The Aircraft Apprentice Scheme was a training programme for Royal Air Force ground crew personnel which ran from 1920 to 1966. Formation World War I saw the beginning of aerial combat. By 1 April 1918 the Royal Flying Corps and the Royal Naval Air Service had amalgamated into the Royal Air Force. Hugh Trenchard had been appointed Chief of the Air Staff and quickly discovered that specialist groundcrew were in very short supply. Wartime use of aircraft accelerated the development of new technologies. Aircraft power plants were vastly different from those that powered buses and lorries. Airframes, with their need to reduce drag and provide control in the air, were a totally new challenge. Armourers were asked to develop new fusing methods for equally new explosive devices like air-dropped bombs. Aircraft electrical systems included bomb release mechanisms and synchronised gun firing through the propeller via the use of an interrupter mechanism. The addition of a third dimension to navigation meant aircraft instrument makers had to produce new indicators for such things as turn and bank, air speed and an artificial horizon. For these reasons and others, Trenchard instituted the Aircraft Apprentice Scheme to be based at RAF Halton No. 1 School of Technical Training. Because of lack of accommodation at Halton, the school was originally located at RAF Cranwell in 1920. In 1922 the school moved permanently to RAF Halton and was fully operational by 1926. The Aircraft Apprentice School at RAF Cranwell (Nos. 1 and 6 Radio Schools) continued to train apprentices exclusively for the ground and air radio trades. The apprentice school at Cranwell operated until October 1952 before being transferred to RAF Locking. Training Entrance to the scheme involved a highly competitive exam, intelligence and aptitude tests, and medical examinations. Admittance was limited exclusively to males between the ages of 15 and 17½ and the Royal Air Force assumed legal guardianship of the boys in loco parentis. Initially, training was a three-year course, although this was changed briefly to two years for some apprentice entries during the Second World War. Training took place over five and a half days a week, and consisted of both academic and practical training. In addition, basic military training was given. Originally, applicants were required to be British subjects and of "pure European descent" (and were required to prove this if there was any doubt). Apprentices were later accepted from both Commonwealth