"Pig Foot Pete", performed by Martha Raye in the film, was a 1942 Academy Award nominee for Best Song. However, on the ballots the song was attributed to Hellzapoppin', though it never appeared in that film. The Academy has no record of how the error occurred.
For the torpedo chase, Lou Costello did his shots in front a a rear projection screen. For the long shots it's Pat Costello, Lou's brother, doubling him.
Maj. Robert Lee Scott was more than just the "technical advisor" for this film. As the base commander at Cal Aero, the training facility where "Keep 'Em Flying" was filmed, he would not permit a civilian to perform the scene where a trainer is taxied fast through the four hangars, which were built end-to-end. In his book, 'Day I Owned the Sky', Scott (author of 'God Is My Co-Pilot') revealed that he performed the stunt himself.
The original trailer was actually a one-reel recruitment short, running about nine minutes, for the Army Air Corps which included clips from this film.
The songs "I Won't Forget the Dawn", "What Kind of Love Is This" and "You Don't Know What Love Is" were written for the picture by Don Raye and Gene de Paul but not used.
This was originally planned for production after Ride 'Em Cowboy. The huge success of Abbott and Costello's previous service comedies, Buck Privates and In the Navy, caused Universal to produce this first. The War Department also announced a recruitment campaign called "Keep 'Em Flying Week" which Universal could use as a patriotic tie-in.