The Bristol Bulldog is a British Royal Air Force single-seat biplane fighter designed during the 1920s.
More than 400 Bulldogs were produced for the RAF and overseas customers, and it was one of the most famous aircraft used by the RAF during the inter-war period.
The Type 105 was an unequal span single bay biplane powered by a supercharged Bristol Jupiter VII air-cooled radial engine driving a two-bladed propeller.
The structure was all-metal with a fabric covering, using members built up from rolled high-tensile steel strips riveted together.
In order to ensure the maximum field of view there was a large semi-circular cut-out in the trailing edge of the upper wing and the inboard section of the lower was of reduced chord.
Frise ailerons were fitted to the top wing only.
It was armed with a pair of 0.303 in (7.7 mm) Vickers machine guns mounted one either side of the cockpit.
The prototype Bulldog first flew on 17 May 1927.
Initial testing was entirely satisfactory, and it was delivered to RAF Martlesham Heath in June.
After consideration of all the types entered to meet the specification, the Bulldog and the Hawker Hawfinch were selected for more detailed evaluation.
The manoeuvrability and strength of the Bulldog were praised by the RAF.
It had poor spin recovery characteristics, which were remedied by fitting an enlarged fin and rudder, but this led to difficulties in taxiing in a crosswind.
A second prototype with a lengthened rear fuselage was ordered for further evaluation in comparison with the Hawfinch.
In this form, the Type 105A or Bulldog Mk. II, it was first flown by Cyril Uwins on 21 January 1928 and shortly afterwards delivered to Martlesham Heath.
Performance was so close to that of the Hawfinch that a decision was deferred until the aircraft had been evaluated by service pilots; the eventual choice of the Bulldog was made largely because it was easier to maintain.
An initial contract for 25 aircraft was placed: Bristol accordingly laid down 26 airframes, the extra one being intended as a company demonstration aircraft.
The first of these were delivered on 8 May 1929 and deliveries were complete by 10 October.
Later production aircraft were of a refined version, the Mk. IIA with revised wing spars and a stronger fuselage, powered by the uprated Jupiter VII F.
One production aircraft was modified for use as an advanced trainer: after evaluation by the Central Flying School at Upavon this was ordered by the RAF, the production aircraft differing from the prototype in having slightly swept wings and an enlarged fin to improve spin recovery.
Variants
Bulldog Mk. I
Single-seat day and night fighter prototype, two built.
High-altitude Bulldog
Modification of first prototype with enlarged wings intended for an attempt on the world altitude record.
Bulldog Mk. II
Second prototype and initial production version.
Powered by a 440 hp (330 kW) Bristol Jupiter VII radial piston engine; 92 built by Bristol.
Bulldog Mk. IIA
Powered by a 490 hp (370 kW) Bristol Jupiter VIIF radial piston engine and revised detail design; 268 built by Bristol.
Bulldog Mk. IIIA
Development powered by a Bristol Mercury IV enclosed within a Townend ring with a revised wings and stronger fuselage.
Only two built, one of which was converted to become the prototype Mk. IV.
Bulldog Mk. IVA
Development of the Mk.III to meet specification F.7/30 for a four-gun day-and-night fighter.
Not ordered by the RAF, 17 sold to Finland, armed with two 7.7 mm Vickers guns; 18 built by Bristol.
Bulldog TM (Type 124)
Two-seat training version; 59 built.
Powered by an Armstrong Siddeley Cheetah IX of 310 hp (230 kW).
J.S.S.F.
(Japanese Single-Seat Fighter)
Two aircraft license-built by Nakajima Aircraft Works, Japan.
