Dewoitine D.500

The Dewoitine D.500 was an all-metal, open-cockpit, fixed-undercarriage monoplane fighter aircraft, used by the French Air Force in the 1930s. Introduced in 1936, the design was soon replaced by a new generation of fighter aircraft with enclosed cockpits and retractable undercarriage, including the 510's successor, the Dewoitine D.520.

The D.500, designed by Émile Dewoitine, was based on C1 specifications issued in 1930 by the French Air Ministry, and was to be a replacement for the Nieuport 62. The prototype first flew on 18 June 1932. In November 1933, sixty aircraft were ordered, with the first production D.500 flying on 29 November 1934. Aircraft armed with a 20 mm cannon firing through the propeller hub - instead of two nose-mounted machine guns - received the designation D.501.

A total of 381 D.500s and its derivatives were built.

The D.500 and D.501 entered service in July 1935, with the more powerful D.510 joining them in October 1936. They were the primary fighters employed by the Armée de l'Air until their replacement by the Morane-Saulnier M.S.406 in 1939. As of September 1939, the D.500/501 had been relegated to regional defense and training squadrons. At the start of World War II, D.510s were still in operation with three Groupes de Chasse (Fighter Groups), two Escadrilles Régionale de Chasse (Regional Fighter Squadrons in North Africa), and two Escadrilles de Aéronautique Navale (Naval Aviation Squadrons).

In Morocco, one escadrille of D.510s (ERC571) was activated in November 1939. These planes lacked cannon. In May 1940, this escadrille merged with ERC 573 to form GC III/4. This groupe was disbanded by the end of August 1940. At Dakar, one groupe designated GC I/6, remained in service until being replaced by Curtiss H-75s at the end of 1941.

Fourteen D.501s (named D.501L), originally sold to Lithuania, and two D.510s ostensibly intended for the Emirate of Hedjaz saw service in the Spanish Civil War, arriving in mid-1936. When the French government found out about the delivery of the D.510s, they demanded the return of the 12Y engines. The aircraft were then refitted with Klimov M-100s (a Soviet-built copy of the 12Y) from a Tupolev SB bomber. 

The aircraft served with the Republican forces. The two 510s were posted to the 71st Coastal Defense Group. Neither engaged enemy fighters. In 1938, one was irreparably damaged while landing and the other was destroyed on a runway during a bombing attack.

In 1938, 18 Chinese D.510s saw action against the Japanese, including the defense of Chengdu and the Chinese wartime capital Chongqing.

Variants
D.500.01
First prototype aircraft.

D.500
First production version with a Hispano-Suiza 12Xbrs engine with 515 kW (690 hp), it was armed with 2 × 7.7 mm Vickers machine guns or 2 × 7.5 mm. Darne machine guns in the nose, provision for 2 × additional Darnes in the wings. 101 built.

D.501
Dewoitine BA 112.
Re-engined with a Hispano-Suiza 12Xcrs engine, it was armed with a 20 mm Hispano-Suiza S7 cannon between the engine cylinder banks firing through the propeller hub and 2 × wing-mounted machine guns. 157 built.

D.503
The sole D.511 prototype fitted with a 12Xcrs engine with a circular radiator in the nose, it had the same armament as the D.501. Its first flight was on 15 April 1935, it was found to perform worse than the D.500. The aircraft was briefly the personal mount of René Fonck.

D.510
Re-engined with Hispano-Suiza 12Ycrs producing 640 kW (860 hp), armed with a 20 mm Hispano cannon and 2 × 7.5 mm MAC 1934 machine guns in the wings. 
Its first flight was on 14 August 1934, 120 built.

D.511
Prototype with D.500 fuselage and tail, it had smaller wings, a cantilever undercarriage and a 12Ycrs engine. 
One prototype was built in 1934 but never flown; it was converted to the D.503.

AXD1
The short designation for the single Dewoitine D.510 supplied to the Imperial Japanese Navy Air Service for evaluation in 1935.

Dewoitine Navy Type D Carrier Fighter

Long service designation for the D.510 which was supplied to the IJNAS in 1935.
Operators
Republic of China Air Force - 24 D.510
French Air Force 98 x D.500, 130 x D.501 and 88 x D.510
Aviation Navale 30 x D.501
Japanese Imperial Navy 2 x D.510 designated as AXD
Lithuanian Air Force - 14 x D.501
Polish Air Forces in exile in France
Soviet Air Force 1 x D.510 for evaluation
Spanish Republican Air Force. 7 x D.500 and 2 x D.510 in the Escuadrilla Internacional.
Royal Air Force - One x 510 for evaluation
Venezuelan Air Force - 3 D.500

Specifications D.510
Crew: one
Length: 7.94 m 
Wingspan: 12.09 m 
Height: 2.42 m 
Wing area: 16.50 m² 
Empty weight: 1,496 kg 
Loaded weight: 1,929 kg 
Powerplant: 1 × Hispano-Suiza 12Ycrs V12 engine, 640 kW (860 hp)
Maximum speed: 402 km/h at 5,000 m 
Range: 700 km 
Service ceiling: 11,000 m 
Rate of climb: 14.85 m/s 
Wing loading: 117 kg/m² 
Power/mass: 330 W/kg 
Time to altitude: 1.32 min to 1000 m 
Guns: 1 × 20 mm Hispano-Suiza HS.9 cannon, 60 rounds
4 × 7.5 mm  MAC 1934 mg, 300 rpg