
Revealing mistake: When Margaret whistles for the "third wave" she places Winchester's French horn on the ground, and there are three shots facing the jeep as it closes in on the horn - in the first two shots the horn's normal, but in the last shot the horn's already semi-squashed before the jeep even runs over it.
Answer: The C-42 was a military variant of the Douglas DC-2. Very few C-42's were built, so it's questionable that Potter would specifically have seen that particular model, but, given his military background, it's not entirely unreasonable that he might use the military designation even when the aircraft in question is actually a civilian DC-2.
Tailkinker ★