DE HAVILLAND DH.98 MOSQUITO
- The De Havilland Mosquito
was developed in the course of 1938-39 by a design team headed by R E
Bishop in accordance with an original concept for a high-speed two-seat
unarmed bomber of wooden construction proposed by Capt Geoffrey de Havilland.
Development proceeded during 1940 to Specification B.l/40, written round
the DH proposal and covering a bomber/reconnaissance aircraft with pro-vision
for development of a fighter variant also, powered by 1,280 hp Merlin
RM35M engines. Initial contract placed March 1, 1940, for 50 bomber/reconnais-sance
aircraft, including one prototype; amended July 1940 to include one fighter
prototype and in January 1941 to include a reconnaissance prototype, with
many subsequent amendments and additions to contracts which eventually
covered pro-duction of 6,411 De Havilland Mosquitoes in Britain, 1,134
in Canada and 212 in Australia, production continuing until 1950. In the
UK, production shared between de Havilland at Hatfield, Leavesden and
(post-war) Chester, Airspeed at Christchurch, Percival at Luton and Standard
Motors at Coventry; Canadian and Australian production was by the de Havilland
companies at Toronto and Sydney respectively. De Havilland Mosquito prototype
(W4050) with span of 52 ft 6 in (16.0 m), first flown at Hatfield November
25, 1940, with 1,460 hp Merlin 21 engines; gross weight, 16,000 Ib (7,264
kg) and speed of 392 mph (631 km/h) recorded in FS gear at full-throttle
height of 22,000 ft (6,705 m), establishing De Havilland Mosquito as world's
fastest operational aircraft at that time, a distinction retained by subsequent
De Havilland Mosquito marks for next 2'/2 years. Merlin 61s fitted in
prototype and first flown June 20, 1942, when speed of 414 mph (666 km/h)
recorded in MS gear at weight of 17,800 Ib (8,081 kg). Merlin 77s fitted
in October 1942 and span increased to 59 ft 2 in (18.03 m); speed of 437
mph (703 km/h) achieved at 29,000 ft (8,839 m) at 18,000 Ib (8,172 kg)
- the fastest of any De Havilland Mosquito. Flown with dummy four-gun
dorsal turret aft of cabin, July 1941.
De Havilland Mosquito PR Mk I: Ten of initial production batch
completed in photo-recce configuration, including one proto-type, first
flown June 10, 1941. Span 54 ft 2 in (16,51 m), as for all production
aircraft; short nacelles for 1,300 hp Merlin 21 engines; three vertical
and one oblique camera; gross weight 18,050 Ib (8,195 kg). Two had extra
fuel and high-er weight; two modified for tropical ser-vice. Issued to
No 1 PRU, Benson and flew first operational sortie September 17, 1941.
De Havilland Mosquito F Mk II: Variant of basic DH.98 design evolved
to Specification F.21/40 as two-seat twin-engined day and night long-range
fighter and intruder, with Merlin 21 or 23 engines in long nacelles, and
four 20-mm cannon in the lower front fuselage plus four 0.303-in (7.7-mm)
Brownings in the nose. Prototype (from initial De Havilland Mosquito produc-tion
batch) first flown May 15, 1941. Production aircraft carried AI Mk IV
or Mk V (with arrow-head aerials), and used primarily as UK-based night
fighters, in overall black finish, often referred to as NF Mk Us. Total
589 built (including 199 converted to NF Mk XII & XVII), initial deliveries
to No 157 Sqn, March 1942. Twenty-five modified as Special Intruders for
No 23 Sqn, without AI and with extra fuel. Two flown with dorsal four-gun
turrets, on September 14 and December 5, 1941, respectively, but not further
developed. One fitted with Turbinlite airborne searchlight in nose for
trials with Nos 151, 532 and 85 Sqns in 1943. One to RAAF in Australia
as pat-tern for FB Mk 40.
Max speed, 370 mph (595 km/h) at 22,000 ft (6,706 m). Initial
climb, 3,000 ftlmin (15.2 m/sec). Ceiling, 36,000 ft (10,973 m). Max range,
1,705 mis (2,743 km). Empty weight, 13,431 Ib (6,098 kg). Gross weight,
18,547 Ib (8,420 kg). Span, 54ft 2 in (16.51 m). Length, 40ft 6 in (12.34
m).
De Havilland Mosquito T Mk III: Dual control unarmed training version,
initially with Merlin 21 and later with Merlin 23 and 25. Five of initial
production batch com-pleted as Mk Us with dual controls, the first of
these being one of the two exam-ples with dorsal turrets, flown on December
5, 1941. 200 built at Leavesden up to July 1945, 164 more post-war at
Leavesden and Hatfield. Fourteen to RAAF and 24 to RCAF.
De Havilland Mosquito B Mk IV: Initial day and night bomber variant.
Ten aircraft in ini-tial production batch started as PR Mk I airframes
but completed as bombers, known initially as PR/Bomber Conversion Type
but redesignated B Mk IV Series 1 before service, including the bomber
pro-totype first flown mid-September 1941, also considered as prototype
for B Mk V. B Mk IV Srs Is had Merlin 21s, short nacelles and bomb load
of 2,000 Ib (908 kg) in two or four bombs. Deliveries to No 105 Sqn began
November 1941 but large-scale operations awaited arrival of B Mk IV Srs
2, the first example of which flew March 1942, this having long-tail nacelles,
Merlin 21 or 23 engines and provision for 50-Imp gal (227-1) wing drop
tanks. First operation (four aircraft to Cologne) on May 31, 1942. Production
of 300 B Mk IV Srs 2, less nine converted to other versions in pro-duction.
Post-delivery modifications of 27 to PR Mk IV, with cameras as PR Mk I;
20 to carry one 4,000-lb (1,816-kg) bomb each in bulged bomb-bay, with
gross weight of 21,500 Ib (9,760 kg), commenced operations with Nos 627
and 692 Sqns February 23, 1944; 36 aircraft modified 1943 to carry Highball
anti-ship-ping spinning bomb for operations with No 618 Sqn, 24 of these
later having arrester gear, Merlin 25s and other mods for carrier-based
operations in Pacific, but no operations undertaken. Data for standard
B Mk IV Srs 2:
Max speed, 380 mph
(611 km/h). Cruising speed, 265 mph (426 km/h). Rate of climb., 2,500
ft/win (12.71 m/sec). Ceiling, 34,000 ft (10,363 m). Max range, 2,040
mis (3,282 km). Empty weight, 13,400 Ib (6,084 kg). Gross weight, 21,462
Ib (9,744 kg).
De Havilland Mosquito PR Mk IV: Twenty-seven B Mk IV Srs 2 converted,
April 1942 onwards, to have cameras as PR Mk I.
De Havilland Mosquito B Mk V: Proposed version of B Mk IV with
provision for two 1,000-Ib (454-kg) internal and two 500-lb (227-kg) underwing
bombs. Tests on B Mk IV prototype; no production.
De Havilland Mosquito PR Mk V: Projected photo-recce version with
same wing as B Mk V and extra fuel capacity. Not built.
De Havilland Mosquito FB Mk VI: Day and night fighter-bomber/intruder,
armed with four machine guns and four cannon as F Mk II, plus two 250-lb
(113-kg) bombs in rear of bomb-bay and one 250-lb (113-kg) under each
wing; (increased to 5.00-lb/227-kg bombs in Srs 2 aircraft); alter-native
wing loads included SCI, mine, depth charge, four 60-lb (27-kg) rockets
each side or 50- or 100-Imp gal (227- or 455-1) drop tank. Prototype first
flew June 1, 1942; total of 2,305 built. Merlin 21, 23 or 25, and some
aircraft with AI Mk IV, V or XV radar. First deliveries to No 418 Squadron
May 1943. Nine Mk VI aircraft (plus one Mk IV and three Mk III) modified
for use by BOAC, in civil markings, on courier service between Scotland
and Sweden, making 520 round trips between February 1943 and May 1945.
Thirty-eight supplied to RAAF.
De Havilland Mosquito NF Mk VI: Projected night-fighter in parallel
with FB Mk VI, not built.
De Havilland Mosquito B Mk VII: Initial Canadian production version,
based on B Mk V design and powered by 1,460 hp Packard-built Merlin 31s.
Twenty-five built, first flight September 24, 1942. All retained in Canada;
six transferred to USAAF as F-8 with cameras for PR duties.
De Havilland Mosquito PR Mk VIII: Similar to PR Mk IV but fitted
with Merlin 61s with two-speed two-stage superchargers. One B Mk IV converted
to prototype and flown October 20, 1942, and four others converted from
B Mk IVs in production.
De Havilland Mosquito PR Mk IX: As PR Mk VIII but powered by 1,680
hp Merlin 72 engines. First of 90 production examples flown April 1943.
Service introduction June 1943 by No 540 Sqn; also flown by No 60 Sqn,
SAAF, 1944-45. At least eight modified to have 1,710 hp Merlin 76/77 engines
with paddle blade pro-pellers, and one with 1,705 hp Merlin 67s (RM10SM).
De Havilland Mosquito B Mk IX: As B Mk IV but powered by 1,680
hp Merlin 72 engines. First of 54 production examples flown March 24,
1943; provision for four 500-lb (227-kg) bombs internal and one under
each wing. Normal gross weight 22,823 Ib (10,360 kg), or 24,753 Ib (11,238
kg) with 100-Imp gal (454-1) drop tanks. Some modified to carry 4,000-lb
(1,816-kg) bomb in bulged bomb-bay and Oboe in nose; a few fitted with
H2S Mk VI.
De Havilland Mosquito NF Mk X: Proposed night fighter, similar
to NF Mk II with Merlin 61 engines. Not built.
De Havilland Mosquito FB Mk X: Proposed fight-er-bomber, similar
to FB Mk VI with Merlin 101 engines. Not built.
De Havilland Mosquito FB Mk XI: Proposed fight-er-bomber, similar
to FB Mk VI with Merlin 61 engines. Not built.
De Havilland Mosquito NF Mk XII: Night fighter derivative of Mk
II with AI Mk VIII radar in 'thimble' nose replacing nose machine guns.
Two prototype Mk II conversions at Hatfield mid-1942 followed by 97 by
Marshalls at Cambridge, 1943. Initial deliveries to No 85 Sqn, February
28, 1943.
De Havilland Mosquito NF Mk XIII: As Mk XII but based on FB Mk
VI, with provision for wing drop tanks, and Merlin 21 or 23 engines. Total
of 270 built, delivered February 1944 onwards.
De Havilland Mosquito NF Mk XIV: Proposed pro-duction night fighter,
as Mk XIII with Merlin 72/73 engines. Not built.
De Havilland Mosquito NF Mk XV: Specialised high-altitude night
fighter, with pressure cabin, Merlin 61, 73 or 77 engines and span extended
to 59 ft 0 in (17.98m). Prototype flown September 14, 1942, with guns
in nose as single-seater and in November as two-seater with AI Mk VIII
in nose and four guns in ventral pack, followed by four similar production
conversions of Mk II airframes in 1942-43. Issued to No 85 Sqn March 1943,
operated at altitudes up to 44,600 ft (13,594m).
De Havilland Mosquito PR Mk XVI: Similar to PR Mk IX, but with
pressurised cockpit. Pressure cabin prototype flown August 8, 1942, and
first pressurised PR De Havilland Mosquito (a converted B MK IV) in July
1943. Production deliveries began November 1943; first operational use
by No 140 Sqn, February 1944. Total of 433 built of which 79 supplied
to USAAF units in UK including six trials aircraft with H2X in nose. Twenty-three
to RAAF and also used by No 60 Sqn, SAAF, in Italy, 1944-45.
De Havilland Mosquito B Mk XVI: Similar to B Mk IX with pressure
cabin, based on pro-totype development (see PR Mk XVI). First production
B Mk XVI flown October 1943; 80 built with Merlin 72/73 and 320 with Merlin
76/77; all but first 12 with bulged bomb-bay for 4,000-lb (1, 816-kg)
bomb. Some fitted with Oboe H2S and other bombing navaids. Initial deliveries
to Nos 109 and 139 Sqns, end-1943.
Max speed (with 4,000-lb/1,816-kg
bomb), 408 mph (656 km/h) at 28,500 ft (8,687 m) and 329 mph (529 km/h)
at sea level. Intitial operating ceiling, 28,500 ft (8,687 m). Operational
range, 1,100 mis (1,770 km) with 597 Imp gal (2,714 I) including two 100-Imp
gal (454-1) drop tanks. Empty weight, 14,901 Ib (6,765 kg). Gross weight,
25,200 Ib (11,440 kg). Span, 54 ft 2 in (15.51 m). Length, 40ft 6 in (12.34
m).
De
Havilland Mosquito NF Mk XVII: Similar to NF Mk XII but fitted with
American SCR 720 (AI Mk X). First flown March 1943, and total of 90 'converted
from F Mk Us by Marshalls of Cambridge in 1943 after one prototype at
Hatfield.
De Havilland Mosquito FB Mk XVIII: As FB Mk VI with 57-mm, 6-lb
(2.7-kg) Molins gun in fuselage replacing four 20-mm cannon; also armed
with four 0.303-in (7.7-mrrf) machine guns and two 500-lb (227-kg) bombs
or eight 60-lb (27-kg) RPs under wings. Total of 27 converted from FB
Mk Vis; first flown June 8, 1943; initial operations October 24, 1943,
with No 248 Sqn, Coastal Command. Sometimes referred to as the 'Tse-tse'.
De Havilland Mosquito NF Mk XIX: Similar to NF Mk XIII but fitted
with American SCR 720 (AI Mk X) radar in 'bull nose' fairing able to accommodate
either US or British equipment, and Merlin 25s. First flown April 1, 1944;
280 built.
De Havilland Mosquito B Mk XX: Principal Canadian production version,
similar to B Mk VII with 1,460 hp Packard-built
Merlin 31 or 33 engines and North American equipment. Two-hundred-and
forty-five built, 1943-June 1944, of which 98 to RCAF, 34 to USAAF as
F-8 with cameras for PR duties and balance to RAF in UK, August 1943 onwards.
De Havilland Mosquito FB Mk 21: Canadian pro-duction equivalent
of FB Mk VI, built in
1943. Two with Merlin 31s and one with Merlins 33s.
De Havilland Mosquito T Mk 22: Canadian pro-duction equivalent
of T Mk III, with Merlin 33s. Six built in 1943.
De Havilland Mosquito B Mk 23: Projected Canadian production equivalent
of B Mk IX with Packard Merlin 69s or 76s. Not built.
De Havilland Mosquito FB Mk 24: Similar to FB Mk 21 with Packard
Merlin 301 engines. Two commenced 1943, only one com-pleted, cancelled
before flight February
1944.
De Havilland Mosquito B Mk 25: Canadian pro-duction version to
succeed B Mk XX,
with 1,620 hp Packard Merlin 225 engines. Total 400 built, June 1944 onwards,
of which 51 to RCAF and bal-ance to RAF in UK. Few modified to carry 4,000-lb
(1,816-kg) bomb in deep-ened bay. One converted to have two-stage modified
Merlin 68s by Marshalls of Cambridge, January 1945.
De Havilland Mosquito FB Mk 26: Similar to FB Mk 21 with Packard
Merlin 225 engines. Production totalled 337, October 1944 onwards; 197
to RCAF, balance to RAF, used principally in Middle East.
De Havilland Mosquito T Mk 27: Similar to T Mk 22 with Packard
Merlin 225 engines. Forty-nine built, 1945, of which 19 to RCAF.
De Havilland Mosquito 28: Unused mark number for Canadian production.
De Havilland Mosquito T Mk 29: Dual control con-versions of FB
Mk 26; 39 completed 1945.
De Havilland Mosquito NF Mk 30: As NF Mk XIX with two-stage 1,680
hp Merlin 72s; later 1,710 hp Merlin 76 and finally 1,690 hp Merlin 113
engines. First flown March 1944; 530 built and operational service began
June 13, 1944, with No 219 Sqn.
Max speed,
338 mph (544 km/h) at sea level and 424 mph (682 km/h) at 26,500ft (8,077
m). Initial rate of climb, 2,250 ftlmin (11.4 m/sec). Operational ceiling,
35,000 ft (10,668 m). Cruising speed, 288 mph (463 km/h) at sea level
and 380 mph (611 km/h) at 30,500 ft (9,296 m). Cruising range, 1,180 mis
(1,900 km). Empty weight, 15,l$ff Ib (6,880 kg). Gross weight, 21,105
Ib (33,958 kg). Span, 54ft 2 in (16.51 m). Length, 41 ft 4 in (12.59 m).
De
Havilland Mosquito NF Mk 31: Proposed var-iant of NF Mk 30 with Packard-built
Merlin 69s. Not built.
De Havilland Mosquito PR Mk 32: Lightened ver-sion of PR Mk 16
with extended wingtips for very high altitude operation. Five built, first
flown August 1944, opera-tional from December with No 540 Sqn.
De Havilland Sea Mosquito TR Mk 33: Variant of FB Mk VI evolved
to Specification N.I5/44 for a carrier-borne torpedo-reconnaissance fighter/bomber.
Converted Mk VI with arrester gear made first deck landings on HMS Indefatigable,
March 25, 1944. Second converted Mk VI in August 1945 had folding wing
and two Sea De Havilland Mosquito prototypes with fixed wings flown in
1945 followed by first production TR Mk 33 on November 10, 1945, with
Merlin 25 engines, folding wings, four-bladed propellers, JATO provision,
four 20-mm cannon, underwing bombs as FB Mk VI and provision for two 500-lb
(227-kg) bombs in rear bomb-bay in lieu of a 2,000-lb (908-kg) torpedo,
bomb or mine externally under fuselage. Length increased to 42 ft 3 in
(12.88 m) by ASH radar in nose.
De Havilland Mosquito PR Mk 34: Very-long-range reconnaissance
version with extra fuel in deepened fuselage and two 200-Imp gal (909-1)
wing drop tanks. Total fuel capac-ity 1,269 Imp gal (5,769 1) giving cruising
range of 3,600 mis (5,792 km) at 300 mph (483 km/h) at 25,000 ft (7,620
m), on Merlin 113/114 engines and gross weight of 25,500 Ib (11,577 kg).
Four F.52 vertical and one F.24 oblique cam-eras. First flown December
4, 1944, and 231 built. Service principally post-war.
De Havilland Mosquito B Mk 35: Final De Havilland Mosquito bomber
variant. Similar to B Mk XVI with 1,690 hp Merlin 113/114 engines. First
flown March 12, 1945, and 276 built, completed early 1948. Some post-war
conversions to TT Mk 35.
De Havilland Mosquito NF Mk 36: As NF Mk 30 with Merlin 113 engines
and British AI Mk IX radar. First flown May 1945 and 163 built for post-war
service.
Sea De Havilland Mosquito TR Mk 37, De Havilland Mosquito NF Mk 38 and
TT Mk 39: Post-war production and conversion programmes.
De Havilland Mosquito FB Mk 40: Australian pro-duction version,
by de Havilland at Bankstown, Sydney, based on FB Mk VI. Prototype converted
from British-built Mk II with Packard Merlin 31s and flown on July 23,
1943. Production totalled 100 with Merlin 31s and 112 with Merlin 33s
and paddle-blade propellers, first flown July, 23, 1943, and deliveries
to RAAF commencing March 4, 1944, and contin-uing post-war. Service with
No 1 Sqn against Japanese targets, and with Nos 87 and 94 Sqns.
De Havilland Mosquito PR Mk 40: Six FB Mk 40 converted for PR role,
May-October 1944, with increased internal fuel, drop tanks and three vertical
and two oblique cameras.
De Havilland Mosquito PR Mk 41: Twenty-eight FB Mk 40 converted
for PR role, 1947-48, with Merlin 69s.
De Havilland Mosquito FB Mk 42: One FB Mk 40 converted with Merlin
69 engines.
De Havilland Mosquito T Mk 43: Twenty-two con-verted FB Mk 40s
as dual control trainers with Merlin 33s, June 1944 onwards.
