The R180 radial design uses five Volkswagon air cooled cylinders and a supercharger. The supercharger pressure filling of the cylinders overcomes the side valve’s tendency toward lower volumetric efficiency. The side valves reduce the over all cylinder height and exposed diameter of the engine.
A feature of the R180 is the all cylinder compression relief. Originally added to make electric starting easier, with the relief valve open, there is no possibility of hydraulic lock in the bottom cylinder. The crankcase of the first engine was built up from plate but further engines use castings. Testing has been carried out in a Fly Baby.
In 2010 a complete set of engineering drawings and parts list with item numbers and suppliers for stock automotive components sold for US$130.00. The kits available in 2010 were:
Unmachined aluminum castings US$1,400.00
Machinist kit, including machined case, heads, subheads, and mount lugs cam finished master rod and link rods (no bushings or knuckle pins) crank (main, pin, weights, cheekplate tail) complete drawings assembly guide video. It excludes standard automotive components $5,200.00
Complete kit, plans, and video. Complete and ready to assemble includes Ignition and Engine Mount Design, but Fuel System Sold Separately US$9,995.00
Assembled engine run tested and performance verified including Ignition and Engine Mount Design but Fuel System Sold Separately US$12,000.00
Standard automotive components 5 VW Piston, Ring, & Cylinder Sets Tapered, Roller, and Ball Bearings Valves, Valve Seats, Valve Springs, Valve Keepers, Valve Locks Aircraft and Automotive Bolts, Nuts, and Washers GM Ignition Components A specific, itemized list is included with the kits.
Horsepower 75 @ 2150 rpm Weight 122 lbs. Displacement 180 cubic inches Bore 3.625 inches Stroke 3.5 inches Compression Ratio 7:1 Intake Valve 1.8 in. Exhaust Valve 1.2 in. Valve Lift (all) 0.250 in. Valve Clearance 0.014 in. Ignition Timing Start TDC Ignition Timing Run 38 deg. btc Supercharger drive ratio 9:1 Supercharger flow 1450 fpm Oil Pump Capacity 5.5 qt./min. @ 2150 rpm Scavange/feed pump 8:3 ratio Main/thrust bearings Tapered roller Master rod bearings Two row ball Link rod bearings Plain journal bearings
Cycle: 4 stroke No cylinders: 5 Bore: 94 mm Stroke: 89 mm Compression: 8 Displacement: 3080 cc Cooling: Air Ignition: Double electronic Reduction: None Weight: 54 kg Max pwr: 75 hp at 2150 rpm Kit Price 1998: $9600
The GAF-125 was developed by Hawk Industries Inc. from Yucca Valley, CA. This company specialised in equipment and tools for the off-shore oil industry, and was looking for a more efficient way to transport their products all over the country. Road transport was too slow most of the time, and loading their large and unusually-shaped products onto conventional aircraft often posed many expensive and time-consuming problems.
And so in July 1977, the president of the company, Ernest “Ernie” Hauk, together with designer Larry Stewart, initiated the development of a freighter aircraft that was to overcome these problems. The design was named the GAF-125 GAFHawk, with GAF meaning General Aviation Freighter. The name later changed to GAFHawk 125. The design would have to meet many demands: rear loading door for easy on/off loading, STOL capability for remote airstrips, square-section fuselage for maximum loading efficiency, single engine to lower maintenance time and cost, single-pilot operation etc.
The company obtained 1956-built Piper PA-22-150 Tri-Pacer N6911B (msn 22-4186), which was almost completely disassembled in the workshops of Hawk Industries’ Aircraft Division on Aviation Drive, at the small airport in Yucca Valley, California. The little aircraft was then rebuilt, but in an extensively modified form. It was made to look like a miniature version of the GAFHawk design, to serve as a small scale flying testbed for the GAFHawk’s development. The aircraft was appropriately named the MiniHawk, and first flew in 1978.
Looking like a miniature version of the actual GAFHawk, this little aircraft served as a flying testbed for the GAFHawk’s development. It is now preserved at Roy Williams Airport in Joshua Tree, CA. Photo taken by AirNikon in May 2004.
In 2006 the MiniHawk testbed N6911B was also still registered, with its status quoted as “In Question”, and no registered owner. It just says “Sold to Hawk International”, which was the new name for Hawk Industries’ aircraft division.
The MiniHawk eventually went to Roy Williams Airport in Joshua Tree, only 15 km (9.5 miles) from Hawk Industries’ workshops in Yucca Valley. The little aircraft is now preserved there, swiveling freely on a short pole and acting as a big windsock.
Genesis of the Fury design lay in the Typhoon and its, successor, the Tempest. Early troubles with the Napier Sabre engine and the failure of the Rolls Royce Vulture caused delays in the Typhoon and cancellation of the Tornado programme, and switched the spotlight to the Rolls Royce Griffon and Bristol Centaurus engines. Simultaneously, the Typhoon proved unsuitable as a medium attitude fighter on account of its thick wing, and in 1941, Sydney Camm put forward proposals for the Typhoon II with a thinner, eliptical wing and leading edge radiators. Alternative powerplants included Sabre, Centaurus and Griffon, and in time, with these engines, the fighter appeared as the Tempest I, II and III. The wing radiator scheme was not adopted and the Tempest I was abandoned, while the Sabre ¬powered Mark V was the only version to see combat in World War II. The Griffon Tempest III and IV were also abandoned.
The Centaurus Tempest II was dogged by engine delays but, when it finally arrived, proved the best of the Tempest family. Camm had long advocated use of the Centaurus, having in January 1940 suggested its substitution in the Tornado. Some time after the Vulture Tornado programme had been scrapped, a Centaurus 12 was tested in a Tornado airframe but initially with little success. When, however, a captured Focke¬Wulf Fw 190A was examined late in 1941, numerous alterations to the British radial engine installation were made by Bristol, with considerable benefit to the test bed’s performance.
The Centaurus Tornado continued flying in 1942 and it was the results that led to the Tempest II. A parallel development was the submission of the Hawker Light Fighter design to the Air Ministry in the autumn of 1942, again alternative versions being powered by the Sabre IV, Griffon 61 and Centaurus IV. These were to be much lightened versions of the Tempest and were the original Fury design schemes. Principal difference from the earlier design lay in the abbreviated wing centre section which now resulted in the main wheels, when retracted, almost meeting on the centreline of the aircraft.
Following their submission in 1942, the designs became the subject of Air Ministry and naval fighter specification N.7/43 in 1943. Contracts were issued for a number of prototypes of what was to become the Fury and, long before these were flown, orders for 400 production aircraft were placed to be shared equally by the RAF and the Fleet Air Arm. The entire Sabre production became earmarked for the Typhoon and Tempest (the latter forming Britain’s main fighter defence against the flying bombs), and the Griffon was required for such established aircraft as the Spitfire, Barracuda and Firefly. Only the Centaurus (still suffering from cooling and lubrication difficulties) remained available for the Hawker fighter, and even this was scheduled for the Far East in the Tempest II.
The Fury used the same high-speed aerofoil section which had been specially developed for the Tempest to delay the compressibility effects first encountered with the Tornado and Typhoon. The wing consisted of two Tempest outer sections bolted together on the fuselage centreline, instead of being attached to the sides of the fuselage as on the Tempest. The monocoque fuselage and tail unit were completely new structures.
The first Bristol Centaurus 12-engined prototype flew for the first time on 1 September 1944. It was subsequently re-engined with a Centaurus 15. Although two other Centaurus-engined prototypes were built, the second to fly (on 27 November 1944) was powered by a Rolls-Royce Griffon 85 engine driving two Rotol three-bladed co-axial contra-rotating propellers. One of the Griffon-engined prototypes was subsequently re-engined with a Napier Sabre VII driving a five-bladed propeller, and flown in June 1946. A second Sabre-engined Fury was also flown.
With the end of the War came widespread cancellation of contracts for military aircraft. Only three prototype Furies (two RAF and one naval) had flown and, with the introduction of the Gloster Meteor jet fighter to the RAF an established fact, the Air Ministry lost interest in the Fury project and cancelled its order for 200 fighters. Registered G AKRY, the first F.2143 Fury prototype (originally NX798) was eventually sold to Egypt. The first example to fly was the RAF’s Fury Mk 1 on 1 September 1944, whilst the Hawker Sea Fury prototype took to the air for its maiden flight on 21 February 1945. However, the return of peace led to large-scale defence cutbacks, Hawker’s newest fighter suffering badly with all the RAF examples and half of the Royal Navy aircraft being cancelled, although the manufacturer did ultimately achieve modest export sales of the land-based Fury, customers including Egypt, Iraq and Pakistan.
Pakistan Air Force 1958
The Admiralty, although obliged to forego 100 aircraft, retained its interest in the project and instructed Hawker to continue trials with its prototypes, SR661 and SR666. By the end of 1945 the latter had flown and set a pattern that was to become familiar over the following eighteen years. Production aircraft were derived from the three prototype ‘Hooked’ Furies, with various degrees of navalisation including folding wings and arrester gear. The fully-navalised Sea Fury with arrester hook and folding wings did not fly until October 21, 1945.
By now named the Sea Fury it having been the intention to call RAF aircraft simply Fury, with its thin eliptical wings and finely cowled radial engine behind a large five blade Rotol propeller.
Fifty Sea Fury F.10s were ordered for the Royal Navy, each powered by an 1,841kW Bristol Centaurus 18 eighteen-cylinder two-row radial sleeve-valve air-cooled engine.
Demands were voiced for the Sea Fury to carry bombs, and so, in 1948, appeared the Mark II fighter bomber ¬capable of carrying rockets, drop tanks, mines, napalm or 1,000 pound (454 kg) bombs. With this aircraft the Royal Navy went to war over Korea in 1950.
As soon as deliveries started to the Fleet Air Arm in 1946, other countries looked at the design with views to adopting it for their own forces. First was Holland. The Royal Netherlands Navy had received an ex British aircraft carrier, HMS Venerable, and, under the name Karel Doorman, the new vessel was about to be commissioned. The Dutch Government placed an order for ten Sea Furies and followed these with licence built aircraft in 1948. The Sea Fury FB.51 was similar to the FB.11 but had Dutch language instruments and other minor changes for service with the Royal Netherlands Navy. Deliveries from Hawker were supplemented by production under licence by Fokker in the Netherlands.
The Royal Navy’s aircraft first flew in pro¬duction form as the Sea Fury F.Mk 10 on 7 September 1946, entering service with No. 807 Squadron in July 1947. It brought with it a 450 mph (724 kmh) performance, an 11.5 minute climb to 30,000 feet (9 144 m) and an armament of four 20 mm guns a performance unsurpassed by any shipboard fighter in the World at that time.
Manufacture of the Sea Fury F.10 as a pure fighter was short-lived and only 50 were com¬pleted. Production then switch¬ing to the Sea Fury FB.Mk 11 fighter-¬bomber derivative which could carry up to 907 kg (2,000 lb) of external ord¬nance and which also featured a leng¬thened arrester hook plus provision for rocket-assisted take-off gear. This variant became the definitive Sea Fury, deliveries beginning in May 1948, and by the time the line closed in the early 1950s 515 had been completed, as well as 60 examples of the Sea Fury T.Mk 20 two-seat trainer. By then the Sea Fury had also been engaged in combat in Korea, emerging victorious over the jet-powered MiG¬15 on at least two occasions.
It was as the result of foreign interest in the Sea Fury that the two seat trainer version came into existence. In 1947 Iraq had questioned the possibility of providing a two seat variant on which her pilots could train, prior to graduating to the fighter. So successful did the project appear that the prototype was purchased by the Admiralty, leading to the T. Mark 20. The Sea Fury T.20 was a two-seat trainer version for the Royal Navy, based on the F.10. One 20mm cannon was deleted from each wing to allow for the installation in the wings of equipment displaced from the fuselage by the second cockpit. Bombs and rockets or long-range drop tanks could be carried beneath the wings as on the FB.11 fighter bomber.
Pakistan proved to be the largest customer for Furies, for between 1949 and 1954, ninety three single seaters and five trainers were delivered. The Fury FB.60 and 61 were single-seat and two-seat Furies for Pakistan, the single Trainer having a ‘tunnel’ enclosure over the two cockpits.
Iraq ordered a total of fifty five fighters and fighter bombers and took delivery of five trainers as well between 1950 and 1953, but little is known of their service life until their retirement in the early 1960s. 30 Centaurus-engined Fury Is were ordered for the Iraqi Air Force in 1946. Thereafter two Fury Trainers, each with a second separate cockpit introduced immediately aft of the fighter cockpit (first flown on 15 January 1948), were delivered to Iraq, together with another batch of 25 Fury Is and Trainers. Retaining the wing folding and tail-hook mechanisms of the ship-borne fighters, they lacked the hydraulic operation and became known as Baghdad Furies, similar in all other respects to those serving with the navies (although Iraq did receive in that number some Fleet Air Arm Sea Furies diverted from the assembly line.) Egypt received thirteen single seaters (including one of the original Fury prototypes).
Egypt received 12 Sea Furies.
By 1954 large numbers of war ¬scarred and otherwise dilapidated Sea Fury carcases languished at the naval storage units at Anthorn, Donibristle and Abbots¬inch, until early in 1957 it became known that they were to be offered for disposal. Hawker, whose Blackpool factory was threatened with closure by the ramifications of the 1957 Defence White Paper, determined to make good a number of these old aircraft and set about finding markets overseas. Having repurchased around two hundred of the old fighters and trainers, the company was able to negotiate an order with the Burmese Government and, by widespread cannibalisation, sold eighteen single seaters and three trainers to that country. It was being sold as a counter insurgency (or COIN) aircraft for such duties the Batista Government of Cuba followed Burma in 1958 placed an order for fifteen fighters and two trainers. Despite great secrecy and testing of unmarked aircraft in this country, word leaked out that Britain was trading military aircraft with a politically unsuitable cus¬tomer and a scandal threatened. However, despite Batista’s demise, the contract was honoured and full payment was com¬pleted by the Castro regime before trade sanctions were imposed. Western Germany has been taking delivery of Sea Fury two ¬seaters in small numbers almost every year since 1959 and, to 1963, sixteen have been delivered to the D.L.B. for target towing under civil contract to the Luftwaffe. A single¬ seater had been added to the number. Iraq presented four examples to Morocco.
Australia ordered 101 Sea Fury Mark II in 1948. The first was delivered in May 1949, and the last was delivered in 1953.
By the mid- 1950s the Sea Fury had been supplanted by more modern types with the Fleet Air Arm, but some export Sea Furies continued to fly with the air arms of Burma and Cuba for a few more years.
The Royal Canadian Navy equipped Squadrons VF-870 and VF-871 with the Sea Fury. These Squadrons flew 75 Sea Furies from February, 1948 to April, 1957 operating from HMCS Magnificent. The RCN Sea Fury aircraft were replaced by the RCN’s first jet fighter, the McDonnell F2H3 Banshee in 1957.
A total of 860 Sea Fury airplanes were built, including a number of tandem two seat trainers. This type exists in very small numbers in the United States where modified versions have scored notable wins on the air-racing circuit.
Fury Max speed: 445 mph at 20,000 ft. Cruising speed: 400+ mph at 20,000 ft. Max range with over load tanks: 2,000 miles Armament: four 20 millimetre cannons, rockets or two 1000 lb bombs.
Sea Fury FB.Mk 11 Engine: one 2,480-hp (1849-kW) Bristol Centaurus 18 Wing span: 11.70 m (38 ft 4.75 in) Wing area: 26.0 sq.m (280 sq ft) Length: 10.57 m (34 ft 8 in) Height: 4.84 m (15 ft 10.5 in) Wheel track: 12 ft Empty weight: 4191 kg (9,240 lb) Maximum take-off weight: 5670 kg (12,500 lb) Maximum speed: 740 km/h (460 mph) at 5485 m. (18,000 ft) Fuel capacity: 200 Imp.G External fuel: 2 x 45 or 90 Imp.G Initial Rate Of Climb: 7 minutes to 20000ft Max ROC: 4320 fpm Service ceiling 10910 m (35,800 ft) Range 1127 km (700 miles) on internal fuel Takeoff run: 960 ft Armament: four 20-mm cannon, plus up to 907 kg (2,000 lb) of external ordnance / 8 x 60lb rockets or 2 x 1000lb bombs Crew: 1
The performance of the Typhoon was such that speeds of around 805km/h could be attained in a dive. It was, therefore, numbered among the high-performance aircraft of World War II which began to be affected by the problems of compressibility, with the accelerated airflow over the cambered upper surface of the wing beginning, locally, to approach the speed of sound. It was in April 1941 that discussions were opened between Hawker and the Ministry of Aircraft Production on the subject of Typhoon development. Proposals for a Typhoon Mk II included the installation of a Sabre IV engine of higher power and driving a four-bladed propeller, improved view and a cleaned-up tail.
Hawker proposals (submitted in August 1941) included the suggestion that the Typhoon Mk II should have thin elliptical wings of 12.8m span and 27.9sq.m area, with a 15% thickness/chord ratio at the root and 10% at the tip. The introduction of a new thin-section wing made it necessary to reduce the amount of fuel carried in the wings and an extra bay was inserted in the fuselage behind the engine to accommodate an additional fuel tank. The lengthening of the fuselage called for increased fin area.
Tempest II
Work had been going on in the Hawker design office since 1940 on the development of a new thin wing section. It had already been established that the N.A.C.A.22-series wing section employed by the Typhoon was entirely satisfactory at speeds in the vicinity of 400 m.p.h. but encountered compressibility effects at higher speeds. In dives approaching 500 m.p.h. a very sudden and sharp increase in drag was experienced, accompanied by a change in the aerodynamic characteristics of the fighter, which affected the pitching moment and rendered the machine nose heavy. No actual design work on the new wing was begun until September 1941, and the wing section eventually adopted for development had its point of maximum thickness at 37.5% of the chord. The thickness/cord ratio was 14.5% at the root and 10% at the tip, giving a wing five inches thinner at the root than that of the Typhoon.
This thin wing could not contain a comparable quantity of fuel to that housed by the Typhoon’s wing, so a large fuselage tank had to be adopted. This necessitated the introduction of an additional fuselage bay, increasing the overall length by twenty-one inches forward of the c.g. This added length found its inevitable compensation after initial prototype trials in a larger fin and tailplane. The wing area was also increased, and an elliptical planform was adopted, presenting a chord sufficient to permit the four 20-mm. Hispano cannon to be almost completely buried in the wing. All these modifications added up to a radically changed Typhoon, but it was as the Typhoon II that two prototypes were ordered in November 1941. However, in the middle of the following year the name Tempest was adopted. Alternative installations of the Sabre engine were designed for these prototypes; the first (HM595) had a Sabre II and a front radiator similar to that of the standard Typhoon, while the second (HM599) had a Sabre IV engine and wing leading-edge radiators.
In June 1942 it was proposed that six Tempest prototypes should be completed: one with a Sabre VI (Tempest I); two with Centaurus (Tempest IIs); one with a Rolls-Royce Griffon 2B (Tempest III); one with a Griffon 61 (Tempest IV); and one with a Sabre III (Tempest V). Owing to heavy commitments Hawker could not undertake to build more than three and the Mks I, II and V were chosen.
Hawker Tempest prototype
Piloted by Philip Lucas, the first prototype Tempest was flown on September 2, 1942, but prior to this, in February 1942, a production order had been placed and the first production machine flew in June 1943 with Bill Humble at the controls. During flight trials the first Tempest prototype had exceeded 477 m.p.h. in level flight, and the first production model was essentially similar to the first prototype with the chin-type radiator. This was designated Tempest V, and the initial production batch, the Series I, had Mk. II cannon which projected slightly ahead of the wing leading edge, but the Series II had the short-barrelled Mk. V cannon which did not project, and also featured a detachable rear fuselage, small-diameter wheels and a rudder spring tab. Powered by a 2,420 h.p. Sabre IIB engine, the Tempest V attained a maximum speed of 435 m.p.h. at 17,000 feet. The 820-mile range of the Tempest V in clean condition was an appreciable improvement over that of the Typhoon, and was due not only to the small additional quantity of fuel carried but to the aerodynamic refinement of the later machine which permitted a higher cruising speed for the same power.
The first squadrons to be equipped with Tempest Vs were Nos. 3 and 486 at Newchurch, Dungeness, the first of these receiving its equipment early in 1944. By May five Tempest Vs had been lost due to engine failure, and this was discovered to be due to an over speeding of the propellers, resulting in an uncontrollable increase in engine revolutions, the failure of the bearings and the collapse of the oil system. In June modified propellers were fitted which solved the problem, and two days after the invasion of the Continent, on June 8, 1944, the Tempests met enemy aircraft in combat for the first time, destroying three Bf 109G fighters without loss to themselves. On June 13 the first V1 flying bombs were launched against England, and the Tempest, being the fastest low-medium altitude fighter in service with the R.A.F., became the mainstay of Britain’s fighter defense against the pilotless missiles, destroying 638 of these weapons by the beginning of September. The Tempest V was also employed on the Continent for train-busting and ground-attack duties.
With the 2nd TAF in Europe, they not only made a valuable contribution in the close-support role, but claimed the interception and destruction of 20 Messerschmitt Me 262 jet-powered aircraft.
Meanwhile the second prototype (HM599), designated Tempest I, had proved sufficiently promising for production plans to be initiated. In the light of experience gained with the Centaurus-powered Tornado and the suitability of the Tempest fuselage for the radial engine, a Centaurus version of the Tempest was also initiated as the Mark II, and production drawings were prepared in parallel with those of the Mark I. In the event, the Tempest I was later abandoned while the Mark II was allowed to proceed to the production stage following the successful flight trials with the prototype, LA602, which commenced on June 28, 1943. The first production Tempest II flew fifteen months later, but the first unit, No. 54 Squadron, was not equipped with this fighter until November 1945, and was thus too late to participate in the war. The Tempest II was powered by the 2,500 h.p. Bristol Centaurus V or VI eighteen-cylinder, air-cooled, two-row radial, and attained a maximum speed of 440 m.p.h. at 15,900 feet and 406 m.p.h. at sea-level. Its range on internal fuel was 775 miles and initial climb rate was 4,520 ft./min.
Schemes for the utilization of the Griffon IIB and the Griffon 61 engines accounted respectively for the Tempest III and Tempest IV designations, neither passing the project stage. Nor did an alternative armament proposal based on the use of 0.5-in. machine-guns. The final Tempest variant was the Mark VI, which, appearing in 1945, was powered by the 2,700 h. p. Sabre VA engine and, except in having small intake ducts in the wing roots, was outwardly indistinguishable from the Tempest V. By and large, both the Typhoon and Tempest escaped the fate of so many aeroplanes of being used as test-beds for a variety of experiments. The Typhoon was designed in a naval fighter variant to meet the requirements of specification N.11/40, and one prototype was converted to this standard under the Hawker project designation P.1009. Another Typhoon modification, the P.1010, was to have had leading-edge radiators and a turbo blower, but work on this was not proceeded with. As part of their engine development program, Napier’s designed an annular cowling for the Sabre to replace the familiar chin-type radiator bath. The first such installation was on a Typhoon IB (R8694), but most of the development was undertaken with a Tempest V (NV768) which flew with several different types of annular radiator and hollow spinner. Another experimental Tempest V (SN354) had a 40-mm. gun under each wing in a long fairing.
Tempest V Srs.2 NV768 with an experimental annular radiator fitted by Napiers in 1945. Standard Tempest V Srs.2 EJ823 alongside.
The Tempest VI was a tropicalised version of the Mk V with a 1,714kW Sabre V engine. This entered RAF service post-war, as did the Tempest II with Bristol Centaurus power plant.
A majority of Tempest IIs were deployed overseas. Three squadrons were based in Germany with the British Occupation Forces and four squadrons went to India. The large stocks of Tempest II in India in 1947 allowed eighty-nine of these aircraft to be supplied to the newly independent Indian Air Force. The following year twenty-four Tempest IIs were delivered to Pakistan.
The Tempest II, 450 of which were built, was the RAF’s last single-seat piston-engined fighter bomber. It was largely replaced by the de Havilland Hornet during 1948, but a few squadrons still flew Tempests until 1951, including several squadrons in Germany.
Many Mk V and Mk VI aircraft were converted subsequently to serve as TT.5 or TT.6 high-speed target tugs.
Tempest Mk V Engine: 1 x Napier Sabre IIA, 1626kW / 2150 hp Wingspan: 12.50 m / 41 ft 0 in Wing area: 28.06 sq.m / 302.04 sq ft Length: 10.26 m / 33 ft 8 in Height: 4.90 m / 16 ft 1 in Max take-off weight: 6142 kg / 13541 lb Empty weight: 4082 kg / 8999 lb Wing loading: 44.9 lb/sq.ft / 219.0 kg/sq.m Max. speed: 370 kt / 686 km/h / 426 mph ROC: 3000 fpm / 914 m/min Service ceiling: 11125 m / 36500 ft Range: 1190 km / 739 miles Armament: 4 x 20mm Hispano cannon Bombload: 2000 lb / 907 kg Crew: 1
Tempest Mk VI Engine: 1 x Napier Sabre V, 2340 hp Wingspan: 12.50 m / 41 ft 0 in Wing area: 28.06 sq.m / 302.04 sq ft Height: 4.90 m / 16 ft 1 in Length: 10.26 m / 33 ft 8 in Height: 4.90 m / 16 ft 1 in Max take-off weight: 6142 kg / 13541 lb Empty weight: 4082 kg / 8999 lb Wing loading: 44.9 lb/sq.ft / 219.0 kg/sq.m Max. speed:704 km/h / 438 mph ROC: 3000 fpm / 914 m/min Service ceiling: 11125 m / 36500 ft Range: 1190 km / 739 miles Armament: 4 x 20mm Hispano cannon Bombload: 2000 lb / 907 kg Crew: 1
Air Ministry Specification F.18/37 was concerned with the design and development of two advanced interceptor fighters with one of two 24-cylinder engines in the 2,000 h.p. class then under development –the Napier Sabre “H” type and the Rolls-Royce Vulture “X” type: one with a Rolls-Royce Vulture engine was identified initially as the R (Rolls-Royce) type fighter; the second, with a Napier Sabre engine, was known as the N (Napier) type. Sydney Camm had commenced investigating the possibilities of just such a fighter in March 1937, and had already roughed out a design built around the Napier Sabre engine and housing twelve 0.303-in. Browning guns with 400 r.p.g. in its 40-foot wings. At the proposal of the Air Ministry, Camm also prepared studies for an alternative version of his fighter powered by the Rolls-Royce Vulture engine, and increased the ammunition capacity of both machines to 500 r.p.g.
Further discussions over military loads and equipment followed, and revised tenders were submitted to the Air Ministry at the beginning of 1938 for both the Type ” N ” and the Type ” R “, as the alternative Sabre and Vulture powered fighters had become known. These tenders were formally accepted on April 22, 1938, and four months later, on August 30, two prototypes of each fighter were ordered. Structurally both types were similar: the wings were all-metal, the front fuselage was of steel tubing, and the aft section consisted of a stressed-skin, flush-riveted monocoque – the first Hawker designs to employ this form of construction. Uniformity between the two fighters was, in fact, achieved to a remarkable degree, but the designs did differ in the Vulture powered fighter made use of a ventral radiator while the Sabre driven machine had one of “chin” type.
Construction of the two fighters proceeded in parallel, and work progressed simultaneously on the preparation of production drawings. As a result of the slightly more advanced development status of the Vulture engine which had been designed along more conventional lines than the Sabre, the Type “R” was the first of the two fighters into the air, flying on 24 February 1940.
The initial flight trials of the prototype were promising, and a production order for 1,000 Tornados was placed at the beginning of November, it being proposed that the new fighter should be built both by Hawker and by A. V. Roe at Woodford. However, the flight test program soon began to run into trouble. Compressibility effects, about which little was known at that time, began to manifest themselves, and it was decided that the ventral radiator bath was unsuitable for the speeds approaching 400 m.p.h. that were being achieved for the first time. The radiator was, therefore, moved forward to the nose, a position already selected for that of the Type “N”, by now dubbed Typhoon; but the first prototype Tornado (P5219) only flew long enough to indicate the beneficial results of the change before it was totally destroyed.
On December 30, 1939, the first Napier Sabre engine had been delivered to Hawker Aircraft, and the first prototype Typhoon (P5212) emerged from the experimental shop to fly on February 24, 1940. It too became the subject of a quantity production order which, it was planned, should become the responsibility of Gloster Aircraft, whose assembly lines were emptying of Gladiator biplanes and whose design office was already immersed in the development of the Gloster Meteor, the first British turbojet-driven aircraft. Although, like those of the Tornado, the first flights of the Typhoon prototype indicated a promising fighter, the machine proving relatively easy to fly at high speeds, its low speed qualities left much to be desired, and it had a marked tendency to swing to starboard during take-off. The “X” form of the Tornado’s Vulture engine had not permitted installation above the front spar as was the Typhoon’s Sabre and, in consequence, the overall length of the former was 32 ft. 6 in. as compared with the 31 ft. 10 in. of the latter. Owing to the size and weight of the Sabre and the need to preserve c.g. balance, the Typhoon’s engine was fitted so close to the leading edge of the wing that severe vibration was experienced as the slipstream buffeted the thick wing roots. On an early test flight the stressed-skin covering began to tear away from its rivets, and the Typhoon’s pilot, Philip G. Lucas, only just succeeded in bringing the prototype in to a landing.
Apart from structural teething troubles, the Sabre engine, although a compact and exquisite power plant, called for a considerable amount of development, and it was perhaps fortunate for the future of the Typhoon that, in May 1940, the war situation led to the cancellation of all priority for Typhoon and Tornado development in order to allow every effort to be put into the production of sorely needed Hurricanes. Design development was allowed to continue, and development on the Typhoon included the design of a modified wing containing two 20-mm. Hispano cannon in place of the six 0.303-in. Brownings, the construction of an experimental set of wings containing a total of six cannon, and the initiation of a design study of a Typhoon variant with thinner wings of reduced area and lower profile drag. This latter study was later to arouse interest at the Air Ministry and eventually result in the Tempest. By October 1940 enthusiasm had been revived and production of the Tornado and Typhoon reinstated, production deliveries of both being scheduled for the following year.
The first production Typhoon IA (R7082) with the 2,200 h.p. Sabre IIA engine was completed by Gloster and flown on May 26, 1941. Production of this version, with its twelve Browning guns, was in limited quantity, and those built were used principally for the development of operational techniques. Typhoon IA production aircraft began to enter RAF service in September 1941, and went into action in the summer of 1942. Initial usage proved a great disappointment, with unsatisfactory high-altitude performance, inferior rate of climb and frequent engine breakdowns. When structural failure of the tail unit caused a number of fatal accidents it was suggested that the Typhoon should be withdrawn from service. Fast action was taken to overcome the shortcomings, and introduction of the Sabre II engine brought improved reliability. Typhoon I A were armed with 12 x 7.7mm Browning machine-guns.
The cannon-armed Typhoon IB was following the Mark IA, and the Air Ministry was pressing for its rapid service introduction to counter the new Focke-Wulf Fw 190. Nos. 56 and 609 Squadrons based at Duxford began to receive their Typhoons in September 1941, before the fighter was fully developed, and these squadrons were forced to take on part of unearthing the new machine’s numerous faults. In the first nine months of its service life far more Typhoons were lost through structural or engine troubles than were lost in combat, and between July and September 1942 it was estimated that at least one Typhoon failed to return from each sortie owing to one or other of its defects. Trouble was experienced in power dives – a structural failure in the tail assembly sometimes resulted in this component parting company with the rest of the airframe. During the Dieppe operations in August 1942, when the first official mention of the Typhoon was made, fighters of this type bounced a formation of Fw 190s south of Le Treport, diving out of the sun and damaging three of the German fighters, but two of the Typhoons did not pull out of their dive owing to structural failures in their tail assemblies.
Despite this start to its service career, operations continued and the accident rate declined as the engine teething troubles were eradicated, although the tail failures took longer to solve, despite immediate strengthening and stiffening as soon as the trouble manifested itself. In November 1942 No. 609 Squadron, led by Wing Commander Roland Beamont, was moved to Manston in an attempt to combat the near-daily tip-and-run raids which were being made by Fw 190s and could rarely be intercepted by Spitfires. The Typhoon enjoyed almost immediate success. The first two Messerschmitt Me 210 fighter bombers to be destroyed over the British Isles fell to the guns of Typhoons, and during the last daylight raid by the Luftwaffe on London, on January 20, 1943, five Fw 190s were destroyed by Typhoons.
On November 17, 1942, Wing-Commander Beaumont had flown a Typhoon on its first night intrusion over Occupied France and, subsequently, the fighter was employed increasingly for offensive duties, strafing enemy airfields, ships and railway transport. The success of the Typhoon in the ground-attack role led to trials with two 250-lb. or two 500-lb. bombs which were carried on underwing racks. This load was later increased to two l,000-lb. bombs, but the Typhoon was not to find its true element until it was adapted to carry airborne rocket projectiles – four under each wing. By D-Day, in June 1944, the R.A.F. had twenty-six operational squadrons of Typhoon IBs. Without its underwing load the Typhoon IB weighed 11,300 Ib.; and with two 500-lb. bombs and the necessary racks, 12,400 lb. Maximum speed was 398 m.p.h. at 8,500 feet and 417 m.p.h. at 20,500 feet, and an altitude of 20,000 feet could be attained in 7.6 minutes. Between the prototype and production stages several design changes had been made. These included the re-design of the fin and rudder, the redisposition of the wheel fairings and the introduction of a clear-view fairing behind the cockpit. On the first few Typhoon IAs the solid rear fairing was retained; later a transparent fairing was fitted, but this was abandoned in favor of the first sliding ” bubble ” hood to be used by an operational fighter.
The Typhoon IB, by now affectionately known as the “Tiffy”, distinguished itself particularly in the Battle of Normandy, where it 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 F.R.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. equipment, special night-flying cockpit and other modifications. Production of the Typhoon, which was entirely the responsibility of Gloster Aircraft, totaled 3,330 machines.
Hawker Typhoon JP843
Typhoons were operated by 32 RAF squadrons, and used by the RCAF and Free French squadrons within the RAF.
Work had been going on in the Hawker design office since 1940 on the development of a new thin wing section. It had already been established that the N.A.C.A.22-series wing section employed by the Typhoon was entirely satisfactory at speeds in the vicinity of 400 m.p.h. but encountered compressibility effects at higher speeds. In dives approaching 500 m.p.h. a very sudden and sharp increase in drag was experienced, accompanied by a change in the aerodynamic characteristics of the fighter, which affected the pitching moment and rendered the machine nose heavy. No actual design work on the new wing was begun until September 1941, and the wing section eventually adopted for development had its point of maximum thickness at 37.5% of the chord. The thickness/cord ratio was 14.5% at the root and 10% at the tip, giving a wing five inches thinner at the root than that of the Typhoon.
This thin wing could not contain a comparable quantity of fuel to that housed by the Typhoon’s wing, so a large fuselage tank had to be adopted. This necessitated the introduction of an additional fuselage bay, increasing the overall length by twenty-one inches forward of the c.g. This added length found its inevitable compensation after initial prototype trials in a larger fin and tailplane. The wing area was also increased, and an elliptical planform was adopted, presenting a chord sufficient to permit the four 20-mm. Hispano cannon to be almost completely buried in the wing. All these modifications added up to a radically changed Typhoon, but it was as the Typhoon II that two prototypes were ordered in November 1941. However, in the middle of the following year the name Tempest was adopted.
By the end of 1945, none remained in front-line service.
As part of their engine development program, Napier’s designed an annular cowling for the Sabre to replace the familiar chin-type radiator bath. The first such installation was on a Typhoon IB (R8694), but most of the development was undertaken with a Tempest V (NV768) which flew with several different types of annular radiator and hollow spinner.
Typhoon Mk. IB Crew: 1 Engine: 1 x Napier “Sabre IIA”, 1605kW / 2150 hp Max take-off weight: 5170 kg-6,010 kg / 11398 lb-13,250 lb Empty weight: 3992 kg / 8801 lb Wing loading: 40.8 lb/sq.ft / 199.0 kg/sq.m Wingspan: 12. 67 m / 41 ft 8 in Length: 9.74 m / 31 ft 10 in Height: 4. 67 m / 15 ft 5 in Wing area: 25.9 sq.m / 278.79 sq ft Max. speed: 673 km/h / 418 mph Cruise speed: 530 km/h / 329 mph Service ceiling: 10360 m / 34000 ft Initial climb rate: 3,000 ft/min / 914 m/min Range w/max.fuel: 1530 km / 951 miles Range w/max.payload: 980 km / 609 miles Armament: 4 x 20mm cannon, 900kg of weapons / 8x rockets
Sydney Camm and his team responded to Specification F.18/37 that called for a single-seat interceptor, with two tenders. One was referred to as the “R-type” and the other as the “N-type”. These were to use fundamentally similar airframes and differ essentially in the type of engine installed. The “R-type”, which was to be named Tornado, initially appeared the most promising and was powered by a 24-cylinder X-type Rolls-Royce Vulture – basically two 12-cylinder Peregrine V engines driving a common crankshaft. The first of two prototypes was flown on 6 October 1939 with a 1760hp Vulture II, provision being made for an armament of 12 7.7mm machine guns. The similarly-powered second prototype, flown on 5 December 1940, had provision for a four 20mm cannon armament. In May 1940, the war situation led to the cancellation of all priority for Typhoon and Tornado development in order to allow every effort to be put into the production of sorely needed Hurricanes. Design development was allowed to continue, however, and during 1940 three alternative engine installations were proposed for the Tornado–the Fairey Monarch, the Wright Duplex Cyclone, and the Bristol Centaurus – and experimental drawings for the Centaurus installation were completed. By October 1940 enthusiasm had been revived and production of the Tornado and Typhoon reinstated, production deliveries of both being scheduled for the following year. A Tornado assembly line was laid down by Avro, the production model being intended to receive the Vulture V of 1980hp, with which both prototypes were reengined. The Vulture, meanwhile, was suffering various problems, such as connecting rod bolt failures, and as the Merlin possessed absolute priority, Rolls-Royce was forced to abandon the production of this X-type engine. This led to cancellation of the initial production batch of 201 Tornados, only one production example being completed and flown on 29 August 1941. But this was fated to be the only production Tornado, for difficulties with the Vulture resulted in the decision to remove this power plant from the aero-engine development program, this decision also canceling production of the Tornado. The Tornado weighed 8,200 lb. empty and 10,580 lb. loaded. Its maximum speed was 425 m.p.h. at 23,000 feet. However, in February 1941, Hawker’s received a contract to convert a Tornado to take a 2210hp Bristol Centaurus CE.4S 18-cylinder air-cooled radial engine. Among the modifications required were a new center fuselage and engine mounting. The new prototype (HG641) was assembled from Tornado production components and flown for the first time on October 23, 1941. The first Centaurus installation had an exhaust collector ring forward of the engine from which a single external exhaust stack pipe led back under the root of the port wing. This arrangement soon proved unsatisfactory, so the oil-cooler duct was enlarged and led forward to the nose, while twin exhaust pipes led back from the front collector ring through this fairing to eject under the belly of the fuselage. A level speed of 421 m.p.h. was attained with the Centaurus-Tornado, and this was slightly higher than that attainable by the Sabre-powered Typhoon, but the Typhoon airframe could not be adapted to take the radial engine. When a captured Focke-Wulf Fw 190A was examined late in 1941, numerous alterations to the British radial engine installation were made by Bristol, with considerable benefit to the test bed’s performance. The second prototype Tornado (P5224) had, in the meantime, been completed, and the sole production Tornado (R7936) later played a useful role as a test-bed for deHavilland and Rotol contraprops. The Centaurus Tornado continued flying in 1942 and it was the encouraging results that led to the Tempest II.
Hawker Tornado Engine: Rolls Royce Vulture V, 1953 hp Length: 32 ft 10 in / 10.01 m Height: 14 ft 8 in / 4.47 m Wingspan: 41 ft 11 in / 12.78 m Wing area: 282.986 sq.ft / 26.29 sq.m Max take off weight: 10670.0 lb / 4839.0 kg Weight empty: 8379.0 lb / 3800.0 kg Max. speed: 346 kt / 641 km/h / 398 mph Service ceiling: 34908 ft / 10640 m Wing loading: 37.72 lb/sq.ft / 184.0 kg/sq.m Crew: 1
The family tree of the Hurricane can be traced back to a ‘Fury monoplane’ proposal of 1933, then to be powered by the Rolls-Royce Goshawk evaporative-cooled power plant. Instead it was decided in early 1934 to adapt this design to incorporate the new PV.12 engine which Rolls-Royce had developed – and which was the direct forbear of the famous Merlin. From that time the airframe/engine combination bore so little relation to the Fury that it then became identified as the ‘Interceptor Monoplane’.
In 1933, Hawker‘s chief designer Sir Sidney Camm realised that something even better than the Fury was needed and the Hawker Fury monoplane was the result – a cantilever monoplane with fixed under-carriage and 660 h.p. Rolls Royce Goshawk engine. At this time 4 machine guns were considered adequate; but higher speeds reduced the time an enemy could be held in the pilot‘s gun sights and eventually plans were amended to accommodate 8 machine guns all mounted in the wings. The new Rolls Royce Merlin I was fitted and the aeroplane outstripped the original conception – it was no longer the Fury monoplane – the name Hurricane was chosen.
This finalised design was submitted to the Air Ministry in 1934, and in the following year a prototype was ordered to Specification F.36/34, and the Air Ministry asked for an armament of no less than eight machine-guns.
In 1934, the monoplane layout was still very new for combat aircraft and thick airfoils for monoplanes were much in vogue for structural rea-sons, if nothing else. Hurricane designer Sir Sydney Camm seemed to have had misgivings from the start. “When its design had gone beyond the point of no return,” he once admitted, “I had a sudden foreboding that it would be no good. Strength had to be an important factor in this ship, but I always wished that the wing had been thinner. If we had had more time, the Hurricane would have been the greatest aircraft of all time.” But if Hawker hadn’t frozen the design and gone ahead with mass production when it did, even without an official order. It was Hawker’s gamble in laying down a production line of 1,000 Hurricanes before the Air Ministry ordered such a vast quantity was available the Battle of Britain.
The Hawker engineer Frank Murdoch was responsible for getting the Hurricane into production in sufficient numbers before the outbreak of the war, after an eye-opening visit to the MAN diesel plant in Augsburg in 1936.
The prototype Hurricane K5083 flew on November 6, 1935 at Brooklands, piloted by Hawker’s chief test pilot, Flt.-Lt. “George” Bulman and powered by a 767kW Merlin ‘C’ engine. On landing he reported that it handled perfectly and was free from vices. Even at this date the retractable undercarriage was considered by many an extravagant novelty.
Hurricane prototype K5083 in early 1936
Advanced features such as an enclosed cockpit and retractable undercarriage were combined with traditional methods of construction using a tubular metal structure and fabric covering, meant that the Hurricane could be easily and rapidly produced in existing facilities.
In February 1936, the prototype Hurricane (as yet un-named), powered by an early Merlin C producing 990 hp and driving a Watts fixed-pitch two-bladed wooden propeller, was tested at the Aircraft and Armament Experimental Establishment at Martlesham Heath, giving service pilots their first opportunity to experience the performance.
Convinced that the RAF would buy the new fighter the Hawker company decided, in March 1936, to proceed with the production drawings and to make plans for large scale production. Three months later the Air Ministry confirmed that 600 Hurricanes were to be included in its expansion Plan F (which also provided for 300 Spitfires) to be delivered by March 1939. The target was missed by six months. There had been a succession of relatively minor but time-consuming problems with prototype development, especially related to the Merlin, and the early intention to fit the Merlin F (Mk.1) in the production Hurricane was changed to make use of the improved Merlin G (Mk.II), which required a redesign of the installation and the front fuselage profile before production could begin. The cockpit canopy also produced problems with five failures recorded on the prototype before a satisfactory design was evolved.
Convinced that the RAF would buy the new fighter the Hawker company decided, in March 1936, to proceed with the production drawings and to make plans for large scale production. Three months later the Air Ministry confirmed that 600 Hurricanes were to be included in its expansion Plan F (which also provided for 300 Spitfires) to be delivered by March 1939. The target was missed by six months. There had been a succession of relatively minor but time-consuming problems with prototype development, especially related to the Merlin, and the early intention to fit the Merlin F (Mk.1) in the production Hurricane was changed to make use of the improved Merlin G (Mk.II), which required a redesign of the installation and the front fuselage profile before production could begin. The cockpit canopy also produced problems with five failures recorded on the prototype before a satisfactory design was evolved.
The first production Hurricane I, LIS47, flew at Brooklands on October 12, 1937, fitted with an early example of the Merlin II and at a weight of 5459 lb (2476 kg), a contract for 600 having been placed in June 1936. This was increased to 1000 in November 1938.
The second aircraft was in the air on 18 October, and production deliveries then built up rapidly. Meanwhile, during 1936, the prototype had been fitted with the planned armament of eight Browning machine guns and first firing trials had been made. Design of a metal-covered wings was in hand, but to avoid production delays the Hurricane I retained the fabric-covered wing, in which the guns were grouped in two quartets, positioned to fire just outside the propeller disc and requiring no synchronisation gear. Each gun was provided with 300 rounds, and the two batteries were harmonised to converge at 650 yards (594m), although with experience this distance was to be reduced eventually to 200 yards (183m).
Hawker Hurricane Mk 1
Although of cantilever monoplane configuration, its construction was typical of the Fury from which it stemmed, and even its wings were fabric-covered in early Mk Is, with a metal leading edge and trailing-edge flaps. The tailwheel-type landing gear had hydraulically retractable main units of wide track. Armament of production Mk Is comprised four 7.7mm Browning machine-guns in each wing, making this the RAF’s first eight-gun fighter. Designated the Hurricane I, it was outfitted with a Rolls-Royce Merlin II or III engine, fabric-covered wings, and a wooden prop. It lacked armor and selfsealing fuel tanks.
In Yugoslav, Ikarus and Zmaj shared the order for the production of Hurricane MK1.
A second major version of the Hurricane made its first flight on 11 June 1940 and, as the Hurricane IIA powered by a Merlin XX, would begin to reach the Squadrons on 4 September 1940. Improvements included wing alterations for increased armament, redesigned engine mount, strengthened fuselage, and tanks protected with self-sealing rubber.
The Hurricane I was improved with an armoured bulkhead introduced forward of the cockpit and, when Hawker Aircraft’s second production batch began leaving the assembly line in September 1939, a bullet-proof windscreen had been standardised. This batch also adopted the Merlin III which features a shaft capable of taking either Rotol or de Havilland three-bladed constant speed propeller. While some Hurricanes were produced during 1939 with the DH two-position propeller, a major conversion programme was started on 24 June 1940 to fit the Rotol constant speed unit which allowed the pilot to select optimum power for the various stage of flight. Significantly improving the Hurricane I’s climb performance, Rotol propellers had been fitted to all Hurricanes by mid-August 1940. With the 81th Hurricane of the second batch, the fabric covered wing gave place to an all metal stressed skin wing and, on 2 February 1940 the first Hurricane with rear armour protection for the pilot was flown.
By the end of 1939, the RAF had received more than 600 Hurricane Is and production was at a rate of 100 a month. Gloster began Hurricane production flying its first Hurricane I at Hucclecote on 20 October 1939.
No.111 Sqn RAF August 1938
By December 1937 No. 111 Squadron at Northolt was beginning to re-equip with the type, and were fully equipped by February 1938. Early in the new year made front page news when S/Ldr. J. W. Gillan, Officer Commanding lll Sqn., flew from Edinburgh to Northolt (assisted by a tail wind) at an average speed of 408 m.p.h.
By July 1939, twelve regular squadrons were flying the Hurricane I, to be followed by six Auxiliary Air Force squadrons. By the outbreak of war in 1939, 500 Hurricanes had been delivered and by August 7, 1940, when the Battle or Britain started, there were 32 Hurricane squadrons as against 19 Spitfire squadrons. By that time, the Hurricane had already been in action in France, Norway and Malta. At the outbreak of war in September, 1939, the Royal Air Force returned to France equipped with Hurricanes. Before this, Hurricanes of No. 46 Sqn. took part in the fighting in Norway, brought into action by the aircraft carrier “Glorious”. When the order came to evacuate, the Squadron flew all its Hurricanes on to the “Glorious” without arrestor gear rather than resort to destroying them, but this effort was in vain when the carrier was subsequently sunk. Similarly, Hurricanes flown from H.M.S. Argus reinforced the Gladiators in the Battle of Malta. In the Battle of Britain, the Hurricane bore the brunt of the fighting.
Hurricanes downed more enemy aircraft than did the Spits in the Battle, and the highest-scoring RAF pilot in the Battle, a Polish sergeant named Josef Frantitek (with a score of 17, all in a single month) flew Hurricanes.
One of the significant statistics of the Hurricane’s contribution to this hard-fought battle was the fact that these aircraft destroyed more enemy aircraft than the combined total of all other defence systems, air or ground. Even that factor must be equated with the information that at the beginning of the battle (on 8 August 1940) approximately 65% more Hurricanes than Spitfires (2,309 to 1,400) had been delivered to the RAF’s Fighter Command.
After the Russian invasion of Finland in 1940, slowly reinforcements began to arrive for the Finnish air force. The first to come were 5 Gloster Gladiators, 12 Hurricanes, 17 Lysanders and 24 Blenheims, all from Britain. After that, 76 Morane-Saulnier and Koolhoven F.K. fighters arrived from France. Italy sent 17 Fiat fighters, Sweden 12 Gloster Gladiators, and the USA 44 Brewster Buffalo, of which however only 5 reached Finland in time. Even the Union of South Africa sent 25 Gloster Gladiators. Pilots and ground personnel from a number of countries also volunteered to assist them.
After 1940, Hurricanes served largely in the Middle East and North Africa, with a distinctive sand filter under the nose to protect the Merlin’s innards. They were tried as night fighters over Britain after the Luftwaffe switched to night raids, but the night-fighting Hurricanes had generally poor success.
The aeroplane had now changed slightly from the early production mark, among other modifications, a 3-blade controllable pitch airscrew was fitted. A ventral fin faired the fixed tail wheel to improve handling qualities and metal had replaced fabric covering on the wings. Subsequent Hurricane versions included the Mk IIA with Merlin XX and eight guns; Mk IIB with 12 guns; and Mk IIC with four 20mm cannon. Mk IID with two 40mm Vickers ‘S’ guns and two 7.7mm guns (plus additional armour for low attack) were used extensively in the Western Desert. The final production version was the Mk IV with a wing able to accept armament comprising two Browning machine-guns plus two 40mm guns, or eight rocket projectiles, or two 110kg or 225kg bombs, or long-range fuel tanks. The Hurricane V (only two built) was powered by a Merlin 27 or 32 engine.
The Hurricane Mark II first flew on June 11th, 1940 with Merlin XX two-stage supercharged engine. A special set of mainplanes were made to accommodate the various armament. The Mk. IIA retained the eight Brownings. On the Mk. IIB these were increased to no less than 12 guns. Four 20 mm. Hispano cannons replaced the rifle-calibre guns on the IIC, and on the Mk. IID two 40 mm. Vickers cannon with two Brownings firing tracer ammunition for sighting. To increase the range, 90 gallon drop tanks were suspended below the wings on the IIC and armed with 4×20 mm. cannon the Hurricane a familiar sight with its Vokes sand filter during the North African campaign.
In August 1941 Great Britain decided to lend fighter plane support to Russia. British 151st Wing was set up in Leconfield near York, to train Soviet aircrews in the assembly, maintenance and operation of the fighters. Then Nos 81 and 134 Squadrons, comprising 39 Hurricane Mk.IIB, were shipped to the Soviet Union along with their pilots and ground personnel. The old British aircraft carrier Argus transported 24 of the Hurricanes, and the other 15 were packed and sent along on other vessels as deck cargo. The convey put to sea from Iceland on 21 August 1941 and docked at Murmansk on August 28. Here the 24 Hurricanes took off from Argus and landed at Viange airport about 15 miles away, which served 151st Wing as their main airbase during their stay in the Soviet Union.
On Sunday 3 August 1941, the first aerial victory won by a British Hurricane catapulted from a CAM ship took place when Lt. Robert Everet of 804 Sqn, based on the steamer Maplin, shot down a Focke-Wulf Fw 200C Condor of German 40 Sqn, 1st Bomber Wing in the North Atlantic. Instead of making a sea landing near his mother ship, the pilot decided to fly the 300 miles to Scotland, and landed there at Loch Earn.
CAM freighter carrying a Sea Hurricane
By 1942, most Hurricanes had been switched to ground attack, with a powerful variety of weapons: 12 Brownings; or four 20mm cannon that slowed you down by 30 mph when you fired them; or a pair of Brownings plus two 40mm cannon with just 20 armor-piercing rounds. Another variant was the “Hurribomber”, with racks for two 250-pounders, or even two 500-pounders, sometimes delivered by skip-bombing. Rocket rails were also commonly fitted. In the Far East, Burma and India, the Hurricane remained the principal British fighter opposing the Japanese right up to the war’s end. Some 3,000 Hurricanes (one in five of all built) were given to the Soviet Union, most shipped by convoy around the North Cape to Murmansk.
Hawker Hurricane MkII converted by the Soviets with a back seat and machine gun position.
After early experience of deck landing Hurricanes, an arrestor hook was fitted and in this form was known as the Sea Hurricane Mk. IB. Sea Hurricanes joined the Royal Navy in January 1941 and became the first carrier-based British single-seat monoplane fighter when taken to sea by HMS Furious in July 1941. Under the ‘Catfighter’ scheme, Sea Hurricane IA were equipped for catapult launch from the decks of CAM merchant ships (catapult-equipped merchantmen) to counter the threat posed by Germany’s Focke-Wulf Fw 200 Condors, introduced in the spring in 1941. Only the Mk IA was specially built. The approximate figure of 800 Sea Hurricanes which entered service included 50 Mk IA and about 750 conversions of Mk II and Canadian-built aircraft.
These were 35 ordinary merchant ships that had been modified to carry a Hurricane on a rocket launch rig on the bow. These CAM ships, carrying ordinary cargo as well, accompanied the great convoys sailing from Britain to Russia and the Mediterranean, and from Canada to Britain. The Hurricats were assigned to convoy defense against the Luftwaffe’s Focke-Wulf Condor long-range, four-engine reconnaissance bombers, which were not only attacking convoys, but tracking them for U boats and other bomber units. If a Hurricat pilot was lucky, he could make it back to shore after launch and combat if not, he had to ditch (not recommended, since the Hurri-cane invariably turned over and sank) or else bail out over the convoy.
Apart from its role as a purely fighter aeroplane, the Hurricane served as a fighter bomber with two 250 lb. and later two 500 lb bombs below the wings. The aeroplane was also used for night fighting and pioneered the use of rocket projectiles until the advent of the Typhoon. In this guise it was known as the Mk. IV.
Mention must be made of at least one interesting experiment. A supplementary wing of identical shape and area was fitted to a standard Mk. I Hurricane to enable it to take off with a much greater load. This wing was released in flight. A long series of tests were conducted but the project did not proceed beyond the experimental stage. Another version of the Hurricane was equipped with floats.
During the Second World War Gloster built 2,750 Hurricanes and 3,330 Typhoons,
The Hurricane was eventually replaced on Hawker’s production lines by the Typhoon, the Tempest, the Fury and the Sea Fury.
Hurricane evolution effectively stopped at the Mark IV.
In November 1938, the Canadian Car and Foundry Company was awarded a contract to produce Hawker Hurricanes for the RAF at its Fort William plant. The initial order was for forty aircraft (P5170 to P5209) to Mk 1 specification with British made Rolls Royce Merlin III engines and eight .303 Browning machine guns. These models depended almost entirely on British materials such as steel tubing, aluminium sheeting and metal castings which were formed, pressed and machined at Fort William, since the Canadian aircraft industry did not at that time have the capability to produce these items from scratch.
With the outbreak of war, shipping delays and losses created problems with such a system and as late as 1941 shortages of imported British materials reduced production considerably. Mr G C Kemp, a foreman at that time, recollects that at one point a delay in the arrival of Merlin engines was overcome by flying as many as thirty Fairey Battles into Fort William, where the engines were removed and fitted into the Hurricanes. In time, with new Canadian sources of supply and the introduction of the Packard Merlin engine from the US, production rose to reach a peak of 700 aircraft in 1942. In all, between January 1940, when the prototype (P5170) flew, and June 1943, when the last Hurricane left the plant at Fort William, 1,451 aircraft of various marks were built, representing some 10% of all Hurricanes produced and almost half of Can Car’s total production during the war years.
The Hurricane 1 was in many ways a transitional design between the wood, metal and fabric biplanes of the 1920s and 1930s and the metal skinned monoplane fighters of the 1940s. It incorporated a metal frame with a combination of wooden fairing and fabric over the fuselage and fabric covering the wings. All of the CCF built Hurricanes however had aluminium covered wings and indeed, when Mr A D Norton, head of the Tool Design Section at Can Car, visited the Hawker works in England in 1939, he found the development of the metal skinned wings less advanced than at Fort William. Apart from that, the basic structure of the Hurricane changed little in its lifetime. Some were fitted to carry bombs, some had catapult fittings, others had arrester gear, some were tropicalised and at least two were fitted with skis by the RCAF. The normal elements used to differentiate the variants, however, were powerplant and armaments.
The initial order for forty machines was renewed and in total 160 Mk 1 aircraft were built in five different batches. Most of these seem to have been sent directly to Britain, where they were distributed as the need arose rather than being assigned by batch to any one squadron, this being made possible by the inter-changeability of components among British and Canadian-built aircraft. Twenty were delivered before the Battle of Britain and some of these participated in the fierce aerial fighting of August and September 1940.
The majority of the Hurricanes built by CCF at Fort William were Mk X or Mk XII variants, equivalent to the British built 1 and IIB, and amounting to 900 aircraft or 62% of the total. Both were equipped with Packard engines, the Merlin 28 in the case of the Mk X and the Merlin 29 in the Mk XII, while the latter carried twelve Brownings compared to the eight of the Mk X. Most of the Hurricane Xs were initially sent to Britain, but some were later tropicalised and used in India. After many requests, about thirty of these aircraft were also released for use by the RCAF in Canada.
Those sent to Britain seem to have been modified quite regularly as the Hurricane evolved into its intruder and ground attack role. Many with serial numbers between AM270 and AM369, for example, built as Mk Xs were later designated IIB or IIC, presumably because of changes in armaments and the addition of external bomb racks or fuel tanks rather than the wholesale replacement of the Packard Merlin with its Rolls Royce equivalent, although, of course, the latter may have applied in some cases also. With some, multiple conversions took place. Hurricane AM280, for example, started life as a Mk X but appears in late 1941 or early 1942 on the books of 1 Squadron as a Mk X converted to IIB configuration. Later in 1942 and 1943 it is referred to variously as a Mk X/11C with 534 Squadron and a “Mk X, modified with four cannon wings with 3 Squadron.
Unlike the Mk Xs, the Hurricane XII’s (RCAF 5376 to 5775) with their Merlin 29 engines and twelve Browning guns armament remained in Canada with the RCAF, flying defensive patrols along the east and west coasts, but without becoming involved in combat. This applies also to a batch of fifty Hurricane XIIAs, built as Sea Hurricanes for the Fleet Air Arm, but subsequently released for service with the RCAF. These aircraft were similar to the Mk XII in that they had Merlin 29 engines, but were fitted with eight gun Mk 1 or Mk X wings. The situation with the Mk XII variants is complicated by the fact that some of the later aircraft shipped to Britain without engines, instruments or armament were fitted with Merlin XX engines and either twelve Browning or four cannon wings and designated Mk 1IB/XII or IIC/XII although during construction in Canada they were nominally IIB or IIC. This applied to aircraft of the JS219 to JS468 batch which began to appear in Britian in 1942 to be used in intruder activities or as night fighters with the Turbinlite squadrons. Others of this group served with various squadrons in the Middle East and India.
The final four batches of Hurricanes (PJ660 to P.1695, PJ711 to PJ758, PJ779 to PJ813 and PJ842 to PJ872), built to Mk IIC specifications, were also intended for shipping to Britain for the fitting of engines, instruments and armament. Although some doubt has been expressed as to whether or not these were actually constructed, aircraft with serials from the second, third and fourth groups are recorded as serving in India in 1943 and 1944, flying escort to bombing raids or involved in low level fighter bomber activity over Burma.
Hurricane production continued until 1944. In all, Hawker produced 10,030, supplemented by 2750 from Gloster, and 1451 from Canada.
More than 4,000 Hurricanes were supplied to other air forces, including Belgium, Canada, Egypt, Eire, Finland, India, Persia, Poland, Portugal, Romania, South Africa, the Soviet Union, Turkey, and Yugoslavia.
Prototype Engine: 767kW Merlin ‘C’ Weight: 5672 lb / 2572 kg Speed: 315 mph / 506 kph at 16,200 ft / 4957 m with 6 lb/sq.in boost TO run: 800 ft / 245 m T/O speed: 81 mph / 130 kph Time to 15,000 ft / 4570 m: 5.7 min Time to 20,000 ft / 6100 m: 8.4 min Service ceiling: 34,500 ft / 10,515 m Est absolute ceiling: 35,400 ft / 10,800 m
Mk I Engine: Rolls-Royce Merlin II or III, 990-1030 hp Prop: Rotol 3 blade wood Length: 31.4 ft. (9.55 m) Height: 13 ft. 11 in Wing span: 40 ft. (12.2 m) Wing area: 257.5 sq. ft MAUW: 6600 lb Weight empty: 4,670 lb. (2,118 kg) Max speed 325 mph @ 20,000 ft Service ceiling 36000 feet. Initial climb rate 2,950 fpm Range: 460 miles (740 km) Armament: 8 x 7.7mm / 0.303in Browning machine-guns Bomb load: 1,000 lb. (450 kg) Crew: 1
Hurricane I Engine: Rolls-Royce Merlin II, 990hp Prop: 2 blade wood fixed pitch Wing span: 40 ft. (12.2 m) Wing area: 257.5 sq. ft Length: 31.4 ft. (9.55 m) Height: 13 ft. 11 in Weight empty: 4,732 lb. / 2,146 kg Normal loaded weight: 6056 lb / 2747 kg MTOW: 6202 lb / 2813 kg Fuel capacity: 97 ImpGal / 441 lt Range: 680 miles / 1094 km at 275 mph / 442 kph at 15,000 ft / 4575 m Endurance: 4.2 hr at econ cruise Econ cruise: 162 mph / 261 kph Max speed 312 mph / 502 kph @ 20,000 ft Time to 15,000 ft / 4575m: 7 min Service ceiling 33,000 ft / 10,058m TO to 50 ft / 15.2m norm wt: 1800 ft / 549 m TO to 50 ft / 15.2m max wt: 1890 ft / 576 m Armament: 8 x 7.7mm / 0.303in Browning machine-guns Crew: 1
Hurricane II Engine: One Rolls-Royce Merlin XX, 1,030 hp at sea level, 1,460 hp at 6,250ft in M gear and 1,435hp at 11,000ft in S gear. Propeller: Rotol three-bladed constant speed 11 ft 3 in diameter. Span, 12.2 m / 40 ft 0 in Length, 9.8 m / 32 ft 3 in Overall height, tail down, one blade vertical, 13 ft 3 in Wing area, 24.0 sq.m / 258.33 sq ft Weight empty: 4,670 lb. (2,118 kg). Max take-off weight: 3540 kg / 7804 lb Fuel capacity, 69 Imp gal in two wing tanks, 28 Imp gal in res fuselage tank, total 97 Imp gal. Optional fuel: two 45 Imp gal drop or 90 Imp gal fixed ferry tanks under wings. Max speed: 316 mph. (508 kph) Ceiling: 10850 m / 35600 ft Range w/max.fuel: 740 km / 460 miles Undercarriage track, 7 ft 10 in Aspect ratio, 62:1 Dihedral, 35 deg on outer wing panels Crew: 1. Armament: 4 x 20mm cannon. Bomb load: 1,000 lb. (450 kg)
Hurricane IIA Engine: Rolls-Royce Merlin XX, 1260 hp Time to 20,000 ft / 6095 m: 8.2 min Max speed: 342 mph / 550 kph at 22,000 ft / 6705 m Armament: 12 mg or 4 cannon
Mk IIB Engine: RR Merlin 25, 1280 hp. Wing Span: 40 ft Length: 32 ft 3 in Height: 13 ft 1 ft Tare weight, 5,467 lb Empty equipped weight, 6,266 lb Normal loaded weight, full armament and internal fuel, 7,233 lb. Max speed, 328 mph at 18,000 ft clean, 310mph with tropical filter Initial rate of climb, 2,950 ft/min clean, 2,800 ft/min with tropical filter Time to 15.000 ft, 55 min. to 25,000 ft, 95 min Service ceiling, 36,000 ft Range, 465 mls at 177 mph clean, 935 mls with two 45 Imp gal drop tanks, 436 mls clean with tropical filter. Armament: Twelve BSA-built Browning machine guns of 0.303-in calibre with a total of 3,988 rounds in 12 magazines (5,238 rounds in some aircraft). Provision for two 250-lb or 500-lb bombs.
Mk IIC Max speed, 327 mph at 18,000 ft clean, 301 mph with tropical filter Initial rate of climb, 2,750 ft/min clean, 2,400 ft/min with tropical filter Time to 15,000 ft, 6 min, to 25,000 ft, 10 min Service ceiling, 35,600 ft Range, 460 mls at 178mph clean, 920 mls with two 45 Imp gal drop tanks, 426 mls clean with tropical filter. Tare weight, 5,658 lb Empty equipped weight, 6,577 lb Normal loaded weight, full armament and internal fuel, 7,544 lb Max overload weight with drop tanks, 8,044 lb Armament: Four Hispano Mk I or Mk II cannon of 20-mm capacity with 90 rpg. Provision for two 250-lb or 500-lb bombs under wings.
Mk IID Armament: two 40mm Vickers ‘S’ guns and two 7.7mm guns
Mk IV Armament: two Browning machine-guns plus two 40mm guns, or eight rocket projectiles, or two 110kg or 225kg bombs, or long-range fuel tanks.
Hurricane V Engine: Merlin 27 or 32 engine. No built: 2
Sea Hurricane IA
Sea Hurricane Mk II C Engine: Rolls Royce Merlin XX, 1262 hp Length : 32.251 ft / 9.83 m Height: 13.091 ft / 3.99 m Wingspan: 39.993 ft / 12.19 m Wing area: 257.475 sq.ft / 23.92 sq.m Max take off weight: 8101.2 lb / 3674.0 kg Weight empty: 5880.7 lb / 2667.0 kg Max. speed: 297 kt / 550 km/h Cruising speed: 184 kt / 341 km/h Service ceiling: 35597 ft / 10850 m Cruising altitude: 20013 ft / 6100 m Wing load: 31.57 lb/sq.ft / 154.0 kg/sq.m Maximum range: 843 nm / 1561 km Range: 400 nm / 740 km Crew: 1 Armament: 4x 20mm MG
Canadian Car and Foundry Co Hurricane Mk 1 Engine: British made Rolls Royce Merlin III Armament: eight .303 Browning machine guns.
Canadian Car and Foundry Co Hurricane Mk X (British built Mk 1) Packard Merlin 28 Armament: 8 x Brownings
Canadian Car and Foundry Co Hurricane Mk XII ( British built Mk. IIB) Packard Merlin 29 Armament: 12 x Brownings
Canadian Car and Foundry Co Sea Hurricane XIIA Engine: Merlin 29 Armament: eight gun
