The Hawker Hurricane is a British single-seat fighter aircraft of the 1930s–40s which was designed and predominantly built by Hawker Aircraft Ltd. for service with the Royal Air Force (RAF). It was overshadowed in the public consciousness by the Supermarine Spitfire's role during the Battle of Britain in 1940, but the Hurricane inflicted 60 percent of the losses sustained by the Luftwaffe in the engagement, and fought in all the major theatres of the Second World War. The Hurricane originated from discussions between RAF officials and aircraft designer Sir Sydney Camm about a proposed monoplane derivative of the Hawker Fury biplane in the early 1930s. Despite an institutional preference for biplanes and lack of interest from the Air Ministry, Hawker refined their monoplane proposal, incorporating several innovations which became critical to wartime fighter aircraft, including retractable landing gear and the more powerful Rolls-Royce Merlin engine. The Air Ministry ordered Hawker's Interceptor Monoplane in late 1934, and the prototype Hurricane K5083 performed its maiden flight on 6 November 1935. The Hurricane went into production for the Air Ministry In June 1936 and entered squadron service in December 1937. Its manufacture and maintenance was eased by using conventional construction methods so that squadrons could perform many major repairs without external support. The Hurricane was rapidly procured prior to the outbreak of the Second World War in September 1939, when the RAF had 18 Hurricane-equipped squadrons in service. The aircraft was relied on to defend against German aircraft operated by the Luftwaffe, including dogfighting with Messerschmitt Bf 109s in multiple theatres of action. The Hurricane was developed through several versions: bomber-interceptors, fighter-bombers, and ground support aircraft as well as fighters. Versions designed for the Royal Navy known as the Sea Hurricane had modifications enabling operation from ships. Some were converted as catapult-launched convoy escorts. By the end of production in July 1944, 14,487 Hurricanes had been completed in Britain and Canada, with others built in Belgium and Yugoslavia. During the early 1930s, when Hawker Aircraft company developed the Hurricane, RAF Fighter Command had just 13 squadrons, equipped with the Hawker Fury, Hawker Demon, or the Bristol Bulldog, all biplanes with fixed-pitch wooden propellers and non-retractable undercarriages.[1][2] At the time, there was an institutional reluctance towards change within the Air Staff; some senior figures were prejudiced against the adoption of monoplane fighter aircraft, while mid-level officers were typically approachable on the subject and design concepts that made use of such configurations.[2] In 1934 the British Air Ministry issued Specification F.5/34 in response to demands within the Royal Air Force (RAF) for a new generation of fighter aircraft. Earlier, during 1933, British aircraft designer Sydney Camm had conducted discussions with Major John Buchanan of the Directorate of Technical Development on a monoplane based on the existing Fury.[3] Mason attributes Camm's discussions with figures within the RAF, such as Squadron Leader Ralph Sorley, as having provoked the specification and some of its details, such as the preference for armaments being installed within the wings instead of within the aircraft's nose.[4] Camm's initial submission in response to the earlier fighter specification F.7/30 was the Hawker P.V.3, a development of the Fury biplane.[5] However, the P.V.3 was not among the proposals which the Air Ministry selected to be constructed as a government-sponsored prototype. After the rejection of the P.V.3 proposal, Camm started work on a new design involving a cantilever monoplane arrangement with a fixed undercarriage, armed with four machine guns and powered by the Rolls-Royce Goshawk engine. The original 1934 armament specifications for what would evolve into the Hurricane were for a similar armament fitment to the Gloster Gladiator: four machine-guns, two in the wings and two in the fuselage, synchronised to fire through the propeller arc. By January 1934, the proposal's detail drawings had been finished, but these failed to impress the Air Ministry enough for a prototype to be ordered.[6] Camm's response to this rejection was to further develop the design, introducing a retractable undercarriage and replacing the unsatisfactory Goshawk engine with a new Rolls-Royce design, initially designated the PV-12, which went on to become famous as the Merlin. In August 1934, a one-tenth scale model of the design was produced and dispatched to the National Physical Laboratory at Teddington. A series of wind tunnel tests confirmed the aerodynamic qualities of the aircraft were in order, and in September 1934, Camm again approached the Air Ministry. This time, the Ministry's response was favourable, and a prototype of the "Interceptor Monoplane" was promptly ordered.[7]