France (1936-1953)
Fighter – 900 Built

The Dewoitine D.520 was the most advanced French fighter aircraft of the World War II period to have been employed in large numbers during the Battle of France. It was superior to the Morane-Saulnier MS.406 and Bloch MB.152. Often considered the only French fighter able to challenge the dominance of the Luftwaffe’s Bf 109E, the D.520 garnered a strong reputation and popularity among the general public in France. Though this aspect of its history is typically overlooked, the Dewoitine would also see extensive service after the Battle of France, particularly in the air force of the Vichy Regime, but also with Germany’s Italian and Bulgarian allies.

Dewoitine: French Pioneer of Interwar Metal Monoplanes

The Constructions Aéronautiques Emile Dewoitine (Emile Dewoitine Aeronautical Manufacturing) society was founded in 1920 under the lead of the eponymous engineer. Dewoitine had previously been employed by Latecoere during the First World War, which gave him experience on the subject of military aviation.

Dewoitine’s company was located in South-Western France, in Toulouse – an ideal location for strategic industry, as it was about as far as one could be in France from what was still viewed as a potential future adversary in 1920, namely Germany.

Dewoitine’s main products quickly became monoplane fighters. Though other types of planes were also developed, it was with parasol wing monoplanes that Dewoitine met its initial success. While the company failed to procure major domestic orders, Dewoitine fighters such as the D.1, D.9, or D.25 were export successes, seeing service in a number of countries such as Switzerland, Czechoslovakia, Turkey, Italy or Argentina. Dewoitine’s fighters were occasionally quite innovative – for example, the Dewoitine D.9 was an entirely metal parasol wing fighter, which was quite remarkable for a plane which first flew in 1924. While rejected by France, it was licence-produced by Italy as the Ansaldo AC.3, with 150 being manufactured for the Regia Aeronautica. Dewoitine also manufactured small numbers of D.9s for Belgium, Switzerland, Yugoslavia and Hungary.

In large part due to none of its planes being adopted by France’s military, Dewoitine faced considerable woes in the late 1920s, being liquidated in January of 1927, before being re-founded the next year. The 1930s would prove more fruitful for Dewoitine. Most notably, the company won some sizeable contracts in the mid 1930s for its Dewoitine D.500, D.501 and D.510, which were low wing, or cantilever-wing, monoplanes, the latter two featuring, a 20 mm autocannon firing through the propeller hub. With more than 300 aircraft ordered for French service, and some limited export contacts, the Dewoitine cantilever wing monoplanes powered the company through the 1930s, and formed the bulk of France’s fighter force all the way up to 1938-1939.

Dewoitine first experimented with a cantilever-wing monoplane fighter with a retractable landing gear in the form of the D.513 fighter which first flew in January of 1936. It generally proved quite disappointing, suffering from instability, and was unable to reach the speed that was expected of it, while also suffering from cooling and landing gear problems, leading to the fighter quickly being discontinued.

The Birth of the “520”

In the French Air Force’s nomenclature, the role of single-seat fighters was classified “C1” (C for chasseur, the French equivalent of fighter, and 1 for single-seat). The air force department in charge of equipment procurement, the Service Technique Aéronautique (STAé – ENG : Aeronautical technical service), would regularly publish calls for aircraft manufacturers to design fighters to fill this role along with a series of required specifications. By late 1936, the last design request had been formulated more than two years prior, in March of 1934. The aircraft from this program, which was being considered for adoption, Morane-Saulnier’s MS.405 (which would become the MS.406), was still in the prototype phase, and had yet to receive orders for production.The MS.405 was already a fairly modern fighter, being a cantilever wing monoplane with a retractable landing gear. But Dewoitine believed that more advanced fighters using the same features could be developed. Anticipating a new design request for the C1 role, Dewoitine began development of a single-seat fighter in late 1936. It was not long before the STAé issued a new request. On the 12th of January 1937, aircraft manufacturers were asked to design a fighter able to reach a maximum speed of 520 km/h, climb to 8,000 meters in less than 15 minutes, land on a runway of 400 meters, and featuring a centerline Hispano-Suiza 20 mm HS.9 autocannon and two 7.5 mm MAC 34 machine-guns, equivalent to the armaments on the D.520 and MS. 405/406.

As the Dewoitine fighter project was still very early in development when the specifications were issued, its design took them into account. The requested maximum speed, 520 km/h, ended up being the project’s number designation.

Another major event happened in March of 1937, when Dewoitine’s Constructions aéronautiques Emile Dewoitine was nationalized by the French state. This was part of a massive nationalization plan that concerned all aspects of France’s defense industry, which was being run by the socialist-leaning popular front government in power since May 1936. Though this meant Dewoitine’s company was now state property, Emile Dewoitine was not displaced in his function as main engineer and leader of the company. The company, however, took a new name – Société Nationale des Constructions Aéronautiques du Midi (SNCAM – ENG: National Society of Aeronautical Constructions of the Midi -‘Midi being the area allotted to the company near Toulouse).

Though Dewoitine was still in full control of his company, all of the reorganization that took place in 1937 meant that work on the D.520 was mostly postponed or paused, resuming only in 1938. On the 3rd of April 1938, SNCAM obtained a contract for the construction of a prototype. Production of the first D.520 began and the prototype, D.520-01, would take off for the first time on the 2nd of October 1938.

Design of the Dewoitine fighter

The fighter aircraft designed by Dewoitine and his team was a low, cantilever-wing monoplane fighter that used an Hispano-Suiza 12Y in-line engine. The plane used riveted duralumin construction, both in structure and skinning.

The D.520’s wings used a one-piece, reinforced single-spar structure. Two MAC 34 7.5 mm machine-guns with gun cameras were installed towards the front, closer to the fuselage, while further inboard in the wings, a 120 liter fuel tank was located. To the rear were the flaps, which were also the only part of the aircraft covered with fabric instead of duralumin. Without the flaps, the wings had a surface of 13 square meters. The flaps had a surface area of 1 square meter, and each wing had a surface area of 14 square meters in total. When counting the wing root, where the fuselage and wings meet, the surface area was 16 square meters. On the first prototype, there was no radiator in the fuselage, and instead a radiator was installed under each wing.

The D.520-01 prototype used a Hispano-Suiza 12Y-31 V12 890 hp engine, without the cannon installed, though later prototypes, followed by production models would use more powerful versions of the Hispano-Suiza 12Y engine with provision for a 20 mm gun firing through the propeller hub. Between the engine and pilot, a 396 liter fuel tank was located (though typically it would only be filled for ferrying, and not combat operations). With a total fuel capacity of 636 litres, the D.520 had high endurance, with a ferrying range of up to 1,500 km in good weather.

The landing gear of the D.520 opened outwards. The definitive production model of the D.520 had a length of 8.6 meters, a wingspan of 10.2 meters, and a height of 3.435 meters.

Prototype Testing

The first prototype, D.520-01, was in some ways more of a demonstrator than a true prototype. From the start, the prototype had a number of differences from the standard models. The model of Hispano-Suiza 12Y that was used, the 12Y-21, did not have a provision for a propeller-hub-firing cannon, and with 890 hp, was less powerful than what was later installed. The wing machine-guns were not mounted either. During its first flight, the prototype failed to reach the desired speed of 520 km/h, not exceeding 480, and several issues were found. The two wing radiators caused too much drag, and a fuselage-mounted radiator was chosen instead. The tail’s control surfaces were found to be too small, and were enlarged. New exhaust pipes were also installed. The 12Y-21 engine was replaced by a 12Y-29, which produced 910 hp. Lastly, a variable pitch propeller was also installed.

The first D.520 prototype undertook a second flight on the 11th of January 1939. This second attempt was much more successful, and showed great promise. It possessed good dive capabilities, with the prototype reaching more than 800 km/h in a dive, and reached 525 km/h in level flight, exceeding the 520 km/h required of the specifications.

The second prototype of the D.520, D.520-02, had its first flight on the 28th of January, 1939. This prototype was much closer to the production model. It was fully armed, including the 20 mm propeller mounted autocannon, and had incorporated all the changes the D.520-01 had undertaken, as well as some new ones: a new landing gear and larger empennage. On the 5th of May, the third prototype, D.520-03, took to the air for the first time. This example featured the 12Y-31 engine, with full armament.

With successful trials of the second prototype, a production order for the D.520 was first placed on the 7th of April 1939, with 200 fighters ordered. The successful trials of the third prototype led to an additional order, initially for 600 aircraft, though reduced to 510 in June. In September, France entered into conflict with Germany, which saw widespread industrial mobilization and orders for new equipment. The total number of D.520s on order rose to 1,280 and through most of 1939, production was being set up at SNCAM’s facilities at Toulouse. Orders continued to accumulate, with 2,250 aircraft on order in April of 1940, including 120 for the navy.

In the meantime, testing continued on the D.520 prototypes. On the 11th of January 1940, D.520-02 was flown by pilot Leopold Galy in diving trials. During a dive from an altitude of 8,000 meters, the aircraft reached a speed of over 900 km/h – Leopard Galy indicated that the instruments showed the speed that the aircraft reached as 920 km/h.

Production Model: Features and Performance

The first D.520s from the production run took to the air in November of 1939. A number of additional features had been added to Dewoitine’s fighter. The newer Hispano-Suiza 12Y-45 engine was chosen, as this model produced 935 hp and featured a much improved Szydlowski-Planiol supercharger, providing the Dewoitine with better high-altitude performance.

The armament of the production model consisted of a Hispano-Suiza HS.404 20 mm autocannon firing through the propeller hub (the prototypes used the earlier HS.9). The HS-404 had a rate of fire of 700 rpm, with a drum magazine holding only 60 rounds, the D.520 could expend its 20 mm ammunition in 9 seconds of continuous fire. The MAC 34 machine-guns were provided with more ammunition. Chambered for the 7.5×54 mm French cartridge adopted in 1929, the MAC 34 machine-guns had 675 rounds each. With a rate of fire of 1,200 rounds per minute, the MAC 34 would expend their ammunition in a little over half a minute. These machine-guns were electrically heated to avoid ice jamming the gun action at high altitudes.

Empty, the D.520 had a weight of 2,050 kg. The aircraft had a structural weight of 892 kg, the engine block empty 517 kg, additional engine accessories 373 kg, empty fuel tanks 56.4 kg, and additional equipment 252 kg. 650 kg would be added on average to get the plane into operation: 337 kg of fuel (the aircraft’s fuel tanks had a capacity of 636 litres), 226 kg including the guns and their ammunition, and an average of 87 kg for the pilot and his equipment. The weight of the plane in operation would therefore be 2,740 kg. With a wing surface of 16 square meters, this meant the D.520 had a quite high wing load of 195 kg/cm2. The D.520 used a three-bladed Ratier variable pitch propeller, with a diameter of 3 meters.

The plane had an automatic fire extinguishing system controlled from the cockpit. As for fuel capacity, the plane featured a 396 liter self-sealing fuel tank located between the cockpit and the engine. Each wing featured a 120 liter fuel tank. The D.520’s fuel capacity of 636 liters was fairly considerable by 1940, and would give it a better range than most one-engined fighters used in Western Europe, with a ferry range of about 1,500 km.

The D.520 could reach a maximum speed of about 535 km/h at the altitude of peak engine performance, which was 6,750 m, and with the engine running at 2,400 rpm. Cruising speed at the same altitude was of 400 km/h with the engine running at 2,000 rpm. The stall speed was 125 km/h.

The rate of climb was 12 meters per second for the first 1,000 meters of flight. 4,000 meters could be reached in a little under 6 minutes, and thanks to its supercharger, the D.520 retained a good climb rate at high altitude. It reached 6,000 meters in 9 minutes and 8,000 meters in a little under 14 minutes. The D.520 would typically be capable of reaching those altitudes before the Bf 109E. The ceiling of the Dewoitine fighter was 11,000 meters.

Though the first examples of the D.520 were completed in November of 1939, some changes were still made, notably, the engine block was lengthened by 16 cm, meaning the first examples produced had to be retrofitted. The D.520 would only commence delivery to the air force in January of 1940, and by May, only a single fighter group had been equipped, though several would receive the new type as production was hastened during the Battle of France.

The aircraft were painted in the standard French air force camouflage scheme of brown, green, and gray color during their manufacturing process. The rudder section was painted in the colors of the French flag. The type of the aircraft (Dewoitine D.520) as well as the aircraft’s production number were indicated in black letters over this French flag-colored tail. French roundels were featured on the wings and on the central fuselage. The underside was typically painted in the same metallic gray color as parts of the fuselage and wings. The propeller hubs and propeller were painted in black.

Future Production Models as Planned in 1940

Improved versions of the D.520 were quickly scheduled for production, and it was planned that these improved models would quickly be introduced to the production lines in the summer of 1940, if everything went well.

The D.521 was an experimental aircraft which mated the D.520 fuselage with the British Merlin III engine. Only one prototype was built, and it was not meant for serial production. The D.522, 523, 524 and 525, however, were D.520s powered by more powerful versions of the Hispano-Suiza 12Y engine.

The D.522 actually went back to the old Hispano-Suiza 12Y-31 860 hp engine block, which was significantly less powerful than the 12Y-45 on paper. It would, however, be fitted with a new Hispano-Suiza supercharger, larger in size than the Szydlowski-Planiol and providing better high-altitude performance. The planned production run for the D.522 was of 75 aircraft, from the 526th to the 600th Dewoitine fuselages, which would likely have meant the production run would have commenced in July of 1940. The D.522 would then have been succeeded by the D.523.

The D.523 used the 12Y-51 model of the 12Y engine, but retained the Szydlowski-Planiol supercharger. This new model of the 12Y produced up to 1,000 hp at optimal altitude. One D.523 prototype was produced (using the 45th D.520 fuselage), and underwent trials from the 9th to the 14th of May 1940. It was able to reach a maximum speed of 570 km/h at the optimal altitude, and climbed faster than the D.520 by a significant margin. This would have made this model a powerful rival to German Bf 109E and F fighters.

Though the D.525 was nominally the last, it was to be produced between the 523 and 524, and was more closely related to the 523 than the 524 was. The D.525 merely combined the 12Y-51 engine from the D.523 and the Hispano-Suiza supercharger from the D.522. Just 30 were to be produced, fuselages 751 to 780.

Finally, the D.524 was to be the last direct derivative of the D.520 scheduled for production by 1940. Its main improvement over previous models was to be the Hispano-Suiza 12Z engine – the most refined model of Hispano-Suiza’s 12Y engine yet, it was to produce 1,300 hp. While very promising in concept, the D.524 was yet to reach the prototype stage by the Invasion of France. While D.520 variants using the 12Z would come to be built at prototype stage later, the D.524 was canceled with the fall of France. It was expected to reach a maximum speed of around 616 km/h at 7,000 m, and climb to 8,000 m in 8’20’’.

By the armistice of June 1940, which put a temporary end to the D.520’s production run, about 440 aircraft had been manufactured, of which closer to 350 had been accepted by the French Air Force. This meant that no further D.520-derived models would see production, and plans to produce them were indefinitely shelved and never revisited.

A floatplane fighter version of the D.520, the HD 780, had also been designed, with one prototype being produced. It incorporated many differences, such as folding, gull-shaped wings, a larger engine block, and two large floats. The prototype was completed in March of 1940, but remained inside its factory and would never take flight.

Into GC I/3

While the first serial-production D.520 had been delivered in November of 1939, these aircraft would later have to be revised and were by no means ready for service.

The D.520 would start effectively entering service during the first months of 1940, with the first squadron, GC I/3, being entirely outfitted with the type in the months of April and early May 1940. There, the D.520 replaced the Morane-Saulnier MS.406. Although another monoplane fighter with a retractable landing gear, the Morane was a plane which had noticeably lower performance in comparison to the Hawker Hurricane or Bloch MB.152, let alone the “triad” of modern fighters available by 1940, which would consist of the Spitfire Mk.I, the Bf 109E and the D.520.

As such, by the start of the campaign, the French Air Force had one squadron fully outfitted with the new fighter type. This fact, however, was tempered to a considerable extent. As mentioned previously, the fighters had only just been delivered to the squadron by the time fighting began in May of 1940. In other words, there had been little to no time for the pilots to accommodate with the newer fighter and become properly accustomed to it – which would prove a larger issue than anticipated, as the D.520 would prove a quite complicated and technical plane to pilot. Many of the pilots which flew the D.520 into combat during the Battle of France – perhaps even more so in the squadrons which would receive the plane during the campaign, would engage in combat during some of their first ten or even five flights of the D.520. Under these circumstances, one could hardly expect good performance with the pilots under such duress.

As hostilities began on the 12th of May, GC I/3 quickly moved into position at the airfield at Wez-Thuisy, in the Marne region of North-East France. From this point, the squadron would be engaged for the rest of the campaign all the way until the 17th of June, when it would retreat to the other side of the Mediterranean to avoid the capture of its planes.

The typical missions of the squadron were defensive, as simply put, the French Armée de l’Air struggled to impose any form of threat against the Luftwaffe. A large number of reasons for this can be attributed to this defensive role of the French air force. One could easily identify the comparative lack of modern fighters in comparison to a Luftwaffe that now universally operated the Bf 109E, a lack of coordination between the French air and ground forces, and many other limiting factors. As such, the D.520 would typically be used to try and intercept flights of German bombers, typically Heinkel He 111s or Dornier Do 17s, as these harassed French logistical centers and cities. In this role, the D.520 would enjoy some successes. It was faster at straight and level flight, and a better climber than previous French fighters, which was quite significant as the German bombers were moderately fast aircraft. The Morane Saulnier MS.406, notably, always struggled to catch the fast German bombers, while the D.520 could do so with relative ease.

The D.520 was credited with its four first victories on the 13th of May, when planes from GC I/3 shot down an He 111 bomber from KG 55 as well as three Henschel Hs 126 reconnaissance planes. The next two days, 14th and 15th, would see very heavy engagements for the squadron. On the morning of the 14th, the squadron would be engaged against a strike force of Dornier Do 17 and He 111 bombers under escort by Bf 109Es. The D.520 of GC I/3 would claim six confirmed kills in the morning, two on He 111s, two on Dornier Do 17s and two on Bf 109s, plus a claimed but unconfirmed kill on another Bf 109. In the late afternoon, D.520s of the squadron would engage in combat against a flight of Bf 110 heavy fighters from ZG 26. As often when the Bf 110 was faced with single-engine fighters without backup from Bf 109s, this ended up fairly bloody for the German squadron which lost four planes, with an additional probable Bf 110 killed claimed by the French.

On the 15th, defence against German raids in the morning would see the squadron claim three confirmed and a probable Dornier Do 17 kills, as well as a confirmed Bf 110 and He 111. In the early hours of the afternoon, D.520s would claim one confirmed and two probable Bf 109s.

The squadron’s actions would wind down in the following days, as it retreated from its first airfield to a new one in Meaux-Esbly, closer to Paris. With German pressure now concentrating against the encircled French and British forces in the North, action would be more sporadic. Between the 15th of May and the 3rd of June, the squadron would claim confirmed kills on an He 111, a Bf 109 and a Do 17, as well as further probable kills for another He 111 and another Dornier 17.

From early June onward, with the Dunkirk pocket liquidated by German advance, attention would shift towards the south once again as Germany progressed further into France, while the French organized a fairly desperate defense on the so-called “Weygang Line.” On the 3rd of June 1940, the squadron claimed its first Ju 88 kill, as well as claiming another Bf 109, and probable shoot downs on three Dornier Do 17s and a Heinkel 111. The 5th and 6th of June were particularly intense in terms of combat with German fighters, with the D.520 claiming four Bf 109s and an Hs 126 on the 5th, and a further two confirmed and two probable 109s as well as a confirmed Do 17 on the 6th. The 7th saw the squadron claim a confirmed Do 17 and Bf 109, and two further probable Do 17s.

The 9th of June 1940 saw the D.520 make the most claims of the Battle of France. The squadron was engaged against a raid of Dornier Do 17s escorted by Bf 109s around noon, claiming four fighters and a bomber. In the late afternoon, the squadron was engaged again against Dornier Do 17s and Junkers Ju 87s once again escorted by Bf 109s, seeing the French fighters down a confirmed Do 17 and Bf 109 as well as two Ju 87s, with a further two probable Do 17 and Bf 109.

The 9th of June 1940 would also begin to see the squadron retiring from its airfield near Paris to go further south, to avoid the now very threatening German advance on the ground. Though a further few engagements were fought fromt the 14 to 16th, most of the action was now behind the squadron. From the 17th to the 21st of June, the squadron would jump from airfield to airfield, from Southern France, to Algeria, finally settling in Kaala-Djerda and later Tunis-El Aouina in French Tunisia.

GC I/3 had claimed a considerable number of victories during the campaign, showing the qualities of the aircraft despite the general lack of training that was to be found in a squadron only recently introduced to its fighter. In total, the squadron claimed 55 confirmed and 19 probable victories. This was at the cost of 32 D.520s lost – of which 21 were lost in aerial combat, the rest being victims of either bombing runs or accidents. This was a rather decent success for a unit which had just received the new fighter type.

Other Squadrons

A number of other squadrons did receive the Dewoitine D.520 during the campaign and used it against German and later Italian forces.

The first squadron to receive D.520s after GC I/3 was GC II/3, which transitioned to the D.520 in 10 days from the 10th to the 20th of May. This was a very short transition for the new fighter, which many would imagine to be fairly worrying for the performance of the squadron. Nonetheless, GC II/3 would perform quite admirably during the campaign. Engaged heavily from the 20th of May onward, it would claim a single victory, an He 111, on its first day of combat, five confirmed and two probable victories on Dornier Do 17s, He 111s and Me 110s on the 21st, and ten confirmed victories (eight Ju 87s and two Hs 126s) on the 22nd. During the entire duration of the campaign, GC II/3 would claim 31 confirmed and 15 probable victories at the cost of 20 D.520s, though only three pilots were killed. The squadron notably counted on Czechoslovak pilot Cukr Vaclav, who would claim two confirmed kills and six shared kills, as well as French Capitaine Raymond Clausse, with three confirmed, and two probable kills on his own, as well as two confirmed, and two probable shared kills.

Other squadrons received their D.520s later in the campaign and would see the fewer kills , among other factors, due to the D.520 being received later in the campaign, at which point German air superiority had more or less been established, and sometimes having to work in mixed squadrons that still incorporated slower Morane-Saulnier MS.406s. GC II/7 was one such mixed squadron, receiving their first D.520s around the 25th of May, while at the same time retaining Moranes until at least the 1st of June. The D.520s of the squadron would still claim more than a dozen victories at the cost of nine of their own aircraft.

GC III/3 fought the most intense parts of its campaign with MS.406s, but was refitted with the D.520 in late May, seemingly not engaged from the 20th of May to the 5th of June, during the transitional period. Going back into action with the Dewoitine, pilots of the squadron would go on to claim eight confirmed, and one probable victory in June, with three confirmed Bf 109s shot down, and another probable, one each of the He 111, Me 110, Dornier Do 17, and two Hs 126s.

GC III/6 is one of the most well known of the D.520 squadrons despite receiving the aircraft late into the campaign. By mid-June 1940, the squadron was in the process of converting from the MS.406 to the D.520, when the entry of Italy into the war forced it to be put into action against Italian aircraft. Under these conditions, French pilot Capitaine Pierre le Gloan would first shoot down two Fiat BR.20 bombers on the 13th of June. On the 15th, Le Gloan took off on a routine patrol around 11:45 pm, originally comprised of three Dewoitines, but soon reduced to two due to technical issues of one aircraft forcing it to return to base. The two remaining fighters, operating near Saint-Tropez on the Mediterranean coast, encountered a force of twelve Fiat CR.42 biplanes of the Italian squadron 23e Gruppo CT. The two D.520s engaged the biplanes. Le Gloan damaged two, one that caught fire and was later written off, and the other pilot ejected, before the faster French fighters broke off. Le Gloan’s wingman’s guns jammed, forcing him back to base as well. Not content with merely two CR.42 shot down though, Le Gloan encountered a further patrol of CR.42s from 18e Gruppo, shooting one down before evading the others in a dive using the largely superior speed of the 520. Le Gloan then returned to Luc airfield, where GC III/6 was stationed, shooting down a CR.42 attempting strafing runs. Lastly, he would down a BR.20 attempting photo reconnaissance of the airfield, attempting to identify the effects of Italian strafing. The Dewoitine was out of cannon ammunition by this point and the BR.20 had to be shot down by machine-gun fire, requiring a total of five passes. This action would have been sufficient to make Le Gloan an ace not just in a day, but in a single sortie, though he had already scored two victories previously. While it was performed using the higher speed of the D.520 against slower biplanes, which would not effectively pursue the French fighter, it remains an impressive feat and likely the most famous action of the D.520 during the campaign of France. Le Gloan’s victories also appear to be the only confirmed ones scored by GC III/6 with the D.520.

Two other French army squadrons, GC II/6 and III/7, began transitioning to the D.520 in June but could not be made operational on the aircraft in time to meaningfully take part in the Battle of France. This was also largely the case for two ground-based squadrons of the French navy’s Flottile F1C, AC 1 and AC 2, which received a few D.520s in the later stages of the Battle of France.

The Tricolor Cockade and the Balkenkreuz: Dewoitine versus Messerschmitt

A topic which inevitably comes up when discussing the D.520 is its comparison with the mainstay German fighter at the time, the Bf 109E. This comparison has been a considerable subject of debates, particularly in France, where a significant amount of pride has often been instilled in the D.520 as the only modern indigenous French fighter that saw intense action and was able to challenge the German fighter.

In practice, the duel between the two aircraft was a rather complicated matter – which was known to the French air force, as a Bf 109E captured during the Phoney War was quite extensively tested in comparison to the D.520 in April of 1940.

The Bf 109 had a clear climb rate advantage over the D.520, which was particularly felt at low altitude, due to being better engined than the French fighter, which was sometimes found to be lacking in horsepower. German engine cooling was also found to be superior, which allowed the aircraft to run for longer at full throttle, while French pilots would often have to temporarily limit running the engine at full throttle to avoid overheating. This would usually allow the German fighter to dictate the terms of engagement, but considering the mostly defensive use of the D.520s, the Bf 109s were forced to provide cover to German bombers, and were often operating in escort, and not air superiority sweeps.

Where the D.520 is often said to have had an advantage is in maneuverability. The D.520 had the advantage of more subtle and less abrupt controls in comparison to the Bf 109E, which would typically give an advantage to the French fighter in a prolonged dogfight. The Dewoitine also enjoyed good engine torque, and in comparison to the BF 109E the cockpit of the D.520 offered far greater visibility which would prove an advantage in such a situation. This was not, however, a massive advantage, and the comparative trials held in April of 1940 saw a duel typically last for several minutes before one of the two aircraft could mount an advantage over the other. In turning fights, the D.520 had a known issue where it was vulnerable to stalling and temporary loss of control during some turns. This was an issue if the enemy fighter was in a favorable position at the moment, though in some engagements it was found that the stalling could be used as an evasive maneuver if the enemy fighter was at a considerable speed advantage. In general, the D.520 was found to still be more comfortable to pilot than the 109 in prolonged dogfights. In turnfights, the D.520 would typically win when the turns were towards the right, but the Bf 109 could be expected to win those towards the left.

In general, while French patriotism would encourage many French authors to claim the D.520 as equal or sometimes even superior to the Bf 109, in practice, the German fighter could arguably be claimed to usually have a slight edge – its ability to dictate the terms of engagement was not entirely compensated for by the maneuverability of the French fighter. This, however, does not paint the full picture. While one may ponder at length over whether the D.520 could be considered equal or slightly inferior to the Bf 109E, it remains clear that it was highly superior to the pre-existing fighters in the French air force, such as the Curtiss H75, Bloch MB.152, and particularly the Morane-Saulnier MS.406, when it came to intercepting fast German bombers such as the He 111, and particularly the Do 17 and Ju 88. The MS.406, notably, would often struggle to catch up with German bombers, while the D.520 could do so relatively easily – giving the French air force a far better tool against enemy bombers, though obviously one which arrived way too late. As such, the D.520 represented a major improvement in the capability of the French air force – which would have been further reinforced by additional new fighter types entering service in June of 1940, the Bloch MB.155 and Arsenal VG.33, with the later managing even better performance than the D.520, with a less powerful engine of the same type, and likely offering a serious competitor to the Bf 109 and Spitfire had the war not abruptly interrupted for the French Third Republic.

An Arrow through the Cockade: Vichy’s Workhorse

Absolutely defeated on the ground by a better equipped, led, and coordinated German army, France was forced into an armistice with Germany, negotiated on the 22nd of June 1940 and going into effect on the 25th of June 1940. In this Compiègne Armistice, the Third Reich inflicted on its French archenemy what was, in many ways, a revenge and repeat of Versaille, with the French as the victim, seriously limiting the size of the French army and its ability to produce new equipment.

However, strategic requirements are a more important matter than symbolism. The French government was in control of many colonial areas around Africa and Asia which Great-Britain was now interested in seizing to further their situation and, with the sinking of the French fleet of Mers-El Kébir on the 2nd of July 1940, this set a major precedent of hostility between the new French regime and the British. Under these conditions, allowing the new Vichy French government to retain a military that could offer resistance to British and Free French attempts to seize colonial territories and naval assets was a useful prospect for Germany. As such, France was allowed to keep a number of squadrons and military units operational – most notably in French North Africa and the French Levant, but also Metropolitan France to an extent.The air force was allowed more strength than the army, which could not operate any armored vehicles outside of Panhard 178s downgraded to a machine-gun armament in mainland France.

As such, authorization was given for the Vichy regime to maintain squadrons I/3, II/3, III/6, II/7 and AC1 operating the D.520. All would be stationed first in French North Africa, with all being located in Algeria outside of II/7 operating in Tunisia. The motive behind putting Vichy’s best fighters in French North Africa was that this location was now the most valuable colony still in the hands of the regime, and was much more vulnerable than the French mainland to potential attack attempts by the Allies. At the same time, while the D.520’s range could allow it to comfortably ferry over the Mediterranean and generally operate in a theater where longer ranges could be desirable, Vichy did retain a number of squadrons operating the shorter-ranged Bloch MB.152 in Metropolitan France. With the Bloch fighter unable to reasonably make the crossing, and ill-equipped to reasonably protect French North Africa, the D.520 was pretty much the only possible choice outside of a now incredibly outdated MS.406 that was on its way out of Vichy’s air force.

During their service life, Vichy aircraft were given a number of recognition markings to differentiate them from British or Free French aircraft and avoid friendly fire incidents from German or Italian planes. At first, this manifested in the form of a white line going through the rear and center of the fuselage, with the cockade superimposed on top and an arrowhead in the direction of the front of the plane. This was put on from the late summer of 1940 onward. From early 1941 onward, these were judged insufficient to reasonably identify Vichy’s aircraft, and they saw their tail sections and propeller hubs painted yellow to further ease identification; it is with these identification markings that the Vichy D.520 would fight during the Levant campaign in May of 1941. In the summer of 1941, the recognition markings were pushed even further, with orange stripes included within the yellow sections, and in many cases, parts of the engine cover painted in the same yellow and orange scheme as the tail.

In April of 1941, with German approval, production of the D.520 resumed to fulfill an order for 550 new planes for Vichy’s air force. The goal was now to make the D.520 the standard fighter of the French air force to the greatest extent possible, first replacing the MS.406 in the squadrons then operating it, and in the further future the MB.152 and MB.155 operated by the fighter groups in Metropolitan France. Two new fighter groups operating the D.520 were created, GC I/2 in Châteauroux, Metropolitan France, and GC II/6 intended for French Occidental Africa, while four squadrons operating other types were re-equipped with the D.520 in Metropolitan France, these being GC I/1, GC III/9 and GC II/1. The last squadron, GC II/5, located in Casablanca, Morocco, was in the process of switching during the Allied invasion of French North Africa, Operation Torch, in November of 1942.

In a fairly cruel twist of irony, what was once the only fighter able to offer resistance to Germany’s Luftwaffe, by 1940 now flew for the Vichy Regime, and only truly became the most common French fighter under this collaboration government. The D.520 would see considerable action in defending Vichy’s colonial territories against British, Free French and American intervention, now fighting a whole different set of aircraft. However, this would once again be under lackluster conditions; pilot training under Vichy was not as extensive and long as under the pre-armistice conditions, partly due to lack of fuel restricting the flight hours which would be performed. While the pilots who fought under Vichy during the Levant campaign and Operation Torch had had more time to accustom themselves to the D.520 than those flying during the Battle of France, these were often the same men from the same squadrons which had now made the switch to the D.520 during the Battle of France. They flew fewer hours per year overall, and as such had their skills not as “well maintained” as their Allied counterparts that were regularly flying combat missions against the Regia Aeronautica and Luftwaffe over North Africa and the Mediterranean.

Under the Vichy regime, studies were also performed in outfitting the D.520 with more powerful engines in order to make the Dewoitine a viable fighter for later in the war. This resulted in the D.520Z, fitted with a Hispano-Suiza 12Z 1,600 hp engine. This project would result in work on a prototype, completed in February of 1943 with German approval, but would only fly in 1947. A project modernizing the D.520 further, the M.520T, would never even reach prototype stage. Vichy had hoped the D.520Z would be serially produced, and postwar trials indeed indicated the fighter had respectable performance even by mid-war standards, being able to reach 659 km/h at 9,150 meters, and could climb to 4,000 meters in 4 minutes 10 seconds, to 8,000 meters in 8 minutes 22 seconds, and to 11,000 m in 14 minutes 19 seconds. This was a very significant improvement in comparison to the D.520, though it came at the cost of the 12Z being a sometimes unreliable engine that would require a lot of maintenance. The occupation of the Vichy regime would prevent any further development, despite a production of up to 230 having been hoped for in the middle of 1942.

Dewoitines Against Hurricanes: The Levant Fiasco

On the 1st of April 1941, a coup in previously British-influenced Iraq brought to power a pro-Axis government, the Golden Square, which would result in the Anglo-Iraqi War lasting for much of the month of May. Germany and Italy, eager to use this opportunity to open another front against the British Empire in the Middle-East, pushed Vichy France to allow Axis planes to use the French colonies of Syria and Lebanon as a base to get to Iraq and support their troops against British Commonwealth forces.

After the end of this campaign, this breach of Vichy’s non-belligerence in favor of Axis support would lead to British, Australian, Indian, and Free French troops invading the Vichy colonies of the Levant. The Vichy regime attempted to put up a defensive effort, which, in the air, relied on Dewoitine fighters.

Prior to May of 1941, only the older MS.406 were located in Levant. With the rise of tensions as the colony now hosted Axis planes, GC III/6 was relocated from Algeria to Rayack in Lebanon on the 27th-28th of May 1941. This airfield would be used until late June, when the squadron would move to Alep. During the Levant campaign, GC III/6 would be joined by GC II/3, which moved into the Levant, transiting through Axis-occupied Greece and would operate from Homs and later Alep during the campaign. The French Navy’s AC 1 squadron would be deployed to the Levant as well.

The opposition the French would face consisted of Hawker Hurricane and Curtiss Tomahawks (P-40), as well as occasionally older Gloster Gladiators, escorting bomber formations typically composed of Blenheim bombers.

The French squadrons put up considerable opposition in the air, with the D.520 still being a decent adversary for the fighter aircraft they were facing. GC II/3’s scoreboard was fairly moderate, with two Blenheims and a Tomahawk shot down on the 2nd of July, with one confirmed and one probable Tomahawk on the 11th of July. GC III/6, present in the operations for longer, would feature a much more accomplished score-board during the campaign. They claimed 16 confirmed and 2 probable Hurricanes, a Fulmar, a Maryland, a Tomahawk, and three Gladiators. Pierre le Gloan, still flying with GC III/6, claimed seven victories: six Hurricanes and a Gladiator. As for the Navy’s AC 1 squadron, it would claim seven confirmed and one probable kill.

Though these were some considerable victories, the D.520 suffered some significant losses during the campaign, with about 40 planes lost, though only eight pilots were killed. Most of these were not shot down in flight. The issue the French faced in Levant were limited aviation facilities that featured little to no anti-aircraft defenses. Against a considerably numerically superior adversary, this resulted in the French being unable to defend their airfields against strafing runs, which decimated the fleet of Dewoitine aircraft. As British forces were progressing through the region swiftly, the three D.520 squadrons were redeployed to Algeria transiting through Greece in early July, so that the remaining fighters, and most importantly their pilots, could participate in the defense of French North Africa, now that the French Levant was irredeemably lost.

It should be noted that two D.520s left behind by Vichy’s air force in the Levant would be captured by the Free French and re-used for a short while in order to train the pilots of Free French GC 3 “Normandie.” This squadron would, from late 1942 onward, be deployed to the Soviet Union, operating with great success using Soviet Yak fighters for the remainder of the war, and gaining great fame as the only Western Allied fighting unit on the Eastern Front, and a highly successful squadron by both Free French and Soviet standards. Previously, the Free French had operated three D.520s that had defected from France to England in June of 1940. Two were conscripted into the force which attempted to seize Dakar in September of 1940, and following the failure of this attempt, they were unloaded in French Equatorial Africa, a colony which joined the Free French. One was lost in an accident, and the other left at its airfield when Free French pilots moved to Egypt to be equipped with Hawker Hurricanes.

 

French Droplets on the Torch

In November of 1942, with the war in the desert in Libya clearly going to the advantage of the Allies, French North Africa appeared as an increasingly appealing territory to seize to further the position of the Allies in North Africa. The large colony, comprising Morocco, Algeria and Tunisia, was however fairly well defended, with the heaviest military forces still in the hands of the Vichy Regime located there. In terms of squadrons using the Dewoitine, these being GC I/3, II/3, III/3, III/6, II/7 and AC 1.

The Anglo-American landings were performed on the 8th of November. For air cover, they relied on large numbers of Grumman F4F Wildcat/Martlet and some Hawker Sea Hurricanes, which were still fighters the D.520 could hope to challenge – and the French squadrons did put up some considerable opposition to Operation Torch.

GC I/3, operating near Oran, racked up a considerable score on the 8th of November, shooting down six Fairey Albacore light naval bombers, five Douglas C47 transport planes, five Hurricanes or Sea Hurricanes, and even a Spitfire. GC III/3, operating near Oran, appears to have claimed nine victories for seven D.520s lost. GC II/3, III/6 and II/7 were not located in areas as hot as the major Algerian harbour of Oran, and appear not to have claimed any victories during the battle. The French Navy’s AC 1 operating in Morocco claimed two F4F Wildcats for no aerial losses.

However, while the French Dewoitines could still put up quite a fight against an F4F in the air, the numerical superiority of Allied fighters, and lack of French airfield defences would once again come back to haunt the French air force, with the AC 1 losing 19 of its 27 D.520s against strafing and bombing runs during the three-days of fighting during Operating Torch.

Luckily for the French, the colonial authorities of North Africa swiftly decided not to continue a vain opposition to Allied advances, and instead sided with the Allies against the Axis. With this, the Vichy squadrons, comprising a little over 130 D.520s, were now fighting against Axis troops. One was repainted in American colors and tested by the US Army Air Corps.

However, the end of the service of the D.520 in North Africa would be fairly swift, with the squadrons soon refitted with fighters such as Hurricanes and Spitfires for further operations, the D.520 no longer being seen as an up-to-date fighter and they lacked the facilities in France likely necessary for the manufacture of spare parts. The Dewoitine was relegated to a training role, in which it was still used in early 1944.

Case Anton: The Dewoitine Under the Balkenkreuz

Days after French North Africa was invaded by the Allies, attention would now turn to the unoccupied part of France under the jurisdiction of the Vichy Regime. On the 11th of November 1942, Germany launched Case Anton, the Wehrmacht rushing to take control of Southern France, facing no resistance from Vichy troops that had been ordered to stay in their barracks and not oppose the Germans invaders. With this swift move, Germany captured around 250 Dewoitine D.520 fighters as well as the facilities which were in the process of producing more.

The French production facilities would continue to work during German occupation, albeit at a reduced rate, seeing as the D.520 was a very low priority by late 1942. About 60 further fighters would be completed under German occupation.

Within the Luftwaffe, the D.520 was put to use as a trainer aircraft. Though now obsolete as a frontline fighter, it could still provide a decent introduction to modern, metal monoplanes with retractable landing gear. For this purpose, JG 101 was outfitted with the D.520 and operated in occupied France, mostly from Pau, in the South, where it would be free from sweeps and raids performed from the British Isles. JG 103, operating during the remainder of the war in the Netherlands or Austria, also used the D.520, as did JG 105, operating near Paris and Chartres, and JG 107 in Nancy. In German service, the D.520s were painted in a light gray color with darker gray spots on much of the aircraft, something typically found on many late-war German aircraft. The underside of the aircraft, and in some cases the nose and tail sections, were painted in a garish yellow color, likely for identification purposes as a training aircraft. The planes received a Balkenkreuz marking on the central fuselage and a swastika on the tail.

The D.520 was noted to not always be a very easy plane to pilot, as it had some unforgiving flight characteristics and suffered from some mechanical issues, such as landing gear which at times failed to retract completely. However, in comparison to German fighters of the time, it offered much smoother and lighter controls for the pilot in comparison to the now quite heavy Bf 109G which were being operated by this point. There would nonetheless be several accidents, with at least three German pilots killed and two wounded on the Dewoitine. A number were also destroyed by Allied bombings of French airfields used by the Luftwaffe.

Outside of a training aircraft, there was another use the Germans could find to the D.520 by the second half of the war. It offered a convenient ‘hand-me-down’ aircraft to outfit the air forces of Axis states which requested fighters from Germany, without diverting any frontline German fighters being manufactured by this point. Two German allies would be outfitted with considerable numbers of D.520 in this fashion, Italy and Bulgaria, though it is sometimes claimed some outfitted Romania as well.

The French Fighter of the Regia Aeronautica

The Regio Esercito (Italian Army) captured 30 Dewoitines during the Battle of France, with many more being transferred to Italy after German capture in France.

The D.520s were assigned to various Regia Aeronautica (Italian Air Force) fighter groups, tasked with intercepting American bombers in the defense of various major cities, an endeavor which was met with mixed results. As Italy began to fall, some Dewoitines were destroyed by retreating Italians, or recaptured by the Germans.

It is of note that the Italians regarded the D.520 largely inferior for various reasons, but did praise the aircraft’s armament, making mention of the formidable 20mm cannon.

The Shield of Bulgaria

The other Axis air force which received a large number of D.520s was the Bulgarian Air Force. Though a member of the Axis powers, Bulgaria had chosen to remain out of Operation Barbarossa, and to not declare war on the Soviet Union, with its contribution to the war effort mostly consisting of its occupation of parts of Greece and Yugoslavia as well as economic cooperation with the Reich. As such, providing fighters for the Bulgarian Air Force may have seemed to be a lower priority for Germany in comparison to other allies, such as Hungary and Romania, which were actively fighting on the Eastern Front. However, Bulgaria was nonetheless at war with the Western Allies and, from 1943 onward, the subject of air raids increasing in frequency and intensity.

The D.520 seemed to be an appropriate hand-me-down for this lower priority but not insignificant part of the Axis, especially as the aircraft, while obsolete against modern fighters by 1943, could still be used against bombers and Bulgaria was still mostly out of reach of Allied single-engined fighters. Up to 150 D.520s appear to have been offered to Bulgaria, of which 120 would be ordered and 96 effectively delivered, the first 48 in August of 1943.

A major advantage of the D.520 for Bulgaria was that the old Czechcoslovak fighters already in use by the Bulgarian air force, the Avia B-71 and B-135, already used engines of the Hispano-Suiza 12Y family, albeit older models. This meant that Bulgarian mechanics would already have some experience with engines similar to those found on the Dewoitines, and that some amount of parts commonality could be expected, easing the logistical burdens Bulgaria would suffer in comparison to obtaining a fighter with an unrelated engine.

The Bulgarian Dewoitines were painted in schemes generally similar to the German ones, with a light gray base, dark upper, along with mottled spots in between. They, however, made more use of brown and green colors as well. The cross of the Bulgarian air force was painted on the aft fuselage, with the individual fighter number behind it. A yellow or white band was sometimes featured in front of the cross, behind the cockpit. The tips of the wings and sometimes the propeller hub were also painted in yellow.

The Bulgarian Dewoitines were delivered to the 6th IP (Fighter Regiment), where they formed the core of the 1st and 2nd groups. They would be operated in intercept missions, fighting along with Bf 109G-2 fighters also operated by the Bulgarians. American raids at this time typically consisted of B-24 bombers escorted by P-38 twin-engine fighters. While these escorts were significantly faster and better armed than the Dewoitines, the Bulgarian fighters could still count on their superior maneuverability to avoid being shot down. It appears the first victories by Bulgarian Dewoitines were scored on the 24th of November 1943, when three to four American planes were shot down by a Bulgarian fighter force composed of 24 D.520s and 16 Bf 109s. The first loss in combat appears to have been on the 10th of December, when one of 22 D.520s flying to intercept a flight of 60 B-24s and 60 P-38s was shot down. Ten days later, on the 20th, D.520s would score two victories, including an escorting P-38. On the 10th of January, Bulgarian pilots, flying 23 D.520s and 16 Bf 109s, in cooperation with 30 German Bf 109s, would claim four B-17s and four P-38s for the loss of a D.520.

The 30th of March 1944 saw the largest air raid of the war on Bulgaria, with more than 360 B-17s and B-24s attacking Sofia. The Bulgarian air force scrambled all aircraft it could muster, including some Avia B-135s from training schools in addition to 28 D.520s from the first group of 6th Fighter Regiment (I/6) and 6 from the 2nd group (II/6). The Dewoitine-equipped groups claimed a B-17 for I/6, and two bombers and a P-38 for II/6. By this point however, losses were starting to increase for Bulgarian fighters, with 4 to 5 D.520s lost against P-38s and defensive fire from the bombers. By the spring of 1944, American air raids now included P-51 and P-47 escorts in addition to the P-38, further complicating the task of Bulgarian pilots. The D.520s appear to have been falling out of favor in comparison to Bf 109s for interception purposes by this point. While 44 Dewoitines were still available to the Bulgarian air force on the 1st of May 1944, they would claim their last victory on 5th of May with a B-17 shot down. Losses started to mount at this point, mostly due to bombing runs against Bulgarian airfields as well as lack of spare parts to support continued operation. By the 1st of September 1944, only 32 D.520s were still in Bulgarian hands, with only about half in flying condition. Overall, the D.520s appear to have claimed 5 B-17s, 2 B-24s and 4 P-38s, attacking in intercept missions against the USAAF, at the loss of seven D.520 in combat. Eight to ten were actually lost in accidents, and overall, eight Bulgarian pilots were killed flying the Dewoitine.

As Soviet forces reached Bulgaria, a communist coup took over on the 9th of September 1944 and Bulgaria joined the war on the side of the Soviet Union. Remaining Bulgarian D.520s would operate against German forces from September to November, with a further two planes being lost, before the type was sent away from the frontlines in November of 1944. D.520s would remain in use by Bulgarian flight schools until 1947, when the type was finally retired from the service of the Bulgarian air force, and surviving aircraft were scrapped.

The Dewoitine into Liberation

By the 6th of June 1944, the D.520 was no longer used as a frontline fighter by any air force in the West. The Luftwaffe and Free French air force both operated the type as a trainer, with many of the Luftwaffe’s fleet of Dewoitines based in France.

While in the first two months following Operation Overlord, Allied progress would remain fairly slow and confined to Normandy, the breakthrough of Operation Cobra in late July saw a lightning-fast liberation of France by a combination of Allied mobile troops, and uprisings by the Forces Françaises de l’Intérieur (French Forces of the Inside or FFI) the leading organized French resistance. This would result in many D.520s being left behind on overrun airfields.

A first use of the D.520 by the FFI would be by a group of resistance fighters taking over the German occupied airfield at Châteauroux on the 20th of August 1944, where they found several damaged aircraft. Cannibalizing parts from different planes, the FFI managed to repair a single Dewoitine. Repainted in French colors, with a Cross of Lorraine on the tail, a French flag on the empennage, and “FFI” painted on the central fuselage, the Dewoitine was flown by a pilot that had not flown since the Battle of France, but ended up belly-landing. Two days later, German troops fleeing Southern France temporarily occupied Chateauroux again, with the FFI camouflaging their plane, and going into hiding until German forces finally left on the 10th of September.

A more organized and professional use of the Dewoitine by the Free French, or French Forces of the Interior (FFI) would be accomplished by the Marcel Doret fighter group. Following the Allied Landings in Provence on the 15th of August 1944, much of Southern France was liberated by Allied troops and FFI uprisings in the following days, including at German airfields in Southern France, the facilities of the Morane-Saulnier, the SNCASE-Dewoitine factories in Toulouse, and the surrounding area. This resulted in a considerable number of Dewoitines falling into the hands of the FFI, which would very swiftly put them to use. Under the command of Marcel Doret, the most prolific French test pilot in the pre-war era, a fighter group was established, operating two squadrons of D.520s, one in Toulouse and one in Tarbes, both in Southern France. This group was grown as the “1er Groupe de Chasse FFI” (1st FFI fighter group), or more colloquially as the “Doret group”. It appeared to have had a strength of 18 D.520s.

 

The Doret group was officially dissolved on the 1st of December 1944 – in practice, it was integrated into the formal structure of the French army as GC 2/18 “Saintonge.” The group was deployed to the Western French coast and used in recon missions as well as escorting Douglas A-24 Banshee bombers over the remaining German “pockets”, areas on the coast which remained under German control due to the presence of highly fortified U-Boat bases the Allies preferred to blockade, rather than attempt a costly take-over. In February of 1945, the D.520s were transferred to GC I/18 Vendée, continuing to see use in similar operations. This fighter group, the last operating the D.520 as a frontline fighter, was dissolved in October of 1945.

The camouflages used by the FFI were based on the German camouflages the D.520 were found with when captured, meaning a lighter gray base with darker gray spots. In some cases, the same brown as present on the D.520 previously in the service of the French air force was reintroduced on parts of the plane. Green could sometimes also be found. The FFI repainted the plane’s tail control surface with the French flag, as found on French air force aircraft prior to the armistice and the capture of the French fighters. A red cross of Lorraine was often found in the white stripe of this tail making. In the first months of operation, the D.520s also received the black and white invasion stripes in order to avoid any form of friendly fire incidents. In some cases, “FFI” appears to have been written in black letters in the white parts of the invasion stripes on the central fuselage. The D.520s also received French roundels on their wings, and later had their invasion stripes removed, with the space left on the central fuselage used for another roundel. A number in a circle was also present on the tail of many aircraft for identification purposes.

A number of FFI D.520s were also exhibited during an aviation exhibition in Paris in the spring of 1945.

The Undying Trainer

One would expect the conclusion of the war to finally have buried the old D.520, by this point completely obsolete against modern prop fighters, let alone jets. Nonetheless, the plane saw continued use in the training role it had often been relegated in the later phases of the war.

This trainer role saw a final variant of the D.520 be designed and produced, the D.520 DC, double commande (dual control.) As the name suggests, this was a D.520 with an extended cockpit to the rear, intended for two men, a cadet and an instructor. The plane would receive dual controls allowing the instructor to take over control of the plane.

The modification had been devised by a French air force adjutant, with a first D.520, n°243, converted in the autumn of 1945. This was a very much makeshift conversion, using pedals from an Fw 190, a control stick from a no longer flyable D.520, and seemingly a seat from an A-24 Banshee for the instructor. Nonetheless, after a first flight in October of 1945, impressions were positive, and after a few modifications were performed, a dozen of D.520s were converted to the DC standards in early 1946. These planes would be used to train a number of French air force cadets, including the first few women to obtain military pilot licenses in the French air force.

The training service of both DC and single-seat D.520s would continue in the following year, though the type was progressively retired as more modern aircraft, including jets, were introduced. The last flight of a D.520 in the French air force was performed on the 30th of September 1953.

Surviving Aircraft

A D.520 is present on static display at France’s Musée de l’Air et de l’Espace du Bourget (ENG: Museum of Air and Space of the Bourget) near Paris. It is painted as a fighter of GC III/6, the squadron of the type’s most successful pilot, Pierre le Gloan.

A D.520 in flyable condition is currently in the hands of the Conservatoire de l’Air et de l’Espace d’Aquitaine (Air and Space Conservatory of Aquitaine). It was restored to airworthiness from 2005 onward, after having been in storage for decades. A third D.520 is present in a hangar of the French navy, awaiting restoration alongside a number of other aircraft.

A fourth D.520, n°408, was part of the Musée de l’air et de l’espace as soon as it was phased out of service in 1957. Surviving as a warbird, it tragically crashed in July 1986, killing the pilot.

Variants

• D.520-01 – The first prototype, utilizing a Hispano-Suiza 12Y-21 generating 890hp. No armament fitted. Numerous modifications included changes to the radiators, tail, exhaust, a 12Y-29 engine, and propeller.
• D.520-02 – A fully armed prototype. Implemented all prior modifications, along with improved landing gear, and a larger empennage.
• D.520-03 – Prototype with upgraded 12Y-31 Engine
• D.520 – Main Production Version, fitted with the Hispano-Suiza 12Y-45 engine. Around 900 produced.
• D.521 – Prototype utilizing the British Merlin III Engine.
• D.522 – Version fitted with the slightly older Hispano-Suiza 12Y-31, fitted with a new Hispano-Suiza supercharger, providing better high-altitude performance. Production was scheduled to start in July 1940, but never occurred due to the German invasion of France.
• D.523 – Fitted with the improved Hispano-Suiza 12Y-51 mated to a Sydlowski-Planiol supercharger, producing up to 1,000 hp at altitude. Also offered significant speed and climb advantages over the original D.520. Only one prototype produced.
• D.524 – Scheduled for 1940 production, would have used the Hispano-Suiza 12Z engine, a refined version of the 12Y engine, expected to have produced 1,300 hp. None built.
• HD 780 – Prototype floatplane naval version of the D.520 featuring foldable, angled, gull wings, increased engine size, and two floats. Was completed in March 1940 but never flown.
• D.525 – Combined the Hispano-Suiza 12Y-51 engine with the Hispano-Suiza supercharger used on the D.522. Only 30 produced.
• D.520Z – Produced under the Vichy Regime in 1943 with German approval, this prototype installed the Hispano-Suiza 12Z engine, making 1,600 hp, a considerable boost in power. First flight didn’t take place until 1947.
• M.520T – Project to further modernize the D.520, never reached the prototype stage.
• D.520DC – A two seat trainer version developed immediately post-war. DC roughly indicates ‘dual control.’

Operators

• French Armée de l’Air (French Air Force) – The French Air Force hastily produced and deployed to active squadrons mere months before hostilities broke out between Germany and France. After the conclusion of the Battle of France, and subsequent armistice, the aircraft would continue to serve under the air force the Vichy Regime.
• Forces Françaises de l’Intérieur (FFI / Free French Forces) – Organized FFI forces operating in recaptured areas of France after Allied breakthroughs in 1944 assembled a few small squadrons and began flying reclaimed D.520s, most notably the “Doret Group,” before being reabsorbed into the formal structure of the revitalized French Army.
• Regia Aeronautica (Italian Air Force [Axis]) – The Italians managed to acquire several dozen D.520s throughout the course of the war, and pressed them into domestic service defending and intercepting allied bombers over the Italian mainland.
• Luftwaffe (Nazi Germany) – During Germany’s various incursions into France, several hundred D.520s came under their control, in addition to continuing serial production under German occupation. The Dewoitines that found their way into German service were primarily used as trainers, or were transferred to Axis allies, namely Italy and Bulgaria.
• Bulgarian Air Force – As Bulgaria was an ally of the Axis powers, upwards of 98 D.520s were transferred to the country’s air force, and used to intercept Allied bomber raids.

Conclusion – The Incarnation of “Trop peu et trop tard”: The D.520 in French Mythos

Since the end of the Second World War, the D.520 has progressively gained a near-mythical status in French military enthusiast circles. The reasons for this are quite easy to identify. The D.520 was the best performing French fighter introduced in large numbers during the Battle of France, and seemingly the only one which posed a credible threat to the Bf 109. However, it arrived too late, and numbers too small to Germany’s advance. In this regard, it was one of a considerable amount of fairly advanced pieces of equipment the French army was close to introducing in 1940, but never could due to the Armistice, similar in this fashion to its fellow Bloch MB.155 and Arsenal VG.33 fighter aircraft, the two Richelieu-class battleships, and the MAS 40 semi-automatic rifle of the French army.

This massive place in French mythos, reinforced by Pierre Le Gloan’s commendable combat record with the type, could be said, however, to have caused some bias to exist in some French analysts, where placing the D.520 as an equal to the Bf 109 has become sort of tradition. While the D.520 was much closer to competing with the German fighter in comparison to the previous MS.406 or MB.152, in some ways, the German fighter could be said to still be a little better performing. It is also questionable whether or not the D.520 could have evolved to become a mainstay fighter for the French air force for the rest of the war, as the Spitfire was for the Royal Air Force and the Bf 109 for the Luftwaffe. In some ways, the VG.33 airframe, which slightly outperformed the D.520, with a previous and weaker version of the same engine, may eventually have provided a better long-term mainstay fighter for France. In any case though, difficult circumstances prevented the VG.33 from ever reaching service, but the D.520 would have the opportunity to live an active service life in a number of air forces, one which saw it in action against both Axis and Allied forces alike.

Dewoitine D.520C-1 specifications
Wingspan	10.18 m /
Length	8.75 m /
Height	2.55 m /
Wing Area	16 m² /
Engine	Hispano-Suiza 12Y-45
Power at Critical Altitude	935 hp at 4,200 m
Max RPM	2,400 RRM
Propeller	Three-bladed Ratier or Chauvière (3 m diameter)
Empty Weight	2,050 kg /
Maximum Takeoff Weight	2,740 kg /
Wing Load	195 kg/m²
Fuel Capacity	400 liters standard 640 liters with wing fuel tanks
Time to Altitude	4,000 m in 5’13” 6,000 m in 7’57” 8,000 m in 13’24”
Maximum Speed	425 km/h at sea level 535 km/h at 6,750 m
Cruising Speed	400 km/h
Stall Speed	125 km/h
Range	Around 900 km with standard fuel load 1,500 km at max fuel fuel load (equipped w/ wing tanks)
Maximum Service Ceiling	11,000 m /
Crew	1 Pilot
Armament	20 mm HS-404 firing through the propeller hub with 60 rounds 4x MAC34M39 machine-guns with 675 rounds per gun in the wings
Number Completed	Around 900 (produced 1939-1944)

Gallery

Credits

• Written by Marisa Belhote
• Special Thanks for Contributions to the Italian Section by Arturo Giusti
• Edited by Henry H., Stan L. and Ed J.
• Illustrations by Ed Jackson

Sources

• Joseph-Bibert fichiers: https://www.bibert.fr/Joseph_Bibert_fichiers/D520.htm
• Notice technique du canon Hispano-Suiza Type 404: https://www.bibert.fr/Joseph_Bibert_fichiers/Notice%20du%20canon%20HISPANO%20SUIZA%20404.pdf
• La revue de l’aérophile, July 1943: https://www.bibert.fr/Joseph_Bibert_fichiers/D520_fichiers/1943_07%20L_Aerophile%2003.jpg
• Icare, Syndicat national des pilotes de ligne, 1970: https://gallica.bnf.fr/ark:/12148/bpt6k3201047s/f1.image.r=Dewoitine%20520
• Aviation-Magazine, 15th of August 1959: https://gallica.bnf.fr/ark:/12148/bpt6k5323473g/f21.image.r=Dewoitine%20520
• Cols bleus : hebdomadaire de la Marine française, French Navy, September 1985: https://gallica.bnf.fr/ark:/12148/bpt6k9784779r/f10.image.r=Dewoitine%20520
• Bulletin de la Société académique des Hautes-Pyrénées, 1984: https://gallica.bnf.fr/ark:/12148/bpt6k6535053x/f125.image.r=Dewoitine%20520?rk=901292;0
• Danel, Cuny, Le Dewoitine D. 520, Docavia n° 4
• L’Armement des avions de chasse français
• L’aviation française 1939-1942, Dominique Breffort, Histoire & Collections éditions, 2011
• Ciel de gloire.fr:
• http://www.cieldegloire.fr/gc_3_06.php
• http://www.cieldegloire.fr/gc_2_03.php
• http://www.cieldegloire.fr/gc_2_07.php
• http://www.cieldegloire.fr/gc_3_03.php