Avro 621 Trainer
Avro 621 Tutor
Designed as a replacement for the Avro 504N, the original Avro Trainer of 1929 featured a welded steel-tube structure and a 115kW Armstrong Siddeley Mongoose IIIA radial engine. Twenty-two were built for the RAF and three for the Irish Army Air Corps.
Design of the Avro 621 Tutor was of a basic biplane type with twin tandem seating for the student and instructor respectively in the tubular-shaped fuselage. Windscreens were afforded each seating position as were redundant control systems. The biplane structure was connected via a series of struts between them while the engine was fitted to the extreme forward portion of the design rotating a two-blade propeller. Landing gear were of the traditional World War 1 static design and a tail wheel was fitted at rear.
After evaluation Avro began mass production of the 621 for the RAF under the new name of Tutor. Some 200 Tutor trainers were still in operational use with British forces by the time of the Second World War. More than 390 were built, including 14 Sea Tutors with single-step Alclad floats and powered by a 160kW Lynx engine. The Sea Tutor was treated against corrosion by sea-water, and a metal propeller and hand-turning gear were also standard. The Sea Tutor was one of the few seaplanes that could not be converted into landplane form.
Tutors were delivered to Denmark, Greece, Poland and South Africa, plus others for civil use. Fifty-seven were built under licence in South Africa for the air force and a very small number in Denmark for the navy.
The UK line would stop production of the 621 by 1936 by which time some near 800 models would be in circulation. In total, 852 were built.
Engine: 1 x Armstrong Siddeley Lynx IVC, 179kW / 237 hp
Take-off weight: 1115 kg / 2458 lb
Empty weight: 839 kg / 1850 lb
Wingspan: 10.36 m / 34 ft 0 in
Length: 8.08 m / 27 ft 6 in
Height: 2.92 m / 10 ft 7 in
Wing area: 27.96 sq.m / 300.96 sq ft
Wing load : 8.2 lb/sq.ft / 40.0 kg/sq.m
Max. speed: 196 km/h / 122 mph
Cruise speed: 169 km/h / 105 mph
Service ceiling: 4940 m / 16200 ft
Range: 402 km / 250 miles
Crew : 2