Avro Type 621 Tutor

The Avro 621 Tutor is a two-seat British training biplane from the interwar period, designed and produced by A.V. Roe. The Avro 621 was a simple but rugged initial trainer that was used by the Royal Air Force as well as many other air arms worldwide. 

Avro Type 621 Tutor
Class Aircraft
Type Trainer
Manufacturer Avro
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1926
Country Name Operational Year Retirement Year
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United Kingdom - UK (Great Britain) 1933 1941 View
ManufacturerName Production From Production To Quantity
Avro 795 View

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.


  • Avro 621 Trainer (Mongoose powered) : Two-seat primary training aircraft.
  • Avro 621 Tutor (Lynx powered) : Two-seat primary training aircraft.
  • Avro 621 Tutor II : One aircraft was modified into a two bay biplane.
  • Avro 621 survey version :  Three built and served in what was the Tanganyika.
  • Avro 646 Sea Tutor : Two-seat seaplane fitted with twin floats, 15 built 

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.

Role Trainer
Manufacturer Avro
Designer Roy Chadwick
First flight 1929
Introduction 1933
Retired 1941
Primary user Royal Air Force
Number built 606
Variants Avro 626, PWS-18

General characteristics

  • Crew: Two (student, instructor)
  • Length: 26 ft 4.5 in (8.04 m)
  • Wingspan: 34 ft 0 in (10.36 m)
  • Height: 9 ft 7 in (2.92 m)
  • Wing area: 301 ft (27.96 m)
  • Empty weight: 1,844 lb (836 kg)
  • Loaded weight: 2,493 lb (1,131 kg)


  • Maximum speed: 104 knots (120 mph, 193 km/h)
  • Cruise speed: 84 knots (97 mph, 156 km/h)
  • Range: 217 knots (250 miles, 402 km)
  • Service ceiling: 16,000 ft (4,877 m)

End notes