sentences:  Costello's brother Pat Costello was used as Lou's stunt double.Cinematographer Elmer Dyer filmed the aerial sequences with Paul Mantz looking after the aerial "stunts".Although "Keep 'Em Flying" was filmed after "Ride 'Em Cowboy", the film was released first to coincide with the War Department's "Keep 'Em Flying Week".Reviews from critics were generally not as positive as those for previous Abbott and Costello films.