Air Ministry Specification F.7/30 sought a single-seat day and night fighter, powered by a Rolls-Royce Goshawk engine, carrying a four-gun armament. It required the use of the Rolls-Royce Goshawk engine, a development of the Kestrel engine, with evaporative cooling (sometimes termed steam cooling). Much of the requirement were both very demanding and complex.
The general performance requirements sought a maximum speed in excess of 250 mph, with general characteristics in well in advance of its contemporaries in respect of handling, maneuverability, range, rate of climb and service ceiling.
Apart from the four synchronised Vickers guns, mandated equipment included full radio communications ability and specific night flying equipment. Part of the detail of the specification highlighted 'Night Operations and because of this, excellent all-round view was demanded as well as flame-damped exhausts and low wing loadings.
Having issued the Specification, contracted prototypes were government funded for the Blackburn Aircraft Company F.3 (K2892), the Westland Aircraft PV4 and the Vickers Supermarine Type 224. The Hawker Aircraft Company also offered their Type 123 and PV3 on a private venture basis.
Several of the designs were of unusual configuration, apparently driven by the Specification’s emphasis on all-round unobstructed field of view for the pilot. The Blackburn F.3 was no exception and was a very compact design of just under 37 ft wingspan and 27 ft length.
The pilot sat high in an open cockpit, over the upper-wing centre (this wing being mounted on the fuselage centreline), with the Rolls-Royce Goshawk III engine was mounted low on the fuselage centreline. A biplane second wing was mounted entirely below the fuselage, with a central steam condenser filling the gap between the wing and the bottom of the fuselage.
Two spatted wheels were attached to the lower-wing leading edge, giving an exceptionally wide undercarriage track. The design was initially provided with a tail skid, this being later replaced with a tail wheel. The wheel spats were also removed at the same time.
Two of the fixed, forward-firing guns were fitted above the upper-wing roots, with the other two mounted in the sides of the lower fuselage, just above the steam condenser.
The aircraft was first taxied on 20th July 1934, beginning full ground trials on 17th August. However, there were continual cooling problems with the Rolls-Royce Goshawk engine, which was a problem that also beset all the other contenders. Ground handling was also difficult, said to be due to the powerful engine, short fuselage and high centre of gravity.
By early September, cracks and dents had appeared in the duralumin-skinned fuselage and the company were unable to meet the agreed delivery date for the aircraft.
In the event, K2892 remained unflown and was transferred to RAF Halton as an instructional airframe.
Variants & Number Built
One prototype only, K2892, never flown.
|Powerplant||One 695 hp Rolls-Royce Goshawk III|
|Span||36 ft 10.75 in|
|Maximum Weight||3,960 lb|
|Capacity & Armament||One pilot; four fixed forward-firing Vickers Mk III machine guns|
|Maximum Speed||190 mph at 14,500 ft (estimated)|
None - The sole prototype was scrapped following unsuccessful trials.