The joke Rascal heard from the waist gunner of Windy City is pretty funny, even if the telling of it is under less than ideal situations, nor can anybody remember his name.
After the crew is told to stand at the ready, and Dennis decides it's a good time to "double double check" everything, Luke is annoyed. As the shot moves to the other crew exiting the bomber, you can still hear Dennis and Luke in the background, with Luke answering every check in an increasingly snarky voice.
It's dark to be sure, but when Dennis' thermos of tomato soup explodes after a flak hit, the ensuing freak out between Dennis and Luke, with each of them saying the other's hit, and then suggesting the other must be in shock since he doesn't think he's hit, is morbidly funny.
The pilot, Dennis, suggests everyone come work for him at his family's furniture business after the war. The silence on the intercom is deafening.
Dennis: (bitterly) Like I said, don't give it a thought.
Luke: That's just what we need; you ordering us around for the rest of our lives. (''sarcastically') Let's do the pre-flight check!
Then the whole crew pitches in mocking Dennis's by-the-book, uptight reminders.
It's a very odd moment of comedy, but before the flight, when they're all waiting around, Danny is teased into reading a poem he's written about being an airman: 'Those that I fight I do not hate,/Those that I guard I do not love', etc. The crew, initially sarcastic, ends up being deeply moved by the poem. Later on, when Danny has been seriously injured, the thing that makes him come out of unconsciousness is the sudden realisation that it's not by him at all, but by William Butler Yeats. This is especially funny if you knew all along that the poem was by Yeats and thought that the film was gambling that the audience wouldn't notice.