Trivia: During the attack by Heinkels from Norway across the North Sea English Squadron Leader says "help yourself everybody, there's no fighter escort." In reality the Heinkels had an escort of twin engine Me 110s. In 1968 there were no airworthy Me 110s so the movie ignored them.
Trivia: The RAF Office with the skin grafts that we see later in the film is William Foxley. He was a trainee navigator during WW2 and received those burns attempting to rescue a fellow airman from a crashed bomber.