Comrades in Arms: Part 2 - S6-E13
Visible crew/equipment: While Margaret and Hawkeye are hiding under the mat, just as the armed North Korean collapses to the floor the shadow of the moving boom mic is visible on the wall.
Comrades in Arms: Part 2 - S6-E13
Other mistake: During the surgery, after Hawkeye and Margaret reach the 8063rd, Margaret is explaining the procedure. She says that they are using a new vascular clamp designed at the 4077th. It appears that this is the clamp designed and built three episodes later in episode 16 "Patent 4077."
Comrades in Arms: Part 2 - S6-E13
Audio problem: When Hawkeye and Margaret are being driven into camp, everybody is cheering. Watch the driver of the jeep. He hits the horn button a number of times, but the horn is never heard.
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 ★