Factual error: Hannay travels to Scotland on The Flying Scotsman which ran from London to Edinburgh, The Forth Road Bridge is actually 12km further West of the Port of Edinburgh, so Hannay couldn't jump off the Flying Scotsman onto the Forth Bridge.
The 39 Steps (1935)
1 factual error
Directed by: Alfred Hitchcock
Starring: Robert Donat, Lucie Mannheim, Godfrey Tearle, Madeleine Carroll
Revealing mistake: The serial number of the autogyro has been reversed, showing that the stock shot has been reversed for effect.
Trivia: Director Alfred Hitchcock has a cameo role in this film - he is seen tossing some litter as Richard and Annabella run from the music hall.