Hawker Hart
The Hawker Hart was a British two-seat biplane light bomber designed by Sydney Camm and powered by the Rolls-Royce Kestrel. First flown in 1928, it could outpace every RAF fighter then in service, and it entered squadron service in January 1930. Production passed 1,000 aircraft, more than four hundred of them for the RAF, and the type served at home, in India and in the Middle East through the 1930s. Its basic design proved adaptable, giving rise to a family of Hawker derivatives, and individual Harts lingered in training and communications work until 1943. Two examples are on display with the RAF Museum, at London and at Cosford, and a Swedish-built B 4 survives in Sweden.
Why It Mattered
History of War ranks the Hart among the most significant RAF aircraft of the early 1930s: a light day bomber faster than the fighters meant to intercept it. It had been designed to meet a specification calling for 160 mph, yet it reached a top speed of 184 mph, outpacing every RAF fighter in service when it first appeared, the 178 mph Bristol Bulldog II included. In the RAF's 1931 annual air exercises, the only aircraft capable of intercepting a Hart was another Hart. The RAF Museum judges that, although designed as a bomber, the Hart had a performance superior to any fighter aircraft then in existence. Its arrival pushed the RAF to seek faster fighters, and it spurred quick work on the Hawker Fury, the RAF's first 200 mph fighter. The Hart and its variants went on to become a mainstay of the Royal Air Force during the 1930s.
Design Notes
Sydney Camm designed the Hart around the Rolls-Royce F.XIB inline engine, better known as the Kestrel, whose 525 hp and small frontal area let him draw a sleekly streamlined aircraft with a distinctive pointed nose. The Hart was a single-bay biplane with a metal structure: a steel-tube fuselage covered by aluminium panels and fabric, and wings built with steel spars and duralumin ribs under fabric. Its crew of two sat in individual tandem cockpits. The pilot operated a single fixed Vickers machine gun, while the observer behind him manned a Lewis gun on a ring mount and aimed the bombs lying prone beneath the pilot's seat. Up to 520 lb of bombs could be carried under the wings.
Operational History
The prototype Hart, serial J9052, first flew in June 1928. The type entered squadron service in January 1930 with No. 33 Squadron, replacing the larger and slower Hawker Horsley. Seven home-based regular bomber squadrons were equipped with the Hart, as well as eleven auxiliary and reserve units, and over four hundred Harts were built for the Royal Air Force. Less than two years after its introduction at home, Harts were in use by overseas squadrons in the Middle East and India. The Hart saw extensive service on the North-West Frontier of India, and during the Abyssinia Crisis of 1935–1936 Harts were sent out to the Middle East. It was also an export success, seeing service with the air forces of Egypt, British India, South Africa, Estonia and Yugoslavia, and with Sweden, where it was designated B 4. Production was spread across several British companies, and total output passed 1,000 aircraft. By 1938 the Hart had been withdrawn from front-line service in Britain. Four Swedish Harts saw action as dive bombers with the volunteer squadron F19, fighting for Finland during the 1939–1940 Winter War. Harts were still in Middle East service in 1939 and saw limited active service there in 1940. The type then lingered in communications and training roles until it was declared obsolete in 1943, and South African Harts were still performing communication duties that year.
Afterlife
The Hart's basic design proved remarkably adaptable: six more of Hawker's 1930s aircraft were based on it. The RAF Museum names the Audax, Demon, Hardy, Hind and Hector among the later versions Camm's team developed from the design. As a bomber the Hart itself was replaced by the Hind in 1935–36, a derivative distinguished mainly by its more powerful engine. A dedicated trainer version had been designed in 1932, because the RAF's existing training aircraft could not prepare pilots for the Hart's performance. Survivors on public display include the RAF Museum's Hart II G-ABMR at its London site, presented in the markings of J9941, and a Hart Trainer at the museum's Cosford site. A licence-built Swedish B 4 is displayed by the Swedish Air Force Museum near Linköping.