The Avro Type 557 Ava was a British twin-engined
biplane torpedo bomber
A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...
of the 1920s. It was developed by
Avro to meet a requirement for a
heavy
Heavy may refer to:
Measures
* Heavy (aeronautics), a term used by pilots and air traffic controllers to refer to aircraft capable of 300,000 lbs or more takeoff weight
* Heavy, a characterization of objects with substantial weight
* Heavy, ...
torpedo bomber for the
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...
but was unsuccessful, only two prototypes being built.
Design and development
The British
Air Ministry
The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of State ...
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
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ...
or an equivalent weight of bombs and produced responses both from
Blackburn Aircraft (the
Cubaroo) and
Avro.
Roy Chadwick
Roy Chadwick, CBE, FRSA, FRAeS (30 April 1893 – 23 August 1947) was an aircraft design engineer for the Avro Company.
Born at Marsh Hall Farm, Farnworth, Widnes, the son of the mechanical engineer Charles Chadwick, he was the chief designer ...
, chief designer of Avro, initially produced a single-engined design, the Avro 556 powered by a
Napier Cub
The Napier Cub was an unusual and very large experimental 16-cylinder 'X' pattern liquid-cooled aero engine built by the British engine company D. Napier & Son. The Cub was the only Napier 'X' engine design. First flown on 15 December 1922 ...
engine, similar to the Cubaroo. This was rejected in favour of a twin-engined aircraft using two
Rolls-Royce Condor
The Rolls-Royce Condor aircraft piston engine was a larger version of the Rolls-Royce Eagle developing up to 675 horsepower (500 kW). The engine first ran in 1918 and a total of 327 engines were recorded as being built.
Variants
''Note:'' ...
engines, the Avro Type 557 Ava and winning an order for two prototypes from the Air Ministry.
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.
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
rudder
A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...
s, of which the centre rudder was soon removed.
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.
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.
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.
Variants
;Ava Mk I
: First prototype. Wooden construction.
;Ava Mk II
: Second prototype. Metal construction.
Specifications (Ava Mk I)
See also
References
External links
Avro Ava– British Aircraft Directory
{{Avro aircraft
557 Ava
1920s British bomber aircraft
Cancelled military aircraft projects of the United Kingdom
Biplanes
Twin piston-engined tractor aircraft
Aircraft first flown in 1924