Hey Oddone I remember Your thinking of D.B. Cooper
Interesting Program on National Geographic referred to this as the "Worlds only unsolved Hyjacking"
D.B. Cooper Flight 305 North West Orient from Seattle to Mexico November 24th 1971
Was an interesting TV Documentary on National Geographic about this guy where a group of people re-enacted what was assumed to have occured even the jump at night and also having the rigg etc dropped into a pool from above along with a sack of "money" just to see how long you could stay afloat.
Made interesting viewing some more back ground info here
http://www.answers.com/topic/d-b-cooper