It is thought he got lost flying a Mosquito over Germany and crashed while following Lancaster bombers home. Now a secret tape reveals a Lancaster gunner mistook Gibson's plane for a similar German Junkers 88 night-fighter and thought he was under attack.
Bernard McCormack recalls he opened fire and the Mosquito went down near a Dutch town — the spot where Gibson crashed. Racked by guilt, he taped the confession before he died in 1992.
No account of the shooting down is in RAF war records. But the tape and the Lancaster crew's combat report were discovered during research for a remake of 1955 movie The Dambusters. Researcher James Cutler, 62, said: "It could only have been Gibson's plane. The RAF killed one of its greatest heroes."