Attenuation and Simplified Testing Procedure of HIC for Aircraft Crash Safety Evaluation

The aircraft seats facing bulkheads, interior walls, class dividers, lavatory, front seat back or instrument panels of aircraft have presented problems demonstrating the compliance with the Head Injury Criteria (HIC) requirement. Full scale sled tests provide means of assessing the response of the occupants and the potential head injuries in an aircraft crash which is extremely costly, time-consuming, and provide too much scatter on the HIC. These factors have motivated the Federal Aviation Administration, seat and airframe manufacturers as well as research providers such as the National Institute for Aviation Research (NIAR) to pursue alternative testing procedures to replace the full-scale sled tests. This paper presents the results of a series of baseline sled tests of the system seat/ATD/restraint/bulkhead conducted at the NIAR horizontal sled which will be used to validate component test devices. Analytical approach including the nonlinear finite element modeling of the bulkhead as well as multibody modeling of the Hybrid II Anthropomorphic Test Dummy (ATD) were used for the design of simple energy absorbing bulkhead that would attenuate the HIC requirement.