‘The Mystery of D.B. Cooper’ Trailer: HBO Documentary Tries to Identify the Notorious Air Pirate In 1971, a man calling himself Dan Cooper hijacked a 727 airplane, stole $200,000, and parachuted out of the sky. Where he landed, no one knows: he was never seen or heard from again. But he certainly landed in the annals of folkloric history as a man who envisioned an audacious robbery and actually got away with it.