SUPERMARINE SPITFIRE (Griffon,
fighter) - Two prototypes
ordered early-1940 to allow development of version of the Supermarine
Spitfire powered by the Rolls-Royce Griffon, offering some 50% more power
than 1940-standard Merlin for little increase in frontal area.
Supermarine Spitfire IV: Initial designation for two
Griffon-engined prototypes defined by Specification F.4/41, developed
in parallel with Supermarine Spitfire III (see earlier entry) with similar
airframe features, as Supermarine Type 337. First aircraft (DP845) flown
November 27, 1941, with Griffon IIB, four-bladed propeller, retractable
tailwheel, and standard-span wing with slotted flaps. Redesignated Supermarine
Spitfire XX early-1942 and then modified to Mk XII prototype. Second prototype
(DP851) flown on August 8, 1942, as Mk XX (which see). Production order
for 750 Supermarine Spitfire IVs placed August 1941, later cancelled.
Supermarine Spitfire F Mk XII: Interim Griffon-engined
fighter for low-altitude operations, put into production pending availability
of Mk XIV. Mk XX (DP845) flown as Mk XII prototype on April 10, 1942,
with Griffon IIB, Mk VC armament, broad-chord, pointed, rudder; also flown
with reduced-span wings and fixed tailwheel. Production (Supermarine Type
366) of 100 by Supermarine, with 1,735 hp Griffon III or Griffon IV; a
few early aircraft flown with full-span wing and fixed tailwheel; reduced-span
wing, retractable tailwheel were later standardised. Deliveries began
late-1942; in service February 1943, used by Nos 41 and 91 Sqns until
September 1944.
Max speed, 397 mph (639 kmlh) at 17,800ft (5,425 m). Gross weight,
7,415 Ib (3,363 kg). Span, 32 ft 7 in (9.93 m). Length, 30ft 9 in (9.37m).
Supermarine Spitfire XIV: Second Griffon-engined production
variant, combining 2,035 hp two-stage, two-speed Griffon 65 with features
of Mk VIII airframe. Development (Supermarine Types 369 and 373) based
on six Supermarine Spitfire VIIIs fitted with various Griffon 60-series
engines, flown during 1943. Initial (Supermarine Type 379) production
configuration, Supermarine Spitfire F Mk XIV, featured
full-span wing with 'C'-type armament of two 20-mm cannon and four 0.303-in
(7.7-mm) machine guns; retractable tailwheel; enlarged fin-and-rudder;
extra leading-edge fuel tank and structural improvements. The Supermarine
Spitfire F Mk XIVE had 'E'-wing armament of two 20-mm cannon
(outer bays) and two 0.50-in (12.7 mm) machine guns (inner bays); later
aircraft, without change of designation, used cut-down rear fuselage with
360-deg vision canopy, requiring further enlargement of rudder chord and
height. Supermarine Spitfire FR Mk XIV and Supermarine Spitfire
FR Mk XIVE were fighter-reconnaissance versions with oblique
F.24 camera and extra fuel tank in rear fuselage; all had 360-deg vision
canopy. Production of all four Mk XIV variants totalled 957, by Supermarine.
Deliveries began October 1943 and service use January 1944, with No 610
Sqn. F and FR variants operational in Europe up to end of war, some in
fighter-bomber role with underwing rockets and/or bombs. Introduction
into Far East theatre too late for wartime use.
Max speed, 448 mph (721 kmlh) at 26,000ft (7,925 m). Time to 20,000
ft (6,100 m), 7 min. Service ceiling, 44,500 ft (13,564 m). Max range,
850 mis (1,368 km). Empty weight, 6,600 Ib (2,994 kg). Gross weight, 8,500
Ib (3,856 kg). Span, 36ft 10 in (11.23 m) or 32 ft 7 in (9.93 m). Length,
32 ft 8 in (9.96 m). Wing area, 242 sq ft (22.48 m2) or 231 sqft (21.46
m2).
Supermarine Spitfire XVIII: Fully productionised Griffon-Supermarine
Spitfire, similar in general to F Mk XIVE with cut-down rear fuselage
and enlarged rudder. Also featured lengthened fuselage (33 ft 3'/4 in/10.14
m); stronger wing and u/c, and additional fuel in rear fuselage. Production
totalled 200 Supermarine Spitfire F Mk XVIII and 100
Supermarine Spitfire FR Mk XVIII, the latter with one
oblique and two vertical cameras in rear fuselage. No prototype; first
production aircraft flown June 1945 and in service too late for wartime
use.
Supermarine Spitfire XX: Redesignation of Supermarine
Spitfire IV first prototype (which see). Second prototype (DP851) first
flown August 8, 1942, with Griffon IIB and full-span wing, plus structural
changes leading towards Supermarine Spitfire 21.
Supermarine Spitfire 21: Major redesign (Super-marine
Type 356) of basic Supermarine Spitfire, launched in 1942 to take full
advantage of two-speed, two-stage Griffon engine variants. Supermarine
Spitfire XX (DP851) modified to serve as preliminary prototype, first
flown October 4, 1942, with Griffon 61; five-blad-ed propeller; extended-span,
pointed-tip wings (as on Supermarine Spitfire VII); broad-chord rudder
and revised canopy. Full Mk 21 prototype (PP139) flown on July 24, 1943,
with modified wing planform to incorporate larger ailerons; more fuel
in wing, increased u/c track and longer mainwheel oleo legs, and four
20-mm cannon armament. Name Victor provisionally adopted, but dropped
before first production Supermarine Spitfire F Mk 21
flown on March 15, 1944, externally similar to PP139. The extended 'high-altitude'
wing-tips were not used on subsequent production aircraft, a few of which
had Griffon 85 engines with contra-props. Deliveries began early-1945
to equip No 91 Sqn, operational by April 1945. Production total, 120 by
CBAF.
Max speed, 450 mph (724 kmlh) at 19,600ft (5,975 m). Initial climb,
4,850 ft/min (24.79 ml sec). Service ceiling, 43,000 ft (13,105 m). Range
(clean), 580 mis (933 km). Empty weight, 7,160 Ib (3,247 kg).
Gross weight, 11,290 Ib (5,121 kg). Span, 36ft 11 in (11.26 m). Length,
32 ft 11 in (10.04 m). Wing area, 243.6 sq ft (22.63 m2).
Supermarine Spitfire F Mk 22: Similar to Mk 21 but with
cut-down rear fuselage, 360-deg vision hood and enlarged vertical and
horizontal tail surfaces. One prototype (with Mk 21 tail unit) and 287
production aircraft, deliveries starting March 194£ too late for
wartime service.
Supermarine Spitfire 23: Intended variant based on Mk
22 with improved 'laminar flow' wing. Prototype wing development (Supermarine
Type 372) using Griffon-engined Supermarine Spitfire VIII QG204), first
flown January 1944, and Mk 21 prototype (PP139). Production plans cancelled.
Supermarine Spitfire F Mk 24: Post-war development of
Mk22.
