The M.S.406 was a French Armee 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 restarted in earnest in 1940, 400 were lost in combat and on ground for only 175 kills in return (as well as more destroyed on the ground). The Finns scored further 121 kills with Morane-Saulnier 406 (code letters MS). The top Morane ace was W/O Urho Lehtovaara with 15 kills on Morane, of total 42. The Finnish nicknames were Murjaani (blackmoor), a twist from its name, and Matimaha (roe-belly) and Riippuvatsa (hanging belly) for its bulged ventral fuselage.