- All-Star Cast: Laurence Olivier, Trevor Howard, Christopher Plummer, Michael Caine, Ian McShane, Michael Redgrave, Robert Shaw, Ralph Richardson, Curd Jürgens and Susannah York to name a few.
- Backed by the Pentagon: Averted, as the aircraft needed for the movie had mostly been retired long before. The Spanish Air Force had just retired their fleet of locally build Messerschmitt 109s, which was purchased by the production. The Spanish Air Force was also still using a locally built version of the Heinkel He.111 bomber, and these were leased by the production. The British Hurricane and Spitfire aircraft used in the movie needed to be purchased and restored.
- Box Office Bomb: Budget-$14 million. Box office-$2 million (though worldwide distribution bumped this up to $13 million - still a loss, but not as big of one). Since it was released in the middle of The Vietnam War, people were not in the mood for a war film.
- Cast the Expert: W.G. Foxley, who plays Squadron Leader Evans, was an RAF navigator, whose face and hands were badly burned, attempting to rescue a fellow crew member after a bomber crash in 1944. Due to his injuries, he lost an eye and several fingers, as well as his other facial injuries.
- Dawson Casting: Many of the actors were too old to play pilots. In reality most of the pilots during the Battle of Britain were only in their twenties.
- Doing It for the Art: This film became regarded as a patriotic tribute to "the few", that many of those involved in the production, actors and technicians, reduced their normal fees to work on this film. Much of the large budget went toward the acquisition, restoration, modification, maintenance, and operation of the vintage aircraft.
- Hostility on the Set: Michael Caine tells in his autobiography that there were severe arguments with the German former Luftwaffe pilot Adolf Galland, who served as a Technical Advisor for this movie. Galland maintained that Luftwaffe did not really lose the Battle of Britain, something Harry Saltzman was all to eager to bring up. Caine noted the humour in a Canadian Jew and a German arguing over who won the war.
- Irony as She Is Cast: Although Laurence Olivier played Air Chief Marshal Sir Hugh Dowding of the Royal Air Force, he was by all accounts one of the worst pilots in the history of the British military. He joined the Royal Navy during the Second World War and more than once survived near catastrophe during his flying lessons (reportedly destroying five planes). Eventually, the actor and the navy came to the mutual conclusion that he could serve his country better on the ground, and he was granted leave to aid the war effort by making films.
- Referenced by...: It is no coincidence if the voice giving orders to the Spitfire squadron in Dunkirk is that of Michael Caine.
- Underage Casting: Inverted. Michael Caine (then 36) initially thought he was too young to play a squadron leader. However, veterans of the battle told him he was actually too old for the part.
- Vindicated by Cable: VHS and DVD sales were sufficient to finally let the movie turn a profit.
- What Could Have Been:
- There were to have been scenes featuring Lord Beaverbrook. Alec Guinness was hired to play Lord Beaverbrook, but these scenes were cut from the script shortly before filming.
- Rex Harrison was originally cast as Sir Keith Park.
- Timothy Dalton auditioned for a part.
- Harry Saltzman rejected Christopher Lee for a part because he felt that audiences wouldn't accept Dracula in the RAF.
- John Barry was considered to score the film, but he ruled himself out.
- The production attempted to make surviving Junkers Ju 87 Stukas airworthy, but it was deemed too expensive.
Trivia / Battle of Britain