The D.520 fighter arrived in too small numbers to make an impact for the Armee de l'Air in the opening months of the Second World War. After the signing of the Armistice in June 1940 the
Dewoitine D.520 would serve with a number of different air forces and post-war was used as a trainer.
During 1936 the French Government issued details for a new fighter. The new aircraft would have a speed of 310 mph and climb to 26,000 ft in fifteen minutes. The design team, led by Emile
Dewoitine, submitted their aircraft, however the Morane-Saulnier MS.406 was the favoured option. Undeterred Dewoitine continued working on the aircraft, which would have self-sealing fuel
tanks, armour for the pilot and apart from the ailerons and tail surfaces would be of all metal construction, as a private venture with the 3rd April 1938 seeing three prototypes ordered.
The D.520.01 would be the first prototype to fly when, powered by the 890-hp Hispano-Suiza 12Y-21 engine and with Marcel Doret at the controls, it took to the skies on the 2nd October 1938.
This was followed on the 28th January 1939 by the second prototype, the D.520.02, which featured a number of changes, including strengthened undercarriage and a redesign of the tail unit.
A third prototype, known as the D.520.03, would fly in May 1939. In between these two flights, the 17th April 1939 saw 200 D.520s ordered and by May 1940 2,200 had been ordered with 120 of
these destined for the Aeronavale.
The production Dewoitine D.520 would be powered by the 935-hp Hispano-Suiza 12Y-45 engine which gave the aircraft a top speed of 335 mph, range of 930 miles and a service ceiling of 34,450 ft.
Armament was one 20mm cannon and four 7.5mm machine-guns. The D.520 would enter Armee de l'Air service during November 1939 when Groupe de Chasse I/3 received the first examples. By the time
the Battle of France began (10th May 1940 - 25th June 1940) there were less than eighty D.520s in service with the Armee de l'Air and only Groupe de Chasse I/3 had its full complement of thirty six
aircraft.
The Dewoitine D.520 was in action for the first time during the Battle of France on the 13th May 1940 when aircraft from Groupe de Chasse I/3 claimed three aircraft for none lost during its
first combat. A further four Groupe de Chasse reached operational status using the D.520 before the Armistice between France, Germany and Italy on the 25th June 1940. A sole Aeronavale squadron
was also equipped with the aircraft. Prior to the Armistice an order had been issued for a number of French aircraft types to make their way to North Africa to stop them being captured by the
advancing German forces. After the Armistice the D.520 would serve with various air forces. A handful would serve with the Free French Air Force and a number would serve with the Vichy French Air
Force, taking part in Operation Torch which started on the 8th November 1942.
Both the Luftwaffe and Regia Aeronautica would also use the Dewoitine D.520. During its service with the Regia Aeronautica they played a role in defending Italy from Allied bombers. After the
Armistice signed by Italy with the Allies on the 3rd September 1943, seeing Italy join the Allies, their D.520s would see combat against the Luftwaffe. The Luftwaffe would use the aircraft as a
trainer before they gave a number to the Bulgarian Air Force. Its use with the Bulgarian Air Force saw it used to intercept Allied bombers.
After the Second World War (1939 – 1945) the remaining D.520s would serve with the Armee de l'Air as training aircraft with the 3rd September 1953 seeing the final flight of the Dewoitine D.520.
In total 891 were built.