Survivability and injuries from use of rocket-assisted ejection seats: analysis of 232 cases.
BACKGROUND
Ejection injury has been documented with respect to non-rocket-assisted seats, but there is little information on injuries associated with rocket-assisted seats. This study analyses the survivability of military accidents and the injuries associated with rocket-assisted ejection.


METHODS
A total of 232 Royal Air Force accident reports were accessed and aircrews' injuries were related to the aircraft parameters of ejection, aircrew anthropometry, and the ejection seat and parachute dynamics. Ejection sequences were simulated using a computerized modeling tool to provide information relating to the dynamic response index, acceleration of the ejection seats, and performance of the parachutes.


RESULTS
Ejection survival was 89.2% overall, 95.7% for within envelope ejections and 23.8% for out of envelope ejections. There were 29.4% of aircrew who sustained spinal fractures. Another 14.2% of aircrew sustained a head injury and the incidence of head injury in Tornado ejectees was higher than the other aircraft types. Compared with 5.8% of ejectees from aircraft with an arm restraint system, 11.2% of aircrew sustained upper limb flail injuries from ejecting from aircraft without an arm restraint system. Arm flail injuries occurred at a higher aircraft speed at ejection compared with ejections where no arm flail injuries were sustained. There was also 18% of aircrew who sustained lower limb parachute landing injuries.


CONCLUSIONS
Information from this study has lead to a redesign of the Tornado ejection seat headbox, an improvement in the Tornado ejection catapult dynamics, an upgrade of escape system parachutes, and provided evidence that future aircraft should be fitted with an arm restraint system.
Lewis
Matthew E
ME
RAF Centre of Aviation Medicine, RAF Henlow, Bedforshire, UK. hlw-cam-aioc@henlow.raf.mod.uk
D000060:Accidents, Aviation; D000401:Aircraft; D006801:Humans; D008889:Military Personnel; D006113:United Kingdom; D014947:Wounds and Injuries / Q000453:epidemiology*