The Hawker Typhoon (Tiffy in RAF slang), was a British single-seat fighter-bomber, produced by Hawker Aircraft. It was designed to be a medium–high altitude interceptor, as a replacement for the Hawker Hurricane but several design problems were encountered and it never completely satisfied this requirement.
Its service introduction in mid-1941 was plagued with problems and for several months the aircraft faced a doubtful future. When the Luftwaffe brought the formidable Focke-Wulf Fw 190 into service in 1941, the Typhoon was the only RAF fighter capable of catching it at low altitudes; as a result it secured a new role as a low-altitude interceptor.
Through the support of pilots such as Roland Beamont it became established in roles such as night-time intruder and a long-range fighter.
From late 1942 the Typhoon was equipped with bombs and from late 1943 RP-3 ground attack rockets were added to its armoury. Using these two weapons, the Typhoon became one of the Second World War's most successful ground-attack aircraft.
Design and development[]
Before Hurricane production began in March 1937, Sydney Camm had begun to design its replacement. Two preliminary designs were similar and were larger than the Hurricane. These later became known as the "N" and "R" (from the initial of the engine manufacturers), because they were designed for the newly developed Napier Sabre and Rolls-Royce Vulture engines respectively. Both engines used 24 cylinders and were designed for over 2,000 hp (1,491 kW); the difference between the two was primarily in the arrangement of the cylinders – an H-block in the Sabre and an X-block in the Vulture. Hawker submitted these preliminary designs in July 1937 but were advised to wait until a formal specification for a new fighter was issued.
In March 1938, Hawker received from the Air Ministry Specification F.18/37, for a fighter which would be able to achieve at least 400 mph (644 km/h) at 15,000 feet (4,600 m) and specified a British engine with a two-speed supercharger. The armament fitted was to be twelve Browning machine guns with 500 rounds per gun, with a provision for alternative combinations of weaponry. Camm and his design team started formal development of the designs and construction of prototypes.
The basic design of the Typhoon was a combination of traditional Hawker and more modern construction techniques; the front fuselage structure, from the engine mou
ntings to the rear of the cockpit, was made up of bolted and welded duralumin or steel tubes, while the rear fuselage was a flush-riveted, semi-monocoque structure. The forward fuselage and cockpit skinning was made up of large, removable duralumin panels, allowing easy external access to the engine and engine accessories and most of the important hydraulic and electrical equipment.
The shallow-angle inverted gull wing had a span of 41-foot-7-inch (12.67 m), with a wing area of 279 sq ft (29.6 sq m). The airfoil was a NACA 22 wing section, with a thickness to chord ratio of 19.5% at the root tapering to 12% at the tip. The wing possessed great structural strength, provided plenty of room for fuel tanks and a heavy armament, while allowing the aircraft to be a steady weapons platform. The inner wings, outboard of the fuselage had a 1° anhedral, while the outer wings, attached just outboard of the undercarriage legs, had a dihedral of 5½°. Each of the inner wings incorporated two fuel tanks; the "main" tanks, housed in a bay outboard and to the rear of the main undercarriage bays, had a capacity of 40 gallons; while the "nose" tanks, built into the wing leading edges, forward of the main spar, had a capacity of 37 gallons each. Also incorporated into the inner wings was an undercarriage with a track of 13 ft 6¾ in.
Although the Typhoon was expected to achieve over 400 mph (644 km/h) in level flight at 20,000 ft, the thick wings created a large drag rise and prevented higher speeds than the 410 mph at 20,000 feet (6,100 m) achieved in tests. The climb rate and performance above that level was also considered disappointing. When the Typhoon was dived at speeds of over 500 mph (805 km/h), the drag rise caused buffeting and trim changes. These compressibility problems led to Camm designing the Typhoon II, later known as the Tempest, which used much thinner wings with a laminar flow section.