[sailor76]

Cooper ordered the pilot to remain below an altitude of 10,000 feet and to keep the airspeed below 150 knots. An experienced skydiver would easily be able to dive at 150 knots.

http://www.crimemuseum.org/crime-library/d-b-cooper/

150 KN is about 175mph. Not a problem for an experienced jumper especially if he flared his body out and slowed down to a terminal velocity of about 120mph

[wastoute]

Having exited an aircraft at 120 mph I would not care to do it again. It was like being thrown into a brick wall. I think it would be hard to exit at 175 or even 150 and maintain consciousness.