Airplane seats are tested using some of the same methods highway safety authorities use on car seats. The plane seats are tested on sleds, using
crash-test dummies borrowed from automobile testing. There are a variety of test criteria, including one for head trauma that is the same as that used by the National Highway Traffic Safety Administration.
BORROWING FROM AUTOMOBILES
The changes to the seats themselves, and the floor structure that supports them, will not be obvious to passengers. But the air bags are visible. They are built into one side of the lap belt, which appears a little thicker.
The air bags also borrow technology from automobiles. They are set off by a shock meter that comes directly from cars. And like the systems used in cars and trucks, the seat belt air bags in planes are designed not to deploy inappropriately — in cases of air turbulence, for example.
In fact, said Hagan, this is simple, because the air bag sensor system watches for shocks on the axis on which the plane is traveling; it does not monitor up-and-down or side-to-side movements of the kind produced by turbulence, he said.
The air bags are widely used in first or business-class cabins, where the seat in front is too far away or angled in such a way that it cannot function as a cushion. In coach class, the air bag has started out for use in front rows, exit rows and bulkhead seats, near galleys or toilets. In other seats, the passenger gets some protection from the seat back directly ahead, which is designed to break in a controlled fashion, providing a cushion.
Singapore Airlines flies 777s with wide intervals between seats and uses the air bag, Hagan said. JAL, Cathay Pacific and Virgin also use them, he said.
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