At the time this movie was filmed, Errol Flynn and David Niven shared a rented house at Malibu, which they named "Cirrhosis-by-the-Sea" because of all the hard drinking and sex they were having with several women.
The filmmakers needed several shots of the planes taking off and landing. They assembled a squadron of 17 vintage WW1 aircraft, most of them Nieuports. Flying them proved just as hazardous as in WW1. By the time filming ended, stunt flyers had crashed 15 of them.
Courtney (Errol Flynn) says that his father was a professor of biology at Queen's. In fact, Errol Flynn's father, Theodore Thomson Flynn, was a professor of biology, first at the University of Tasmania and later at Queen's University in Belfast, Northern Ireland. In Tasmania he did pioneering work on the declining population of the thylacine, or "Tasmanian wolf", which went extinct in 1936.
One of the Nieuports used in the movie is now on display at the Army Aviation Museum at Fort Rucker Alabama.