Crashworthy concepts for airframe structures of general aviation aircraft have been investigated under the sponsorship of NASA Langley Research Center. Several crashworthy concepts of energy-absorbing lower floor structures were developed. Design support tests were conducted to determine the performance of these concepts. Five concepts were selected for fabrication as full-scale floor test sections. These floor test sections were designed to have a high strength structural platform, capable of attaching crashworthy, energy-absorbing seats, supported by an underfloor crush zone that provides energy absorption and controls the loads to this platform. The design of these floor sections was analytically verified with NASTRAN for the static conditions and with KRASH for the dynamic conditions. From the five selected concepts, eighteen floor sections (three or four sections of each concept) were fabricated and delivered to the NASA Langley Research Center where they were tested under static and dynamic loading conditions. As a result of this investigation, it appears as though several of the crashworthy concepts are feasible and can be incorporated into the airframe design of future general aviation aircraft.