Pertinent human and animal experiments applicable to space flight and crash impact forces are analyzed in this survey of the literature on human tolerance to rapidly applied accelerations. Human tolerance to sudden acceleration depends on the direction in which the accelerating force is applied to the body, the magnitude of the accelerating force, how long the accelerating force is applied, how rapidly the accelerating force is applied, and how the occupant's body is supported during acceleration. Using a trapezoidal pulse of seat or platform acceleration to compare data, it is shown that adequate torso and extremity restraint is the primary variable in tolerance to rapidly applied accelerations. The harness or restraint system must be arranged to transmit the major portion of the accelerating force directly to the pelvic structure and not via the vertebral column. When conditions of adequate restraint have been met, other variables such as direction, magnitude, and onset rate of rapidly applied accelerations govern maximum tolerance and injury limits. Adequately stressed, aft-faced passenger seats offer maximum complete body support with minimum objectionable harnessing. Such a seat, whether designed for 20-, 30-, or 40-G dynamic loading, would include a lap strap, chest (axillary) strap, and winged-back seat to increase headward and lateral G protection; a full-height integral head rest; arm rests (load-bearing) with recessed hand-holds and provisions to prevent arms from slipping either laterally or beyond the seat back; and leg support to keep legs from being wedged under the seat. For crew members and others whose duties require forward-facing seats, maximum complete body support requires lap, shoulder, and thigh straps; a lap-belt tie-down strap; and a full-height seat back with integral head support.

  • Corporate Authors:

    National Aeronautics and Space Administration

    Glenn Research Center, 21000 Brookpark Road
    Cleveland, OH  United States  44135
  • Authors:
    • Eiband, A M
  • Publication Date: 1959

Media Info

  • Features: References;
  • Pagination: 96 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00394074
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: NASA-Memo-5-19-59E, HS-026 419U, N-62-70341
  • Files: HSL, USDOT
  • Created Date: May 31 1985 12:00AM