At about the 53 minute mark Pappy and a nurse jump into a jeep to race off to see about arriving planes, but at the front left of the jeep, Meatball the dog can be seen left behind on the beach as the jeep races off. When the jeep arrives at the landing strip at about the 53 and 55 minute mark, Meatball the dog is sitting on the nurse's lap in the jeep.
During Casey's speech to the men about being put in charge, from one angle, Anderson is smoking a cigarette but from another, he's drinking alcohol.
When the squadron is issued flak vests, they are taken out of boxes marked as "flack" vests. Not only is it spelled wrong, the word flak is an abbreviation of the German word "Flugabwehrkanone" (anti plane cannon) from which it is derived. Shipping crates containing military equipment would be lettered with more proper terminology not something akin to a slang phrase.
Near the end, an airplane is show having be shot and trailing smoke. As the airplane zooms toward the ground and the underside is visible it is almost comically apparent that it is an effects smoke generator.