The Bristol Boarhound was a British army cooperation and liaison aircraft, 1st flight 1925.
It was a two-seat biplane with wings of equal span, of steel frame construction with fabric covering.
The Boarhound was built as a private venture to Air Ministry Specification 8/24 (later superseded by Specification 20/25) for an Army cooperation aircraft to replace the Bristol Fighter, first flying on 8 June 1925 as the Type 93 Boarhound.
The Boarhound, designed by Captain Frank Barnwell, was a two-bay biplane which used a method of steel construction which involved high-tensile steel strips, rolled into cusped and flanged sections, which were riveted together to form longerons and struts.
The resulting structure was lighter, stronger and cheaper than one made from drawn tubes.
It had a deep fuselage allowing bulky radio and camera equipment to be carried and was powered by a Bristol Jupiter IV engine with variable timing.
The Boarhound was evaluated alongside the Armstrong Whitworth Atlas, de Havilland Hyena and Vickers Vespa.
The Jupiter’s variable timing gear gave poorer power at low altitudes, a disadvantage for an army cooperation aircraft, and the Atlas was considered superior.
The Directors of Bristol decided, however, to continue development of the aircraft as a private venture for a general-purpose bomber to replace the Airco DH.9A.
A second aircraft was therefore built, the Type 93A Beaver, flying on 23 February 1927.
This was rejected in favour of the Fairey IIIF, which used the preferred Napier Lion engine, of which large numbers were in store.
The Boarhound I (registered G-EBLG) and the Beaver (registered G-EBQF) were withdrawn from use at Filton Aerodrome in April 1927.
A further two aircraft were produced as reconnaissance fighters as the Type 93B Boarhound II.
Variants
Type 93 Boarhound
Army cooperation aircraft, powered by Jupiter IV engine, one built.
Type 93A Beaver
General-purpose aircraft, one built.
Type 93B Boarhound II
Fighter-reconnaissance aircraft for Mexico, powered by 450 hp (340 kW) Jupiter VI engine, two built.
Specifications
Boarhound I
Crew
2
Length
31 ft 6 in (9.60 m)
Wingspan
44 ft 9 in (13.64 m)
Height
11 ft 8 in (3.56 m)
Wing area
464 sq ft (43.1 m2)
Empty weight
2,900 lb (1,315 kg)
Gross weight
4,460 lb (2,023 kg)
Powerplant
1 × Bristol Jupiter IV 9-cylinder air-cooled radial piston engine,
425 hp (317 kW)
Propellers
2-bladed fixed-pitch propeller
Performance
Maximum speed
137 mph (220 km/h, 119 kn)
Endurance
3 hours
Service ceiling
22,000 ft (6,700 m)
Time to altitude
10,000 ft (3,048 m) in 10 minutes 38 seconds
Wing loading
9.61 lb/sq ft (46.9 kg/m2)
Power/mass
0.095 hp/lb (0.156 kW/kg)
Armament
Guns
1 × forward-firing .303 in (7.7 mm) Vickers machine gun on side of fuselage
1 × .303 in (7.7 mm) Lewis Gun on Scarff ring (observer)
