Abstract:
A selectable profile energy absorber (SPEA) system was developed for crashworthy helicopter troop seats. This system combines information from an on-seat sensor and the aircraft data bus to tailor the energy absorber force profile not only to the weight of the occupant, but also to the predicted crash severity. The development testing was conducted using a vertical seat orientation on a drop tower under the U.S. Army Aircrew Survivability Technologies Project. This second Transport Rotorcraft Airframe Crash Testbed (TRACT 2) presented the opportunity for Safe, Inc. to independently test the SPEA system on a troop seat in an airframe undergoing a combined vertical and forward crash impact. The SPEA system is designed to use the lowest possible EA force profile considering the available stroking distance. Despite a component failure, the SPEA delivered a peak lumbar force of 572 lbf in a 50th-percentile male ATD and stroked 10 of an available 12 inches.