Visible crew/equipment: While Hawkeye's being questioned by the prosecuting counsel, we can see the curved chalk foot marks on the floor right behind Hawkeye's chair, such as when council asks where Hawkeye was when the camera was stolen.
Visible crew/equipment: While Colonel Potter, Margaret, and Father Mulcahy are in the mess tent, we see that BJ and Hawkeye arrive back at camp in the jeep, and when they walk into the mess tent the curved chalk foot marks can be seen on the floor under the table, between Potter and Mulcahy.
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 ★