Morane-Saulnier M.S.406

The M.S.406 was a French Armée de l'Air fighter aircraft built by Morane-Saulnier starting in 1938. Numerically it was France's most important fighter during the opening stages of World War II but was under-powered, weakly-armed and lacked full armour protection when compared to its contemporaries. Most critically, it was out-performed by the Messerschmitt Bf 109E during the Battle of France. The M.S.406 held its own in the early stages of the war (the so-called Phony War), but when the war restarted in earnest in 1940, 387 were lost in combat or on the ground (for various reasons) for 183 kills in return. The type was more successful in the hands of Swiss and Finnish air forces who developed indigenous models.

Morane-Saulnier M.S.406
Class Aircraft
Type Fighter
Manufacturer Morane-Saulnier
Origin France
Country Name Origin Year
France 1935
Country Name Operational Year Retirement Year
Japan 1938 1943 View
ManufacturerName Production From Production To Quantity
Morane-Saulnier 1176 View

M.S.405

In 1934, the Service Technique Aéronautique (Aeronautical Technical Service) of the Armée de l'Air issued the "C1 design" requirement for a new and completely modern single-seat fighter with a monoplane layout and retracting landing gear.

Morane-Saulnier's response was the M.S.405 developed by Engineer in Chief Paul-René Gauthier. The MS.405 was a low-wing monoplane of mixed construction, with fabric-covered wooden tail, but a bonded metal/wood material (Plymax) skin fixed to duralumin tubing. Plymax consisted of a thin sheet of duralumin bonded to a thicker sheet of plywood. Morane-Saulnier had a long history of producing warplanes dating back to pre-World War I years, but in the inter-war period, they had concentrated on civil designs. The aircraft was a departure for them, being their first low-wing monoplane, first with an enclosed cockpit, and first design with retracting landing gear. Prior to this, their most modern designs were fixed-gear parasol monoplanes.

The new 641.3 kW (860 hp) Hispano-Suiza 12Ygrs engine driving a two-pitch Chauvière propeller powered the first M.S405-1 prototype, which flew on 8 August 1935. Development was very slow, and the second M.S.405-2 prototype with a 671.1 kW (900 hp) Hispano-Suiza 12Ycrs engine didn't fly until 20 January 1937, almost a year and a half later. With the new engine the fighter reached 443 km/h (275 mph), fast enough to secure an order for a further 16 pre-production prototypes, each including improvements on the previous version.

M.S.406

The result of these changes was the M.S.406. The two main changes were the inclusion of a new wing structure which saved weight, and a retractable radiator under the fuselage. Powered by the production 641.3 kW (860 hp) HS 12Y-31 engine, the new design was over 8 km/h (5 mph) faster than the 405, at 489 km/h (304 mph). Armament consisted of a 20 mm (0.787 in) Hispano-Suiza HS.9 or 404 cannon with 60 rounds in the V of the engine and fired through the propeller hub, and two 7.5 mm (0.295 in) MAC 1934 machine guns (one in each wing, each with 300 rounds). A weakness of the MAC 1934 was its operation at high altitudes. It was found that at altitudes over 20,000 ft, the guns had a tendency to freeze. Heaters were added to the guns for high-altitude use.

M.S.410

While the 406s were entering service in 1939, an upgrade series was started to improve the design. The result was the M.S.410, which included a stronger wing, simpler fixed radiator in place of the earlier retractable design, four belt-fed MAC guns in place of the earlier two drum-fed weapons, and exhaust ejectors for additional thrust. The added thrust boosted the top speed to 509 km/h (316 mph), an improvement of about 16 km/h (10 mph) over the 406.

Production had just started when France fell, and only five examples had been completed. Production was allowed to continue under German supervision, converting earlier 406s to the 410 standard, but many of these received only the new wings. Altogether 74 planes were modified.

M.S.411, M.S.412

A single example of the M.S.411 was constructed by converting the 12th aircraft of the pre-production line with the 406 wing and the 745.7 kW (1,000 hp) Hispano-Suiza 12Y-45 engine. A later modification was started as the M.S.412 with the 783.0 kW (1,050 hp) Hispano-Suiza 12Y-51 engine, but this was not completed by the time the war ended.

M.S.450

In 1939, Hispano started prototype deliveries of the new Hispano-Suiza 12Z engine of 969.4 kW (1,300 hp). One was fitted to a modified 410 to create the M.S.450, giving dramatic improvements in performance, especially at altitude. However the engine did not enter production before France fell, and the similarly modified Dewoitine D.520 (the D.523/D.551) was considered a better design for the engine anyway.

Other variants

The M.S.406 airframe was also used in a number of other projects. The M.S.430 was a two-seat trainer built by inserting a "plug" in the central fuselage with an extra cockpit for the trainee pilot, and using the much less powerful 290.8 kW (390 hp) Salmson 9 radial engine. The M.S.435 was a more powerful version with the 410.1 kW (550 hp) Gnome-Rhône 9K engine.

In the late 1930s, a war with Germany was clearly looming, and the Armée de l'Air placed an order for 1,000 airframes in March 1938. Morane-Saulnier was unable to produce anywhere near this number at their own factory, so a second line was set up at the nationalized factories of SNCAO at St. Nazaire converted to produce the type. Production began in late 1938, and the first production example flew on 29 January 1939. Deliveries were hampered more by the slow deliveries of the engines than by lack of airframes.

By April 1939, the production lines were delivering six aircraft a day, and when the war opened on 3 September 1939, production was at 11 a day with 535 in service. Production of the M.S.406 ended in March 1940, after the original order for 1,000 had been delivered to the Armée de l'Air, and a further 77 for foreign users (30 for Finland and 45 for Turkey). Additional orders for Lithuania and Poland were canceled with the outbreak of the war.

The MS 406 equipped 16 Groupes de Chasse and three Escadrilles in France and overseas, and 12 of the Groupes saw action against the Luftwaffe. The aircraft was very manoeuvrable and could withstand heavy battle damage, but was outclassed by the Bf 109 and losses were heavy (150 aircraft lost in action and 250-300 lost through other causes). After the armistice, only one Vichy unit, GC. 1/7, was equipped with the MS. 406.

Germany took possession of a large number of M.S.406s and the later M.S.410s. The Luftwaffe used a number for training, and sold off others. Finland purchased additional M.S.406s (as well as a few 406/410 hybrids) from the Germans, while others were passed off to Italy and some 48 to the Air Force of the Independent State of Croatia in 1943. Those still in French hands saw action in Syria against the RAF, and on Madagascar against the Fleet Air Arm. Both Switzerland and Turkey also operated the type; the Swiss actually downed a number of both German and Allied aircraft, 1944–45.

Before the Pacific campaign proper, Vichy authorities in French Indochina were engaged in a frontier war against Thailand, during 1940–41. A number of M.S.406s stationed in Indochina downed Thai fighters before the French Air Force abandoned the theatre. Some examples of the M.S.406 were captured by the Thai Air Force.

In Finnish service

The M.S.406 had a parallel career in Finland. In February 1940, the first 30 French fighters were allocated to LeLv 28, commanded by Major Jusu. These aircraft received the Finnish designations MS-301 to MS-330. They were used in combat during the Winter War, against the USSR and carried out 259 operational sorties and shot down 16 Soviet aircraft. In modified form, the M.S.406 were later involved in the Continuation War. Between November 1939 and 4 September 1944, Lv28 scored 118 aerial victories flying the Morane M.S.406 (the unit flew Bf 109Gs for a time, as well). The unit lost 15 aircraft. Total Finnish kills were 121. The top Morane ace in all theatres was W/O Urho Lehtovaara, with 15 of his 44.5 total kills achieved in Moranes. The Finnish nicknames were Murjaani ("moor" or "Negro"), a twist on its name, and Mätimaha (roe-belly) and Riippuvatsa (hanging belly) because of its bulged ventral fuselage.

General characteristics

  • Crew: one pilot
  • Length: 8.17 m (26 ft 9 in)
  • Wingspan: 10.62 m (34 ft 10 in)
  • Height: 2.71 m (8 ft 10 in)
  • Wing area: 17.10 m (184.06 ft)
  • Empty weight: 1,893 kg (4,173 lb)
  • Loaded weight: 2,426 kg (5,348 lb)
  • Powerplant: 1 x Hispano-Suiza 12Y31 liquid-cooled V-12, 640 kW (860 hp)

Performance

  • Maximum speed: 486 km/h (290 mph) at 5,000 m (16,400 ft)
  • Range: 1,000 km (620 mi)
  • Rate of climb: 13.0 m/s (2,560 ft/min)
  • Wing loading: 141.9 kg/m (29.1 lb/ft)
  • Power/mass: 260 W/kg (0.16 hp/lb)

Armament

  • Guns:
    • 1 x 20 mm Hispano-Suiza HS.404 cannon
    • 2 x 7.5 mm MAC 1934 machine guns

End notes