These experiments exposed for the first time human subjects simultaneously to decompression events and to mechanical forces. The selected profiles simulated an accidental decompression and subsequent emergency descent of a high altitude/multi Mach transport aircraft. Using the uniquely versatile centrifuge of the Naval Air Development Center, the volunteers, accompanied by on board observers, experienced a simulated take off and climbing flight, including a nose up rotation of 22 degrees, a cruising flight of 20 minutes at 8,000 feet cabin altitude, a decompression up to 37,000 feet within 3 minutes, one minute dwelling time at 37,000 feet, and a linear descent to 8,000 feet within 6 minutes. This decompression profile is identical to 'Limit IV', which is identified as 'worst possible case' in the SST Tentative Airworthiness Standards, Part 25 of the Federal Aviation Administration. The dynamic simulation included a moderate +G sub z load shortly after the decompression event, which simulated the pilot's maneuvers to 'ease' from the cruising flight into the emergency descent and a G sub x load, which simulated the deceleration in the direction of the flight path, due to the decrease of speed from multi-Mach to subsonic values. The ten subjects underwent the experimental conditions in forward facing and rearward facing position. In half of the experiments the overhead mask delivery mode was employed; in the other half the seatback delivery mode. The masks were presented when the cabin altitude reached 12,000 feet. It was shown that a healthy male population (average age 27.7 years) had no difficulties to reach for and don the mask correctly. The average donning time was 12.2 seconds. Earlobe oximetry and the modified number writing test of Lottig did not reveal hypoxic conditions at any time.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Integrated Simulation of Atmospheric Pressures and Dynamic Forces During Accidental Decompression and Subsequent Emergency Descent of High Altitude Transport Aircraft


    Contributors:
    H. J. vonBeckh (author) / W. P. Baas (author)

    Publication date :

    1975


    Size :

    47 pages


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English