My father served in the US Army in World War II. These are the lyrics of the song he taught us, which he said that Army guys sang to poke fun at Air Corps / Air Force guys:

Up in the air, junior bird men
Up in the air, upside down!
Up in the air, junior bird men
Keep your eyes upon the ground, upon the ground!

And when you hear the doorbell ringing,
And you get your wings of tin,
You can bet those junior bird men
Have sent their boxtops in!