|National origin||United Kingdom|
|First flight||February 1928|
Design and development
The Gnatsnapper was a submission to Air Ministry specification N.21/26 for a carrier fighter, which called for an aircraft powered by a Bristol Mercury II engine and capable of at least 160 mph at 10,000 ft. However, when the first available Mercury was delivered to Gloster in September 1927, it was apparent that it would not be satisfactory since it failed to produce the expected output of 450 hp, was 160 lb overweight, and was moreover unreliable. In order to expedite flight trials, work was therefore started on a second prototype (N227) which was fitted with a 450 hp Bristol Jupiter VII engine. The aircraft first flew in this form in February 1928. More examples of the Mercury were delivered during that year and although the aircraft was flown using them, it was obvious that it was still not satisfactory and, having missed the N.21/26 evaluation (in which no type had been declared the winner), the aircraft was refitted with the Jupiter and delivered to the A & AEE for evaluation, which proved entirely successful.
In 1930, a new carrier fighter competition (N16/30) was announced by the Air Ministry, for which Gloster were requested to re-design the Gnatsnapper to use the 540 hp Armstrong Siddeley Jaguar VIII. Designated the Gnatsnapper II, the aircraft was submitted for evaluation but was badly damaged in a landing accident before the trials had been completed, eliminating it from the competition, which was eventually won by the Hawker Nimrod. After repair, the aircraft was substantially modified to accept a 525 hp Rolls-Royce Kestrel IIS evaporatively cooled engine, with the condensers in the leading edges of the wings, this version being designated the Gnatsnapper III. It was subsequently used by Rolls-Royce as a flying test-bed for the ill-fated Goshawk engine, and ended its career as a company hack.
A second prototype (N254) had been ordered in May 1929. This was first flown in the spring of 1930, powered by a Mercury IIA. This is thought to be the airframe that had been abandoned in 1927 when the Mercury failed to meet expectations. Although an attempt to make this aircraft meet the requirements of N.16/30 was made, the obvious superiority of the Nimrod caused Gloster to stop development work on the type.
Specifications (Gnatsnapper II)
Data from Gloster Aircraft since 1917 
- Crew: 1
- Length: 24 ft 7 in (7.48 m)
- Wingspan: 33 ft 6 in (10.20 m)
- Height: 10 ft 11 in (3.32 m)
- Wing area: 360 ft² (33.4 m²)
- Empty weight: 3,095 lb (1,403 kg)
- Loaded weight: 3,804 lb (1,725 kg)
- Powerplant: 1 × Armstrong Siddeley Jaguar VIII 14-cylinder air-cooled radial, 540 hp (403 kW)
- Maximum speed: 154 knots (177 mph, 285 km/h)
- Stall speed: 46 knots (53 mph, 85 km/h)
- Range: 426 NM (490 mi, 789 km)
- Service ceiling: 24,500 ft (7,470 m)
- Wing loading: 10.6 lb/ft² (51.6 kg/m²)
- Power/mass: 0.14 hp/lb (0.23 kW/kg)
- Endurance: 5 hr
- Climb to 20,000 ft (6,100 m): 19 min
- Aircraft of comparable role, configuration and era
- James 1971, pp.166-167.
- Mason 1992, p.201.
- James, Derek N. Gloster Aircraft since 1917. London: Putnam, 1971. ISBN 0-370-00084-6.
- Mason, Francis K. The British Fighter Since 1912. Annapolis, Maryland: Naval Institute Press, 1992. ISBN 1-55750-082-7.
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