CRASHWORTHINESS ANALYSIS OF COMMUTER AIRCRAFT SEATS.

During the past several years, the Federal Aviation Regulations (FAR) have been significantly modified with respect to seat/restraint system strength, attachment of seats to the aircraft structure, and the means by which they are to be evaluated. Aircraft accident data, human tolerance levels, and aircraft structural characteristics have been considered in the development of these new standards. Dynamic testing is now required for seats to be installed in general aviation aircraft, transport category aircraft, and rotorcraft. Performance criteria are similar to those specified by the Federal Motor Vehicle Safety Standards for automobiles but also include a limit on pelvic force, in order to prevent spinal injuries which may be caused by the vertical component of impact force. A category of aircraft that has not as yet been affected by the rule modifications is the commuter type aircraft, which seats 10 to 19 passengers. Since this airplane is closer in size to general aviation aircraft than to large transports, it is also covered by FAR Part 23. The Federal Aviation Administration is currently involved in the conduct of a test program addressing commuter aircraft occupant crash safety. In support of this effort, a research program the includes full-scale aircraft drop tests, sled tests of seats, and computer simulations is being conducted. This report describes the use of the SOM-LA (Seat/Occupant Model - Light Aircraft) program in modeling three commuter aircraft seats. The predicted response of the seats to a potential set of test conditions is described. Crashworthiness, Aircraft seats, Restraint systems, Computer simulation.