Aid Station - S3-E19
Continuity mistake: After Hawkeye and Trapper finish their toast to the Ritz Brothers, they toss their glasses over they shoulders. Trapper's flips in a lazy arc, and Hawkeye's in a flatter arc. When Radar is at the door, the glasses hit the door at a much higher speed and shatter.
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 ★