Shadow in the Cloud

The animated segment at the beginning of the film is based on Private Snafu, a series of adult-oriented instructional shorts meant to educate enlisted personnel on army discretion, hygiene, combat readiness and daily life. They were produced between 1943 and 1945, and given that they were not meant to be public, were free from censorship restrictions. The title character, parodied in the film, comes from the military acronym "Situation Normal, All Fucked Up".

The B-17's ball turret couldn't be entered from inside the aircraft when it was on the ground, as it required the ball turret guns to be pointed downward for the hatch to be opened and there wasn't enough clearance between the aircraft and the ground to do so.