He was a Scottish pilot, and the former chief test pilot of Hawker Siddeley in the 1970s. He flew the first production Harrier aircraft in December 1967, and the first two-seat Harrier in April 1969. In 1949 he joined the Royal Air Force with 6FTS and 226 OCU, and flew the Gloster Meteor VIII with 222 Squadron. In 1953 he joined the Day Fighter Development Unit at the Central Fighter Establishment.

He joined Hawker Siddeley in 1954. He first flew the Hawker Siddeley P.1127 in August 1962; he was the third pilot to fly the P.1127. On 27 December 1967, he was the first the fly the first production Harrier GR1 XV738. On 24 April 1969 he was the first to fly the two-seat Harrier XW174; six weeks later on 4 June 1969 in this aircraft, he was forced to eject at low level (100ft), over Larkhill in Wiltshire, when the engine failed at 3,000ft. On ejection from the aircraft he broke his neck; he needed a bone graft, and surgeons had to operate via his throat. He returned to flying nine months later, and received the Queen's Commendation for Valuable Service in the Air in the 1969 Birthday Honours. After this incident, all Hawker aircraft were fitted with canopy severance cord to shatter the canopy before ejection occurred.

He became deputy chief test pilot in 1969. He became chief test pilot in 1970. He was the first to fly the Hawk HS1182 (XX154) at around 7pm on 21 August 1974 and reached 20,000ft in a 53-minute flight; this aircraft currently flies with the Empire Test Pilots' School. The Hawk entered service with the RAF in November 1976