Dewoitine D.500 / D.510 is a family of single-seat French WW2 fighters with an open cockpit and fixed landing gear. The aircraft was developed at the Dewoitine design bureau under the leadership of Emile Dewoitine.

The first of the two prototypes took off on August 14, 1934. The aircraft had a more powerful Hispano-Suiza 12crs engine with a three-bladed propeller, on the previous modifications a two-bladed propeller was used, the letter "c" in the engine designation indicated that the engine was cannon, i.e. adapted to mount a cannon firing through the propeller hub. A larger radiator was used, and the fuel supply was increased.

D.510 was the first in France to cross the 400 km / h. Insufficient directional stability forced to increase the area of ​​the keel, which became larger in area than that of the D.500.

The first batch of 25 aircraft was ordered in May 1936, the entire French Air Force from 1936 to September 1937 received 88 aircraft, taking into account prototypes and export vehicles, 120 aircraft were built.

For the first time in combat, a fighter was used in December 1936 during the Spanish Civil War. The aircraft has also been in service with China since July 1938. From January 1939 he took part in the Sino-Japanese War. French fighters were limitedly used in the Strange War; during the Battle of France they were in service with individual air defense units.

One D.510R (the letter R meant that the aircraft was made for Russia) in September 1936, was received at the French airfield of Villacoublay by Soviet representatives. This aircraft was further tested at the Air Force Research Institute, see below its photo at the Chkalovskaya airfield. We were mainly interested in the French motor-gun, which had no analogues then. The HS 12 Ybrs, acquired in 1935 under license, did not have such a gun. This engine was produced in our country under the name M-100, its further development VK-103, VK-105PF and VK-107A were installed on all Yakovlev fighters and on the Petlyakov Pe-2 bomber.

Photo	Description
	Drawing D 510
	The D-510R at 'Chkalovskaya' airfield in the USSR

In the photo, to the left of the cockpit, you can see the Venturi tube, which is the source of pressure drop for powering the gyroscope in the direction indicator.

Variants

• D.500 First production version with a Hispano-Suiza 12Xbrs engine with 515 kW (690 hp), it was armed with 2 x 7.7 mm (.303 in) Vickers machine guns or 2 x 7.5 mm (.295 in) Darne machine guns in the nose, provision for 2 x additional Darnes in the wings. 101 built.
• D.501 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 x 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 in 15 April 1935, it was found to perform worse than the D.500. The aircraft was briefly the personal mount of Rene Fonck.
• D.510 Re-engined with Hispano-Suiza 12Ycrs producing 640 kW (860 hp), armed with a 20 mm Hispano cannon and 2 x 7.5 mm (.295 in) 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.

Bibliography

• "Encyclopedia of military engineering" /Aerospace Publising/