Cory Doctorow at Boingboing drops a fascinating post about how the Federal Government does crash tests on jet airliners. Hit the link for the silent video from inside the plane filled with crash test dummies, and the link to the original post on CoolGov. Gorgeous and terrifying, and well worth a look.
I remember seeing a program about the test pilots whose job it was to try to break 747s and such, and the part I vividly remember showed a pilot in an elaborately protected cockpit flying low over an airfield and trying to knock the tail off the plane by dragging it along the runway. Crazy.