Evaluation of the Instrumented Ball Impact Procedure to Assess Head Impact Protection in Airplanes

The instrumented ball impact test procedure, defined in Federal Aviation Administration (FAA) Advisory Circular (AC) 25-17, is one of the means of compliance with requirements for head impact protection for structures in aircraft interiors. A series of tests was performed based on this procedure, using a 13 lb. and a 16 lb. bowling ball instrumented to measure impact accelerations. Drop tests with the ball were conducted on various materials, including Ensolite and rigid foam pads. The results of the instrumented ball tests were compared with head impact results on the same pad materials in sled tests using an anthropomorphic test dummy (ATD). A comparison of the instrumented ball pass/fail criteria of AC 25-17 and the contemporary Head Injury Criteria (HIC) from ATD head impacts is presented.