The D 500 was designed by Emile Dewoitine to a 1930 requirement for the Aviation Militaire. It was of all metal monoplane construction, with neat cantilever low wings, a fixed, spatted landing gear, and open cockpit. Intended to meet the demands of the 1930 C1 programme and eventually selected as winning contender, the D 500 was powered by a 12-cylinder Vee Hispano-Suiza 12Xbrs (HS 72) engine rated at 660hp for take-off and 690hp at 4000m. Armament comprised two 7.7mm Vickers guns in the fuselage, these later being supplanted by 7.5mm Darne guns with provision for two similar wing-mounted weapons.

The prototype was first flown on June 18, 1932, and at the end of November 1933, orders were placed for 60 D 500s of which 45 were to be built by Liore-et-Olivier and 15 by SAF-Avions Dewoitine. Of the former, 40 were to be powered by the HS 12Xbrs engine and the remaining five by the HS 12Xcrs (HS 76) with provision for a 20mm Hispano-Suiza S7 (Oerlikon) cannon mounted between the cylinder banks. With this installation and twin wing-mounted machine guns the fighter was designated D 501.

Dewoitine D.501 Article

The SAF-Avions Dewoitine order was eventually to comprise eight D 500s, five D 501s and two D 510s. The first production D 500 was flown on 29 November 1934, contracts having meanwhile been placed for a further 50 D 500s and 80 D 501s to be built by Liore-et-Olivier and 60 D 501s by Ateliers et Chantiers de la Loire, deliveries to the Armee de l’Air commencing May-June 1935. Three D 500s were ordered by Venezuela at the beginning of 1934 and delivered in July 1935, and in the following year 14 D 501s were supplied to Lithuania. The Armee de l’Air received 100 D 500s and 133 D 501s, 30 of the latter type also being supplied to shore-based elements of France’s Aeronautique Navale. Small numbers of D 500s and D 501s equipped Escadrilles Regionale de Chasse in the early months of World War II, but had been relegated to tuitional tasks by 1940.

A further improved model, the D 510, first flew on August 14, 1934. It had a larger area rudder and a revised engine mounting to accommodate the 860 hp HS 12 Ycrs power¬plant.
Two of the 15 D 500 series aircraft (the second and tenth) comprising the initial production contract for the new low-wing fighter monoplane placed with SAF-Avions Dewoitine were fitted with the Hispano-Suiza 12Ycrs (HS 77) engine as prototypes for the D 510. Heavier and longer than the HS 12Xcrs (HS 76) of the standard D 501 fighter, the HS 12Ycrs similarly catered for a 20mm cannon between its cylinder banks, and was rated at 775hp at sea level and 860hp at 4000m. The first of the D 510 prototypes flew (without the cannon fitted) on 14 August 1934, the second (with cannon) following on 10 December. Apart from engine, the D 510 was fundamentally similar to the D 501, the cannon being complemented by a pair of 7.5mm wing guns. In May 1935, the Ministere de l’Air placed an initial contract for 35 (later reduced to 25) D 510s, these being delivered from 9 October 1936. Seven more D 510s were then built for the Armee de l’Air as agreed replacements for a similar number of D 501s taken from the service’s deliveries as part of the Lithuanian order. Follow-on contracts then called for a total of 80 more aircraft from which a contract for 24 D 510s from the Chinese Central Government was to be fulfilled. Other export D 510s were single examples to the UK and the Soviet Union, and two to Japan for evaluation purposes, and two, unofficially, to Republican Spain. These last had been the first two of a cancelled contract for Turkey and were ostensibly sold to the Hedjaz (Saudi Arabia). When it was revealed that the two D 510s had arrived in Spain, the French government insisted that their engines be returned to France. Eventually, both aircraft were fitted with M-100 (licence-built HS 12Ybrs) engines from a Tupolev SB bomber and allegedly saw some combat. Three Groupes de Chasse were still flying with the D 510 at the beginning of World War II, but re-equipped during the first months of the conflict. Two Escadrilles Regionale de Chasse in North Africa converted to D 510s in September-October 1939, flying them until mid-1940, and two escadrilles of the Aeronautique Navale formed on D 510s in December 1939 and May 1940.

One hundred and twenty were built, 90 going to the Armee de l’Air, for whom the D 510 was the first fighter capable of a level speed exceeding 400 km/h (248 mph).
Before the Second World War, most D 510s served in metropolitan France or Tunisia but on the outbreak of war, Groupes de Chasse GC 1/ 1, 11/ 1 and 118 were equipped with this model, and some D 501s were still in service in France with ERC (Escadrilles Regionales de Chasse) 561 and 562. Some D 501s were also still in service in North Africa when France capitulated in May 1940.
Prior to the outbreak of war, Dewoitine had export orders from China (24 D 510C), the Hejaz (two D 510), Japan (two D 510J), Lithuania (14 D 510L), Britain (one D 510A), the USSR (one D 510R) and Venezuela (three D 500V). There is some doubt whether those destined for Venezuela were ever received, and it is probable that some or all of the Lithuanian batch and the two for the Hejaz went instead to the Republican forces in Spain during the Civil War.

D 501
Take-off weight: 1787 kg / 3940 lb
Empty weight: 1287 kg / 2837 lb
Wingspan: 12.09 m / 39 ft 8 in
Length: 7.56 m / 24 ft 10 in
Height: 2.70 m / 8 ft 10 in
Wing area: 16.50 sq.m / 177.60 sq ft
Max. speed: 367 km/h / 228 mph
Range: 870 km / 541 miles

D.510
Engine: Hispano-Suiza 12Ycrs (HS 77), 775hp at sea level, 860hp at 4000m
Take-off weight: 1929 kg / 4253 lb
Empty weight: 1496 kg / 3298 lb
Span: 12.092 m (39 ft 8 in)
Length: 7.94 m / 26 ft 1 in
Height: 2.42 m / 7 ft 11 in
Wing area: 16.50 sq.m / 177.60 sq ft
Maximum speed: 393 km/h (244 mph)
Range: 700 km / 435 miles
Armament: 1 x 20mm cannon, 2 x 7.5mm wing guns

Transferred by the SAF-Avions Dewoitine to the Liore-et-Olivier (LeO) concern owing to the workload imposed on the parent company by the D 50bis (future D 500), the D 37 (later D 370) was a private venture contender in the 1930 C1 programme.
Evolved in 1931 in parallel with the D 500, the D 37 was devel¬oped via the D 53 (strengthened D 27) and first flown on 1 October 1932 with a 700 hp Gnome Rhone 14 Kbrs Mistral Major 14-cylinder two-row radial engine driving a four blade propeller. The prototype was built at Argenteuil by Liore et Olivier and was entered for the 1932 French fighter competi¬tion by the Societe Aeronautique Frangaise, a new company formed by Emile Dewoitine following his return from Switzerland.
It was subsequently subjected to an extensive series of modifications: a G-R 14Kbs engine gave place, in turn, to a G-R 14Kds affording 800hp for take-off and 740hp at 4500m; the engine cowling was changed; the undercarriage was redesigned, and the wing introduced dihedral and reduced chord.
Yet more redesign was embodied by a second prototype, the D 371, which appeared late February 1934. Twenty-eight D 371s were ordered for the Armee de l’Air with the G-R 14Kf s engine of 930hp for take-off and 880hp at 3250m, and an armament of four underwing 7.5mm MAC 34 machine guns.
Fourteen were ordered by Lithuania, and these, having two synchronised 7.7mm Browning guns in the fuselage and two Darne guns of similar calibre in the wings, were designated D 372s. Republican forces in Spain received the 14 D 372s (930 hp Gnome Rhone 14 Kfs) ordered by Lithuania. The Lithuanian government relinquished its D 372s in favour of D 501s, the former being sold to the Spanish Republican government and ferried to Spain during August 1936, where they were later joined by 10 of the 28 Armee de l’Air D 371s.
In March 1036, Escadrilles 7C 1 and 7C2 of the Aeronavale at Hyeres began to replace their Wibault 74s with 20 examples of the D 373, similar to the 372 except for wing flaps and deck landing gear. These had flotation gear, a 30cm reduction in wing span and an armament of four Darne guns within the wing.
These were followed by 25 D 376s with wing folding.
The last D 371 left the factory at the end of December 1935, the Armee de l’Air fighters following the Navy’s D 373s. The remaining D 371s equipped an escadrille at Bizerte, Tunis, until 1939, but were little flown owing to constant problems with their engines.
Standard armament of the D 37 was four underwing 7.5 mm (0.295 in) MAC 1934 or Darne machine guns, but the D 371 prototype was a testbed for two long barrelled 20 mm (0.79 in) Oerlikon S cannon mounted in the wing centre section, and some D 373/376s were fitted with 13.2 mm (0.520 in) Hotchkiss machine guns. Performance of the D 371 included a climb to 4500 m (14 764 ft) in 5.18 minutes and to 10000 m (32810 ft) in 21.85 minutes.

The French Government declared on 25 July 1936 that it would not send arms to Spain, but its Air Minister, Pierre Cot, secretly permitted a consignment of aircraft to be dispatched. At the end of July, about 70 aircraft were sent across the border to Barcelona, including Potez 54 bombers and Dewoitine 371 fighters.
This version’s service effectiveness was limited, due to extensive grounding brought about by frequent engine troubles, and those still serving with ERC 574 in Tunisia were replaced by Morane Saulnier 406s in November 1940. The D 373/376s, 27 of which constituted the entire Aeronavale fighter strength upon the outbreak of war, were similarly replaced by Potez 63 fighters in January 1940.

D 31
Engine: 800¬hp Gnome Rhone 14 Kd

D.37
Armament: 4 x 7.5 mm (0.295 in) MAC 1934 or Darne machine guns

D.371
Span: 11.80 m (38 ft 8.5in)
Length: 7.44 m (24 ft 5 in)
Height: 3.40 m / 11 ft 2 in
Wing area: 17.45 sq.m / 187.83 sq ft
Take-off weight: 1884 kg / 4154 lb
Empty weight: 1320 kg / 2910 lb
Maximum speed: 380 km/h (236 mph)
Armament: 2 x 20 mm (0.79 in) Oerlikon S cannon
Climb to 4500 m (14 764 ft): 5.18 minutes
Climb to 10000 m (32810 ft): 21.85 minutes
Range: 900 km / 559 miles

D 372
Engine: 930 hp Gnome Rhone 14 Kf

D.373
Engine: 930 hp Gnome Rhone 14 Kf

D.376

The D 27 was evolved to meet the requirements of the STAe 1926 C1 leger programme for lightweight fighters.
Incorporating a split-axle (with independently articulated wheels) rather than cross-axle undercarriage, the D 27 was powered by the SLM Saurer built 500hp Hispano-Suiza 12Mb (HS 57) 12-cylinder Vee engine and had an armament of two synchronised 7.7mm guns. The fuel was carried in a tank which formed the underside of the centre fuselage. In emergency this tank could be jettisoned.

The liquidation of the Construction Aeronautique E Dewoitine in January 1927 resulted in the transfer of development of the D 27 to the EKW in Switzerland, where a prototype flew on 3 June 1928.

By the end of 1929, three had been ordered by Romania, one by Argentina and three by Yugoslavia (of which two were to be assembled by Zmaj at Zemun), and the prototype was undergoing evaluation by the Swiss Fliegertruppe in competition with Alfred Comte’s AC-1.

The five prototypes and two of a strengthened model, the D 53, were flown experimentally for a time on board the aircraft carrier Bearn.
In the autumn of 1928, the EKW initiated a pre-series of 12 D 27 fighters, these adopting a redesigned tail and a revised wing of 0.45sq.m less area, modifications first tested in the Laboratoire Eiffel wind tunnel. Meanwhile, in March 1928, Emile Dewoitine had reestablished himself in France, forming the Societe Aeronautique Francaise-Avions Dewoitine.

The second and third pre-series D 27s were delivered to France in April 1929, the former being re-engined with the 400hp HS 12Jb as the D 272 F-AJTE for Marcel Dorset for aerobatic demonstrations. After 267 flight hours it was accidently destroyed in 1936.

The latter undergoing STAe evaluation at Villacoublay from 28 May equipped with two 7.7mm Darne guns. On 29 November 1929, a contract was issued by France’s DGT (Direction Generale Technique) of the Ministere de l’Air for the second and third pre-series aircraft plus three (later increased to four) additional fighters to be assembled by Liore-et-Olivier.

The D 27 was offered to the Forces Aeriennes Terrestres as the D 271 with the 500hp HS 12Hb engine and as the D 273 with a Gnome-Rhone Jupiter VII with a compressor enabling 425hp to be delivered at 4000m, but neither model was adopted.

At the end of 1929, however, the decision was taken in principle to re-equip the fighter element of the Swiss Fliegertruppe with the D 27, a pre-series of five being ordered from the EKW as D 27 IIIs, with deliveries commencing in 1931. A pre-production batch of 15 followed, additional contracts being placed for 45 D 27 IIIs to bring deliveries to the Fliegertruppe to 66 (including the prototype). Sixty six were delivered from 1930 to the Swiss Fliegertruppe, which also received 11 examples of the D 26, a version fitted with a 250 hp Wright Cyclone radial engine. Fifty six of the Swiss D 27s were still in first line fighter squadron service when war broke out in 1939. During the following year, they were withdrawn to training units, from which they did not disappear completely for another decade.

On November 30, 1930, Dewoitine chief test pilot Doret broke the world 1000 km (621 mile) closed circuit speed record flying a Dewoitine D 27 at an average of 286.227 km/h (177.854 mph).

Swiss D 27 III
Take-off weight: 1415 kg / 3120 lb
Empty weight: 1038 kg / 2288 lb
Wingspan: 10.30 m / 33 ft 10 in
Length: 6.56 m / 21 ft 6 in
Height: 2.78 m / 9 ft 1 in
Wing area: 17.55 sq.m / 188.91 sq ft
Max. speed: 298 km/h / 185 mph
Range: 425 km / 264 miles
Armament: 2 x 7.5 mm (0.295 in) machine guns
Service ceiling: 8300 m / 27231 ft
Climb to service ceiling: 11 minutes

The Dewoitine D 27 was designed in Switzerland and built there by the EKW state aircraft factory at Thun. It first flew in 1929, with an SLM Saurer built Hispano Suiza 12 Mc engine of 600 hp, and a total of 85 were built at Thun between 1929 33. Sixty six of these were delivered from 1930 to the Swiss Fliegertruppe, which also received 11 examples of the D 26, a version fitted with a 250 hp Wright Cyclone radial engine.

Dewoitine D.26 Article

Most of the D 26s were used as advanced trainers, but after World War II a number survived doing duty as tugs for sailplanes.

The D 25 tandem two-seat day and night fighter was developed in response to the 1925 C2 (two-seat fighter) programme. Based on the single-seat D 21, but with local reinforcement of the aft fuselage to permit installation of an open turret for a gunner. The D 25 was powered by a 450hp Lorraine-Dietrich 12Eb water-cooled W-type engine, the D 25 entered flight test in 1926, but the C2 programme for which it was intended was abandoned and the type was offered for export.
Four were ordered by Argentina in 1928, and these, fitted with an armament of two 7.9mm synchronised Madsen guns and two similar weapons on a ring mount in the rear cockpit, were built under subcontract by the Hanriot company (which also built the last 10 D 21 single-seaters for Turkey).

Engine: 450hp Lorraine-Dietrich 12Eb
Take-off weight: 1750 kg / 3858 lb
Empty weight: 1182 kg / 2606 lb
Wingspan: 12.80 m / 41 ft 12 in
Length: 7.64 m / 25 ft 1 in
Height: 3.00 m / 9 ft 10 in
Wing area: 24.80 sq.m / 266.94 sq ft
Max. speed: 222 km/h / 138 mph

At the end of 1925, the second prototype D 12 single-seat fighter was re-engined with a 500hp Hispano- Suiza 12Gb (HS 50) 12-cylinder W-type water-cooled engine and redesignated D 21. The D 21 had the four 7.5 mm (0.295 in) Darne machine¬guns.
Intended for export, the D 21 was first demonstrated in January 1926 at Bruxelles-Evere, the first export order from Turkey, for two D 21s for evaluation. Czechoslovakia ordered three and Argentina 18, plus the prototype. Of these, the three Czech aircraft and seven of the Argentine aircraft were assembled by the EKW in Switzerland.

A manufacturing licence was obtained by Czechoslovakia, Skoda building 26 D 21s during 1928-29 (as Skoda D 1s) with Skoda L engines (derived from the HS 12G) of 562hp. Out dated by the late 20s, they were discharged by the Czechoslovak Army and used by the Police Air Patrol.

Argentina also procured a manufacturing licence and the Fabrica Militar de Aviones (FMA) built 58 examples during 1930-31, but with Madsen machine guns and the licence-built Lorraine-Dietrich 12Eb W-type engine. They became effectively D 12s, although the designation D 21 was retained.

One French built D 21 was sold to Switzerland, where in late 1926 Emile Dewoitine had taken up residence, his French company having been bankrupted by the lack of domestic orders for any type since the D 1, and where, in 1928, there appeared the final development of the D 1 formula, the D 27.

In the autumn of 1927, Turkey placed a follow-on order for 10 D 21s, these being delivered during 1928-29.

Max take-off weight: 1580 kg / 3483 lb
Empty weight: 1090 kg / 2403 lb
Wingspan: 12.80 m / 42 ft 0 in
Length: 7.93 m / 26 ft 0 in
Height: 3.00 m / 9 ft 10 in
Wing area: 24.80 sq.m / 266.94 sq ft
Max. speed: 267 km/h / 166 mph

Skoda D-1
Engine: Skoda L, 500 hp
Span 12.24 m
Length 7.64 m
Top speed 270 kph
Rate of climb: 10m/s
Service ceiling: 9000 m
Endurance: 1hr 30min
Armament: two synchronized machine guns