Plot hole: In this episode, Margaret is required to give a lecture on the use of Levophed, because it is being introduced. However, in the Episode "Period of Adjustment"(8-6), Hawkeye orders an IV of Levophed for one of his patients. (00:12:15)
Visible crew/equipment: When Father Mulcahy and the farmer are talking to BJ and Hawkeye about the wounded cow, the doctors say they'll get help from Colonel Potter, and when they walk away the T-mark can be seen on the ground where they were standing.
Other mistake: When the scene is of the cow in the barn, the background hilly area can be a painted backdrop.
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 ★