Keep 'Em Flying (1941)

Continuity mistake: When Lou is finally convinced that he won't get hurt being the umpire in the "Hit The Umpire" game, he runs to take his place then stops in front of the batter. As Lou runs to take his place he isn't wearing a baseball cap, nor is he holding one in his hands, but in the next shot, when he gets hit in the head by the batter, one has mysteriously appeared on his head.

Continuity mistake: The plane that Bud and Lou are flying keeps changing colors. In some shots the plane is light gray but in other shots the plane is red.

Blackie Benson: Heathcliff! Where are you taking that torpedo?
Heathcliff: I'm not taking it, it's takin' me.

Heathcliff: I gotta go home, I forgot something.
Blackie Benson: What'd you forget?
Heathcliff: I forgot to stay there.

Blackie Benson: No, you don't want to drink. Remember, every time you go into a barroom, the Devil goes in with you.
Heathcliff: If he does, he buys his own drink.