SUPERMARINE SPITFIRE (Merlin,
Fighter) - Single-seat
high-performance fighter, initially evolved by R J Mitchell as private
venture to improve on unsuccessful Supermarine 224 prototype built to
Specification F.7/30 -which gave effect to the first designated Air Ministry
Operational Requirement (OR. 1). By 1934, PV Supermarine 300 design had
been developed to meet OR. 17 and single prototype ordered on December
1, 1934, to conform with Specification F.37/34. Powered by a 990 hp Rolls-Royce
Merlin C with DH two-bladed fixed-pitch wooden propeller, unarmed prototype
K5054 first flown at Eastleigh on March 5, 1936. Successively fitted with
1,035 hp Merlin F and 1,030 hp Merlin II and with full armament of eight
0.303-in (7.7-mm) machine guns, before being written off on second day
of World War II, September 4, 1939.
Supermarine Spitfire I: Initial production version, built
to Specification 16/36; first contract placed June 3, 1936. First aircraft
flown May 14, 1938, with 1,030 hp Merlin II; Merlin III introduced at
175th aircraft. Early aircraft with two-bladed Airscrew Co wooden propeller;
three-bladed metal propeller soon standardised - DH two-position, then
DH or (few only) Rotol constant speed unit. Entered service August 1938
with No 19 Sqn at Duxford and nine squadrons operational by September
1939, with ten more by mid-1940. Designation Supermarine Spitfire IA adopted
retrospectively in 1940 after 30 aircraft designated Supermarine Spitfire
IB when fitted with two Hispano 20-mm cannon each in place of four of
the machine guns. Total Mk I production (excluding conversions to prototypes
of later marks), 1,519 by Supermarine and 50 by Westland. One Mk I exported
to France, mid-1939; 18 ex-RAF Mk Is to Portugal in 1942. One RAAF, one
RNZAF and two RCAF squadrons flew Supermarine Spitfire Is that remained
on RAF strength. Max speed, 346 mph (557 kmlh) at 15,000ft (4,575 m).
Time to 15,000ft (4,575 m), 6.85 min. Service ceiling, 30,500 ft (9,296
m).
Range at normal cruising speed of 304 mph (489 kmlh), 415 mis (668 km).
Empty weight, 4,517 Ib (2,049 kg). Gross weight, 5,844 Ib (2,651 kg).
Span, 36ft 10 in (11.23 m). Length, 29 ft 11 in (9.12 m). Wing area, 242
sqft (22.48 m2).
Supermarine Spitfire II: Similar to Mk I but powered
by 1,175 hp Merlin XII and with operational refinements progressively
introduced on Mk Is. Three (or more) Mk Is flown with Merlin XIIs before
first production Mk II (Supermarine Type 329) completed in June 1940 at
Castle Bromwich Aircraft Factory. Operational use began August 1940 with
No 611 Sqn and production totalled 751 Supermarine Spitfire IIA with eight
machine guns and 170 Supermarine Spitfire IIB with two cannon and four
machine guns. For extended range, Supermarine Spitfire IIA (LR) carried
a 30-Imp gal (136-1) fuel tank flush-fitting under the port wing leading-edge;
limited use by five RAF squadrons in mid-1941. The Supermarine Spitfire
IIC (later, ASR Mk II) was adapted for air-sea rescue duties, with 1,240
hp Merlin XX in place of Merlin XII, rescue packs in the flare chutes
and marker bombs under the port wing. About 50 conversions flown by RAF
squadrons from 1943. Supermarine Spitfire Us from RAF stocks made available
for squadrons of RAAF, RCAF and RNZAF in Fighter Command, together with,
in 1941, three US-manned Eagle squadrons and units of the Forces Aeriennes
Francaises Libres. Later marks flown by most of these units as they became
available.
Supermarine Spitfire III: Single Mk I airframe (N3297)
flown March 1940 with Merlin R.M.3SM (ie, Merlin XX) and operational/
performance improvements including structural strengthening, retractable
tailwheel and short-span wing of 30 ft 6 in (9.30 m). Production plans
cancelled and prototype (Supermarine Type 330) later fitted with Merlin
60/61-series two-speed two-stage engine. Second Mk III conversion (Type
348) in 1941, based on Mk V airframe and used to develop new u/c with
main wheels raked forwards 2 in (1.5 cm) and, later, four-cannon wing
armament.
Supermarine Spitfire V: Third major production version,
combining Mk I/II airframe features with 1,185 hp Merlin 45 single-stage
single-speed engine. Prototype installation in a Mk I first flown December
1940 and 154 Mk I and Mk II conversions made in 1941. First production
Mk V (Supermarine Type 331) flown from CBAF in June 1941 and production
totalled 4,489 at that factory, 1,363 by Supermarine and 635 by Westland.
In addition, some 200 Mk I/II convened to Mk V standard. Service use began
mid-May with No 92 Sqn. Production included 94 Supermarine Spitfire VA
with eight-gun armament, 3,911 Supermarine Spitfire VB with two-cannon/four-mg
armament, and 2,467 Supermarine Spitfire VC introducing new wing (Supermarine
Type 349) in late 1941 that could carry four cannon without mgs, or two-cannon/four
mg arrangement as Mk VB. Total production also included 15 photo-recce
Supermarine Spitfire PR Mk V (see separate entry for photo-recce Supermarine
Spitfires). For service in Middle and, later, Far East, tropical versions
introduced large Vokes dust filter over carburettor air intake under nose,
or small filter developed and fitted at Aboukir in Egypt. To extend range,
Supermarine Spitfire Vs (and later marks) carried flush-fitting belly
tanks of 30- or 45-Imp gal (136- or 205-1) capacity on regular operations,
90-Imp gal (409-1) for special ferry flights or 170-Imp gal (773-1) version
used by 17 aircraft flown from Gibraltar to Malta in late 1942. From end-1942,
'fighter' role prefix resulted in Supermarine Spitfire F Mk VA, F Mk VB
and F Mk VC designations, using Merlin 45, 46, 50, 50A, 55 or 56 medium-altitude
engines. For lower altitude operations, Supermarine Spitfire LF Mk VB
used Merlin 45M, 50M or 55M, with cropped supercharger impellers and combat
boost rating of 1,585 hp. Many Supermarine Spitfire Vs had wing tips removed
('clipped'), reducing span to 32 ft 2 in (9.80 m). Starting 1942, Supermarine
Spitfire Vs were adapted to carry one 250-lb (113-kg) bomb under each
wing, or one 500-lb (227-kg) bomb under fuselage in place of long-range
tank. Some aircraft were fitted with hooks to tow Hotspur gliders at training
schools. One radio-controlled drone version was tested in 1944, and one
captured Mk VB was fitted in Germany with 1,475 hp Daimler-Benz DB 605A.
In Egypt, two Supermarine Spitfire VCs fitted with extended wing-tips,
boosted Merlin 46s and four-blade propellers operated up to 50,000 ft
(15,240 m) to intercept Ju 86P-2s. Supermarine Spitfire Vs operated in
Europe and Middle East by RAF, RCAF, RNZAF and RAAF squadrons from 1941
onwards; in India/Burma from late 1943, and in Australia, where 245 Supermarine
Spitfire VCs and one VB were transferred from RAF to RAAF in 1942-43 (plus
11 lost en route). Starting late-1942, ten squadrons of the SAAF flew
Supermarine Spitfire Vs (and/or Mk IXs) in North Africa, Sicily and Italy,
including No 40 Sqn operating in the 'Tac R' role for which Supermarine
Spitfires carried an oblique camera just behind the cockpit. From mid-1942,
some 600 Supermarine Spitfires (mostly Mk Vs) supplied to USAAF units
flying in the UK and North Africa on 'reverse lend-lease' basis, retaining
RAF serials. Two (or more) Mk VAs to USA in 1941 for evaluation. Supply
of Supermarine Spitfires to Soviet Union began early-1943 with transfer
of 143 Mk VBs; in late-1943 the RAF released 33 Mk VBs to Portugal. One
squadron of the R Egyptian AF was equipped with Supermarine Spitfire VCs.
Supermarine Spitfire VI (F Mk VI): High altitude version
of Supermarine Spitfire VB (Supermarine Type 350), featuring pressurised
cockpit with sealed, jet-tisonable hood, 1,415 hp Merlin 47 with four-bladed
propeller, and extended wing-tips giving 40 ft 2 in (12.24 m) span. Prototype
conversion of Mk V during 1941 and 100 built by Supermarine in 1942; entered
service April 1942 with Nos 616 and 124 Sqns.
Supermarine Spitfire VII: High-altitude fighter evolved
from Supermarine Spitfire VC (Supermarine Type 351) with pressurised cockpit,
sliding hood, increased fuel capacity, rectractable tailwheel, two-stage,
two-speed 1,565 hp Merlin 61 or 1,710 hp Merlin 64 (in Supermarine Spitfire
F Mk VII) or 1,475 hp high-altitude Merlin 71 (Supermarine Spitfire HF
Mk VII). Extended wing-tips usually fitted and, later aircraft, broad-chord
rudder with extended tip. Prototype conversions of Mk VCs flown second
half of 1942; 140 produced by Supermarine, first deliveries September
1942 and operations began same month. One Mk VII to USAAF at Wright Field
in April 1943.
Supermarine Spitfire VIII: Similar to Mk VII but without
pressurised cockpit. Armament as Mk VC, structural and systems improvements
as Mk VII, enlarged rudder (except first few aircraft) and compact Aero-Vee
tropical filter as standard. Prototype development included Mk III (N3297)
fitted with Merlin 61 early-1942. Production (Supermarine Type 360) totalled
1,658 by Supermarine in three designated sub-variants according to altitude
rating of engine: Supermarine Spitfire LF Mk VIII with 1,705 hp Merlin
66; Supermarine Spitfire F Mk VIII with 1,565 hp Merlin 61 or 1,710 hp
Merlin 63; and Supermarine Spitfire HF Mk VIII with 1,655 hp Merlin 70.
Most Supermarine Spitfire VIIIs flew with standard-span wing, but extended
or clipped tips used as required operationally without change of designation.
Service introduction, mid-1943, principally in North Africa, Sicily and
Italy, including some SAAF squadrons. Later, Supermarine Spitfire VIIIs
replaced Mk VCs in squadrons operating in the CBI theatre and equipped
units of the Indian Air Force. In 1944, RAAF took on charge 251 LF Mk
VIIIs for its squadrons in New Guinea; 159 more Mk VIIIs were received
post-war. In fighter-bomber role, some Mk VIIIs carried two 500-lb (227-kg)
bombs under fuselage; later aircraft used 45-Imp gal (205-1) teardrop
long-range tanks in place of earlier slipper type.
Supermarine Spitfire IX: Fourth major production fighter
variant (Supermarine Type 361),
combining Mk VC airframe with two-stage two-speed Merlin 60 series engine
but lacking other improvements designed for (later) Supermarine Spitfire
VIII. Early Merlin 60 and 61 flight-tested in Supermarine Spitfire III
(from August 19, 1941) and a Supermarine Spitfire IA, followed by conversion
by Rolls-Royce of two Mk VCs to Mk IX prototypes with Merlin 61s early-1942.
Further 282 conversions of Mk V airframes by Rolls-Royce; production totals
5,095 by CBAF and 561 by Supermarine. Service use began June 1942 in No
64 Sqn. Early standard aircraft had 'C' wing armament, standard wing span,
Merlin 61 and provision for wing and fuselage bomb racks. Later, designations
used to differentiate altitude rating of engine: Supermarine Spitfire
LF Mk IX with Merlin 66, Supermarine Spitfire F Mk IX with Merlin 61 or
63 and Supermarine Spitfire HF Mk IX with Merlin 70. Broad-chord, pointed-tip
rudder became standard later, as did compact Aero-Vee tropical filter.
Late-production CBAF Mk IXs had cut-down rear fuselage with 360-deg vision
canopy, and Supermarine Spitfire IXE designation (with LF, F or HF prefix)
indicated new wing armament of two 20-mm cannon and two 0.50-in (12.7-mm)
machine guns. More than 50 RAF and Commonwealth squadrons flew Supermarine
Spitfire IXs, primarily in European theatre, and 1,188 Mk IXs were supplied
to the Soviet Union in 1943-44; at least one Mk IX was modified in Russia
to two-seat training configuration. A small number of Supermarine Spitfire
IXs supplemented Mk Vs in USAAF service in Twelfth Air Force. Max speed,
408 mph (657 km/h) at 25,000ft (7,620 m). Time to 20,000ft (6,100 m),
5.7 min. Initial climb, 3,950 ft/min (20.1 mlsec). Service ceiling, 43,000
ft (13,106 m). Range, internal fuel, 434 mis (698 km). Empty weight, 5,634
Ib (2,556 kg). Gross weight, 9,500 Ib (4,309 kg). Span, 36 ft 10 in (11.23
m) or 32 ft 9 in (9.80 m). Length, 31 ft 1 in (9.47 m). Wing area, 242
sq ft (22.48m2).
Supermarine Spitfire XVI: CBAF production of 1,054 Supermarine
Spitfires similar to LF Mk IX but with US Packard-built Merlin 226 engine.
Initially with 'C' wing armament, later with 'E' wing, broad-chord rudder
and cut-down rear fuselage, most operated with clipped wings and all designated
Supermarine Spitfire LF Mk XVI regardless of configuration. Deliveries
began October 1944 and service use from November onwards, particularly
by four RAF squadrons attacking V-2 sites with bombs.
