Factual error: When the crew in the plane gets ready to drop the bombs on the refinery, Hogan (in the pilot seat) tells Carter (who is looking through the bomb sight) exactly when to push the button. In fact, the pilot of a WW2 bomber had no way of even knowing when exactly to release the bombs - it was the job of the bombardier, looking through his targeting optics, to know that. Carter at the bomb sight should be telling Hogan how exactly to steer to get the bombs onto the target.
Continuity mistake: Hogan Gives a Birthday Party when the prisoners capture a German plane. When it is taking off, it is an English Lancaster bomber with a twin tail. As it is flying overhead, it is an American B-17 with a single tail. Finally as it is shown flying, it is a German FW-200 maritime bomber.