TheAvro 521 was a British two-seatfighter first flown in late 1915, based on the504. Only a prototype of the Avro 521 was built. It was powered by a 110 hp (80 kW) Clerget engine, with provision for a .303 in (7.7 mm)Lewis Gun in the rear cockpit.

The prototype underwent trials with the RFC in early 1916, and 25 aircraft were subsequently ordered. However, this contract was cancelled, and there is no evidence of any other Avro 521 being built. The prototype crashed atCentral Flying School Upavon on 21 September 1916, killing pilot Lieutenant W.H.S. Garnett.

Data from Avro Aircraft since 1908^[1]

General characteristics

• Crew: 2
• Length: 28 ft 2 in (8.59 m)
• Wingspan: 30 ft 0 in (9.14 m)
• Height: 9 ft 10 in (3.00 m)
• Wing area: 266 sq ft (24.7 m²)
• Empty weight: 1,150 lb (522 kg)
• Gross weight: 1,995 lb (905 kg)
• Powerplant: 1 ×Clerget 9Z 9-cylinder air-cooled rotary piston engine, 110 hp (82 kW)
• Propellers: 2-bladed fixed-pitch propeller

Performance

• Maximum speed: 94.6 mph (152.2 km/h, 82.2 kn)
• Endurance: 4 hours 30 minutes
• Time to altitude: 14 min to 6,000 ft (1,800 m)

Armament

• Guns: 1 × rear mounted.303 in (7.7 mm)Lewis Gun

• William Green and Gordon Swanborough.The Complete Book of Fighters. Colour Library Direct, Godalming, UK: 1994.ISBN 1-85833-777-1.
• Jackson, A.J.Avro Aircraft since 1908. London:Putnam, 1990.ISBN 0-85177-834-8.

• 1910s British fighter aircraft
• Avro aircraft
• Biplanes
• Aircraft first flown in 1915
• Rotary-engined aircraft

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