Developement and Evaluation of a Device for the Prevention of Arm Flail Injuries.
AIR FORCE AEROSPACE MEDICAL RESEARCH LAB WRIGHT-PATTERSON AFB OH
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Past attempts to provide arm flair protection for USAF emergency ejection seats have not been successful. The devices that have been designed have ranged from mechanically deployed web nets to paddles which retain the arms during the ejection sequence. Although each system has had advantages, factors such as mechanical complexity, lack of crew acceptance, weight, space limitations, and dependence on directional stability of the ejection seat have precluded their acceptance or operational effectiveness. To overcome these factors, the authors designed and tested an active limb restraint system that can be used in current and future escape systems. This system, referred to as the Nonrestrictive Arm Restraint NAR, is a sleeve-mounted strap configuration, as shown in Figure 1. It is attached to the seat by straps which are routed through snubbers to a shear pin on the aircraft floor. Seat motion up the ejection rails activates the system, simultaneously pulling the elbows of the crewmember to his torso and his wrists to the ejection controls. The crewmember is restrained in this position until released at seatman separation. A Laboratory test program was conducted to evaluate the effectiveness of the design. The tests included emergency ground egress, seatman separation, windblast, and upper limb capture and haulback.