Rotorcraft Crash Mishap Analysis (Revised)
Final rept. 7 Mar 2008-30 Jun 2009
SAFE INC TEMPE AZ
Pagination or Media Count:
The method and results of a study using rotary wing crash data from the Army Aviation Mishap database are reported. The study was conducted to support the Full Spectrum Crashworthiness initiative with the objective of providing a current basis for revising the crashworthiness design criteria. For this study, crashes were divided into two types directly to terrain, and those following an inflight obstacle strike. Thirty percent of the crashes studied were post-obstacle crashes and this fraction appears to be higher for the newer generation aircraft. The two crash types differ in both kinematics and outcomes. The post-obstacle crashes were characterized by higher vertical velocities, more vertical impact angles, and a broader distribution of attitude angles. The post-obstacle crashes analyzed were less survivable and more injurious. Data on the impact surface revealed that 16 percent of all crashes occurred onto prepared surfaces, whereas 66 percent occurred onto sod. Crashworthiness was evaluated by estimating the velocity above which all aircraft occupants experienced severe injury. A recommendation is made to reconsider crashworthiness strategies that are functional only for aircraft impacting vertically and close to the normal flight attitude.