Modern-Aviation

The Dewoitine D.520 was a single seat piston-engine fighter designed and built for the French Air Force. Developed from lessons learned in their ill-fated D.513 design, Dewoitine produced a fighter of sleek design and acceptable capability, especially when compared to that of the German Luftwaffe - to which the D.520 squared off valiantly yet unsuccessfully in the Fall of France in 1940. Despite this, the D.520 was generally respected and use continued by the Vichy French Air Force and even in post-war France. The D.520 signified France's first successful and best "modern" fighter design of World War 2.

Design work on the D.520 began as early as 1936, with the first prototypes flying by 1938. Beyond some design modifications and differing engine types (all from the Hispano-Suiza line) the models varied little. From the D520.1 prototype, the base D.520 series was born and ordered up for production by 1939, with the system being fielded by 1940 - to which only some 36 had actually been delivered when the Germans invaded. The D.520 reportedly squared up well against its German counterparts though success in the defense of France was not to be. Some 114 enemy kills were made at a loss of 85 French D.520's before the eventual collapse of the aerial defense. The system stayed in production with the German-sided Vichy French Air Force and was still available in some numbers after the war.

At its core, the D.520 was a basic straight-line fighter most noted for its sleek overall design and set-back cockpit of which was enclosed canopy. The position of the cockpit so far away from the nose undoubtedly took away from the pilots visibility forward and down but the added room in the nose made for an easier engine (which featured a variable-pitch propeller system) and armament installation. Armament consisted of a nose-mounted 20mm cannon and 4 x 7.5mm machine guns, with two machine guns per wing leading edge. Trailing edge flaps were also instituted into the wing design. A single vertical tail surface adorned the empennage and retractable landing gears rounded out the features.

Emile Dewoitine had produced a series of fighters for the French Air Force, starting with the D.101 of 1921. In 1934 most French fighter squadrons used one of the D.500, D.501 or D.510. However, these aircraft were clearly approaching obsolescence, and so in 1934 the French Air Force staff issued a specification for a new fighter. Dewoitine produced the D.513, an all-metal monoplane with retractable undercarriage, powered by an 860 hp Hispano-Suiza engine. The D.513 was not a success, and no order was placed. Dewoitine’s company, the Société Aéronautique Française - Avions Dewoitine was set to close at the end of 1936 once work was complete on the D.510.

In June 1936 Dewoitine left the company to found a new design office. The French Air Ministry was looking for a fighter capable of reaching 520 km/h (323 mph). Dewoitine’s first proposal could not reach this speed, but in January 1937 his team produced the design for the D.520. This aircraft would reach the required speed, now enshrined in the A.23 technical programme of 12 January 1937, but it had just been decided to adopt the M.S. 405, and so no order was placed for the new fighter.

Dewoitine soon found himself in a position to continue working on the new design. On 11 August 1936 a plan was put in place to nationalise the French aircraft industry, in an attempt to increase production and efficiency. Dewoitine’s old company was absorbed by the SNCAM on 4 March 1937. Dewoitine himself was appointed deputy managing director of the SNCAM (Société Nationale de Constructions Aéronautiques du Midi).

It was this position that allowed work to continue on the D.520. For the next year work progressed as a private venture. Finally, on 3 April 1938 the Air Ministry finally placed an order for two D.520 prototypes. The first prototype flew on 2 October 1938. This first prototype could only reach a top speed on 298 mph. A series of modifications followed, and in March 1939 the second prototype reached 327 mph (527 km/h) at 16,400 feet. This was good enough for the Air Ministry, and on 7 April 1939 an order was placed for 200 D.520 fighters.

When the German offensive in the west began on 10 May 1940, GC I/3 was the only unit using the D.520. During the next month four more units converted to the D.520 (including G.C. III/6 on the Italian front). In combat the D.520 proved itself to be an equal to the Bf 109E - the only allied aircraft engaged in France that could really make that claim. In tests against a captured Bf 109E-3 the D.520 was found to be slightly slower but more manoeuvrable.

The five D.520 units scored 108 confirmed victories and 39 probable victories. The confirmed victories included 23 Bf 109s and 9 Bf 110s. In the same period 106 D.520s were lost, although only 26 of those were lost in air-to-air combat. If the D.520 had been available in larger numbers in May 1940 it may well have denied the Luftwaffe control of the air over the western front.

The D.520 remained in use after the Armistice. The German armistice commission allowed the Vichy air force to use the D.520 in Africa. The Germans even placed an order for 550 D.520s themselves (349 were produced between August 1941 and December 1942), using them as training aircraft. Some of these aircraft were sent to equip Vichy squadrons in Syria, where they saw action against the Allies in the summer of 1941. In this campaign the D.520 claimed 30 victories for the loss of 32 D.520s.

The D.520 had one last chance to fight the Germans after the Allied invasion of southern France in August 1944. Within days of the Allied landing the French Forces of the Interior formed a fighter group (Premier Groupe de Chasse FFI) which fought alongside the allies in southern France, using D.520s recaptured from the Germans, before being absorbed into the re-formed French Air Force on 1 December 1944. This fighter group used the D.520 from August 1944 to March 1945. By now the D.520 was effectively obsolete, but the Luftwaffe had been swept from the skies of southern France by Allied air power, and so the D.520 was able to play a role in the mopping up operations in south west France.