Avro Tutor A . V . Roe ' s Type 621 Tutor was a two - seat British radial - engined biplane from the interwar period . It was a simple but rugged initial trainer that was used by the Royal Air Force as well as many other air arms worldwide . Design and development . The Avro Model 621 was designed by Roy Chadwick as an Avro private venture metal replacement for the Avro 504 . Conceived as a light initial pilot trainer , the biplane design featured heavily staggered equal span , single - bay wings ; the construction was based on steel tubing ( with some wooden components in the wing ribs ) with doped linen covering . A conventional , fixed divided main undercarriage with tail skid was used in all but the latest aircraft , which had a tail wheel . The Model 621 was powered either by a 155 hp ( 116 kW ) Armstrong Siddeley Mongoose or Armstrong Siddeley Lynx IV ( 180 hp / 130 kW ) or IVC ( 240 hp / 179 kW ) engine ; later Lynx - powered models had the engine enclosed in a Townend ring cowling . The Mongoose powered version was called the 621 Trainer and the more numerous Lynx - engined aircraft the Tutor . The Tutor also differed by having a more rounded rudder . The first flight of the prototype G - AAKT was in September 1929 , piloted by Avro chief test pilot Captain Harry Albert " Sam " Brown . Operational history . Production was started against an order for three from the Irish Free State and 21 Trainers from the Royal Air Force . The RAF required a replacement for the wooden Avro 504 , and after three years of trials against other machines such as the Hawker Tomtit it was adopted as their basic trainer , supplanting the 504 in 1933 and remaining in this role until 1939 . As well as the 21 Trainers a total of 381 Tutors and 15 Avro 646 Sea Tutors were eventually ordered by the RAF . RAF units to operate the type in quantity included the Royal Air Force College , the Central Flying School and Nos . 2 , 3 , 4 and 5 Flying Training Schools . Subsequently , the Model 621 achieved substantial foreign sales . A . V . Roe and Co exported 29 for the Greek Air Force , six for the Royal Canadian Air Force , five for the Kwangsi AF , three for the Irish AF ( where it was known as the Triton ) and two for each of the South African and Polish AFs . In addition 57 were licence built in South Africa , and three licence built by the Danish Naval Shipyard . A total of 30 Tutors were exported to the Greek Air Force and at least 61 were licence built in Greece by KEA . A number of Greek Tutors was incorporated in combat squadrons after Greece ' s entrance in WWII , used as army co - operation aircraft . Known for its good handling , the type was often featured at air shows . Over 200 Avro Tutors and five Sea Tutors remained in RAF service at the beginning of the Second World War . The 621 was designed as a military trainer and few reached the civil registers . In the 1930s , in addition to 10 prototypes and demonstrators , two were used by Alan Cobham ' s " Flying Circus " and two trainers were retired from the RAF into private use . One 621 was used from new by Australian National Airways . After the war another four ex - RAF 621s appeared on the civil register . Survivors . G - AHSA was used for communication duties during the Second World War , struck off December 1946 and purchased by Wing Commander Heywood . After suffering engine failure in the early stages of the filming of " Reach for the Sky " , it was purchased by the Shuttleworth Collection and restored to flying condition . Up to the end of 2003 , G - AHSA was still flying as K3215 in RAF trainer yellow . Since January 2004 it has flown painted as K3241 in the colours of the Central Flying School . ( The real K3241 built in 1933 , served RAF College Cranwell , until transferred to the CFA in 1936 . )