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. The type was generally free of problems but was largely under-powered, under-armed, as compared to the next generations of fighters appearing then. Most critically it was out perfomed by Messerschmitt Bf 109E's during the crucial early days of the war before France surrendered. Although it was one of the few more modern fighters available in quantity at the time, its shortcomings in performance and light armor resulted in high casualties, despite valiant effort on the part of French pilots. The design held its own in the early stages of the war (the so-called Phony War), when the war opened in earnest in 1940, 400 were lost in combat for only 175 kills in return (as well as more destroyed on the ground).

The aircraft type was initially developed to meet a 1934 specification of the French Government by Morane-Saulnier, which had formerly worked on parasol monoplanes. The first flight was in 1935 as the M.S.405. Seventeen 405 prototypes were made, leading to the production version, the 406. Production began in January of 1939 with deliveries to the French air force beginning in March, although engine shortages hampered production. Later versions of the series and included better armor and more guns, and the aircraft formed the basis of aircraft and variants.

After the fall of France, Germany took possession of a large number of 406's and 410's. The Luftwaffe used a number for training, and sold off a number of others. They saw action in Syria against the RAF, also Finland purchased a number and upgraded them with captured Soviet engines and German cannon, while additional examples were passed off to Italy and Croatia. Both Switzerland and Turkey also operated the type.

Contents

8.1 Specifications (variant described)

8.1.1 General characteristics
8.1.2 Performance

9 Other versions

10 See also

M.S.405

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

Morane-Saulnier's response was the M.S.405, a low-wing monoplane of mixed construction, with fabric covered wood tail, but a bonded metal/wood material (Plymax) fixed to duralumin tubing. Plymax consisted of a thin sheet of duralumin bonded to a thicker sheet of plywood. The plane was a departure for them, their first low-wing monoplane, first enclosed cockpit, and their first with retracting gear. Prior to this their most modern designs were fixed-gear parasol monoplanes.

The new 860 hp (640 kW) Hispano-Suiza HS 12Y-grs engine driving a two-pitch Chauvière propeller powered the first prototype, which flew on August 8th, 1935. Development was very slow, and the second prototype with a 900 hp (670 kW) HS 12Y-crs engine didn't fly until January 20th, 1937, almost a year and a half later. With the new engine the plane reached 275 mph (443 km/h), which was fast enough to secure an order for a further 16 pre-production prototypes, each including improvements on the last 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 that saved weight, and a retractable radiator under the fuselage. Powered by the production 860 hp (640 kW) HS 12Y-31 engine, the new design was over 5 mph (8 km/h) faster than the 405, at 304 mph (489 km/h). Armament consisted of a 20 mm Hispano-Suiza HS-9 or 404 cannon with 60 rounds, which fired through the piston banks in the engine, and two 7.5 mm MAC 1934 machine guns in the wings with 300 rounds each.

By this point a war with Germany was clearly looming, and the Armeé 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 January 29, 1939. Deliveries were hampered more by the slow deliveries of the engines than airframes.

By April 1939 the production lines were delivering six aircraft a day, and when the war opened on September 3rd, 1939, production was at eleven 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 Armeé de l'Air, and a further 77 for foreign users, 30 for Finland and 45 for Turkey. Additional orders for Lithuania and Poland were cancelled with the outbreak of the war.

D-3800

In 1938 Switzerland licensed the M.S.406 for local production as the D-3800. Two of the pre-production M.S.405 samples were completed as M.S.406H and sent to them as pattern aircraft in late 1938 and early 1939. These examples had the earlier wing design of the 406, but were mounted with the newer 12Y-31 engines of the 406.

Pre-production started with a run of eight aircraft from EKW with engines built by Adolph Saurer AG driving a new Esher-Wyss EW-V3 fully-adjustable propeller. Instruments were replaced with Swiss versions, and the drum-fed MAC machine guns with a locally-build belt-fed version. The pre-production models were then followed with an order for a further 74 examples, which were all delivered by August 1940. In 1942 a further two were assembled with spares originally set aside for the original production run.

During 1943 surviving aircraft were modified with new cooling and hydraulic installations, and were fitted with ejector exhausts. These modifications were the same standard as the D-3801 series, making them identical with the exception of the engine installation. At the end of the war the remaining aircraft were used as trainers, until the last one was scrapped in 1954.

M.S.410

While the 406's 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 316 mph (509 km/h), and improvement of about 10 mph (16 km/h) 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 406's to the 410 standard, but many of these received only the new wings.

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 1,000 hp (750 kW) HS 12Y-45 engine. A later modification was started as the M.S.412 with the 1,050 hp (780 kW) HS 12Y-51 engine, but this was not completed by the time the war ended.

D-3801

The Swiss received the uncompleted 412 and finished it, modifying it like their 3800's with their own instruments, propeller and weapons. This was put into production in 1941 as the D-3801, and continued deliveries until 1945 when 207 were completed. Another 17 were built from spares between 1947 and 1948, and remained in service as a trainer and target tug until 1959.

M.S.450

In 1939 Hispano started prototype deliveries of the new Hispano-Suiza 12Z engine of 1,300 hp (970 kW). One was fitted to a modified 410 to create the M.S.450 with dramatically better perfomance, especially at altitude. However the engine never entered 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.

Mörkö-Morane

By 1943 Finland had received their original 30 aircraft, as well as an additional 46 406's and 11 410's purchased from the Germans. By this point the planes were hopelessly outdated, but the Finns were so desperate for serviceable aircraft that they decided to start a modification program to bring all of their examples to a new standard.

The result was the Mörkö-Morane (Finnish for Bogey Morane), sometimes referred to as the LaGG-Morane. Powered by captured Klimov M-105P engines (a licensed version of the HS 12Y) of 1,100 hp (820 kW) with a fully-adjustable propeller, the airframe required some local strengthening and also gained a new and more aerodynamic engine cowling. The result of these changes boosted the speed was to 326 mph. Other changes included a new oil cooler taken from the Me 109, the use of four belt-fed guns like the 410, and the excellent 20 mm MG 151/20 cannon in the engine mounting. Supplies of the MG 151 were limited however, and several received captured 50cal Berezina UBS guns instead.

The first example flew in February 1943. Originally it was planned to convert all of their 406's and 410's to the new standard as soon as possible, but by the end of the Continuation War in 1944, only three examples had been converted (including the original prototype). After the end of the war the total was brought to 41, which served as trainers until September 1948.

Specifications (variant described)

General characteristics

Crew:
Capacity:
Length: m ( ft)
Wingspan: m ( ft)
Height: m ( ft)
Wing area: m² ( ft²)
Empty: kg ( lb)
Loaded: kg ( lb)
Maximum takeoff: kg ( lb)
Powerplant: Engine type(s), kN (lbf) thrust or
Powerplant: Engine type(s), kW ( hp)

Performance

Maximum speed: km/h ( mph)
Range: km ( miles)
Service ceiling: m ( ft)
Rate of climb: m/min ( ft/min)
Wing loading: kg/m² ( lb/ft²)
Thrust/weight: or
Power/mass:

Other versions

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 middle for the trainer pilot and using the much less powerful 390 hp (290 kW) Salmson radial engine. The M.S.435 was a more powerful version with the 550 hp (410 kW) Gnome-Rhône 9K engine.