The Blackburn Type B-7 was a private venture response to Specification G.4/31 which sought a general-purpose aircraft to replace the Westland Wapiti. This requirement attracted ten different designs, including officially supported entries from Handley Page with the HP47, Parnall with the G.4/31 and Vickers with the Type 253.
Private venture prototypes were also offered by Armstrong Whitworth with the AW19, Bristol with the Type 120, Hawker and the PV4, Westland with the PV7, whilst Fairey sumitted two types with the F-1 biplane and the G.4/31 monoplane.
The 'jack-of-all-trades' nature of the specification included requirements to carry / drop a torpedo and to conduct dive bombing. Additionally, there were a range of other subsidiary duties which included casualty evacuation.
With the Blackburn Shark already in production and already carrying essentially similar armament, Blackburn’s entry was in effect, a land-based Shark (with no wing fold or arrestor hook). It did however, feature an increased wing chord to suit the higher weights required to meet the requirement.
Power for the B-7 was provided by the 700 hp Armstrong Siddeley Tiger IV, the same engine as that fitted to the Shark. The aircraft also shared a number of components including the fuselage and wing Warren girder style bracing.
The Blackburn B-7 was first flown at Brough on 28th November 1934, being flown to Martlesham Heath for official competitive trials on between 28th May and the end of October 1935.
The type was found to have the lowest performance of the various G.4/31 contenders but by then official interest in the Specification was waning and none of the prototypes originally offered received a production order. The removal of the need for a torpedo carriage from the requirement (met by B-7) undoubtedly damaged the type’s chances in any case.
The B-7 returned to Brough in October 1935 after the end of the official trials were shortly afterwards it was scrapped.
Variants & Numbers Built
One prototype only carrying Class B registration B-7.
|Powerplant||One 700 hp Armstrong Siddeley Tiger IV|
|Span||46 ft 0 in|
|Maximum Weight||7,027 lb (bomber), 7,762 lb (GP), 8,338 lb (Torpedo)|
|Capacity & Armament||Two crew; fixed forward-firing Vickers gun, defensive Lewis gun fired from rear cockpit, two 500lb bombs carried on underwing racks, one 1,800 lb 18 in torpedo carried between undercarriage legs.|
|Maximum Speed||147 mph at 7,000 ft|
|Cruise speed||100 mph|
|Range||540 miles (475 miles with torpedo)|
Nil. The sole prototype was scrapped following its return from official trials.