Dewoitine D.520

https://en.wikipedia.org/wiki/Dewoitine_D.520

The Dewoitine D.520 was a French fighter aircraft that entered service in early
1940, shortly after the beginning of the Second World War.

The D.520 was designed in response to a 1936 requirement from the French Air
Force for a fast, modern fighter with a good climbing speed and an armament
centred on a 20 mm cannon. At the time the most powerful V 12 liquid-cooled
engine available in France was the Hispano-Suiza 12Y, which was less powerful,
but lighter than contemporary engines such as the Rolls-Royce Merlin and
Daimler-Benz DB 601. Other fighters were designed to meet the specifications but
none of them entered service, or entered service in small numbers, too late to
play a significant role during the Battle of France.

Unlike the Morane-Saulnier M.S.406, which was at that time the most numerous
fighter in the French Air Force, the Dewoitine D.520 came close to being a match
for the latest German types, such as the Messerschmitt Bf 109. It was slower
than the Bf 109E but superior in manoeuvrability. Because of production delays,
only a small number were available for combat against the Luftwaffe.

The D.520 proved to be relatively capable as a dogfighter against the
Luftwaffe's inventory, but lacked sufficient numbers to make a difference.

Following the armistice, the D.520 continued to be used, being operated by both
the Free French Air Force and the Vichy French Air Force. The type was also
returned to production during 1942, although it was manufactured at a lower rate
than it had been during 1940. Additional examples were operated by the
Luftwaffe, Regia Aeronautica, and the Bulgarian Air Force. The D.520 saw combat
service in North Africa, Bulgaria, and the Eastern Front, as well as use in
France and Germany for training and defence purposes. During the type's later
life, it was used as a trainer aircraft. On 3 September 1953, the last D.520s
were finally withdrawn from service.

The Dewoitine D.520 was a French fighter aircraft, intended to be a capable
contemporary of types such as the Messerschmitt Bf 109 and Supermarine Spitfire.
An all-metal structure was used, except for fabric-covered ailerons and tail
surfaces. The wing, even if single-spar, was a solid and rigid unit with a
secondary spar and many reinforced parts. The inwardly retracting undercarriage
had a broad 2.83 m (9.3 ft) track, and was fitted with wide, low pressure tyres.

The D.520 was designed to be maintained easily with many inspection panels, a
rare feature for its time. Recharging the D.520 ammunition was swift and easy;
the machine gun magazines required five minutes each and three minutes for the
20 mm cannon. To fill the machine gun ammunition boxes took 15 minutes, while
five minutes were needed to empty the 20 mm box (the cartridges were not
expelled). The D.520's cockpit was set well back in the fuselage, aft of the
trailing edge of the wings. This gave the pilot good downward visibility, but
the long nose in front of him was a drawback when taxiing on the ground.

A self-sealing fuel tank with a capacity of 396 litres (87 imp gallons) was
mounted between the engine and cockpit, along with two wing tanks which,
combined, carried another 240 litres (53 imp gallons), for a total of 636 litres
(131 imp gallons); this was considerably more than the contemporary Bf 109E,
Spitfire I and early Italian fighters, each with about 400 litres (88 imp
gallons) fuel capacity. The ferry range was from 1,300 km (810 mi) to 1,500 km
(930 mi) at 450 km/h (280 mph) which, from June 1940, allowed D.520s to escape
to North Africa when France fell.


Role
Fighter aircraft

Manufacturer
SNCAM / SNCASE

First flight
2 October 1938

Introduction
January 1940

Retired
1953

Primary users
French Air Force
Luftwaffe
Regia Aeronautica
Bulgarian Air Force

Number built
˜900

Although employing a modern design philosophy for its time, the D.520 was
considered more difficult to fly than the older MS.406. Captain Eric Brown,
commanding officer of the Royal Aircraft Establishment's Captured Enemy Aircraft
Flight, tested the D.520 at RAE Farnborough, saying that “It was a nasty little
brute. Looked beautiful but didn't fly beautifully. Once you get it on the
ground, I was told not to leave the controls until it was in the hangar and the
engine stopped. You could be taxiing toward the hangar and sit back when
suddenly it would go in a right angle.”

The handling changed according to the amount of fuel carried; using the fuselage
tank alone, fuel consumption had no appreciable effect on handling because the
tank was at the centre of gravity, but with full wing tanks, directional control
was compromised, especially in a dive. The flight controls were well harmonized
and the aircraft was easy to control at high speed. The maximum dive speed
tested was 830 km/h (520 mph) with no buffeting and excellent stability both in
the dive (depending on fuel load) and as a gun platform.

Battle of France

The Groupe de Chasse I/3 was the first unit to get the D.520, receiving its
first aircraft in January 1940. These initial xamples were unarmed and used for
pilot training. In April and May 1940, operational units received 34
'war-capable' production D.520s; the type quickly proved to be highly popular
with pilots and ground crew. During comparative trials on 21 April 1940 at CEMA
at Orleans-Bricy against a captured Bf 109E-3, the German aircraft had a 32 km/h
(20 mph) speed advantage owing to its more powerful engine. However, the D.520
had superior maneuverability, matching its turning circle, although displaying
nasty characteristics when departing and spinning out of the turn repeatedly
during the tests. The Bf 109, owing to its slats, could easily sustain the turn
on the edge of a stall.

In air combat, mostly against the Italians, the Dewoitine 520s claimed 114 air
victories, plus 39 probables. Eighty five D.520s were lost. By the armistice at
the end of June 1940, 437 D.520s had been constructed, 351 of these having been
delivered.[35] After the armistice, 165 D.520s were evacuated to North
Africa.[22] GC I/3, II/3, III/3, III/6 and II/7 flew their aircraft to Algeria
to avoid capture.[35] Three more, from GC III/7, escaped to Britain and were
delivered to the Free French. A total of 153 D.520s remained in unoccupied
mainland France.

One of the most successful D.520 pilots was Pierre Le Gloan, who shot 18
aircraft down (four Germans, seven Italian and seven British), scoring all of
his kills with the D.520, and ranked as the fourth-highest French ace of the
war.

Specifications (Dewoitine D.520C.1)

General characteristics
Crew: 1
Length: 8.6 m (28 ft 3 in)
Wingspan: 10.2 m (33 ft 6 in)
Height: 2.57 m (8 ft 5 in)
Wing area: 15.87 m2 (170.8 sq ft)
Empty weight: 2,123 kg (4,680 lb)
Gross weight: 2,677 kg (5,902 lb)
Max takeoff weight: 2,785 kg (6,140 lb)
Powerplant: 1 × Hispano-Suiza 12Y-49 V-12 liquid-cooled piston engine, 710 kW
(950 hp) (from No.351)
Propellers: 3-bladed Chauvière type 3918, 3 m (9 ft 10 in) diameter
pneumatically -operated variable-pitch propeller

Performance
Maximum speed: 560 km/h (348 mph; 302 kn)
Range: 1,250 km (777 mi; 675 nmi)
Service ceiling: 10,000 m (33,000 ft)
Rate of climb: 14.3 m/s (2,810 ft/min)
Wing loading: 167 kg/m2 (34 lb/sq ft)
Power/mass: 0.257 kW/kg (0.156 hp/lb)

Armament

Guns:
1 × 20 mm (0.787 in) Hispano-Suiza HS.404 (60-round drum) cannon
4 × 7.5 mm (0.295 in) MAC 1934 (675 rpg) machine guns





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