Effect of crash pulse shape on seat stroke requirements for limiting loads on occupants of aircraft

An analytical study was made to (1) provide comparative information on various crash pulse shapes that potentially could be used to test seats to the parameter conditions included in Federal Regulations Part 23 x 23.562(b)(1) for dynamic testing of general aviation seats, (2) show the eects that crash pulse shape can have on the seat stroke requirements necessary to maintain a specied limit loading on the seat/occupant under various vertical crash pulse loadings, (3) compare results from certain analytical model pulses with approximations of actual crash pulses, and (4) compare analytical seat results from application of the specied test parameters of the seat test regulation with experimental airplane crash data. Equations for ve models of potentially useful pulse shapes were derived which express the displacement of the aircraft structure and the displacement of the seat/occupant in terms of the maximum deceleration , velocity change, limit seat pan load, and pulse time. From these equations, analytical seat stroke data were obtained under the test conditions as spec-ied in Federal Regulations Part 23 x 23.562(b)(1) for dynamic testing of general aviation seats.