Hawker Hurricane

The Hawker Hurricane, a British single-seat fighter aircraft from the 1930s to the 1940s, was designed and primarily manufactured by Hawker Aircraft Ltd. for the Royal Air Force (RAF). Although it was often overshadowed by the Supermarine Spitfire in the public eye during the Battle of Britain in 1940, the Hurricane was responsible for 60% of the Luftwaffe losses in that campaign and played a crucial role in all major theaters of the Second World War.

The origins of the Hurricane trace back to discussions in the early 1930s between RAF officials and aircraft designer Sir Sydney Camm, focusing on a proposed monoplane variant of the Hawker Fury biplane. Despite a prevailing institutional preference for biplanes and the Air Ministry’s initial lack of interest, Hawker advanced its monoplane design, integrating several innovations that became essential for wartime fighter aircraft. These included retractable landing gear and the powerful Rolls-Royce Merlin engine. The Air Ministry ordered Hawker’s Interceptor Monoplane in late 1934, and the prototype Hurricane, K5083, made its maiden flight on November 6, 1935.

Production of the Hurricane for the Air Ministry began in June 1936, and the aircraft entered squadron service by December 1937. Its construction and maintenance were simplified through conventional methods, allowing squadrons to conduct significant repairs independently. As tensions escalated towards World War II, the RAF quickly amassed Hurricane-equipped squadrons, with 18 in service by September 1939. The Hurricane was pivotal in defending against German aircraft, engaging in dogfights with Messerschmitt Bf 109s across various theaters.

The Hurricane underwent several developments, resulting in versions such as bomber-interceptors, fighter-bombers, ground support aircraft, and fighters. Variants for the Royal Navy, known as Sea Hurricanes, featured modifications like an arrestor hook for ship operations. Some were adapted as catapult-launched convoy escorts. By the end of production in July 1944, a total of 14,487 units had been built in Britain and Canada, with additional production in Belgium and Yugoslavia.

During the early 1930s, as the Hawker Aircraft company developed the Hurricane, the RAF’s Fighter Command consisted of 13 squadrons equipped with biplanes like the Hawker Fury, Hawker Demon, and Bristol Bulldog. These aircraft had fixed-pitch wooden propellers and non-retractable undercarriages. At the time, there was resistance to change within the Air Staff, with some senior figures opposed to adopting monoplane fighters, while mid-level officers were more open to innovation.

In 1934, the British Air Ministry issued Specification F.5/34, responding to demands for a new generation of fighter aircraft. Earlier, in 1933, Sydney Camm had discussions with Major John Buchanan about a monoplane based on the Fury. Camm’s interactions with RAF figures like Squadron Leader Ralph Sorley influenced the specification, including the preference for wing-mounted armaments.

An outline of the “Fury Monoplane,” armed with two guns in the wings and two in the nose, powered by the Goshawk engine, was prepared and discussed with the Air Ministry in December 1933. The design evolved with the PV.12 engine, leading to detailed working drawings of the “Interceptor Monoplane” by May 1934. The complete design was presented to the Air Ministry on September 4.

Camm’s initial response to the fighter specification F.7/30 was the development of the Hawker P.V.3, a derivative of the Fury. However, it was not selected for prototype development. Following the rejection, Camm worked on a new design featuring a cantilever monoplane with a fixed undercarriage, armed with four machine guns and powered by the Rolls-Royce Goshawk engine. By January 1934, detailed drawings of the proposal were finished, but they did not impress the Air Ministry enough to warrant a prototype order.

In response to the rejection, Camm further refined the design, incorporating a retractable undercarriage and replacing the Goshawk engine with the Rolls-Royce PV-12, later known as the Merlin. In August 1934, a scale model was tested at the National Physical Laboratory, confirming satisfactory aerodynamics. In September 1934, Camm approached the Air Ministry again, receiving a favorable response, and a prototype was ordered.

In July 1934, Air Commodore Arthur Tedder chaired a meeting where the Air Ministry’s Science Officer presented calculations showing that future fighters needed eight machine guns. Squadron Leader Ralph Sorley played a vital role in this decision. Although Specification F.5/34 called for eight guns, work had progressed too far to modify the planned four-gun installation immediately. By January 1935, a wooden mock-up was completed, leading to construction approval and the issuance of a new specification, F.36/34, which was later amended to include eight guns.

The mock-up conference with Air Ministry staff took place on January 10, 1935, at Kingston. The ministry ordered a prototype on February 21, 1935, initially armed with two Vickers Mark V machine guns in the fuselage and one Browning machine gun in each wing. Work on stressed skin outer wings began in July, and the contract was altered in August to include wings with eight guns. These wings were delivered in June 1936.

By the end of August 1935, the airframe was completed at Hawker’s Kingston upon Thames facility and transported to Brooklands, Surrey, for assembly. The prototype was re-assembled on October 23, 1935, and ground testing and taxi trials occurred over the following weeks. On November 6, 1935, the prototype K5083 made its first flight, piloted by Hawker’s chief test pilot, Flight Lieutenant George Bulman.

By March 1936, the prototype had completed ten flying hours, covering all major portions of the flight envelope. Despite restrictions on the Merlin engine, the aircraft’s performance impressed in early testing. The prototype was transferred to RAF Martlesham Heath for initial service trials, where RAF test pilot Sammy Wroath praised its simplicity and ease of flight.

During RAF trials, despite issues with the Merlin engine, the aircraft’s performance was lauded. The Hurricane was found to have a maximum speed of 315 mph at 16,200 ft, a climb rate to 15,000 ft in 5.7 minutes, and a stalling speed of 57 mph. However, it exhibited poor spin recovery characteristics, which were resolved by the Royal Aircraft Establishment through aerodynamic modifications.

In early 1936, Hawker’s board decided to proceed with production preparations for 1,000 Hurricanes, even without official authorization. In June 1936, the Air Ministry placed its first order for 600 aircraft, and the type name “Hurricane” was approved. The Hurricane was cheaper to produce than the Spitfire and required fewer person-hours per airframe.

The first production Hurricane I flew on October 12, 1937, and by February 1938, No. 111 Squadron had received 16 Hurricanes. By the outbreak of World War II, over 550 Hurricanes had been produced, equipping 18 squadrons, with 3,500 more on order.

During 1940, the Civilian Repair Organisation was established to repair and overhaul battle-damaged Hurricanes. The Canadian Car and Foundry in Ontario became a major manufacturer, producing Hurricanes from November 1938. Canadian-built Hurricanes participated in the Battle of Britain.

Overall, 14,487 Hurricanes and Sea Hurricanes were produced in England and Canada. The majority were built by Hawker, with significant contributions from Gloster Aircraft Company, Austin Aero Company, and Canadian Car and Foundry. Production also occurred in Yugoslavia and Belgium.

The Hurricane was a low-wing cantilever monoplane with retractable undercarriage and an enclosed cockpit. Its fuselage featured a Warren truss box-girder structure with high-tensile steel longerons and duralumin cross-bracing. The Hurricane was initially armed with eight wing-mounted Browning machine guns and equipped for both day and night flying.

The Hurricane’s wing structure consisted of two steel spars, initially fabric-covered, later replaced with an all-metal stressed-skin wing. The aircraft had a wide wheel-track for stability and was fitted with a variable-pitch propeller to improve take-off performance.

The cockpit was designed for good all-round visibility, and the aircraft’s steel-tube structure allowed for easy field repairs. The Hurricane’s design enabled straightforward assembly under various conditions, contributing to its widespread use during the war. Its reliability, ease of maintenance, and stable gun platform made it well-suited for ground attack and other roles where performance was secondary to practicality. The Hurricane also proved effective as a night fighter and intruder aircraft, intercepting enemy bombers during night raids.