The Hawker Hurricane is a British single-seat fighter aircraft that was designed and predominantly built by Hawker Aircraft Ltd for the Royal Air Force (RAF). Although largely overshadowed by the Supermarine Spitfire, the aircraft became renowned during the Battle of Britain, accounting for 60% of the RAF's air victories in the battle, and served in all the major theatres of the Second World War.
The 1930s design evolved through several versions and adaptations, resulting in a series of aircraft which acted as interceptor-fighters, fighter-bombers (also called "Hurribombers"), and ground support aircraft. Further versions known as the Sea Hurricane had modifications which enabled operation from ships. Some were converted as catapult-launched convoy escorts, known as "Hurricats". More than 14,000 Hurricanes were built by the end of 1944 (including at least 800 converted to Sea Hurricanes and some 1,400 built in Canada by Canadian Car and Foundry).
Design and development
At the time that the Hurricane was developed RAF Fighter Command consisted of just 13 squadrons, each equipped with either the Hawker Fury, Hawker Demon, or the Bristol Bulldog, all biplanes with fixed-pitch wooden propellers and non-retractable undercarriages. Sydney Camm's design to meet F.7/30, the Hawker P.V.3, was essentially a scaled-up version of the Fury and was not among the proposals submitted to the Air Ministry selected for building as a government sponsored prototype. After the rejection of the P.V.3 Camm started work on a cantilever monoplane with a fixed undercarriage armed with four machine guns and powered by the Rolls-Royce Goshawk. Detail drawings were finished by January 1934 but failed to impress the Air Ministry enough for a prototype to be ordered. Camm's response was to further develop the design, introducing a retractable undercarriage and replacing the unsatisfactory Goshawk with a new Rolls-Royce design, the PV-12, later to become famous as the Merlin. In August 1934, a one-tenth scale model was made and sent to the National Physical Laboratory at Teddington. A series of wind tunnel tests confirmed the aerodynamic qualities of the design were in order, and in September Camm approached the Air Ministry again. This time the response was favourable, and a prototype of the "Interceptor Monoplane" was ordered.
, the prototype, photographed before its first flight in November 1935.
Shortly after this the Air Ministry issued Specification F.5/34 which, drawing on the work of Squadron Leader Ralph Sorley, called for fighter aircraft to be armed with eight guns. However by this time, work had progressed too far to immediately modify the planned four-gun installation. By January 1935, a wooden mock-up had been finished, and although a number of suggestions for detail changes were made construction of the prototype was approved, and a new specification (F.36/34) was written around the design. In July 1935, this specification was amended to include installation of eight guns.
Work on the airframe was completed at the end of August 1935 and the aircraft components were taken to Brooklands, where Hawkers had an assembly shed, and re-assembled on 23 October 1935. Ground testing and taxi trials took place over the following two weeks, and on 6 November 1935, the prototype took to the air for the first time at the hands of Hawker's chief test pilot, Flight Lieutenant (later Group Captain) George Bulman. Bulman was assisted by two other pilots in subsequent flight testing; Philip Lucas flew some of the experimental test flights, while John Hindmarsh conducted the firm's production flight trials.
RAF trials of the aircraft at Martlesham Heath began in February 1936. Sammy Wroath, later to be the founding Commandant of the Empire Test Pilot School, was the RAF test pilot for the Hurricane: his report was favorable, stating "The aircraft is simple and easy to fly and has no apparent vices" and going on to praise its control response. The type name "Hurricane" proposed by Hawkers was approved by the Air Ministry on 26 June; an informal christening ceremony was carried out the next month when King George VI paid a visit to Martlesham Heath.
Further testing showed that the Hurricane had poor spin recovery characteristics, with all rudder authority being lost. Hawker's response was to request that spinning tests be waived, but the Air Ministry refused the request; the situation was resolved by the Royal Aircraft Establishment, who established that the problem was caused by a breakdown of the airflow over the lower fuselage, and could be cured by the addition of a small ventral fairing and extension of the bottom of the rudder. This discovery came too late to be incorporated in the first production aircraft, but was introduced in the 61st built and all subsequent aircraft.