A CORRELATIVE INVESTIGATION OF SIMULATED OCCUPANT MOTION AND ACCIDENTREPORT IN A HELICOPTER CRASH

Background: In the late 1980's, an Army Apache helicopter crashed duri ng a training mission, resulting in fatal injuries to the rear seat pi lot and survivable injuries to the front seat copilot. U.S. Army inves tigators assessed the aircraft damage and aircrew injuries, and examin ed the helmets, restraint systems, and crashworthy seats. Hypothesis: Computer simulations that approximate an actual crash event can provid e insightful output (human body motions and forces on the human body) that illuminates our understanding of the injury dynamics and the effe ct of safety systems designed to minimize injury. Methods: Crash kinem atics and vehicle accelerations were derived from the investigation an d inferred from the aircraft damage, and input to a computer-based ana lytical simulation that calculated the dynamics and forces to which th e crew were exposed. Results: We treat the simulation like a looking g lass into the event, revealing how and when safety devices could have responded during the crash, and the nature of injury-producing forces experienced by the occupants. Computer simulated whole-body and head-n eck motion are graphically displayed, along with plots of joint forces , seat stroke, harness belt acceleration, and occupant accelerations. Conclusions: The calculated motions and forces indicated that injuries found in the accident were likely, hence the simulation may indeed be representative of the actual event.