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.
A Tempest II powered by the 1879 kW (2,520 hp) Bristol Centaurus of No.
24 Squadron, Royal Air Force, based at Chilbolton 1946
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 defence 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
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
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. As the Typhoon's immaturity faded it achieved widespread
acclaim as a "rocketeer", being transformed from a fighter of dubious
reliability into one of the Allies' most potent weapons. Likewise, its
progressive development, the Tempest, gained for itself a place in the
history of the air war for its part in reducing the depredations of the
V1 flying bombs against England.
A Tempest Mk V with D-Day Invasion stripes
The design study, known
originally as the Typhoon Mk 11, was submitted to the Air Ministry, and
on 18 November 1941 two prototypes were ordered to Specification
F.10141. There were major changes, however, compared with the earlier
aircraft, resulting in the name change to Hawker Tempest in early 1942.
After cancellation of the Hawker Tornado programme, the alternative
engine installations planned for that aircraft were, instead, applied
to the Tempest. Thus the two original prototypes became the Tempest Mk
1 with Sabre IV and Tempest Mk V with Sabre II, and four more were
ordered. Two Tempest Mk II aircraft were to have the 1879 kW (2,520 hp)
Bristol Centaurus, and two Tempest Mk III aircraft with the Rolls-Royce
Griffon IIB, becoming Tempest Mk IV when re-engined with the Griffon
61. Only one Griffon-engined aircraft was completed, in fact, as one of
the prototype Hawker Furies. Before any of the prototypes had flown the
Air Ministry placed contracts for 400 Tempest Mk Is, although these
orders were transferred later to other versions. The prototype Tempest
Mk 1, its lines not spoiled by the beard radiator of the Typhoon, was
flown on 24 February 1943, and later achieved a maximum speed of 750
km/h (466 mph) at 7470 m (24,500 ft). However, the engine programme
suffered from technical problems and delays, and the Tempest Mk 1 was
The first of the
Tempest prototypes to fly had been the Tempest Mk V, during September
1942. Retaining the Typhoon's chin radiator it had originally a
standard Typhoon tail unit, but this was modified subsequently. The
first of 805 Tempest Mk Vs was flown from Langley on 21 June 1943, one
of the initial production batch of 100 Tempest Mk V Series 1 aircraft
which had four 20-mm British Hispano Mk 11 cannon, their barrels
protruding from the leading edges of the wings; the remaining Tempest
Mk Vs had short-barrelled Mk V cannon, completely contained in the
wings. In 1945, one Tempest Mk V was fitted with a 40 mm 'P' gun under
each wing, similar to the 40 mm cannon installation of the Hawker
Hurricane Mk IID. After the war had ended some were converted for use
as Tempest TT.MK 5 target tugs.
An order for 500
Centaurus-powered Tempest Mk IIs was placed in October 1942, before the
first flight of the prototype. This took place on 28 June 1943, the
aircraft being powered by a Mk IV engine, superseded by the 1879 kW
(2,520 hp) Mk V in production aircraft. These were to have been built
by the Bristol Aeroplane Company, the first Bristol-built aircraft
being flown on 4 October 1944, but only 36 were completed before
production was transferred back to Hawker. The parent company
manufactured a further 100 Tempest F.Mk 11 fighters and 314 Tempest
FB.MK 11 fighter-bombers with underwing racks for bombs or rockets. In
1947 India ordered 89 tropicalised Tempest Mk lIs from RAF stocks, and
in the following year Pakistan ordered 24 similar aircraft. Third and
last production version of the Tempest was the Tempest F.Mk VI with the
1745 kW (2,340 hp) Napier Sabre V engine, first flown on 9 May 1944.
Intended for service in the Middle East, 142 tropicalised Tempest Mk
VIs were built. As in the case of the Mk V, some were converted later
as Tempest TT.MK 6 target tugs.
RAF service began in
April 1944, when Tempest Mk Vs were delivered to New- church, Kent,
where the first Tempest Wing was formed within No. 85 Group. The wing
was active during the build-up to the Normandy invasion, but on 13 June
the first V-1 flying-bornb fell at Swanscombe in Kent, and the Tempests
were among aircraft tasked to combat the menace. Their success can be
measured by the fact that of 1,847 bombs destroyed by fighters between
June 1944 and March 1945, 481 1/2 were accredited to the Tempest Wing.
Until the end of war in
Europe, Tempest MkVs flew 'cab rank' patrols in support of ground
forces, moving up to airfields in France and Belgium as the Germans
fell back. In addition, they engaged in combat the Luftwaffe's
Messerschmitt Me 262 jet fighters, 20 of which were destroyed before VE-Day.
Although plans were
made for 50 Tempest Mk IIs to be sent to the FarEast in May 1945, to
operate with Tiger Force against the Japanese, the war in the Pacific
ended before these aircraft were ready for service. They equipped No.
54 Squadron at Chilbolton in November 1945, this being the only
post-war home-based Tempest Mk 11 unit, the others serving in Germany,
Hong Kong, India and Malaysia. The Tempest Mk VI was also too late to
see wartime service, although this mark was flown later by squadrons in
Germany and the Middle East.
Tempest Mk V)
Seat Fighter & Fighter Bomber
Hawker Aircraft Limited with some Mk IIs being built by the Bristol
V) One 2,180 hp (1626 kW) Napier Sabre IIA 24-cylinder 'H' piston
engine. (Mk VI) One 2,340 hp (1745 kW) Napier Sabre V. (Mk II) One
2,520 hp (1879 kW) Bristol Centaurus radial engine.
Maximum speed 435 mph (700 km/h) at 17,000 ft (5181 m); service ceiling
36,500 ft (11125 m).
Operational: 740 miles (1191 km) on internal fuel. Cruise: 820 miles
(1319 km) at 210 mph (337 km/h) 5,000 ft (1524 m). 1,530 miles (2462
km) with external drop tanks.
9,000 lbs (4082 kg with a loaded take-off weight of 13,540 lbs (6142
41 ft 0 in (12.50 m); length 33 ft 8 in (10.26 m); height 16 ft 1 in
(4.90 m); wing area 302.0 sq ft (28.06 sq m).
20 mm Hispano Mk. V cannon with 150 rounds per gun plus two 500 lbs
(227 kg) or two 1,000 lbs (454 kg) bombs, or eight 60 lbs (27 kg)
Tempest, Tempest Mk I, Tempest Mk V, Tempest Mk II, Tempest Mk III,
Tempest Mk IV, Tempest Mk B Series I, Tempest TT.Mk 5, Tempest F.Mk II
(fighter), Tempest FB.Mk II (fighter-bomber), Tempest F.Mk VI, Tempest
TT.Mk 6 (target tug).
flight (prototype Mk V) 2 September 1942; (Mk 1) 24 February 1943;
(production V) 21 June 1943; (Mk 11) 28 June 1943; (prototype VI) 9 May
1944; (production 11) 4 October 1944.