corporation, it... the lands are located, evidence showing compliance with the corporation laws thereof. Statements...

  16. 25 CFR 213.14 - Corporations and corporate information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Corporations and corporate information. 213.14 Section... Corporations and corporate information. If the applicant for a lease is a corporation, it shall file evidence..., evidence showing compliance with the corporation laws thereof. Statements of changes in officers...

  17. Combat Maintenance Concepts and Repair Techniques for Helicopter Airframe Structures

    DTIC Science & Technology

    1981-01-01

    helicopter airframe and to de- velop concepts for the assessment and repair of airframe combat damage. A computer model was developed to generate...random simulated hallistic strikes on the Black Hawk helicopter airframe. Random shotlines were generated with the model , and cases involving damage...Distribution of Ballistic Hits on Helicopters from Southeast Asia Combat Experience 23 Shotline Simulation Model 24 Conventions for Azimuth and

  18. Economic Effects of Noise Abatement Regulations on the Helicopter Industry.

    DTIC Science & Technology

    1982-12-01

    are estimated. The effects an consumer utilization are also discussed. An appendix compares two independent research studies that used weight...helicopter by subsystem. This thesis proposes that if noise abatement regulations are iqposed on the helicopter industry without due consideration for future...abatement regu- lations on Sikorsky’s s-7S helicopter are estimated. The effects on consumer utilization are also discussed. kn appendix compares two

  19. Review of the transmissions of the Soviet helicopters

    NASA Technical Reports Server (NTRS)

    Chaiko, Lev I.

    1990-01-01

    A review of the following aspects of Soviet helicopter transmissions is presented: transmitted power, weight, reduction ratio, RPM, design configuration, comparison of different type of manufacturing methods, and a description of the materials and technologies applied to critical transmission components. Included are mechanical diagrams of the gearboxes of the Soviet helicopters and test stands for testing gearbox and main shaft. The quality of Soviet helicopter transmissions and their Western counterparts are assessed and compared.

  20. Evaluation of Standard Gear Metrics in Helicopter Flight Operation

    NASA Technical Reports Server (NTRS)

    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.

  1. Helicopter mission optimization study. [portable computer technology for flight optimization

    NASA Technical Reports Server (NTRS)

    Olson, J. R.

    1978-01-01

    The feasibility of using low-cost, portable computer technology to help a helicopter pilot optimize flight parameters to minimize fuel consumption and takeoff and landing noise was demonstrated. Eight separate computer programs were developed for use in the helicopter cockpit using a hand-held computer. The programs provide the helicopter pilot with the ability to calculate power required, minimum fuel consumption for both range and endurance, maximum speed and a minimum noise profile for both takeoff and landing. Each program is defined by a maximum of two magnetic cards. The helicopter pilot is required to key in the proper input parameter such as gross weight, outside air temperature or pressure altitude.

  2. Research requirements to improve safety of civil helicopters

    NASA Technical Reports Server (NTRS)

    Waters, K. T.

    1977-01-01

    Helicopter and fixed-wing accident data were reviewed and major accident causal factors were established. The impact of accidents on insurance rates was examined and the differences in fixed-wing and helicopter accident costs discussed. The state of the art in civil helicopter safety was compared to military helicopters. Goals were established based on incorporation of known technology and achievable improvements that require development, as well as administrative-type changes such as the impact of improved operational planning, training, and human factors effects. Specific R and D recommendations are provided with an estimation of the payoffs, timing, and development costs.

  3. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers put the finishing touches on new paint for the blades of a NASA UH-1H helicopter. They have changed the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen from above by a second helicopter. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  4. NASA helicopter blades get new paint job for safety

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers paint the blades of a NASA UH-1H helicopter, changing the black to a pattern of white and yellow stripes. The pattern provides better visibility in smoke and fire conditions. When the rotors are turning, the stripes create a yellow and white circle that is more easily seen by a second helicopter from above. The helicopters, primarily used for security and medical evacuation for NASA, will be used to deliver water via buckets during brush fires. The change was made to comply with U.S. Fish and Wildlife and Department of Forestry regulations for helicopter-assisted fire control.

  5. Automatic guidance and control laws for helicopter obstacle avoidance

    NASA Technical Reports Server (NTRS)

    Cheng, Victor H. L.; Lam, T.

    1992-01-01

    The authors describe the implementation of a full-function guidance and control system for automatic obstacle avoidance in helicopter nap-of-the-earth (NOE) flight. The guidance function assumes that the helicopter is sufficiently responsive so that the flight path can be readily adjusted at NOE speeds. The controller, basically an autopilot for following the derived flight path, was implemented with parameter values to control a generic helicopter model used in the simulation. Evaluation of the guidance and control system with a 3-dimensional graphical helicopter simulation suggests that the guidance has the potential for providing good and meaningful flight trajectories.

  6. Designing an autonomous helicopter testbed: From conception through implementation

    NASA Astrophysics Data System (ADS)

    Garcia, Richard D.

    Miniature Unmanned Aerial Vehicles (UAVs) are currently being researched for a wide range of tasks, including search and rescue, surveillance, reconnaissance, traffic monitoring, fire detection, pipe and electrical line inspection, and border patrol to name only a few of the application domains. Although small/miniature UAVs, including both Vertical Takeoff and Landing (VTOL) vehicles and small helicopters, have shown great potential in both civilian and military domains, including research and development, integration, prototyping, and field testing, these unmanned systems/vehicles are limited to only a handful of university labs. For VTOL type aircraft the number is less than fifteen worldwide! This lack of development is due to both the extensive time and cost required to design, integrate and test a fully operational prototype as well as the shortcomings of published materials to fully describe how to design and build a "complete" and "operational" prototype system. This dissertation overcomes existing barriers and limitations by describing and presenting in great detail every technical aspect of designing and integrating a small UAV helicopter including the on-board navigation controller, capable of fully autonomous takeoff, waypoint navigation, and landing. The presented research goes beyond previous works by designing the system as a testbed vehicle. This design aims to provide a general framework that will not only allow researchers the ability to supplement the system with new technologies but will also allow researchers to add innovation to the vehicle itself. Examples include modification or replacement of controllers, updated filtering and fusion techniques, addition or replacement of sensors, vision algorithms, Operating Systems (OS) changes or replacements, and platform modification or replacement. This is supported by the testbed's design to not only adhere to the technology it currently utilizes but to be general enough to adhere to a multitude of

  7. Extendable chord rotors for helicopter performance improvement and envelope expansion

    NASA Astrophysics Data System (ADS)

    Khoshlahjeh, Maryam

    A helicopter with a fixed geometry rotor, operating at a fixed rotational speed, performs sub-optimally over the vehicle’s flight envelope. On the other hand, if the rotor geometry and RPM can be varied from one flight condition to another, the aircraft performance can be substantially improved over the operating envelope. The geometry change considered in this study is the variation of rotor chord over a spanwise section of the blade. Simulations are based on a UH-60A Blackhawk helicopter with an effective chord increase of 20% realized by extending a Trailing-Edge Plate (TEP) through a slit in the trailing-edge between 63-83% blade span. Rigid and elastic blade models are studied. Since TEP extension changes the baseline SC-1094R8 airfoil profile, 2D aerodynamic coefficients of the modified profile from Navier-Stokes CFD calculations are used, coupled with 12x12 dynamic inflow and Leishman-Beddoes dynamic stall model in the Rotorcraft Comprehensive Analysis System (RCAS). From the simulations, reductions of up to nearly 18% in rotor power requirement are observed for operation at high gross weight and altitude. Further, increases of around 18 kts in maximum speed, 1,500 lbs in maximum gross weight capability, and 1,800 ft in maximum altitude are observed. Moreover, maneuvering flights can benefit from an extended chord. Required power for a steady level turn could be reduced nearly 7% at the maximum turn rate. Vibratory loads also reduce with TEP. Hub vertical shear, in-plane shear, and in-plane moment 4/rev component are reduced up to 47%, 29.6% and 51%, respectively, in a stall dominant condition. Furthermore, rotor speed variations of ±15% nominal RPM are considered in combination with TEP. Rotor speed reduction alone is most beneficial during low and light flight conditions. However, increasing rotor speed to 105% nominal RPM along with TEP offers additional 2,000 lbs payload capability, 5,000 ft gain in maximum altitude and up to 60 kts increase in

  8. Assessing the Impact of Future Operations on Trainer Aircraft Requirements

    DTIC Science & Technology

    2005-01-01

    unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 This product is part of the RAND Corporation monograph...about 1,100 of the aircraft were purchased through 1972, when the production line was closed (U.S. Air Force, 2003c). The T-38 has been modified...Future Operations on Trainer Aircraft Requirements expanding conflict in Southeast Asia and projections of high pilot production goals raised issues

  9. Identification of stability and control derivatives for AS 355 L2 helicopter with Quad-M/CTA methodology

    NASA Astrophysics Data System (ADS)

    de Oliveira, Sérgio Servilha; Menegaldo, Luciano Luporini

    2012-11-01

    This work presents results obtained from a study of case for H-55 Helicopter System Identification which was carried out by an implementation of Quad-M Methodology purposed for Jategaonkar. The implementation performed was based on Cruz et al whose works were developed in Centro Técnico Aeroespacial (CTA). A comparison between Stability and Control Derivatives tables from these results and those from literature is performed for some important flight conditions. This comparison allows us to conclude about the reliability of the method, to present preliminary SCD tables for the studied aircraft and point to possible future works.

  10. Flight Testing and Real-Time System Identification Analysis of a UH-60A Black Hawk Helicopter with an Instrumented External Sling Load

    NASA Technical Reports Server (NTRS)

    McCoy, Allen H.

    1998-01-01

    Helicopter external air transportation plays an important role in today's world. For both military and civilian helicopters, external sling load operations offer an efficient and expedient method of handling heavy, oversized cargo. With the ability to reach areas otherwise inaccessible by ground transportation, helicopter external load operations are conducted in industries such as logging, construction, and fire fighting, as well as in support of military tactical transport missions. Historically, helicopter and load combinations have been qualified through flight testing, requiring considerable time and cost. With advancements in simulation and flight test techniques there is potential to substantially reduce costs and increase the safety of helicopter sling load certification. Validated simulation tools make possible accurate prediction of operational flight characteristics before initial flight tests. Real time analysis of test data improves the safety and efficiency of the testing programs. To advance these concepts, the U.S. Army and NASA, in cooperation with the Israeli Air Force and Technion, under a Memorandum of Agreement, seek to develop and validate a numerical model of the UH-60 with sling load and demonstrate a method of near real time flight test analysis. This thesis presents results from flight tests of a U.S. Army Black Hawk helicopter with various external loads. Tests were conducted as the U.S. first phase of this MOA task. The primary load was a container express box (CONEX) which contained a compact instrumentation package. The flights covered the airspeed range from hover to 70 knots. Primary maneuvers were pitch and roll frequency sweeps, steps, and doublets. Results of the test determined the effect of the suspended load on both the aircraft's handling qualities and its control system's stability margins. Included were calculations of the stability characteristics of the load's pendular motion. Utilizing CIFER(R) software, a method for near

  11. Flight service evaluation of composite helicopter components

    NASA Technical Reports Server (NTRS)

    Rich, M. J.; Lowry, D. W.

    1982-01-01

    This first interim report presents the technical background for including environmental effects in the design of helicopter composite structures, and test results after approximately two year field exposure of components and panels. Composite structural components were removed from Sikorsky S-76 helicopters commercially operated in the Gulf Coast region of Louisiana. Fatigue tests were conducted for a graphite/epoxy tail rotor spar and static test for a graphite/epoxy and Kevlar/epoxy stabilizer. Graphite/epoxy and Kevlar/epoxy panels are being exposed to the outdoor environment in Stratford, Connecticut and West Palm Beach, Florida. For this reporting period the two year panels were returned, moisture measurements taken, and strength tests conducted. Results are compared with initial type certificate strengths for components and with initial laboratory coupon tests for the exposed panels. Comparisons are also presented with predicted and measured moisture contents.

  12. NASA/FAA helicopter simulator workshop

    NASA Technical Reports Server (NTRS)

    Larsen, William E. (Editor); Randle, Robert J., Jr. (Editor); Bray, Richard S. (Editor); Zuk, John (Editor)

    1992-01-01

    A workshop was convened by the FAA and NASA for the purpose of providing a forum at which leading designers, manufacturers, and users of helicopter simulators could initiate and participate in a development process that would facilitate the formulation of qualification standards by the regulatory agency. Formal papers were presented, special topics were discussed in breakout sessions, and a draft FAA advisory circular defining specifications for helicopter simulators was presented and discussed. A working group of volunteers was formed to work with the National Simulator Program Office to develop a final version of the circular. The workshop attracted 90 individuals from a constituency of simulator manufacturers, training organizations, the military, civil regulators, research scientists, and five foreign countries.

  13. Helmet mounted display systems for helicopter simulation

    NASA Technical Reports Server (NTRS)

    Haworth, Loran A.; Bucher, Nancy; Runnings, David

    1989-01-01

    Simulation scientists continually pursue improved flight simulation technology with the goal of closely replicating the 'real world' physical environment. The presentation/display of visual information for flight simulation is one such area enjoying recent technical improvements that are fundamental for conducting simulated operations close to the terrain. Detailed and appropriate visual information is especially critical for Nap-Of-the-Earth (NOE) helicopter flight simulation where the pilot maintains an 'eyes-out' orientation to avoid obstructions and terrain. This paper elaborates on the visually coupled Wide Field Of View Helmet Mounted Display (WFOVHMD) system technology as a viable visual display system for helicopter simulation. In addition the paper discusses research conducted on the NASA-Ames Vertical Motion Simulator that examined one critical research issue for helmet mounted displays.

  14. Noise reduction experience at Hughes Helicopter, Inc.

    NASA Technical Reports Server (NTRS)

    Janakiram, D. S.

    1982-01-01

    Noise reduction is mostly limited to light helicopters whose noise signature is dominated by their tail rotors. It is primarily hardware oriented. Well known noise reduction techniques such as reduction of rotor speeds with an accompanying increase in solidity to maintain performance, engine noise reduction with the use of exhaust mufflers, and acoustic blanketing of transmission and engine compartment are used. The concept of blade phasing as a means of reducing tail rotor noise is also used. Engine noise (exhaust noise), power train noise and airframe noise becomes important at low rotor tip speeds and means must be found to reduce these noise sources if further noise reductions are desired. The use of a special test rig aids in isolating the various noise sources and arriving at the penalties (performance or payload) involved in quieting them. Significant noise reduction are achieved for the light helicopter with minimum performance or weight penalties because of the dominance of a single noise source (the tail rotor).

  15. Helicopter low-speed yaw control

    NASA Technical Reports Server (NTRS)

    Wilson, John C. (Inventor); Kelley, Henry L. (Inventor); Crowell, Cynthia A. (Inventor)

    1993-01-01

    A system for improving yaw control at low speeds consists of one strake placed on the upper portion of the fuselage facing the retreating rotor blade and another strake placed on the lower portion of the fuselage facing the advancing rotor blade. These strakes spoil the airflow on the helicopter tail boom during hover, low speed flight, and right or left sidewards flight so that less side thrust is required from the tail rotor.

  16. Helicopter crew/passenger vibration sensitivity -

    NASA Technical Reports Server (NTRS)

    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.

  17. Feasibility of Helicopter Support Seek Frost.

    DTIC Science & Technology

    1980-05-01

    of helicopters in this function as a straight forward appiication. Our past and current work activity has required solutions to the type of problems ...climatic conditions permitted, the problems associated, the capabilities thus proven, and the plans for the future. In view of the growing need for more...more of a visibility problem . Again, this can be obviated by climbing to higher altitudes. Performance Effect Based on the initial trials, the British

  18. Detection And Avoidance Of Obstacles By Helicopters

    NASA Technical Reports Server (NTRS)

    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.

  19. Fatigue life estimates for helicopter loading spectra

    NASA Technical Reports Server (NTRS)

    Khosrovaneh, A. K.; Dowling, N. E.; Berens, A. P.; Gallagher, J. P.

    1989-01-01

    Helicopter loading histories applied to notch metal samples are used as examples, and their fatigue lives are calculated by using a simplified version of the local strain approach. This simplified method has the advantage that it requires knowing the loading history in only the reduced form of ranges and means and number of cycles from the rain-flow cycle counting method. The calculated lives compare favorably with test data.

  20. Building vibrations induced by noise from rotorcraft and propeller aircraft flyovers

    NASA Technical Reports Server (NTRS)

    Shepherd, Kevin P.; Hubbard, Harvey H.

    1992-01-01

    Noise and building vibrations were measured for a series of helicopter and propeller-driven aircraft flyovers at WFF during May 1978. The building response data are compared with similar data acquired earlier at sites near Dulles and Kennedy Airports for operation of commercial jet transports, including the Concorde supersonic transport. Results show that noise-induced vibration levels in windows and walls are directly proportional to sound pressure level and that for a given noise level, the acceleration levels induced by a helicopter or a propeller-driven aircraft flyover cannot be distinguished from the acceleration levels induced by a commercial jet transport flyover. Noise-induced building acceleration levels were found to be lower than those levels which might be expected to cause structural damage and were also lower than some acceleration levels induced by such common domestic events as closing windows and doors.