| Bison | |
|---|---|
 Avro Bison II | |
| General information | |
| Type | Fleet spotter/reconnaissance |
| Manufacturer | Avro |
| Status | Retired |
| Primary user | Royal Air Force |
| Number built | 55 |
| History | |
| Introduction date | 1922 |
| First flight | 1921 |
| Retired | 1929 |
TheAvro 555 Bison was a British single-engined fleet spotter/reconnaissance aircraft built byAvro.
The Bison was designed to meet BritishSpecification 3/21 for a carrier-based fleet spotter and reconnaissance aircraft. An order for three prototypes was placed in October 1921, along with three of the competing design fromBlackburn Aircraft, theBlackburn Blackburn.[1] Avro's design, the Type 555 Bison, was a two-bay biplane, powered, like the Blackburn, by aNapier Lion engine. The deep slab-sided fuselage was constructed from steel tubing, with the pilot sitting in an open cockpit forward of the wings, and the engine cowling sloping steeply down ahead of the pilot. An enclosed cabin with large rectangular windows on each side housed the navigator and radio operator and all their equipment, with sufficient headroom to stand upright, while a cockpit for a gunner armed with aLewis gun on aScarff ring was provided in the rear fuselage. The upper wings were mounted directly on the top of the fuselage.[2]
The first prototype flew in 1921, with an order for 12 Bison Is following.[2][3] The aircraft had handling problems, however, caused by interference of the pilots cockpit with the airflow over the upper wing. This was resolved by revising the wing design of the second prototype, raising the centre section of the upper wing by 2 ft (0.6 m) and removingdihedral from the upper wings, flying in this form in April 1923. Further production orders followed with these modifications incorporated as the Bison II, while some Bison Is were modified to a similar standard, sometimes known as the Bison IA.[4] A Bison I was fitted with floats and retractable wheels but tests proved the design was not suitable for seaborne use.[5]
Although designed for a naval requirement the first deliveries were to theRoyal Air Force in 1922 to replace theWestland Walrus for coastal reconnaissance work withNo. 3 Squadron RAF.[6] In April 1923, 3 Squadron was broken up to form a number of Fleet Spotter Flights of theFleet Air Arm. Naval aircraft served onHMS Argus,HMS Eagle andFurious and onshore atGosport,England andHal Far,Malta.[7][8] The aircraft were retired in 1929 when they were replaced by theFairey IIIF.[9]
Data from Avro Aircraft since 1908[10]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
Related lists
