The Hawker Tempest was a British fighter aircraft primarily used by the Royal Air Force (RAF) in the Second World War. The Tempest, originally known as the Typhoon II, was an improved derivative of the Hawker Typhoon, intended to address the Typhoon's unexpected deterioration in performance at high altitude by replacing its wing with a thinner laminar flow design. Since it had diverged considerably from the Typhoon, it was renamed Tempest. The Tempest emerged as one of the most powerful fighters of World War II and was the fastest single-engine propeller-driven aircraft of the war at low altitude.[2] Upon entering service in 1944, the Tempest was used as a low-level interceptor, particularly against the V-1 flying bomb threat, and as a ground attack platform, in which it supported major events such as Operation Market Garden. Later, it successfully targeted the rail infrastructure in Germany and Luftwaffe aircraft on the ground, as well as countering such attacks by German fighters. The Tempest was effective in the low-level interception role, including against newly developed jet-propelled aircraft such as the Messerschmitt Me 262. The further-developed Tempest II did not enter service until after the end of hostilities. It had several improvements, including being tropicalised for combat against Japan in South-East Asia as part of the Commonwealth Tiger Force. As a result of the termination of the Tornado project, Sydney Camm and his design team transferred the alternative engine proposals for the Tornado to the more advanced Tempest.[14] Thus, it was designed from the outset to use the Bristol Centaurus 18 cylinder radial engine as an alternative to the liquid cooled engines which were also proposed. A pair of Centaurus-powered Tempest II prototypes were completed.[36] Apart from the new engine and cowling, the Tempest II prototypes were similar to early series Tempest Vs. The Centaurus engine was closely cowled and the exhaust stacks grouped behind and to either side of the engine: to the rear were air outlets with automatic sliding "gills". The carburettor air intakes were in the inner leading edges of both wings, an oil cooler and air intake were present in the inner starboard wing. The engine installation owed much to examinations of a captured Focke-Wulf Fw 190, and was clean and effective. On 28 June 1943, the first Tempest II, LA602, flew powered by a Centaurus IV (2,520 hp/1,879 kW) driving a four-blade propeller. LA602 initially flew with a Typhoon-type fin and rudder unit. This was followed by the second, LA607, which was completed with the enlarged dorsal fin and first flew on 18 September 1943: LA607 was assigned to engine development.[37][nb 10] The first major problem experienced during the first few flights was serious engine vibrations, which were cured by replacing the rigid, eight-point engine mountings with six-point rubber-packed shock mounts. In a further attempt to alleviate engine vibration, the four blade propeller was replaced with a five blade unit; eventually, a finely balanced four bladed unit was settled on.[38][39] Problems were also experienced with engine overheating, poor crankshaft lubrication, exhaust malfunctions and reduction-gear seizures. Because of these problems, and because of the decision to "tropicalise" all Tempest IIs for service in the South-East Asian theatre, production was delayed.[37][40]
