Bristol Type 105
| Industry | Aerospace |
|---|---|
| Founded | 1910 |
| Founder | Frank Barnwell (designer) |
| Headquarters | United Kingdom |
| Products | Aircraft, including the Bristol Bulldog fighter |
The Bristol Bulldog was a single-seat biplane fighter developed in the 1920s by the Bristol Aeroplane Company for the British Royal Air Force. With over 400 units produced for both the RAF and international operators, it became one of the most iconic RAF aircraft throughout the interwar years.
Background
The Bulldog’s design stemmed from a sequence of fighter concepts led by Frank Barnwell during the 1920s. Initially, in 1924, Barnwell began designing a fighter powered by the Rolls-Royce Falcon engine to fulfill specification F.17/24. However, this plan was abandoned as Bristol preferred utilizing its proprietary engines. The project was revived in 1926 when Barnwell initiated work on what was designated the Bristol 102, aiming to satisfy either specification F.9/26 for a day-and-night fighter or N.21/26 for a naval fighter.
The Type 105 label was later assigned to a new proposal intended to meet F.9/26, powered by the Bristol Mercury engine then under development. These designs showed enough promise that two mock-ups were constructed for Air Ministry inspection in February 1927. Both models shared similar design traits; however, the interceptor designed for F.17/24 was slightly smaller, lighter, and lacked radio equipment. Consequently, Bristol was instructed to adjust the design to comply with the newer interceptor specification F.20/27. Following this, a prototype called the Type 107 Bullpup was commissioned for evaluation, but the alternative design did not receive official endorsement. Bristol deemed it viable enough to produce a prototype for F.9/26 trials as a private venture, opting for a Bristol Jupiter engine due to anticipated Mercury engine shortages.[1]
Design and development
The Type 105 featured an unequal-span single-bay biplane configuration powered by a supercharged Bristol Jupiter VII air-cooled radial engine coupled with a two-bladed propeller. Constructed entirely from metal with fabric covering, its structure utilized rolled high-tensile steel strips riveted together. To maximise pilot visibility, the upper wing incorporated a large semi-circular cut-out along its trailing edge while the inner section of the lower wing had reduced chord length. Frise-type ailerons were installed exclusively on the upper wing. Armament consisted of two 0.303 in (7.7 mm) Vickers machine guns mounted on either side of the cockpit.[2][3]
The prototype Bulldog took to the air for its maiden flight on 17 May 1927. Early tests yielded satisfactory results and it was delivered to RAF Martlesham Heath in June.[4] After evaluating all contenders submitted against the specification, both the Bulldog and Hawker Hawfinch were shortlisted for further assessment.[5] The RAF commended the Bulldog’s agility and structural robustness. Initial issues with spin recovery were addressed by enlarging the fin and rudder; however, this modification introduced challenges when taxiing in crosswinds.[6]
A second prototype featuring an extended rear fuselage was ordered to continue comparative trials with the Hawfinch. This version, known as Type 105A or Bulldog Mk II, first flew on 21 January 1928 piloted by Cyril Uwins, before being delivered to Martlesham Heath shortly thereafter. Since its performance closely matched that of the Hawfinch, final selection awaited evaluation by service pilots; ultimately, maintenance simplicity led to choosing the Bulldog.[5][7] An initial order for twenty-five units was placed; Bristol proceeded with production of twenty-six airframes—the extra intended as a company demonstrator. Deliveries commenced on 8 May 1929 and concluded by 10 October.Template:Fix/category[citation needed]
Later production models were improved as Mk IIA variants featuring reinforced wing spars and a sturdier fuselage structure powered by an enhanced Jupiter VII F engine. One aircraft was converted into an advanced trainer; following evaluation by the Central Flying School at Upavon, this version was adopted by the RAF with production trainers differing from the prototype through slightly swept wings and an enlarged fin to aid spin recovery.[8]
Operational history
Although the Bulldog was never engaged in combat operations with the RAF, during the Abyssinia Crisis of 1935–36, several Bristol Bulldogs were deployed to Sudan to strengthen the forces under Middle East Command. Notably, Douglas Bader, who later gained fame for his World War II exploits, lost both legs after crashing his Bristol Bulldog while performing unauthorised aerobatics at Woodley airfield near Reading. The Bulldog was phased out from RAF Fighter Command in July 1937, mainly replaced by the Gloster Gauntlet, but it remained in use within RAF Service Flying Training Schools for several more years. The aircraft was also exported internationally, serving air forces in countries including Australia, Denmark, Estonia, Finland, Japan, Latvia, Siam, and Sweden.
In 1936, Latvia, aiming to update its fleet with newer aircraft, sold 11 Bulldogs to Basque nationalist forces. These aircraft were incorporated into the Spanish Republican Air Force during the Spanish Civil War and remained operational until the Battle of Santander. During the Winter War starting in 1939, ten Bulldogs were actively engaged by the Finnish Air Force against Soviet forces. Despite being technologically outclassed by their adversaries, Finnish pilots flying Bulldogs achieved two confirmed kills—one against a Polikarpov I-16 and another against a Tupolev SB—at the cost of losing one Bulldog. The first aerial victory for Finland's Air Force was secured by SSgt Toivo Uuttu on 1 December 1939 when he downed an I-16. Later on, Bulldogs were utilized primarily for advanced training roles throughout the subsequent Continuation War with the Soviet Union.
Variants
- Bulldog Mk. I
- Prototype single-seat fighter designed for day and night operations; two units produced.
- High-altitude Bulldog
- Adapted from the first prototype featuring larger wings to attempt a world altitude record.
- Bulldog Mk. II
- Second prototype and initial production model powered by a 440 hp (330 kW) Bristol Jupiter VII radial engine; 92 manufactured by Bristol.
- Bulldog Mk. IIA
- Equipped with a 490 hp (370 kW) Bristol Jupiter VIIF radial engine and updated design elements; 268 constructed by Bristol.
- Bulldog Mk. IIIA
- Variant powered by a Bristol Mercury IV engine enclosed within a Townend ring, featuring redesigned wings and reinforced fuselage. Only two built; one converted to serve as the prototype for Mk. IV.
- Bulldog Mk. IVA
- Modified version of Mk. III developed to meet specification F.7/30 as a four-gun day-and-night fighter. Although not adopted by the RAF, 17 units were sold to Finland armed with two 7.7 mm Vickers guns; total of 18 built by Bristol.
- Bulldog TM (Type 124)
- Two-seat trainer variant; 59 produced. Powered by an Armstrong Siddeley Cheetah IX engine delivering 310 hp.
- "J.S.S.F." (Japanese Single-Seat Fighter)
- Two units manufactured under licence by Nakajima Aircraft Works in Japan.
- B.Kh.6
- Designation used by the Royal Siamese Air Force for the Bulldog Mk. II.[9]
Operators
- Royal Australian Air Force
- No. 1 Squadron RAAF – Bulldog Mk. IIA
- No. 2 Squadron RAAF – Bulldog Mk. IIA
- Finnish Air Force – Bulldog Mk. IVA
- Royal Siamese Air Force Acquired two units for evaluation
- Royal Swedish Air Force Donated two Bulldog Mk. IIA to Finland in 1939
- No. 3 Squadron RAF – Operated from May 1929 until July 1937
- No. 17 Squadron RAF – Served from October 1929 to August 1936
- No. 19 Squadron RAF – Active between September 1931 and January 1935
- No. 23 Squadron RAF – Used from July 1931 through April 1933
- No. 24 Squadron RAF – Utilized a single two-seat Bulldog within the Communications Squadron
- No. 29 Squadron RAF – Employed between June 1932 and April 1935
- No. 32 Squadron RAF – In service from January 1931 to July 1936
- No. 41 Squadron RAF – Operated October 1931 to August 1934
- No. 54 Squadron RAF – Used April 1930 through September 1936
- No. 56 Squadron RAF – Served October 1932 to May 1936
- No. 111 Squadron RAF – Active January 1931 to July 1934
- No. 1 Flying Training School
- No. 3 Flying Training School
- No. 5 Flying Training School
- Central Flying School RAF
- RAF College, Cranwell
- United States Navy – Procured two aircraft during the period of 1929–1930 for testing purposes. On November 25, 1929, one of these aircraft crashed near Bolling Field, resulting in the death of pilot Lieutenant George T. Cuddihy.
Surviving aircraft
- Finland
- BU-59 – Bulldog IVA exhibited as a static display at the Hallinportti Aviation Museum located in Kuorevesi, Jämsä.
- United Kingdom
- G-ABBB – Bulldog IIA preserved and displayed at the Royal Air Force Museum London, situated in London. This particular plane, originally a civilian demonstrator, is painted in the livery of K2227. It suffered significant damage during a crash at the Farnborough Airshow in 1964 but was restored in the late 1990s.
Additionally, a flying replica was built by Ed Storo from Tillamook, Oregon, completed over the span of 2000 to 2022. Due to the rarity of original Bristol Jupiter engines, this replica is equipped with a Pratt & Whitney R-1340 Wasp.
Specifications (Bulldog IIa)
See also
Notes
- ↑ Barnes 1964, p. 212.
- ↑ Lumsden Aeroplane Monthly August 1991, pp. 460–461.
- ↑ Barnes 1964, pp. 212–213.
- ↑ Mason 1992, p. 193.
- ↑ 5.0 5.1 Mason 1992, p. 194.
- ↑ Barnes 1964, p. 213.
- ↑ Barnes 1964, p. 214
- ↑ Barnes 1966, pp. 219–220.
- ↑ "Thai Military Aircraft Designations". designation-systems.net. Retrieved 18 March 2025.
Bibliography
- Andrews, C.F. The Bristol Bulldog (Aircraft in Profile No.6). Leatherhead: Profile Publications Ltd., 1965.
- Barnes, C.H. Bristol Aircraft Since 1910. London: Putnam, 1964.
- "The Bulldog Breed" Part II. Air Enthusiast, Vol. 4, No. 2, February 1973, pp. 91–95.
- Crawford, Alex. Bristol Bulldog, Gloster Gauntlet. Sandomierz, Poland/Redbourn, UK: Mushroom Model Publications, 2005.
- Delve, Ken. Fighter Command 1936–1968: An Operational and Historical Record. Barnsley, South Yorkshire, UK: Pen & Sword, 2008.
- Gerdessen, Frederik. "Estonian Air Power 1918 – 1945". Air Enthusiast, No. 18, April – July 1982. pp. 61–76.
- Granger, Alfred. The Bristol Bulldog (Data Plan No. 2). Hamburg, Germany: Taurus Press, 1973.
- Keskinen, Kalevi; Niska, Klaus; Stenman Kari; Geust, Carl-Frederik. Suomen museolentokoneet (Museum Aircraft in Finland). Espoo: Tietoteos, 1981.
- López, Rafael A. Permuy and Artemio Mortera Pérez. Bristol "Bulldog" (I) (Perfiles Aeronáuticos: La Máquina y la Historia 8) (in Spanish). Valladolid: Quiron Ediciones, 2006.
- López, Rafael A. Permuy and Artemio Mortera Pérez. Bristol "Bulldog" (II) (Perfiles Aeronáuticos: La Máquina y la Historia 9) (in Spanish). Valladolid: Quiron Ediciones, 2006.
- Lumsden, Alec. "On Silver Wings – Part 11". Aeroplane Monthly, Vol 19 No 8, August 1991. pp.458–463.
- Mason, Francis K. The British Fighter since 1912. Annapolis: Naval Institute Press, 1992.
- Thetford, Owen. "On Silver Wings – Part 12". Aeroplane Monthly, Vol 19 No 9, September 1991. pp.522–528.