Morane-Saulnier M.S.325

The M.S.325 was a French Armée de l'Air fighter aircraft built by Morane-Saulnier in 1933 to meet the requirements of 1930 fighter aircraft specification. The design was unsuccessful and was abandoned in 1934.

Design and development
In 1930, when the Jockey legier Chasse, or Plan Caquot light weight fighter program was judged a failure, the Service Technique de l' Aeronautique issued the C1 (monoplace de chasse) requirement. C1 (upgraded on 26 January 1931) called for a single-seat fighter powered by a supercharged engine with a cylinder capacity of between 26 and 30 l. Ultimately no fewer than 10 designs and 12 prototypes were offered, all designed around the 26 l Hispano-Suiza 12Xbrs developing 650 hp at 4500 m, with proven reliability and a relatively small frontal area. The Morane-Saulnier submissions included the M.S.275 which retained the classic parasol monoplane configuration of preceding Morane-Saulnier fighters. In the more innovative M.S.325, a low wing, duralumin-skinned all-metal configuration was employed.

The M.S.325 was relatively modest in its concept still featuring an open cockpit (originally the tail surfaces were fabric covered) and fixed-gear with the semi-elliptical two-spar wings braced by exterior struts. The wings had two jettisonable wing root fuel tanks with a pair of 7.7 mm Châtellerault machine guns mounted one above each of the widely spaced landing gear legs. More unusual was that the incidence of the starboard wing greater than that of the port wing to counter torque; the engine was also canted slightly to port to counter the resultant yaw.

Operational history
M.S.325 C3 No. 01 (Works no. 4120) was flown for the first time by company Chief Test Pilot Michael Détroyat early in 1933 from the factory site, Vèlizy-Villacoublay. The first test results were not satisfactory as tail buffeting was encountered leading to modifications that included lowering the tailplane and adding wing root fairings.

Although testing proceeded, the M.S.325 continued to be hampered by handling problems. In measuring up to other C1 competitors, the M.S.325 was relegated to an "also-ran" status and the Dewoitine D.500 became the chosen design.

Development based around a Hispano-Suiza 12Xers engine with a 20 mm cannon was proposed but eventually, the M.S.325 design was abandoned in favour of the more promising M.S.405 C.1 with only partial performance tests completed.