The United States Army Aviation Engineering Flight Activity conducted a climatic laboratory evaluation of the Boeing Vertol YCH-47D helicopter. Approximately 17-1/2 hours of aircraft operating time and 22 test runs were required to complete the test. The YCH-47D systems, subsystems and components were evaluated at stabilized temperatures ranging from -65 F to +125 F. In some cases, inconclusive results were obtained at the colder temperatures because the test was conducted without rotor blades. The foremost of which are the apparent inability of the flight control hydraulic fluid to warm sufficiently for flight and the pilot's inability to neutralize the flight controls prior to engine start. The YCH-47D performed acceptably from -25 F to 125 F and exhibited potential for operation at a temperature of -50 F. Two deficiencies were identified: (1) failure of the engine control lever to control the engine during start because of excess moisture in the cockpit; and (2) the erratic operation of the hydraulic power transfer units at -50 F. A total of 14 shortcomings were also identified. Further engineering testing below -25 F with rotor blades installed is recommended to determine if the hydraulic fluid temperature can be increased and maintained in flight at a level that would provide satisfactory flight control response and to evaluate the use of MIL-H-5606 hydraulic fluid at the lower temperatures. The operator's manual should specify a minimum temperature for aircraft operation. (Author)


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Climatic Laboratory Evaluation YCH-47D Helicopter


    Contributors:
    J. R. Niemann (author) / C. F. Adam (author) / J. A. Brown (author)

    Publication date :

    1981


    Size :

    222 pages


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English




    Climatic Laboratory Survey Hughes YAH-64 Helicopter

    G. L. Bender / C. F. Adam / R. T. Savage | NTIS | 1982



    ARTIFICIAL ICING TESTS OF THE S-92A HELICOPTER IN THE MCKINLEY CLIMATIC LABORATORY

    Flemming, R. J. / Alldridge, P. / Doeppner, R. et al. | British Library Conference Proceedings | 2004


    Artificial Icing Tests of the S-92A Helicopter in the McKinley Climatic Laboratory

    Flemming, Robert / Alldridge, Philip / Doeppner, Ronald | AIAA | 2004


    Climatic Laboratory Test. OH-58A Helicopter Equipped with XM27E1 Machine Gun Armament System

    D. G. Tyson / J. V. Pincavage / N. J. Donaldson et al. | NTIS | 1970