The Hawker Typhoon (Tiffy in RAF slang) is a British single-seat fighter-bomber, produced by Hawker Aircraft. It was intended 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.
The Typhoon was originally designed to mount twelve .303 inch (7.7 mm) Browning machine guns and be powered by the latest 2,000 hp engines. 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.
The Typhoon became established in roles such as night-time intruder and long-range fighter. From late 1942 the Typhoon was equipped with bombs and from late 1943 RP-3 rockets were added to its armoury. With those weapons and its four 20mm Hispano autocannons, the Typhoon became one of the Second World War's most successful ground-attack aircraft.
Development and production
Even before Hurricane production began in March 1937, Sydney Camm had embarked on designing its successor. 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 Sabreand Rolls-Royce Vulture engines respectively. Both engines used 24 cylinders and were designed for over 2,000 hp (1,500 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 (640 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 .303 inch 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 construction (such as used in the earlier Hawker Hurricane) and more modern construction techniques; the front fuselage structure, from the engine mountings to the rear of the cockpit, was made up of bolted and welded duralumin or steel tubes covered with skin panels, 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 wing had a span of 41 feet 7 inches (12.67 m), with a wing area of 279 sq ft (29.6 sq m). It was designed with a small amount of inverted gull wing bend; the inner sections had a 1° anhedral, while the outer sections, attached just outboard of the undercarriage legs, had a dihedral of 5½°. 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 gun platform. 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 were inward-retracting landing gear with a wide track of 13 ft 6¾ in.
By contemporary standards, the new design's wing was very "thick", similar to the Hurricane before it. Although the Typhoon was expected to achieve over 400 mph (640 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 (800 km/h), the drag rise caused buffeting and trim changes. These compressibility problems led to Camm designing the Typhoon II, later known as theTempest, which used much thinner wings with a laminar flow airfoil..
The first flight of the first Typhoon prototype, P5212, made by Hawker's Chief test Pilot Philip Lucas from Langley, was delayed until 24 February 1940 because of the problems with the development of the Sabre engine. Although unarmed for its first flights, P5212 later carried 12 .303 in (7.7 mm) Brownings, set in groups of six in each outer wing panel; this was the armament fitted to the first 110 Typhoons, known as the Typhoon IA. P5212 also had a small tail-fin, triple exhaust stubs and no wheel doors fitted to the centre-section. On 9 May 1940 the prototype had a mid-air structural failure, at the join between the forward fuselage and rear fuselage, just behind the pilot's seat. Philip Lucas could see daylight through the split but instead of bailing out, landed the Typhoon and was later awarded the George Medal.
On 15 May, the Minister of Aircraft Production, Lord Beaverbrook, ordered that resources should be concentrated on the production of five main aircraft types (the Spitfire and Hurricane fighters and the Whitley, Wellington and Blenheim bombers). As a result, development of the Typhoon was slowed, production plans were postponed and test flying continued at a reduced rate.
As a result of the delays the second prototype, P5216, first flew on 3 May 1941: P5216 carried an armament of four belt-fed 20 mm (0.79 in) Hispano Mk II cannon, with 140 rounds per gun and was the prototype of the Typhoon IB series. In the interim between construction of the first and second prototypes, the Air Ministry had given Hawker an instruction to proceed with the construction of 1,000 of the new fighters. It was felt that the Vulture engine was more promising, so the order covered 500 Tornadoes and 250 Typhoons, with the balance to be decided once the two had been compared. It was also decided that because Hawker was concentrating on Hurricane production, the Tornado would be built by Avro and Gloster would build the Typhoons at Hucclecote. Avro and Gloster were aircraft companies within the Hawker Siddeley group. As a result of good progress by Gloster, the first production Typhoon R7576 was first flown on 27 May 1941 by Michael Daunt, just over three weeks after the second prototype.
In 1941, the Spitfire Vs, which equipped the bulk of Fighter Command squadrons, were outclassed by the new Focke-Wulf Fw 190 and suffered many losses. The Typhoon was rushed into service with Nos. 56 and 609 Squadrons in late 1941, to counter the Fw 190. This decision proved to be a disaster and several Typhoons were lost due to unknown causes and the Air Ministry began to consider halting production of the type.
In August 1942, Hawker's second test pilot, Ken Seth-Smith, while deputising for Chief Test Pilot Philip Lucas, carried out a straight and level speed test from Hawker's test centre at Langley, and the aircraft broke up over Thorpe, killing the pilot. Sydney Camm and the design team immediately ruled out pilot error, which had been suspected in earlier crashes. Investigation revealed that the elevator mass-balance had torn away from the fuselage structure. Intense flutter developed, the structure failed and the tail broke away. Modification 286 to the structure and the control runs partially solved the structural problem. (The 1940 Philip Lucas test flight incident had been due to an unrelated failing.) Mod 286, which involved fastening external fishplates, or reinforcing plates, around the tail of the aircraft, and eventually internal strengthening, was only a partial remedy, and there were still failures right up to the end of the Typhoon's service life. The Sabre engine was also a constant source of problems, notably in colder weather, when it was very difficult to start, and it suffered problems with wear of its sleeve valves, with consequently high oil consumption. The 24-cylinder engine also produced a very high-pitched engine note, which pilots found very fatiguing.
The Typhoon did not begin to mature as a reliable aircraft until the end of 1942, when its excellent qualities — seen from the start by S/L Roland Beamont of 609 Squadron — became apparent. Beamont had worked as a Hawker production test pilot while resting from operations, and had stayed with Seth-Smith, having his first flight in the aircraft at that time. During late 1942 and early 1943, the Typhoon squadrons were based on airfields near the south and south-east coasts of England and, alongside two Spitfire XII squadrons, countered the Luftwaffe's "tip and run" low-level nuisance raids, shooting down a score or more bomb-carrying Fw 190s. Typhoon squadrons kept at least one pair of aircraft on standing patrols over the south coast, with another pair kept at "readiness" (ready to take off within two minutes) throughout daylight hours. These sections of Typhoons flew at 500 feet (150 m) or lower, with enough height to spot and then intercept the incoming enemy fighter-bombers. The Typhoon finally proved itself in this role; for example, while flying patrols against these low-level raids, 486(NZ) Squadron claimed 20 fighter-bombers, plus three bombers shot down, between mid-October 1942 and mid-July 1943.
The first two Messerschmitt Me 210 fighter-bombers to be destroyed over the British Isles fell to the guns of Typhoons in August 1942. During a daylight raid by the Luftwaffe on London on 20 January 1943, four Bf 109G-4s and one Fw 190A-4 of JG 26 were destroyed by Typhoons. As soon as the aircraft entered service, it was apparent the profile of the Typhoon resembled a Fw 190 from some angles, which caused more than one friendly fire incident involving Allied anti-aircraft units and other fighters. This led to Typhoons first being marked up with all-white noses, and later with high visibility black and white stripes under the wings, a precursor of the markings applied to all Allied aircraft on D-Day.
Switch to ground attack
By 1943, the RAF needed a ground attack fighter more than a "pure" fighter and the Typhoon was suited to the role (and less-suited to the pure fighter role than competing aircraft such as the Spitfire Mk IX). The powerful engine allowed the aircraft to carry a load of up to two 1,000 pounds (450 kg) bombs, equal to the light bombers of only a few years earlier. The bomb-equipped aircraft were nicknamed "Bombphoons" and entered service with No. 181 Squadron, formed in September 1942.
From September 1943, Typhoons were also armed with four "60 lb" RP-3 rockets under each wing. In October 1943, No. 181 Squadron made the first Typhoon rocket attacks. Although the rocket projectiles were inaccurate and took considerable skill to aim and allow for ballistic drop after firing, "the sheer firepower of just one Typhoon was equivalent to a destroyer's broadside. By the end of 1943, eighteen rocket-equipped Typhoon squadrons formed the basis of the RAF Second Tactical Air Force(2nd TAF) ground attack arm in Europe. In theory, the rocket rails and bomb-racks were interchangeable; in practice, to simplify supply, some 2nd TAF Typhoon squadrons (such as 198 Squadron) used the rockets only, while other squadrons were armed exclusively with bombs (this also allowed individual units to more finely hone their skills with their assigned weapons).
By the Normandy landings in June 1944, 2 TAF had eighteen operational squadrons of Typhoon IBs, while RAF Fighter Command had a further nine. The aircraft proved itself to be the most effective RAF tactical strike aircraft, on interdiction raids against communications and transport targets deep in North Western Europe prior to the invasion and in direct support of the Allied ground forces after D-Day. A system of close liaison with the ground troops was set up by the RAF and army: RAF radio operators in vehicles equipped with VHF R/T travelled with the troops close to the front line and called up Typhoons operating in a "Cab Rank", which attacked the targets, marked for them by smoke shells fired by mortar or artillery, until they were destroyed.
Against some of the Wehrmacht's heavier tanks, the rockets needed to hit the thin-walled engine compartment or the tracks to have any chance of destroying or disabling the tank. Analysis of destroyed tanks after the Normandy battle showed a "hit-rate" for the air-fired rockets of only 4%. In Operation Goodwood (18 to 21 July), the 2nd Tactical Air Force claimed 257 tanks destroyed. A total of 222 were claimed by Typhoon pilots using rocket projectiles. Once the area was secured, the British "Operational Research Section 2" analysts could confirm only ten out of the 456 knocked out German AFVs found in the area were attributable to Typhoons using rocket projectiles.
At Mortain, in the Falaise pocket, a German counter-attack that started on 7 August threatened Patton's break-out from the beachhead; this counter-attack was repulsed by 2nd Tactical Air Force Typhoons and the 9th USAAF. During the course of the battle, pilots of the 2nd Tactical Air Force and 9th USAAF claimed to have destroyed a combined total of 252 tanks. Only 177 German tanks and assault guns participated in the battle and only 46 were lost – of which nine were verified as destroyed by Typhoons, four percent of the total claimed.
However, after-action studies at the time were based on random sampling of wrecks rather than exhaustive surveys, and the degree of overclaim attributed to Typhoon pilots as a result was statistically improbable in view of the far lower known level of overclaim by Allied pilots in air-to-air combat, where claims were if anything more likely to be mistaken. Allied and German witness accounts of Typhoon attacks on German armour indicate that RPs did kill tanks with fair probability. Horst Weber, an SS panzergrenadier serving with Kampfgruppe Knaust south of Arnhem in the later stages of Operation Market Garden, recalled that, during a battle with British 43rd Wessex Division on 23 September 1944, 'We had four Tiger tanks and three Panther tanks... We were convinced that we would gain another victory here, that we would smash the enemy forces. But then Typhoons dropped these rockets on our tanks and shot all seven to bits. And we cried... We would see two black dots in the sky and that always meant rockets. Then the rockets would hit the tanks which would burn. The soldiers would come out all burnt and screaming with pain.'
The effect on the morale of German troops caught up in a Typhoon RP and cannon attack was decisive, with many tanks and vehicles being abandoned, in spite of superficial damage, such that, at Mortain, a signal from the German Army's Chief of Staff stated that the attack had been brought to a standstill by 13:00 '...due to the employment of fighter-bombers by the enemy, and the absence of our own air-support.' The 20 mm cannon also destroyed a large number of (unarmoured) support vehicles, laden with fuel and ammunition for the armoured vehicles. On 10 July at Mortain, flying in support of the US 30th Infantry Division, Typhoons flew 294 sorties in the afternoon that day, firing 2,088 rockets and dropping 80 short tons (73 t) of bombs. They engaged the German formations while the US 9th Air Force prevented German fighters from intervening. Dwight D. Eisenhower, the Supreme Allied Commander, said of the Typhoons; "The chief credit in smashing the enemy's spearhead, however, must go to the rocket-firing Typhoon aircraft of the Second Tactical Air Force... The result of the strafing was that the enemy attack was effectively brought to a halt, and a threat was turned into a great victory."
Another form of attack carried out by Typhoons was "Cloak and Dagger" operations, using intelligence sources to target German HQs. One of the most effective of these was carried out on 24 October 1944, when 146 Typhoon Wing attacked a building in Dordrecht, where senior members of the German 15th Army staff were meeting; 17 staff officers and 36 other officers were killed and the operations of the 15th Army were adversely affected for some time afterwards.
On 24 March 1945, over 400 Typhoons were sent on several sorties each, to suppress German anti-aircraft guns and Wehrmacht resistance to Operation Varsity, the Allied crossing of the Rhine that involved two full divisions of 16,600 troops and 1,770 gliders sent across the river. On 3 May 1945, the Cap Arcona, the Thielbek and theDeutschland, large passenger ships in peacetime now in military service, were sunk in four attacks by RAF Hawker Typhoon 1Bs of No. 83 Group RAF, 2nd Tactical Air Force: the first by 184 Squadron, second by 198 Squadron led by Wing Commander John Robert Baldwin, the third by 263 Squadron led by Squadron Leader Martin T. S. Rumbold and the fourth by 197 Squadron led by Squadron Leader K. J. Harding.
The top-scoring Typhoon ace was Group Captain J. R. Baldwin (609 Squadron and Commanding Officer 198 Squadron, 146 (Typhoon) Wing and 123 (Typhoon) Wing), who claimed 15 aircraft shot down from 1942 to 1944. Some 246 Axis aircraft were claimed by Typhoon pilots during the war.
3,317 Typhoons were built, almost all by Gloster. Hawker developed what was originally an improved Typhoon II, but the differences between it and the Mk I were so great that it was effectively a different aircraft, and was renamed the Hawker Tempest. Once the war in Europe was over Typhoons were quickly removed from front-line squadrons; by October 1945 the Typhoon was no longer in operational use, with many of the wartime Typhoon units such as 198 Squadron being either disbanded or renumbered.