Factual error: Terry-Thomas's plane gets stuck between the carriages of a Paris-bound train (in fact filmed on the single-line track between Bedford and Hitchin). Just before the train plus plane goes into a tunnel you can see the cooling towers of Bedford's Goldington Power Station (circa 1960) behind TT's head. (01:58:20)
Factual error: The "American" aircraft is really a British design called a Bristol Boxkite.
Suggested correction: Why is this an error? The "American" aircraft was fictional (there was no such thing as the "Phoenix Flyer") so they could have used anything to represent it. The design they used was known to work and was safe. The original Boxkite was actually a British version of The Farman and was similar in appearance the the American Curtiss.
The American pilot, while talking to the movie's heroine, states that his plane is a Curtiss. Check the scene in the restaurant, the night before he saves the German plane with the damaged tail. I tend to think the "Phoenix Flyer" was the name of that individual plane, and not the model of aircraft. That would mean that the pilot of the plane indirectly said that his plane was of American manufacture, as Curtiss was an American company.
Another interesting note is that in the scene with the runaway German plane, Orville Newton's plane is being wheeled out of the hangar, which has a "Bristol Company" sign over the doors. They "just happen" to be borrowing space in the hangar owned by the company that made the original Bristol Boxkites! It's a meaningless detail, but fun that they arranged it that way.
Factual error: Just before the planes start to cross the channel, we have a scene of a reporter with some British soldiers. They wear the cap and collar badges of the Royal Corps of Signals, which wasn't formed until 1920 - 10 years after the film is set.
Factual error: Whilst Newton is trying to fix the wing spar they fly over a Land Rover parked at the back of the hangers.
Factual error: The British pilot takes off in his Avro Triplane even though the American pilot hangs from his tail. By our modern standards, the planes of this era would be considered ultralights. The weight of a human hanging from its tail would put any ultralight so badly out of trim that it would stall instantly, even assuming it could handle the extra weight of a second person at all.
