Battle of Britain

Sir Michael Caine tells in his biography 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, as the Allies had lost almost as many aeroplanes as the Axis did during the battle. He further argued the battle was irrelevant as Adolf Hitler never intended to invade the UK. Galland shared Field Marshal Gerd von Rundstedt's view that Operation Sea Lion was a deliberate bluff to put pressure on the UK to accept Hitler's peace offers while the Axis prepared for Operation Barbarossa.

When ACM Hugh Dowding and the Air Minister are discussing relative aircraft numbers, the minister states, "We have radar." The term radar was not used in Britain in 1940. The term RDF was used. The term radar was invented by the US Navy in 1940 and held as secret until later in the war.

Some TV prints of the film retain the Transamerica/UA production logo, which is now frequently edited out of other UA films of that period.