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.
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.
Trivia: The number of the Berlin hotel room Bruno Stachel stays in the night before he is to be awarded the Blue Max is '22', which equals the number of planes he has shot down. He needed only 20 to win the award, but he had to shoot down two more in order to make up for Willy's kills that he claimed as his own earlier in the film.