In November 1971, a man calling himself Dan Cooper hijacked a plane flying from the US city of Portland to nearby Seattle. He demanded $200,000 in cash and four parachutes. ‘Cooper’ later jumped from the aircraft and has never been seen again. The case remains one of America's biggest criminal mysteries. We hear from the co-pilot on the flight, Bill Rataczak.

(Photo: Artist sketches of D.B. Cooper. Credit: FBI)