The Bristol Type 107 Bullpup was a Bristol Mercury engine powered, single seat, single-bay biplane fighter that was conceived at Bristol Aeroplane Company at the same time as the Bristol Type 105 Bulldog. It was designed against Specification F.20/27 which sought a fast-climbing interceptor against high-altitude bombing raids.
In essence, it was a lightweight scaled-down version of the Bristol Type 105 Bulldog and when compared with the Bristol Type 105 Bulldog IIA, it was around 700 lb lighter and had a wing area of only 230 sq ft (compared to 307 sq ft).
A single example of the Bristol Type 107 Bullpup (J9051) was ordered for Air Ministry for trials against Specification F.20/27 and its first flight was made on 28th April 1928. It was fitted with a Bristol Jupiter VI engine although a Bristol Mercury IIA was subsequently fitted for the Air Ministry trials, which started in March 1929. An increase in rudder size was also found necessary after its first flight.
Delays with the supply of the Bristol Mercury engine prevented further development and the contract ultimately went to the Hawker Fury biplane.
Trials at A & A E E are reported to have shown that the Bristol Type 107 Bullpup recorded a climb to 15,000ft in 10 min 50 sec, compared with 18 min 38 sec for the Bristol Type 105 Bulldog IIA.
Following the trials, The Bristol Type 107 Bullpup was also tested with different engine variations such as a short-chord Townend ring cowling, and a Bristol Jupiter VIIF engine, fitted for the 1930 RAF Display at Hendon. In 1931, a short-stroke Bristol Mercury engine was also fitted with a close-fitting NACA-style cowling.
Engine trials continued into 1934, with a 200-hour endurance test of the sleeve-valve Bristol Aquila I engine. The Bristol Aquila also featured a long-chord, close-fitting cowling and the aircraft was displayed in this form at the SBAC show in June 1935.
Although no production order was ever received, the Bristol 107 Bullpup made a real contribution Bristol’s engine development which included tests with a 440hp Bristol Jupiter VIIF, a 400hp short-stroke Bristol Mercury and a 500hp Bristol Aquila I engine.
|Powerplant||480 hp Mercury IIA|
|Span||30 ft 0 in|
|Maximum Weight||2,850 lb|
|Capacity||Single seat, twin synchronised Vickers machine guns. Provision for the carriage of additional underwing guns below the lower wing.|
|Maximum Speed||190 mph (Mercury IIA)|
Single example (J9051)
None - only aircraft scrapped in 1935, following completion of Bristol Aquila I engine trials.