Review of major injuries and fatalities in USAF ejections, 1981-1995.

Our laboratories are examining injuries and deaths resulting from mechanical forces applied to aircrew members in the course of Department of Defense aviation operations. In this paper we report only on bodily injuries sustained during ejection from US Air force, aircraft for the fiscal years 1981-1996, that is, major injuries and fatalities resulting directly from seat acceleration forces, from aerodynamic forces applied to crew members during escape through the effects of windblast and parachute opening shock; from direct contact: and from parachute landing injuries. Such injuries occur typically to the head, neck, cervical spine, thorax, thoracolumbar spine, ribs, pelvis, and the upper and lower extremities. Injuries are usually caused by anomalies in the ejection sequence or by delaying ejection until too close to the ground. Conversely, a planned ejection in a modern ejection seat in controlled, low speed flight imposes forces well below injury thresholds. In the USAF, 10-50 aircrew eject yearly, with a decline since 1991. We conclude that the risk of fatality is 0-11% and of major injury is 2-25%. Both are remarkably low and decreasing in the later years of this study period. The absolute number of head, neck, and spine injuries is 0-10 yearly and similarly decreasing. The results of this study are intended to provide a basis for estimating potential savings in deaths, injuries, and costs expected from the development of improved protective measures.