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Ava
Role	Torpedo Bomber
Manufacturer	Avro
Designer	Roy Chadwick
First flight	1924
Status	Prototype
Number built	2

The Avro Type 557 Ava was a British twin-engined biplane torpedo bomber of the 1920s. It was developed by Avro to meet a requirement for a heavy torpedo bomber for the Royal Air Force but was unsuccessful, only two prototypes being built.

Design and development

The British Air Ministry produced Specification 16/22 in 1922 for a long-range land-based torpedo bomber. The specification required that the aircraft be capable of carrying a 21 in (533 mm) torpedo or an equivalent weight of bombs and produced responses both from Blackburn Aircraft (the Cubaroo) and Avro.^[1] Roy Chadwick, chief designer of Avro, initially produced a single-engined design, the Avro 556 powered by a Napier Cub engine, similar to the Cubaroo. This was rejected in favour of a twin-engined aircraft using two Rolls-Royce Condor engines, the Avro Type 557 Ava and winning an order for two prototypes from the Air Ministry.^[1] Completed in secret (owing to its armament of a 21 in (533 mm) torpedo, thought to be able to sink the largest warships), the first prototype Ava (serial number N171) flew in mid-1924.^[1]

The Ava was a three-bay biplane of wooden construction, with the un-cowled engines between the wings. It had a biplane tail, initially fitted with triple rudders, of which the centre rudder was soon removed.^[2] The fuselage accommodated two pilots in an open cockpit, with nose and dorsal gun positions and a retractable ventral "dustbin" gun position that could be manned by the navigator/bomb aimer, who otherwise occupied a large enclosed cabin. The 2,000 lb (910 kg) torpedo or equivalent bomb load were carried on external racks under the fuselage.^[1]

The Air Ministry dropped its plans to use the 21 in (533 mm) torpedo but Avro continued with construction of the second prototype, which was of all-metal construction but was otherwise similar to the first prototype, flying on 22 April 1927.^[2] While a modified version of the Ava was proposed to meet Specification B19/27 for a heavy bomber, it was unsuccessful, no further aircraft being built.^[1]

Variants

Ava Mk I: First prototype. Wooden construction.
Ava Mk II: Second prototype. Metal construction.

Specifications (Ava Mk I)

Data from The British Bomber since 1914 ^[1]

General characteristics

Crew: 5
Length: 58 ft 3 in (17.75 m)
Wingspan: 96 ft 10 in (29.51 m)
Height: 19 ft 7.75 in (5.9881 m)
Wing area: 2,163 sq ft (200.9 m²)
Empty weight: 12,760 lb (5,788 kg)
Max takeoff weight: 19,920 lb (9,036 kg)
Powerplant: 2 × Rolls-Royce Condor III V-12 water-cooled piston engines, 650 hp (480 kW) each
Propellers: 2-bladed fixed-pitch propellers

Performance

Maximum speed: 115 mph (185 km/h, 100 kn) ^[3]

Armament

Guns: 3 × 0.303 in (7.7 mm) Lewis Guns (Nose, dorsal and retractable ventral positions)
Bombs: 1 × 21 in (553 mm) torpedo or 4 × 550 lb (250 kg) bombs

References

^ ^a ^b ^c ^d ^e ^f Mason, Francis K (1994). The British Bomber since 1914. London: Putnam Aeronautical Books. pp. 156–157. ISBN 0-85177-861-5.
^ ^a ^b Jackson, A. J. (1990). Avro Aircraft since 1908 (2nd ed.). London: Putnam Aeronautical Books. pp. 209–211. ISBN 0-85177-834-8.
^ Lewis, Peter (1980). The British Bomber since 1914 (Third ed.). London: Putnam. pp. 416–417. ISBN 0-370-30265-6.