Apparently Roy Scheider became quite adept at flying the Gazelle, mocked-up as Blue Thunder, as the movie progressed. Pick-ups, landings and straight-and-level were no problem for him. He is actually flying the heli in some of the on-board sequences. He always had a pilot with him obviously and while I don't think he ever held a licence, in my book, this makes him an honourary helicopter pilot.
R.I.P.