At mission start it looks like you're saluting for the briefest moment. That's a bug.

Now for the actual bug, watch the video, it's kinda funny actually.

Nose dive towards the ground, make sure you're parallel with the ground, it doesn't work if you take the ground on an angle. Then hit the ground, you don't die. You get hurt. You spin in the air its kinda funny. Your helicopter looks like its blown up but its not smoking or on fire + your copilot isn't dead he's in the chopper.. hidden.

Check it out anyways.