Kinematics of U.S. Army Helicopter Crashes: 1979-85

All records of U.S. Army Class A and B mishaps of four types of helicopters occurring from Oct. 1, 1979, through Sept. 30 1985, were reviewed for terrain impact kinematics parameters. During this 6-year period, there were 298 mishaps involving 303 aircraft. Approximately 88% of these crashes were considered survivable. Mean and 95th percentile vertical velocity changes at the most severe terrain impact were similar for all aircraft types except the UH-60, which experienced significantly higher impact velocities (p <0.001). Overall 95th percentile vertical and horizontal velocity changes at the most severe terrain impact were 11.2 m · s^-1 and 25.5 m · s^-1, respectively. Both these values are substantially different from values cited in current design standards. Roll, pitch, and yaw attitudes at impact were similar for all aircraft and agreed with the values in current design standards, except that the distribution of roll angles was considerably wider. The importance of using current kinematic parameters for crashworthiness design standards and crash injury prevention is stressed. Recommendations are made to improve crashworthiness design standards.