|First flight||8 June 1925|
Design and development
The Boarhound was built as a private venture to Air Ministry Specification 8/24 (later superseded by Specification 20/25) for an Army cooperation aircraft to replace the Bristol Fighter, first flying on 8 June 1925 as the Type 93 Boarhound.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 disadavantage 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 only two Boarhound IIs ever built were sold to Mexico in 1928, and were used against rebel forces in April 1929. The Boarhounds proved successful in Mexican service, their metal structure proving suitable for the climate. Two legends of the Mexican Air Force flew the Boarhound II: Pablo Sidar and Alfonso Cruz Rivera.
- 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)
Data from Bristol Aircraft Since 1910 
- Crew: two, pilot and observer
- 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 ft² (43.1 m²)
- Empty weight: 2,900 lb (1,318 kg)
- Loaded weight: 4,460 lb (2,027 kg)
- Powerplant: 1 × Bristol Jupiter IV radial engine, 425 hp (317 kW)
- Maximum speed: 117 kn (135 mph, 217 km/h)
- Service ceiling: 22,000 ft (6,700 m)
- Wing loading: 9.61 lb/ft² (47.0 kg/m²)
- Power/mass: 0.095 hp/lb (0.16 kW/kg)
- Endurance: 3 hours
- Climb to 10,000 ft (3,050 m): 10 min 38 sec 
- 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)
- 2 × 112 lb (50 kg) bombs
- Mason, Francis K (1994). The British Bomber since 1914. London: Putnam Aeronautical Books. ISBN 0-85177-861-5.
- Barnes, C.H. (1964). Bristol Aircraft Since 1910 (First ed.). London: Putnam.
- Jackson, A.J. (1973). British Civil Aircraft since 1919 (Volume I) (Second ed.). London: Putnam. ISBN 0-370-10006-9.
- Donald, David, and Lake, Jon, eds. Encyclopedia of World Military Aircraft. London: AIRtime Publishing, 1996. ISBN 1-880588-24-2.
|Wikimedia Commons has media related to Bristol Boarhound.|