The Handley Page H.P.47 was a British single-engined low-wing

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

built to an

Air Ministry The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of State ...

specification for a general-purpose bomber and

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

aircraft. Only one was built.

Development

The Handley Page H.P.47 was the company's submission to Air Ministry specification G.4/31 which called for a single-engined general-purpose aircraft to replace the

Vickers Vincent The Vickers Vildebeest and the similar Vickers Vincent were two very large two- to three-seat single-engined British biplanes designed and built by Vickers and used as light bombers, torpedo bombers and in army cooperation roles. First flown i ...

in its Imperial role, to act as a bomber flying from unprepared airstrips and to be a torpedo bomber in the

Tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referr ...

, particularly Aden. Handley Page were awarded a contract for one prototype; its designer,

Gustav Lachmann Gustav Victor Lachmann (3 February 1896 – 30 May 1966) was a German aeronautical engineer who spent most of his professional life working for the British aircraft company Handley Page. He was, with Frederick Handley Page, the co-inventor of the ...

had monitored German monoplane progress on behalf of Handley Page, so it was not surprising that the H.P.47 used construction methods similar to those of companies like Junkers. He had also become interested in the use of thick wing sections such as RAF34 for which the centre of pressure moved little with angle of attack, making the design of a single-spar monoplane wing easier. The H.P47 was a low-wing cantilever monoplane. Forward of the single spar the wing was covered with a stressed metal skin, forming a torsion box. Behind the spar it was fabric-covered, the trailing edge carrying flaps inboard, from the wing fillet out to the ailerons, though the centre section was metal-skinned throughout. The leading edge carried slats in three sections to form slots across the whole span when extended.''Flight'' p417 The inboard pair were opened when the flaps were lowered and the outer slots were automatic, with

interceptors An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are ca ...

connected to the ailerons for lateral control at high angles of attack. Behind the radial Bristol Pegasus IM3 engine, producing 650 hp (485 kW) and enclosed in a

Townend ring A Townend ring is a narrow- chord cowling ring fitted around the cylinders of an aircraft radial engine to reduce drag and improve cooling. Development The Townend ring was the invention of Dr. Hubert Townend of the British National Physica ...

, the semi-monocoque, corrugated-skinned fuselage grew in diameter to the pilot's midwing cockpit then remaining constant rearwards to the gunner's position. He sat facing rearwards below the upper fuselage line and out of the slipstream, at a point where the fuselage stepped to a slim and narrowing oval boom. There was usable space inside the fuselage between the cockpits, enough to carry three passengers or two stretcher cases. All the tail surfaces moved; the fin, mounted ahead of the tailplane, moved with the horn-balanced rudder but through smaller angles, changing the camber, and the tailplane and single elevator were similarly coupled. All these rear control surfaces were covered with corrugated stressed skin. Specification G.4/31 included the dropping of torpedoes, so the underside of the aircraft had to be clear and with wing fuel tanks the main undercarriage was fixed. The legs were mounted at the end of the centre section, each with a rearward strut and a long bracing strut outwards to the main spar. These struts were faired and both main and tail wheels were spatted. The main wheels were fitted with brakes. The first flight, without Townend ring, spats or undercarriage fairings, was on 27 November 1934. Several modifications followed, including the abandonment of the forward-sliding front cockpit hood, extension of the rudder and mass-balancing of the elevators. Trials with full military load and with the Pegasus IM3 replaced by a more powerful IIIM3 followed at RAF Martlesham Heath in the G.4/31 trials. The main criticism was of the lack of longitudinal stability and the consequent trimming difficulty. The competition winner was the Vickers Type 246, put into production as the

Vickers Wellesley The Vickers Wellesley was a medium bomber that was designed and produced by the British aircraft manufacturer Vickers-Armstrongs at Brooklands near Weybridge, Surrey. It was one of two aircraft to be named after Arthur Wellesley, 1st Duke of ...

. The H.P.47 continued to fly at the Royal Aircraft Establishment (RAE), testing its combination of slots, interceptors and flaps at low speeds; it was used for engine development, flying until May 1937.

Specifications (General-purpose configuration)

References

Notes

Bibliography

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External links