The French Dewoitine D.520 was the best fighter France had when the Luftwaffe showed up with the Bf 109E in 1940. By comparison, the D.520 was underpowered, but still very agile and had sufficient firepower to fight its rival. Both had superchargers, but the Bf 109E was the fastest fighter in the world at that time at 370 mph. The D.520 was slower at 332 mph, had a ceiling of 39,000 ft, and range of 950 miles. Visibility was good... except for taxing and landings due to its location so aft of the engine. The plane managed to kill 147 German aircraft during its short fight and was again in French hands in '44 after liberation. It fought the last pocket of Germans leaving France and also seized examples were restored to fight in Europe (GCB 1/18, for example). French ace Pierre Le Gloan shot down 18 of his 22 kills in a D.520. Dewoitine had originally planned to put a 1500 hp engine into the airframe but one was not available in 1939-40. Only a 1030 hp Merlin was and that became the sole D.521 prototype that increased speed to 354 mph but went nowhere due to the German victory. A secret D.524 prototype was built partially using a HS engine of 1200 hp but was dismantled. The Germans captured 100s of D.520s and used them as fighter trainers for the LW and also gave some to Rumania and Bulgaria.

* M.S.406 was the other main fighter of the French AF in 1940. It was equally underpowered but had more kills at 175 for a loss of 400!!! The Germans passed this to the Finns who upgraded the engine using a Soviet captured type.