Bristol Bullfinch

Bullfinch

Manufacturer: Bristol Aeroplane Company
Designed by: Frank Barnwell
First flight: 6 November 1922
Number built: 3

The Bristol Bullfinch was an experimental British military aircraft of the 1920s. Variants were built as both parasol wing monoplanes and biplanes, but proved unsuccessful, only three prototypes being built.

Development

The Bullfinch was designed by Frank Barnwell, chief designer of the Bristol Aeroplane Company as a parasol-wing monoplane single-seat fighter, which was convertible to a two-seat biplane, thus meeting the requirements of the Royal Air Force for both a single-seat interceptor fighter and a two-seat reconnaissance-fighter. The potential cost savings associated with this concept, which was planned to be powered by the Jupiter engine, the rights to which Bristol had just acquired from the bankrupt Cosmos Engineering, interested the Air Ministry, who wrote a specification (Specification 2/21) around Barnwell's proposed design, and ordered three prototypes in June 1921.

The Bullfinch monoplane, or Type 52 Bullfinch Mk I, was a cantilever parasol monoplane with a welded steel tube fuselage. The wing was in two halves, joined at the aircraft centreline, with each half tapering from maximum thickness at half span to both the wing root and tips . The wing was wooden in the prototypes, but was planned to be of metal construction for any subsequent production aircraft. To produce the two-seat fighter-reconnaissance version, the Type 53 Bullfinch Mk II, an extra fuselage bay was added aft of the pilot containing a cockpit for the observer, with a cantilever bottom wing attached which compensated for the shift in centre of gravity resulting from the lengthened fuselage.

The first prototype, a Type 52 monoplane flew on 6 November 1922, with the second prototype, also a monoplane, flying in May 1923 . After first flying as a monoplane, the third prototype was converted to biplane configuration, flying in that layout on 17 March 1924. While the single-seater demonstrated reasonable performance, the two-seater was overweight, and proved unable to carry the required military load. No further production occurred.

Variants

Type 52 Bullfinch Mk I Single-seat parasol monoplane. Two built.

Type 53 Bullfinch Mk II Two-seat biplane derivative. One built

Operators

United Kingdom

Royal Air Force

Specifications (Bullfinch I)

Data from Bristol Aircraft Since 1910

General characteristics

Crew: 1 (Bullfinch I) or 2 (Bullfinch II)
Length: 24 ft 5 in (7.44 m)
Wingspan: 38 ft 5 in (11.71 m)
Height: 10 ft 9 in (3.28 m)
Wing area: 267 ft² (24.8 m²)
Empty weight: 2,175 lb (989 kg)
Loaded weight: 3,205 lb (1,457 kg)
Length (Bullfinch II) : 27 ft 6 in (8.38 m)
Wing Area (Bullfinch II) : 391 ft² (36.3 m²)
Empty weight (Bullfinch II) : 2,495 lb (1,134 kg)
Loaded weight (Bullfinch II) : 4,088 lb (1,858 kg)

Performance

Maximum speed: 117 kn (135 mph, 217 km/h) at 15,000 ft (4,600 m)
Service ceiling: 22,000 ft (6,700 m)
Wing loading: 12.0 lb/ft² (58.8 kg/m²)
Endurance: 4 hours
Maximum Speed (Bullfinch II) : 104 knots (120 mph, 193 km/h)
Service Ceiling (Bullfinch II) : 18,000 ft (5,500 m)
Wing Loading (Bullfinch II) : 10.5 lb/ft² ( 51.2 kg/m²)

Armament

2 x— fixed, forward-firing .303 in (7.7 mm) Vickers machine guns
1 x— .303 in (7.7 mm) Lewis Gun on Scarff ring in rear cockpit (Bullfinch II)

Bristol Bullfinch Pictures

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Source: WikiPedia