Stunt Flying by Art Scholl
In 1978 I spent some time formation flying with Art Scholl and doing photography. We had some time to discuss his career, and he told some great stories. One was about this movie. It seems they had several pilots attempt to do an outside loop in this airplane, which is actually a disguised DeHaviland Chipmunk. Then they called in Art, but no one bothered to tell him that anyone else had tried, or that there was any problem. Of course Art was accustomed to flying his Chipmunk in airshows, and quickly figured out the proper entry speed. Too slow and it would do an outside snap roll, too fast and there was not enough elevator power, apparently a very marginal maneuver in this airplane!
Art loved to say the directors complained he was the most expensive stunt pilot in Hollywood, and he would say "Yes, but the others are all dead". Art died in 1985 while filming a scene for "Top Gun"