A flight data recorder - the "black box" in every commercial aeroplane - is a crucial tool for dissecting what went wrong in the aftermath of a crash. Here's the key to its survival.
The black box dismantled here by Prof. Bill Hammack is a Sundstrand FA-542, likely used on a Delta DC-9 in the 1970s. And what makes it so indestructible is Inconel, a superalloy typically found in furnaces, gas turbine blades, NASCAR exhaust systems and other XXXtreme heat environments. Flight parameters are engraved onto an Inconel sheet throughout the trip, ensuring their survival no matter what.
And for those who wonder why they don't just make the whole plane out of what the black box is made of: among other things, Inconel's a terribly difficult metal to shape and machine. [Engineering Guy via Presurfer]