Most of the extras in the Pensacola Florida scenes were actual Navy flight students and flight instructors. Although the Navy objected, director John Ford made certain that the military men were paid "extra" wages.
There is a scene in the movie where we see the director, played by Ward Bond, looking at a clip of a film written by the main character. The clip is from the film Hell Divers, which was actually written by Frank Wead. In the same scene, Bond asks one of the producers "How'd you like that kid with Beery" (Wallace Beery), the producer says "Great. Sign him up." The actor they are talking about is Clark Gable
According to director John Ford, "Everything in the picture was true. The fight in the club - throwing the cake - actually happened. I can verify that as an eyewitness. I ducked it. And the plane landing in the swimming pool right in the middle of the Admiral's tea - that really happened."
After John Dodge (the fictional version of John Ford) gives Spig a job writing for his studio, he is lead out to his new office to begin work and passes in front of numerous actor's head shots. Wayne pauses for a beat in front of one of his earliest head shots before continuing.