The Typhoon was a British single-seat fighter-bomber aircraft, produced by Hawker Aviation starting in 1941. Intended as a replacement for the Hawker Hurricane in the interceptor role, it suffered from performance problems, and it instead evolved into one of World War II’s most successful strike fighters.

Even before the new Hurricane was rolling off the production lines in March 1937, Sidney Camm had moved on to designing its future replacement as a private project. This was to be a massive plane designed around the equally massive Napier Sabre engine. The work proved useful when Hawker received specification F.18/37 in January 1938 from the Air Ministry, which asked for a fighter based around either the Napier Sabre or the Rolls-Royce Vulture engine. The engines were similar in that they were both 24 cylinder designs that were designed to deliver over 2,000 hp (1.5 MW), and different primarily in the arrangement of the cylinders - an H-block in the Sabre and an X-block in the Vulture.

The two resulting models became known as the ‘R’ and ‘N’ (based on the engine manufacturer) and were very similar – the Vulture powered R plane had a rounder nose profile and a ventral radiator, whereas the Sabre powered N had a flatter deck and a chin mounted radiator. The basic design of both continued the Hawker tradition of using ‘older’ construction techniques; the front fuselage was welded steel just like the Hurricane, and the design used a massive 40 foot (12 m) wing that was much thicker than those on designs like the Spitfire. Camm did give in to the times for much of the rest of the plane though, it was semi-monocoque from the cockpit rearward, flush riveted, and had wide set gear. The R version first flew in October 1939, and the RAF was so impressed they ordered 1,000 as the Tornado. Various problems, notably compression effects which were previously unknown to Hawker, slowed the acceptance down. In addition the plane had rather disappointing climb performance, which meant it wouldn’t be the Spitfire-replacing interceptor they were looking for. In February 1940 the first N model, now known as the Typhoon, was delivered. The RAF placed a large order for it as well, but moved production to Gloster Aircraft who otherwise had no designs to produce. Like the Tornado, the Typhoon was soon demonstrating its own problems, including vibrations from the engine causing the wing skinning to peel.

Eventually the RAF cancelled all work on both models in May 1940 so that Hawker could concentrate solely on the Hurricane during the Battle of Britain. This was the design’s first brush with death. Some small scale work continued, changes to streamline the fuselage and supply a much thinner wing were looked at, as well as alternate engines in the form of large radials. In October pressure on the RAF eased and work was allowed to continue on the two original designs. The first full production version Tornado was delivered in early 1941 and demonstrated the then unheard of speed of 425mph fully armed. This was also the last Tornado. While production lines were being drawn up, the Vulture project was suddenly terminated by Rolls-Royce and the Tornado was left without an engine.

Luckily, the Typhoon had ‘good enough’ performance to warrant production. The first production Mk.IA was delivered in May 1941 with twelve Browning .303 guns, but this was followed quickly with the Mk.IB with four Hispano 20mm cannons. By this time the Spitfire V’s were meeting Focke-Wulf Fw 190’s in combat and getting rather beat up, so the Typhoon was rushed into squadron service to counter the new German plane. Sadly this proved to be a disaster. An apparent structural weakness in the tail meant that it tended to break off when pulling out of dives, the Fw’s favourite escape. Once again there was talk of killing the design. The cause of these tail-failures (in which only one of the pilots survived to give any clue to the reason) was found to be fatigue failure of the elevator mass-balance, allowing elevator-flutter to occur which was at it’s greatest when pulling-out of a dive. As a “temporary” measure, rectangular strengthening “fishplates” were riveted around the fuselage/empennage joint - the site of the failures. These fishplates remained a feature on all subsequent Typhoons.

It wasn’t until 1943 that the various problems with the airframe and engine had finally started to be worked out of the system. But by this time the need for a pure fighter was no longer important and the design found itself being converted into a fighter-bomber – much like the Hurricane had before it. The powerful engine allowed the plane to carry a massive load of up to two 1,000 lb (450 kg) bombs, with which the aircraft were nick-named “Bombphoon’s”, although it would become much more famous with four 60 lb (27 kg) rockets under each wing - the so-called “Rocketphoon’s”.

The Mk.IB, now widely known as the Tiffy, distinguished itself particularly in the Battle of Normandy. In one famous case Tiffies of the 2nd TAF decimated a large concentration of armor ahead of Avranches, disposing of no fewer than 137 tanks, and opening the way for the liberation of France and Belgium. For use in the tactical reconnaissance role, the Typhoon FR.IB was developed early in 1945. In this version the two inboard cannon were removed and three F.24 cameras were carried in their place. One Typhoon was also converted as a prototype night fighter, with A.I. (Airborne Interception - ie., radar) equipment, special night-flying cockpit and other modifications. Production of the Typhoon, entirely by Gloster, was 3,330 machines. Hawker developed an improved version of the Typhoon, the Typhoon II but the differences between it and the Mark I were so great that it was later re-named Tempest.

Type

Wings

• Type: Low-wing cantilever monoplane with a straight taper to semi-circular tips.
• Attachment: Attached to the center fuselage by four pins (two per spar), without a center-section.
• Structure:
  • Two-spar all-metal construction with six main ribs and several light ribs.
  • Inner spars feature extruded section booms with N-girder webs; outer spars have extruded T-section booms with single plate webs.
  • D-section member in the gun bay provides torsion resistance and stiffness.
  • Stressed-skin construction outboard of the gun bay, reinforced by stringers.
  • Control Surfaces: Frise ailerons and metal-covered split flaps, which are mechanically interconnected.

Fuselage

• Forward and Center Sections:
  • Rigidly-braced rectangular structure made of steel tubes, assembled with flat plate fittings and machined stampings, covered with detachable metal panels.
• Rear Fuselage:
  • Monocoque structure with stressed skin, flush-riveted to oval-shaped formers and straight longitudinal stringers.
  • The tail unit is a separate integral unit with an integral fin, attached by a circumferential riveted joint and longitudinal finger plates.
  • Quick-detach connection between the front and rear sections.

Tail Unit

• Type: Cantilever monoplane type.
• Structure: All-metal with metal stressed-skin covering the fin and tailplane; metal-covered elevators and fabric-covered rudder. Adjustable trimming-tabs are present.

Landing Gear

• Type: Retractable with Vickers oleo-pneumatic shock absorber legs and Dunlop wheels and brakes.
• Tail Wheel: Dowty oleo-pneumatic unit.
• Operation: Main wheels retract inward into wells in the wing's underside; tail-wheel retracts forward into the fuselage. Wheel wells are sealed by doors when retracted.

Power Plant

• Engine: One 2,200 h.p. Napier Sabre IIA, a twenty-four-cylinder H-type liquid-cooled sleeve-valve engine.
• Mounting: Engine mounted on the front wing spar and supported by a braced tube structure.
• Cooling: Low-velocity duct under the engine houses radiator and oil cooler.
• Propeller: Three or four-bladed de Havilland constant-speed airscrew.
• Fuel Tanks: Four self-sealing tanks in the wings, with additional auxiliary tanks optional under wings. Oil tank located aft of the fireproof bulkhead in the fuselage.

Accommodation

• Cockpit: Enclosed, located over the wing's trailing edge.
• Protection: Bulletproof windscreen, armor forward and aft of the pilot.
• Canopy: Single-piece "blister" type sliding hood.
• Equipment: Adjustable seat, rudder-bar, full electrical equipment, oxygen, radio, etc.

Armament

• Options:
  • Mk. IA: Twelve 0.303 in. Browning machine-guns.
  • Mk. IB: Four 20 mm cannons, all wing-mounted and firing outside the propeller arc.
• Ordnance: One 1,000 lb. or 500 lb. bomb under each wing, or eight rocket projectiles (four under each wing).

Dimensions

• Span: 41 ft. 7 in. (12.67 m)
• Length: 31 ft. 11 in. (9.73 m)
• Height: 15 ft. 3.5 in. (4.66 m)
• Wing Area: 279 sq. ft. (25.92 sq. m)

Weight

• Loaded Weight (Fighter version): 11,500 lbs. (5,220 kg)

Performance

• Maximum Speed: Exceeds 400 mph (640 km/h) in level flight.