Hawker Hart

The H.G. Hawker Hart was designed against Specification 12/26, which called for a high performance two seat light day bomber of all-metal construction.

 

Arguably, the requirement arose following Fairey’s development of the Private Venture Fairey Fox, flown in January 1925. This aircraft exploited the Curtiss D-12 engine, along with the Curtiss-Reed propeller to achieve a day bomber that was some 50 mph faster than contemporary RAF fighters.

 

The Fairy Fox was of wooden construction and only 28 were finally purchased by the RAF. Nevertheless, the design of the Fox effectively forced the modernisation of Air Ministry thinking and it indirectly led to both the monobloc Rolls-Royce Kestrel engine, and the Hawker Hart family of aircraft.

 

 

Specification 12/26 was demanding for its day, resulting in the Hawker Hart, a single bay biplane with all-metal primary structure which was married to a cleanly-cowled 12-cylinder Rolls-Royce Kestrel engine. The first prototype (J9052) was flown for the first time in June 1928.

 

The pilot sat ahead of a rear gunner / bomb aimer, equipped with a Lewis gun for self-defence, which was mounted on a gun-ring of Hawker design. The swept upper-wings featured a deep cut-out in the centre-section, to improve the pilot’s upward view. Splayed-out N-type interplane struts were used and the lower wing was unswept.

 

delivered to the Aeroplane and Armament Experimental Establishment at Martlesham Heath on 8th September 1928, it demonstrated good performance and handling, reaching 176 mph (283 km/h) in level flight and 282 miles per hour (454 km/h) in a vertical dive. The competition culminated in the choice of the Hawker Hart in April 1929, selected ahead of the De Havilland Hound and the Avro Antelope. It also saw the issue of a new requirement (Specification 9/29).

 

As a result, 1,004 Hawker Hart aircraft were built, of which Hawker Aircraft constructed 234. Sub-contract production was undertaken from 1931 by Gloster Aircraft Co Ltd (46), Sir WG Armstrong Whitworth Aircraft Ltd (456), Vickers Aviation Ltd (226), together with aircraft under licence at ASJA in Trollhäten, Götaverken Shipbuilder in Gothenburg and and the State Aircraft Factory in Sweden.

 

The Hawker Hart was an outstanding design, which gave rise to many variants. Developments included the Hawker Demon, Hawker Audax, Hawker Osprey, Hawker Nimrod, Hawker Hind, Hawker Hardy, Hawker Hartbees, Hawker Hector and Hawker Fury biplane. These types are shown elsewhere on this website.

 

 

The RAF used the Hawker Hart in both its original light bomber role, and as the Hawker Hart Trainer fitted with dual control and with all armament deleted. The Hawker Hart Trainer also featured reduced sweep of its upper wing to compensate for changes in centre of gravity when the military equipment was removed.

 

In addition, the Hawker Hart was used in a number of roles, with variants for communications, operation in India and tropical regions.

 

 

The type was also used by Canada (1), Estonia (8), South Africa (320+ ex-RAF), Southern Rhodesia (ex-RAF aircraft), Sweden, Yugoslavia (4 loan aircraft) and Egypt (14 ex-RAF). Swedish aircraft were powered by the 580hp Bristol Pegasus radial engine, four aircraft being built by H.G. Hawker, followed by 42 constructed locally.

 

 

The Hawker Hart was also extensively used for engine testing, various examples being host to various versions of the Rolls-Royce Kestrel, Napier Dagger, Bristol Perseus, Mercury, Pegasus and Jupiter, and the Rolls-Royce PV12 and Merlin.