Gloster F.5/34

The Gloster F.5/34 was a British fighter of the 1930s. It was a single-seat, single-engine monoplane of all-metal cantilever construction; the undercarriage was of the tailwheel type with retractable main units.

Produced in competition with other designs to meet a requirement for a fighter aircraft that could operate in the far East, it was overtaken by more capable designs and the requirement was abandoned with no aircraft being selected.

The F.5/34 was the first monoplane fighter built by Gloster and the last design penned by H.P. Folland for the company. It was developed in response to Air Ministry Specification F.5/34, for a fighter using an air-cooled engine armed with eight machine guns suitable for hot climate use. 

Powered by an 840 hp Bristol Mercury IX nine-cylinder radial engine, the F.5/34, unofficially dubbed the "Unnamed Fighter", was the company's first monoplane landplane design and featured many of the trademark Gloster design elements including the tail and close-fitting cowling that resembled the earlier Gauntlet and Gladiator biplane fighters. 

The low wing cantilever mainplane was built in one piece with light-alloy spars running through from tip to tip and ribs made from channelling with steel and light-alloy tube struts. Duralumin stressed-skin was used on the mainplane and tail unit with fabric-covered Frise ailerons. The fuselage was a monocoque structure built up from light, fabricated oval-section rings with duralumin skinning.

Development was delayed somewhat by the demands of the Gladiator production programme so that flight trials of the first prototype did not commence until December 1937 while the second prototype was not completed until May 1938.

In competition with the Gloster for the requirement were the Bristol Type 146, Martin-Baker M.B.2 and the Vickers Venom, which would be tested by the Aeroplane and Armament Experimental Establishment. Flight Magazine (July 1, 1937) shows the F.5/34 taking off from Hucclecote airdrome and mentions its appearance at the RAF Display of that year. By the time the F.5/34 began its flight tests, the 8-gun Hawker Hurricane was in service and the Supermarine Spitfire in production so that further development of the Gloster fighter was abandoned. 

However, compared to its contemporaries, test pilots found the F.5/34 prototypes had a shorter takeoff, better initial climb, were more responsive and manoeuvrable due to ailerons that did not become excessively heavy at high speed. Handling was considered very good and the all-round cockpit visibility was far better than the other designs. The Gloster F.5/34 debuted at the 1938 Hendon Air Show, but soon after, both prototypes (K5604 and K8089) were relegated to experimental flying and finally as instructional airframes until May 1941.

A legend exists that the F.5/34 was the inspiration for the Japanese Zero, probably stemming from a superficial similarity between the two machines and Gloster's past links with the Japanese such as the Nakajima A2N.

General characteristics
Crew: 1
Length: 9.76 m
Wingspan: 11.63 m
Height: 3.09 m
Wing area: 21.4 m²
Empty weight: 1,900 kg
Loaded weight: 2,449 kg
Powerplant: 1 × Bristol Mercury IX nine-cylinder radial engine, 840 hp (627 kW)
Maximum speed: 509 km/h at 4,875 m
Service ceiling: 9,910 m
Wing loading: 88.8 kg/m²
Power/mass: 0.256 kW/kg
Time to: 6,100 m: 11 min
Armament: Eight 7.7-mm Browning machine guns