The Blackburn B-7 was a single-engine two/three-seat

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

built to a

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

Air Ministry specification for a general-purpose, multitasking aircraft. It first flew in 1934, but no contracts were issued and only one aircraft was completed.

Development

Air Ministry specification G.4/31 called386 for an aircraft to replace the

Westland Wapiti The Westland Wapiti was a British two-seat general-purpose military single-engined biplane of the 1920s. It was designed and built by Westland Aircraft Works to replace the Airco DH.9A in Royal Air Force service. First flying in 1927, the Wa ...

and

Fairey Gordon The Fairey Gordon was a British light bomber (2-seat day bomber) and utility aircraft of the 1930s. The Gordon was a conventional two-bay fabric-covered metal biplane. It was powered by variants of the Armstrong Siddeley Panther IIa engine. A ...

. The task list was long: day and night light bombing,

dive bombing A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact througho ...

reconnaissance In military operations, military reconnaissance () or scouting is the exploration of an area by military forces to obtain information about enemy forces, the terrain, and civil activities in the area of operations. In military jargon, reconnai ...

and army cooperation. The specification attracted interest across the British aircraft industry and eight manufacturers were immediately involved in preparing prototypes, three receiving contracts and the others going forward as private ventures. Blackburn became involved only when the Air Ministry extended the role list to include coastal defence and torpedo bombing, Blackburn's speciality. Their contender became known as the ''B-7'' after the Class B marking it carried and lacking an old-style Blackburn-type number. It was built on the

Shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

production line and had much in common with it.''Flight'' 2 May 1935 The Shark had introduced a new wing construction to Blackburn, each wing having two outward slanting (at about 45°, rather than vertical), slightly distorted N-type

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for ...

s linked by a single strut from the lower front to upper rear spars. As a result of this Warren girder structure, few bracing wires compared to past practice were needed. The wings were slightly staggered and swept and had the same span and much smaller lower wing as the Shark. Unlike the Shark the wings did not fold; another significant difference was that wing area was increased to enhance the load carrying performance by increasing the chord. The B-7 shared with the Shark the semi-

monocoque Monocoque ( ), also called structural skin, is a structural system in which loads are supported by an object's external skin, in a manner similar to an egg shell. The word ''monocoque'' is a French term for "single shell". First used for boats, ...

aluminium-clad watertight fuselage first seen on the M.1/30A and the divided main undercarriage necessitated by the torpedo-dropping role. Accommodation, equipment and armament was similar to that of the Shark. They also shared the 700 hp (520 kW)

Armstrong Siddeley Tiger The Armstrong Siddeley Tiger was a British 14-cylinder air-cooled aircraft radial engine developed by Armstrong Siddeley in the 1930s from their Jaguar engine. The engine was built in a number of different versions but performance and dimensi ...

IV engine. The B-7 first flew on 28 November 1934.

Operational history

The B-7 was flown to

Martlesham Heath Martlesham Heath is a village in Suffolk, England. It is east of Ipswich, This was an ancient area of heathland and latterly the site of Martlesham Heath Airfield. A "new village" was established there in the mid-1970s and this has developed in ...

for competitive trials in May 1935 and completed in October that year. By now, the specification was four years old, requirements had changed and there was little official interest in the results and none of the nine manufacturers was awarded a contract. Shortly afterwards, the B-7 was scrapped.

Specifications (bomber)

References

Notes

Bibliography

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External links

{{Blackburn aircraft B-07 1930s British military aircraft Single-engined tractor aircraft Biplanes Aircraft first flown in 1934 Aircraft with fixed conventional landing gear Single-engined piston aircraft