de Havilland Mosquito

https://en.wikipedia.org/wiki/De_Havilland_Mosquito

The de Havilland DH.98 Mosquito is a British twin-engine shoulder-winged
multi-role combat aircraft, introduced during the Second World War, unusual in
that its frame is constructed mostly of wood. It was nicknamed The Wooden
Wonder, or "Mossie". Lord Beaverbrook, Minister of Aircraft Production,
nicknamed it "Freeman's Folly", alluding to Air Chief Marshal Sir Wilfred
Freeman, who defended Geoffrey de Havilland and his design concept against
orders to scrap the project. In 1941 it was one of the fastest operational
aircraft in the world.

Originally conceived as an unarmed fast bomber, the Mosquito's use evolved
during the war into many roles, including low to medium-altitude daytime
tactical bomber, high-altitude night bomber, pathfinder, day or night fighter,
fighter-bomber, intruder, maritime strike aircraft. It was also used by the
British Overseas Airways Corporation (BOAC) as a fast transport to carry small,
high-value cargoes to and from neutral countries through enemy-controlled
airspace. The crew of two, pilot and navigator, sat side by side. A single
passenger could ride in the aircraft's bomb bay when necessary.

The Mosquito FBVI was often flown in special raids, such as Operation Jericho –
an attack on Amiens Prison in early 1944, and precision attacks against military
intelligence, security and police facilities (such as Gestapo headquarters). On
the 10th anniversary of the Nazis' seizure of power in 1943, a morning Mosquito
attack knocked out the main Berlin broadcasting station while Hermann Göring was
speaking, putting his speech off the air.

The Mosquito flew with the Royal Air Force (RAF) and other air forces in the
European, Mediterranean and Italian theatres. The Mosquito was also operated by
the RAF in the South East Asian theatre and by the Royal Australian Air Force
(RAAF) based in the Halmaheras and Borneo during the Pacific War. During the
1950s, the RAF replaced the Mosquito with the jet-powered English Electric
Canberra.

Development

By the early-mid-1930s, de Havilland had a reputation for innovative high-speed
aircraft with the DH.88 Comet racer. The later DH.91 Albatross airliner
pioneered the composite wood construction used for the Mosquito. The
22-passenger Albatross could cruise at 210 miles per hour (340 km/h) at 11,000
feet (3,400 m), 100 mph (160 km/h) faster than the Handley Page H.P.42 and other
biplanes it was replacing. The wooden monocoque construction not only saved
weight and compensated for the low power of the de Havilland Gipsy Twelve
engines used by this aircraft, but simplified production and reduced
construction time.

Air Ministry bomber requirements and concepts

On 8 September 1936, the British Air Ministry issued Specification P.13/36,
which called for a twin-engine medium bomber capable of carrying a bomb load of
3,000 lb (1,400 kg) for 3,000 mi (4,800 km) with a maximum speed of 275 mph (445
km/h) at 15,000 ft (4,600 m); a maximum bomb load of 8,000 lb (3,600 kg) that
could be carried over shorter ranges was also specified. Aviation firms entered
heavy designs with new high-powered engines and multiple defensive turrets,
leading to the production of the Avro Manchester and Handley Page Halifax.

Overview

While timber construction was considered outmoded by some, de Havilland claimed
that their successes with techniques used for the DH 91 Albatross could lead to
a fast light bomber using monocoque sandwich shell construction. Arguments in
favor of this included speed of prototyping, rapid development, minimisation of
jig building time, and employment of a separate category of workforce. At the
same time, they had to fight conservative Air Ministry views on defensive
armament. Guns and gun turrets would spoil the streamlining, losing speed and
manoeuvrability. The ply-balsa-ply monocoque fuselage and one-piece wings with
doped fabric covering gave smooth aerodynamic performance and low weight,
combined with strength and stiffness. Whilst submitting these arguments,
Geoffrey de Havilland funded his private venture until the eleventh hour. It was
a success beyond all expectations. The initial bomber and photo reconnaissance
versions were extremely fast, whilst the armament of subsequent variants might
be regarded as primarily offensive.

The most-produced variant, designated the FB Mk VI (Fighter-bomber Mark 6), was
powered by two Merlin Mk 23 or Mk 25 engines driving three-bladed de Havilland
hydromatic propellers. The typical fixed armament for an FB Mk VI was four
Browning .303 machine guns and four 20 mm Hispano cannon while the offensive
load consisted of up to 2,000 pounds (910 kg) of bombs, or eight RP-3 unguided
rockets.

Performance

The design was noted for light and effective control surfaces that provided good
manoeuvrability but required that the rudder not be used aggressively at high
speeds. Poor aileron control at low speeds when landing and taking off was also
a problem for inexperienced crews. For flying at low speeds, the flaps had to be
set at 15°, speed reduced to 200 mph (320 km/h) and rpm set to 2,650. The speed
could be reduced to an acceptable 150 mph (240 km/h) for low speed flying. For
cruising, the optimum speed for obtaining maximum range was 200 mph (320 km/h)
at 17,000 lb (7,700 kg) weight.

The Mosquito had a low stalling speed of 120 mph (190 km/h) with undercarriage
and flaps raised. When both were lowered, the stalling speed decreased from 120
to 100 mph (190 to 160 km/h). Stall speed at normal approach angle and
conditions was 100 to 110 mph (160 to 180 km/h). Warning of the stall was given
by buffeting and would occur 12 mph (19 km/h) before stall was reached. The
conditions and impact of the stall were not severe. The wing did not drop unless
the control column was pulled back. The nose drooped gently and recovery was
easy.

Early on in the Mosquito's operational life, the intake shrouds that were to
cool the exhausts on production aircraft overheated. Flame dampers prevented
exhaust glow on night operations, but they had an effect on performance.
Multiple ejector and open-ended exhaust stubs helped solve the problem and were
used in the PR.VIII, B.IX and B.XVI variants. This increased speed performance
in the B.IX alone by 10 to 13 mph (16 to 21 km/h).

Role

Light bomber
Fighter-bomber
Night fighter
Maritime strike aircraft
photo-reconnaissance aircraft

Manufacturer
de Havilland Aircraft Company

First flight
25 November 1940

Introduction
15 November 1941

Status
Retired

Primary users
Royal Air Force

Royal Canadian Air Force
Royal Australian Air Force
United States Army Air Forces

Produced
1940–1950

Number built
7,781

The de Havilland Mosquito operated in many roles, performing medium bomber,
reconnaissance, tactical strike, anti-submarine warfare and shipping attacks and
night fighter duties, until the end of the war. In July 1941, the first
production Mosquito W4051 (a production fuselage combined with some prototype
flying surfaces (see Prototypes and test flights) was sent to No. 1 Photographic
Reconnaissance Unit (PRU), at RAF Benson. The secret reconnaissance flights of
this aircraft were the first operational missions of the Mosquito. In 1944, the
journal Flight gave 19 September 1941 as date of the first PR mission, at an
altitude "of some 20,000 ft".

From mid-1942 to mid-1943, Mosquito bombers flew high-speed, medium or
low-altitude daylight missions against factories, railways and other pinpoint
targets in Germany and German-occupied Europe. From June 1943, Mosquito bombers
were formed into the Light Night Striking Force to guide RAF Bomber Command
heavy bomber raids and as "nuisance" bombers, dropping Blockbuster bombs – 4,000
lb (1,800 kg) "cookies" – in high-altitude, high-speed raids that German night
fighters were almost powerless to intercept.

As a night fighter from mid-1942, the Mosquito intercepted Luftwaffe raids on
Britain, notably those of Operation Steinbock in 1944. Starting in July 1942,
Mosquito night-fighter units raided Luftwaffe airfields. As part of 100 Group,
it was flown as a night fighter and as an intruder supporting Bomber Command
heavy bombers that reduced losses during 1944 and 1945.

The Mosquito fighter-bomber served as a strike aircraft in the Second Tactical
Air Force (2TAF) from its inception on 1 Jun 1943. The main objective was to
prepare for the invasion of occupied Europe a year later. In Operation Overlord
three Mosquito FB VI wings flew close air support for the Allied armies in
co-operation with other RAF units equipped with the North American B-25 Mitchell
medium bomber. In the months between the foundation of 2TAF and its duties from
D day onwards, vital training was interspersed with attacks on V-1 flying bomb
launch sites.

In another example of the daylight precision raids carried out by the Mosquitos
of Nos. 105 and 139 Squadrons, on 30 January 1943, the 10th anniversary of the
Nazis' seizure of power, a morning Mosquito attack knocked out the main Berlin
broadcasting station while Commander in Chief Reichsmarschall Hermann Göring was
speaking, putting his speech off the air. A second sortie in the afternoon
inconvenienced another speech, by Goebbels. Lecturing a group of German aircraft
manufacturers, Göring said:

"In 1940 I could at least fly as far as Glasgow in most of my aircraft, but not
now! It makes me furious when I see the Mosquito. I turn green and yellow with
envy. The British, who can afford aluminium better than we can, knock together a
beautiful wooden aircraft that every piano factory over there is building, and
they give it a speed which they have now increased yet again. What do you make
of that? There is nothing the British do not have. They have the geniuses and we
have the nincompoops. After the war is over I'm going to buy a British radio set
– then at least I'll own something that has always worked.

The Mosquito flew its last official European war mission on 21 May 1945, when
Mosquitos of 143 Squadron and 248 Squadron RAF were ordered to continue to hunt
German submarines that might be tempted to continue the fight; instead of
submarines all the Mosquitos encountered were passive E-boats.

The last operational RAF Mosquitos were the Mosquito TT.35's, which were finally
retired from No. 3 Civilian Anti-Aircraft Co-Operation Unit (CAACU) in May 1963.

In 1947-49, up to 180 Canadian surplus Mosquitoes flew many operations for the
Nationalist Chinese under Chiang Kai-shek in the civil war against Communist
forces. Pilots from three squadrons of Mosquitoes claimed to have sunk or
damaged 500 ships during one invasion attempt. As the Communists assumed
control, the remaining aircraft were evacuated to Formosa, where they flew
missions against shipping.

Specifications

DH.98 Mosquito F Mk II

Fighter version

General characteristics
Crew: 2: pilot, navigator/radar operator
Length: 41 ft 2 in (12.55 m)
Wingspan: 54 ft 2 in (16.52 m)
Height: 17 ft 5 in (5.3 m)
Wing area: 454 ft2 (42.18 m2)
Empty weight: 13,356 lb (6,058 kg)
Loaded weight: 17,700 lb (8,028 kg)
Max. takeoff weight: 18,649 lb (8,549 kg)
Powerplant: 2 × Rolls-Royce Merlin 21/21 or 23/23 (left/right) liquid-cooled V12
engine, 1,480 hp (21 & 23) (1,103 kW) each

Performance
Maximum speed: 318 kn (366 mph (589 km/h)) at 21,400 ft (6,500 m)
Range: 782 nmi (900 mi (1,400 km)) with 410 gal (1,864-litre) fuel load at
20,000 ft (6,100 m)
Service ceiling: 29,000 ft (8,839 m)
Rate of climb: 1,740 ft/min (8.8 m/s)
Wing loading: 39.9 lb/ft2 (195 kg/m2)
Power/mass: 0.189 hp/lb (311 W/kg)

Armament

Guns: 4 × 20 mm (.79 in) Hispano Mk II cannon (fuselage) and 4 × .303 in (7.7
mm) Browning machine guns (nose)

Avionics

AI Mk IV or Mk V radar (NF variants)


DH.98 Mosquito B Mk XVI

The definitive bomber version.

General characteristics
Crew: 2: pilot, bombardier/navigator
Length: 44 ft 6 in (13.57 m)
Wingspan: 54 ft 2 in (16.52 m)
Height: 17 ft 5 in (5.3 m)
Wing area: 454 ft2 (42.18 m2)
Empty weight: 14,300 lb (6,490 kg)
Loaded weight: 18,100 lb (8,210 kg)
Max. takeoff weight: 25,000 lb (11,000 kg)
Powerplant: 2 × Rolls-Royce Merlin 76/77 (left/right) liquid-cooled V12 engine,
1,710 hp (1,280 kW) each

Performance
Maximum speed: 361 kn (415 mph (668 km/h)) at 28,000 ft (8,500 m)
Range: 1,300 nmi (1,500 mi (2,400 km)) with full weapons load
Service ceiling: 37,000 ft (11,000 m)
Rate of climb: 2,850 ft/min (14.5 m/s)
Wing loading: 39.9 lb/ft2 (195 kg/m2)
Power/mass: 0.189 hp/lb (311 W/kg)

Armament

Bombs: 4,000 pounds (1,800 kg)

Avionics

GEE radio-navigation




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