Epic thread bump!
And no, he hasn't been found.
A really interesting look at how hijackings plagued the US (and world) in the 1970s, with a lot of focus on how the airlines resisted additional security:
http://blog.longreads.com/2014/07/29...-in-the-1970s/
It gives an overview on Cooper at the end, but mentions a story about how a Calgarian nearly pulled off the same thing 11 days earlier after hijacking an Air Canada flight from Calgary to Toronto. He failed in "world's dumbest criminal" fashion.