Bill Hagan is blunt in describing the problem with many seating areas in an airliner: “You have objects that are not friendly head-strike surfaces.” The former General Motors engineer is president of AmSafe Aviation, which makes 95 percent of the seat belts used on commercial airplanes. His company leads the way in implementing the use of airbags for airline passengers.
When you talk to somebody like Hagan who is responsible for designing safe occupant spaces in aircraft, you often hear terms like “head-strike surface.” At first these terms create an image that isn’t so pleasant. But new regulations that take effect later this month are aimed at increasing the margin of safety in a crash. That means many more airliners will minimize unfriendly head-strike surfaces by installing airbags in in problematic areas such as front row bulkheads and some of the reclining and bedlike seats often used in first class cabins.
The requirements take effect Oct. 27 and require all new airliners rolling off assembly lines to meet new FAA rules that say seats must withstand 16 times the force of gravity without deforming or detaching from the tracks securing them to the floor. That’s significantly stouter than the 9-g requirement in place since 1952. More importantly, passengers must be protected to this 16-g requirement. Many airliners already are equipped with the 16-g seats, but until now, only entirely new designs created after 1988 — such as the Boeing 777 — have been required to meet this standard. Singapore Airlines Adopts Life-Saving AmSafe Airbags
A large percentage of airplane crashes occur during takeoff and landing when speeds are relatively low and the aircraft usually meets the ground at a oblique angle. “Most are very survivable crash events,” Hagan says.
One of the problems is that in some seating areas the passengers are exposed to surfaces that do not absorb energy in an impact — the “not-so-friendly head-strike surfaces” Hagan referred to. In the event of a crash, most passengers are protected by the seat back in front of them which is designed to absorb much of the energy. But there is nothing to absorb that energy at the bulkhead or behind the immovable exit-row seats. Airlines could remove seats to meet the new requirement, but that would mean lost revenue. Many are opting instead for the seat belt-mounted airbag to meet the 16-g standard.
In the beginning, Hagan explains, the challenge facing engineers was how to mount airbags on the aircraft itself. You can’t mount them as you do in a car, where they’re installed in the dashboard, because “Every interior is different, it’s not practical.” The simple solution was to put the airbag in the seat belt. This not only simplifies the problem of where to place the airbag, Hagan said, but is a safer option. “The airbag inflates away from the occupant where it can’t induce an injury.”
In addition to protecting bulkhead and exit-row passengers, the seat belt airbags have allowed airlines to develop several creative seating arrangements. One example is the pod-type seats used by Singapore Airlines in the Boeing 777.
Singapore Airlines Adopts Life-Saving AmSafe Airbags
During development, the airline was having trouble meeting the 16-g requirement for the first class seats. “They had a lot of head-strike problems” says Hagan. But by using the seat belt airbag, the airline met the safety requirements. The airbags are now the norm on many airlines using similar premium seating arrangements.
Image and video: AmSafe Aviation
FAA Sled Test Without Airbag
FAA Sled Test With Airbag
http://www.wired.com/autopia/2009/10/airbags-help-airlines-meet-new-safety-standards/
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