Air Vice Marshal Stewart William Blacker Menaul, CB, CBE, DFC, AFC (17 June 1915 – 22 May 1987) was an officer in the Royal Air Force (RAF). During the Second World War he served in RAF Bomber Command with the elite Pathfinder Force. After the war he participated in the British nuclear weapons tests in Australia, and was on board the Vickers Valiant that dropped Britain's first atomic bomb on 11 October 1956 during Operation Buffalo.