'But if he starts to tumble,' says Dainese product manager Giovanni Fogal, 'the suit inflates.' While car airbags deflate almost immediately, the D-air Ski stays inflated for up to 10 seconds, to protect the racer until he comes to a stop. The algorithm is smart enough that it won't inflate even in some crash situations, such as when a racer loses an edge and slides to a stop. That data let Dainese's engineers code an algorithm that can tell, based on a racer's acceleration and body position, whether he's about to crash or just at the bottom of a post-jump compression. Dainese spent two years collecting data from test runs, using skiers from the Canadian and Italian national teams. There's even a USB port to download run data. Except for the airbag itself, it's all tucked into a hardened pocket on the back protector.

A rechargeable lithium-ion battery powers the system. A replaceable cold-gas canister provides the near-instant inflation. The D-air Ski has three gyroscopes, three accelerometers and a GPS unit. 'On a motorcycle there are a few fixed elements in play,' says Miller. In both sports, the biggest issue was figuring out how to accurately predict crashes, but skiing is a challenge a racer can be weightless because he's about to crash, or just going off a jump. And adapting it from the motorsports version was tricky.

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