Aircraft Apprentice Scheme 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 based at No . 1 School of Technical Training . This was originally located at RAF Cranwell but later more permanently at RAF Halton , in 1922 . RAF Cranwell and RAF Locking later switched exclusively to training aircraft apprentices in the ground and air radio trades . 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 and other countries . 106 Entry , which passed out in December 1966 , was the last of the Aircraft Apprentice entries . A three - year Technician Apprentice scheme , a two - year Craft Apprentice scheme , and a one - year Administrative Apprentice scheme were initiated in September 1964 , with 107 Entry being the first Technician Apprentice entry , 201 Entry being the first of the Craft Apprentice entries , and 301 Entry being the first of the Administrative Apprentice entries . A one - year scheme for mechanic apprentices was also subsequently introduced ( the 400 series entry apprentices ) . Alumni . It is estimated that as many as forty percent of " Trenchard Brats " ( or just " Brats " ) , as they were known , achieved commissioned rank , and a considerable number achieved Air rank . Graduates of this scheme include several former officers of Air rank , including Air Commodore Sir Frank Whittle , father of the jet engine , Marshal of the Royal Air Force Sir Keith Williamson , Air Chief Marshal Sir Mike Armitage , Air Marshal Sir Graham Miller , and Air Marshal Cliff Spink The Brats ' alumni association , a registered charity , is called the RAF Halton Apprentices Association ( RAFHAA ) , or Old Haltonians . It publishes a magazine called " The Haltonian " three times a year . A triennial reunion for Brats is organised by the association . RAF Halton has its own memorial to the brats opposite Kermode Hall , very close to St George ' s Church , which contains stained glass windows commemorating the 40 , 000 or so apprentices who were trained there . Brats are also remembered at the Halton Grove , which is part of the National Memorial Arboretum , Alrewas , Staffordshire .