IBAHRS - An Inflatable Restraint System for Helicopter Aircrewmembers.

The Inflatable Body and Head Restraint System (IBAHRS) is a new concept in helicopter aircrew restraint which utilizes inflatable airbag technology for increased crash protection. IBAHRS uses a conventional helicopter restraint harness with bladders attached and neatly folded to the underside of the shoulder harness. Inside each bladder is a small solid propellant gas generator. During a crash, an omnidirection crash sensor remotely located on the aircraft, sends an electric current to a squib in each gas generator. This action inflates the bladders with a nontoxic gas in under twenty milliseconds, and removes the slack in the restraint. This tightening action couples the occupant more firmly to the seat and reduces the dynamic overshoot which results with a loose restraint during a crash. The wearer's strike potential with cockpit objects is reduced as is strap loading on his torso when the inflated bladders are compressed during crash loading. A reduction of strap load concentration on the body is achieved because of the increased bearing surface provided when the restraint is inflated. An appendage of the upper restraint inflates under the wearer's chin to reduce potential injury due to violent forward head motion which occurs during a crash. A crotch strap is provided to prevent submaring by the seat occupant. This report describes the current configuration of the advanced development model of IBAHRS and details its principle of operation.