They Call the Wind Korea - S7-E7
Continuity mistake: When Klinger is coming over the hill at the end of the episode, the camera shows him in the outdoor setting, and the spot he's on has sparse vegetation. When the camera goes to a close up of him, the trees and shrubs are thicker and closer to him. This alternates a couple of times.
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 ★