Revealing mistake: Throughout the film, whenever part of a wheeled vehicle lifts off the ground, the wheels stop moving instantly. In real life, the wheels would continue to turn at much the same rate, showing that these are unpowered models being pulled along.
Thunderbirds (1964)
1 revealing mistake in show generally - chronological order
Starring: David Graham, Ray Barrett, Peter Dyneley, Shane Rimmer
Revealing mistake: When the dummy plane is shot out of the sky by the fighter pilot, a piece of the plane shoots off into the top left of the screen and bounces off the sky background. (00:23:05)
Trivia: The shot of Thunderbird 2 flying in the dark is actually reused footage from a previous episode, "The Man from MI5."