Sometime in 1923, Campbell joined the Royal Air Force and on 24th January 1924 he was appointed a Pilot Officer and attached to a Bombing Squadron at Martlesham Heath, close to Woodbridge, Suffolk, where he had been at school. He quickly earned a reputation as a highly skilled pilot which led to his attachment to the Royal Aircraft Establishment at Farnborough. He arrived when the RAE was working on an Airship Development Programme aimed at producing an airborne aircraft carrier.
In October 1926 Campbell and Flying Officer (later Air Vice-Marshal) Ragg took part in an experiment to launch two parasite Gloster Grebe fighters from retractable trapezes under the R33 airship. Campbell was released first at an altitude of 2,500 ft and after diving for about 100 ft levelled out. The Times reported that ‘The aeroplane, with her engine running dropped like a stone and then regaining control, MacKenzie-Richards performed a series of stunts, looping-the-loop, rolling and flying upside down’ whilst Flight recorded that the plane ‘gambolled gaily in the air as if glad to be free, at last, from the maternal apron strings.’ There was difficulty getting Ragg’s engine started but, he too flew freely, and both landed safely. Later, both pilots’ Grebes were successfully released, flown and reattached to the airship using skyhooks. Given the rudimentary nature of flying technology at that time the skill and bravery of those two pilots is exemplary.
As a member of the RAE Aero Club, Campbell won, from scratch, the first race of the day on 4th June 1927 at Ensbury Park Racecourse near Bournemouth flying a de Havilland Humming Bird, a single-seat ultralight monoplane, at 73.5 mph. Sadly, due to two accidents that Whitsun weekend there were to be no more air races at Ensbury Park. Two months later he was successful again, this time at the Hucknall Torkard aerodrome in Nottinghamshire where, starting from scratch he gained third place in the Papplewick Stakes flying the same Humming Bird aircraft (G-EBQP) over the 8.5 mile single-lap course. His prize? £10.
Campbell was killed in an experimental night flying accident at East Grinstead on 9th November 1927. Leaving Croydon at 5.30 pm with Professor Green as his observer he set course for Farnborough but found that his compass was about 30° out and, unable to find Farnborough they decided to return to Croydon. When they estimated they were overhead they lost height but were unable to see lights or anything they recognised. With only 20 minutes of fuel remaining Campbell briefed Green on how to use his parachute whilst looking as best they could for a field in which to crash land. Unable to find one, Campbell turned the aircraft and pushed Green out so that he was clear before pulling the ripcord, thus ensuring his safe landing. Campbell’s body was found only about 200 yards from the crashed machine. His parachute was open and the Coroner concluded that the airplane was already too low when Campbell left the craft, his parachute not having had time to deploy effectively. He is buried at Great Yeldham, Essex.