Patent ID: 7866606

Claim:
An energy absorber system for aircraft survivability comprising a seat frame configured for a backrest of a seat, energy absorbers configured for attachment to the seat frame and providing energy absorption in a plurality of occupant weight ranges, said system providing a controlled range of dynamic response index (DRI) and of lumbar load level in one of said occupant weight ranges and greater energy absorption stroke distance in one of said occupant weight ranges as the occupant weight increases toward its maximum value for the weight range, said energy absorbers providing a plurality of energy absorption force levels throughout an energy absorption stroke, said energy absorbers providing an initial spike energy force level at about 0.1 inches of energy absorption stroke, and then after said initial spike energy force level, a plurality of increasing energy absorption force levels as the energy absorption stroke increases, the energy absorption force levels increasing monotonically over an entire remainder of the energy absorption stroke after said initial spike energy force level, thereby providing a desired maximum acceleration for any said supported weight throughout any of the said plurality of occupant weight ranges.