The NTSB is recommending the FAA require retrofitting shoulder harnesses in all general aviation aircraft that don't have them as the "cheapest and simplest" way of improving crash survivability. In a study that was mainly focused on the potential safety benefits of airbags in GA aircraft, the board determined that while airbags will probably help, installation of shoulder harnesses in lap-belt-equipped planes would make the biggest difference. "Based on an analysis of over 37,000 GA accidents, the Board concluded that the risk of fatal or serious injury was 50 percent higher when an occupant was only restrained by a lap belt as compared to the combination lap belt and shoulder harness," the board said in a statement. The NTSB could only find 10 survivable accidents with which to assess the value of airbags and found that of the 12 occupants of aircraft involved in those accidents, at least two of them avoided more serious injury or death because of the airbags. The board stops short of recommending that airbags be made mandatory and actually makes some safety recommendations about the design and installation of the bags, which deploy from the shoulder harness of specially equipped seatbelts.
The board found that the bag-equipped belts might not work as well on overweight people as on those with a body mass index (BMI) of less than 25 and recommends more work be done in that area. It also wants tighter rules to prevent both intentional and unintentional misuse of bag-equipped belts. For instance, in some aircraft, it's possible to reverse the belts, meaning the wrong airbag will deploy in a crash. The study did find the airbags deployed when needed and didn't go off by mistake. It gave kudos to the airbag manufacturers and aircraft builders for designing and installing the systems even though they aren't required by the FAA. "Although airbags have been mandated in automobiles for over a decade, the aviation industry has no such requirement for small aircraft," said NTSB Chairman Deborah Hersman. "The good news is that over 30 manufacturers have stepped up to the plate and offer airbags as standard or optional equipment." There are about 7,000 airbag-equipped aircraft on the U.S. registry, out of about 224,000 GA aircraft.