Factual error: Set in the first world war, 1914-1918, but throughout the film the scenes of German infantry are armed with British Lee-Enfield No 4 rifles which were first issued in 1941 and fitted with the small British knife bayonets first issued in 1943.
Visible crew/equipment: In the scene where Jeremy Kemp and George Peppard are playing daredevil in their planes and Kemp's plane hits a brick tower there is a shot of the plane plummeting to the ground. The alert viewer can see the shiny metal wires that were used to support and guide the plane on its way to the ground.
Other mistake: The movie concludes with George Peppard crashing a test monoplane. The shot is from James Mason's office, looking out over the airfield. We hear the sound of the diving plane, but do not see it. After the camera has been focused on the field for a few seconds, we see a large explosion, which is meant to represent the crashing plane. The falling plane is missing. From the position of the shot, we should have seen the crashing plane. (00:12:15)
Continuity mistake: Lt. Stachel arrives at the squadron headquarters and the parking area is dry and dusty. He goes inside and when he emerges only minutes later the parking area is muddy and covered with large puddles.
Revealing mistake: In the scene where Lt Stachel and an ordinary soldier search for the wreckage of Stachel's unconfirmed first shoot-down, it is supposed to be dark and pouring rain but blue sky is seen in the background.
Factual error: Some of the German planes that appear in the film are actually just British-made Tiger Moths painted in German airforce markings. The Moth was a type that was only built some years after the end of the First World War.
Continuity mistake: After George Peppard shoots down the English spotter plane at his airfield, fellow pilots crowd round as he confronts his Squadron Leader. The tail of the downed aircraft is behind him. When the shot changes to show George walking away, however, the crowd is standing in a different position in relation to the tailfin. (00:38:10)
Factual error: 1. When Stachel first arrives at the squadron, they already have Fokker DVII's as part of their complement. This machine did not come into service until after Richthofen was killed, yet he makes a brief appearance in the scene where Stachel is shot down. 2. The German markings are of the older style (prior to the introduction of the DVII). From early 1918 the national insignia is supposed to be simplified, like a plus sign, without the flared look of the Maltese cross.