|Typhoon Mk. 1a|
|Maximum Speed||522 km/h|
|On Height||6900 m|
|Maximum Altitude||11,500 m|
|Turn Time||23.7 seconds|
|Rate of Climb||26 m/s|
|Takeoff Run||360 m|
|Armament||12x 7.7mm Browning machine guns (3600 rds)|
Even before the new Hurricane fighter was launched into full-scale production, the engineers of Hawker Aircraft Ltd.'s design office, headed by Sir Sydney Camm, embarked on the development of а next-generation interceptor fighter for the RAF. It was proposed that the new aircraft be equipped with new engines whose power would surpass that of the Rolls-Royce Merlin. Hawker Aircraft received a contract to develop two prototypes: one had a Rolls-Royce Vulture liquid-cooled engine (an Х-block); the second had a Napier Sabre engine (an Н-block). Both engines had 24 cylinders and provided about 2,000 hp.
The first prototype was named the Hawker Tornado and featured a ventral radiator in the same position that the Hurricane did. The second prototype, named the Typhoon, was equipped with a distinctive chin-mounted radiator in the forward fuselage. Since the development of the Rolls-Royce Vulture engine progressed more quickly, the Hawker Tornado was the first to get off the ground in October of 1939. The first Hawker Typhoon (P5212) prototype made its maiden flight some time later, in February of 1940.
After delays caused by the heated Battle of Britain, the full-scale production of Typhoon Mk.IA aircraft, with 2,100 hp Napier Sabre Mk.IIA engines and a de Havilland Hydromatic three-bladed propeller, was launched. Work on the Hawker Tornado was ceased due to serious problems with the Rolls-Royce Vulture engine after the first production airplane had been built.
Subsequent to the results of the plane's flight trials, the vertical empennage area of Typhoon Mk.IA production fighters was enlarged to improve their longitudinal stability. The plane obtained its distinctive rudder with a straight rear edge. The starboard door and the folding part of the canopy were used to enter the fighter's cockpit. In case of a breakdown, both doors and the folding part of the canopy could be jettisoned.
The armament provided for the aircraft consisted of wing-mounted machine guns in the «A» type wing (Mk.IA) and cannons in the «B» type wing (Mk.IB). The first 110 fighters built were of the Typhoon Mk.IA version, with 12 wing-mounted 7.7 mm Colt-Browning Mk.II.303 machine guns, because of the shortage of belt-feed mechanisms characteristic of the British Hispano Mk.II cannons.