SBIR-STTR Award

The current five-point military aviation restraint system (for non-election crew seats) when properly used (i.e., Tightly adjusted, can provide good occupant crash protection. The restraint systems also include an inertial reel on the seat back which is designed to lock the should straps at the onset of a crash, in the same manner that the common automobile seat belt inertial reel locks when lerked quickly. By locking the inertial reel, the crewmember's forward motion is limited to the amount of stretch in the belts, thereby greatly reducing the risk of serious injury (or death) due to head (or upper torso) impact with the instrument panel or control stick. However, military helicopter crewmember's typically will loosen the restraint shoulder straps in order to gain increased comfort and mobility (range of motions). Since the crewmembers are unable to tighten the restraint system in an spending crash situation, the restraint system's ability to adequately protect them during the crash event is degraded. This proposal describes AST's technical approach to solving this problem, our unique capabilities to accomplish the project, personnel qualifications, and related experience.

A frequent cause of death and serious injury in "survivable" helicopter crashes is that crewmembers have a tendency to significantly loosen their restraint system (shoulder straps) to gain comfort and mobility during flight operations. The loosened shoulder straps increase the occupant "flail" envelope and degrade the restraint system's ability to protect the occupant during a crash. Other factors (strap elasticity between the initeria reel and the seatback strap guide, and inertia reel "film-spooling" and prelock payout of the webbing) combine to icnrease the occupant flail envelope by 10 inches. The objective of the SBIR Phase I effort was to study the feasibility of designing a device that would automatically sense crash onset and pretension the occupant's restraint system and reduce/eliminate the negative effects of strap elasticity, and inertia reel film-spooling and prelock payout. In so doing, the pretensioning device can provide better occupant crash protection (by reducing occupant flail), thereby reducing the potential for death or serious injury in survivable crashes. The AST Phase pretensioning device design clearly demonstrated that such a device is technologically feasible and meets all Phase I design goals. The relatively simple design will permit cost-effective production and minimal in-survice maintenance. During the proposed Phase II effort, AST will perform further design optimization and testing of the pretensioning device, leading to commercial development during Phase III.

Keywords:
Crash Protection Aircraft Accidents Aircraft Crashworthiness Restraint Systems Safety Crash Sensor