Sources:
– [Wikipedia — D.B. Cooper](https://en.wikipedia.org/wiki/D._B._Cooper)
– [HistoryLink — Brian Ingram 1980 discovery](https://www.historylink.org/file/23059)
– [Stars and Stripes — Richard McCoy and D.B. Cooper](https://stripes.com/history/2024-02-20/richard-mccoy-db-cooper-skyjacking-13064153.html)
– [The Conversation — Aviation security and Cooper](https://theconversation.com/d-b-cooper-the-changing-nature-of-hijackings-and-the-foundation-for-todays-airport-security-185562)
– [History.com — Who was D.B. Cooper](https://www.history.com/articles/who-was-d-b-cooper)
– [Everything-Everywhere — The Legend of D.B. Cooper](https://everything-everywhere.com/the-legend-of-d-b-cooper/)
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## The Night of the Jump: Reconstructing the Conditions
When Flight 305 climbed away from Sea-Tac at approximately 7:40 in the evening on November 24, 1971, it was carrying a man who had, in the space of a few hours, executed a hijacking with no visible panic and no recorded violence. What happened next—in the air, in the dark, somewhere over the mountains and valleys of southwestern Washington—is a matter of physical reconstruction and informed inference, not direct observation.
The aircraft was a Boeing 727-100. The 727 was designed for short- to medium-range routes, and one of its engineering features was a distinctive tail section: the engines were mounted at the rear of the fuselage rather than on the wings, and the aircraft was equipped with an airstairs system at the rear that could, in earlier versions of the plane, be deployed and operated while the aircraft was in flight. This feature was relatively obscure but was known within the aviation industry. It had been used in at least one prior incident before November 1971, when a man named Martin McNally hijacked another aircraft and jumped from the aft stair—also in 1971, months after Cooper.