Continuity mistake: In the pilot episode it says the year is 1950. In the episode "Radar's Report" in season 2 Radar says it's 1951, yet in the episode "A War for All Seasons" in season 9 we are told at the beginning of the episode they are going from 1950 to 1951.
Factual error: Radar gives the location of the battle as Longitude 70, Latitude 27. This means the Korean war has spread to India. (00:21:00)
For the Good of the Outfit - S2-E4
Factual error: During Henry Blake's command, a model of a Bell UH-1 'Huey' can be seen hanging from the ceiling of the commander's office in several shots. In fact, the Huey's first flight was only in 1956.
Continuity mistake: In the first episodes, Col. Blake's wife is named Mildred, later her name is changed to Lorraine. (In case of confusion, when Col. Potter came to the 4077th, his wife was also named Mildred, but that's not relevant).
Continuity mistake: In the first season of M*A*S*H, Hawkeye mentions that his father lives in Vermont, in the later seasons his father lives in Crab Apple Cove, Maine and has never left there in 30 years.
Continuity mistake: At one time, Col. Potter talks about how his daughter is an only child. In a different episode, he mentions that his son's wife is having a baby.
Other mistake: When Henry is trying to convince Baker how wonderful the camp is, Henry says that they "had 'The Thing' and 'The Blob' both in one week." The movie "The Blob" was made in 1958. This season of M*A*S*H is set in 1951 and 1952 (and the war ended in 1953). (00:03:55)
Character mistake: When Colonel Blake's wife is having a baby, he is on the phone with the hospital as tells them to tell 'Mildred' he loves her and will talk to her soon. His wife's name was Lorraine.
Factual error: During this episode, Sergent Klinger gives a Hershey Chocolate Bar with Almonds (although the 'Hershey' name is obliterated on the bulk box as well as the bar itself, there is no doubt as to what it is) to a wounded North Korean soldier, who accepts it and turns it upside down, revealing a Universal Product Code bar code. Bar codes were not used on products until some 20 years later. (00:12:20)
Good-Bye Radar: Part 2 - S8-E5
Visible crew/equipment: After Radar tells Colonel Potter that he decided to go home after all it cuts to Hawkeye walking into the office, and just as Hawkeye opens the door we can see the top of the set.
Are You Now, Margaret? - S8-E2
Visible crew/equipment: When Williamson and Hawkeye walk into the Swamp and stand near BJ's cot, the edge of the tent set can be seen at the top, left side of the screen.
Continuity mistake: When Henry, Trapper, and Hawkeye get into the jeep with Radar notice the style of jeep and its number is 16930382, but when they're driving to the chopper pad the style differs ― things such as hood, antenna, etc, and its number is 11172419. Then when the chopper takes off the jeep's style is back to the original jeep they were in.
Visible crew/equipment: When Margaret's in her tent reading just as Hawkeye walks in to give her the physical, the chalk T-mark can be seen on the floor.
Visible crew/equipment: After Harper, the JAG, has Trapper and Hawkeye sign and attest to the blood report, when Radar enters Henry's office we can see a crewmember's hand near the floor between the two doors, preventing the closing door from swinging back and forth. (00:22:20)
Continuity mistake: When Hawkeye and Lt. Johnson are sharing Hawkeye's bottle of "wine" there's a closeup of Johnson's hand holding the glass, and in the closeup that hand has short nails, whereas in all other shots Johnson has long nails.
Visible crew/equipment: When they're all in the OR talking about Aggie being at the 4077, Charles compares Colonel Potter's art style to Aggie's, and in the next shot as Potter tells the art critic to tread softly, the boom mic is visible at the top, right side of the screen and just as the mic starts to pull up the shot zooms in on Aggie.
Visible crew/equipment: After Klinger gives the envelope with the forged discharge papers to the driver going to I Corps, just as he walks through the doorway we can see the two actors' tape marks on the ground, where the driver and Sidney were standing when they arrived.
Visible crew/equipment: After the opening credits, in the very first shot in the OR we can see the boom mic dipping into view at the top, left side of the screen.
Communication Breakdown - S10-E6
Visible crew/equipment: While Colonel Potter and Margaret are with Charles, a nurse sees them and announces the presence of a newspaper, then when everyone gathers around Charles while he sets the reading rules, there's a man with blondish shoulder length hair and a beard, wearing a blue button down shirt and white pants who's standing in the background, partially hidden by the signpost.
Factual error: After the opening credits it cuts to Klinger at Mail Call, and Father Mulcahy's reading Ring Magazine which is dated December 1969, 16 years after the Korean War ended.





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 ★