Morane-Saulnier M.S.406 @SA-kuva
France sent 30 Morane-Saulnier to Finland, between 4 and 29 February 1940. By 1943 the Finns had received an additional 46 M.S.406s and 11 M.S.410s purchased from the Germans. By this point, the fighters were hopelessly outdated, but the Finns were so desperate for serviceable aircraft that they decided to start a modification program to bring all of their examples to a new standard.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 aircraft designer Aarne Lakomaa turned the obsolete "M-S" into a first rate fighter, the Mörkö-Morane (Finnish for Bogey or Ogre Morane), sometimes referred to as the "LaGG-Morane". Powered by captured Klimov M-105P engines (a licensed version of the HS 12Y) of 820.3 kW (1,100 hp) with a fully adjustable propeller, the airframe required some local strengthening and also gained a new and more aerodynamic engine cowling. These changes boosted the speed to 525 kilometres per hour (326 mph). Other changes included a new oil cooler taken from the Bf 109, the use of four belt-fed guns like the M.S.410, and the excellent 20 mm (0.787 in) MG 151/20 cannon in the engine mounting. However, supplies of the MG 151 were limited, and several received captured 12.7 mm (0.500 in) Berezin UBS guns instead.
The first example of the modified fighter, MS-631, made its first flight on 25 January 1943, and the results were startling: the aircraft was 64 kilometres per hour (40 mph) faster than the original French version, and the service ceiling was increased from 10,000–12,000 metres (33,000–39,000 ft).
Originally, it was planned to convert all the 41 remaining M.S.406s and M.S.410s with the Soviet engine, but it took time, and the first front-line aircraft of this type did not reach LeLv 28 until July/August 1944.By the end of the Continuation War in 1944, only three examples had been converted (including the original prototype). Lieutenant Lars Hattinen (an ace with six victories) scored three kills with the Mörkö-Morane, one with each Mörkö-Morane in the squadron. More fighters arrived from the factory, though, and the Mörkö-Moranes took part in the Lapland War as reconnaissance and ground attack aircraft. Not all the Mörkö-Morane conversions were completed before March 1945, when the entire re-engining programme was halted. After the end of the war, the total was brought to 41, which served as advanced trainers with TLeLv 14 until September 1948. In 1952 all remaining Finnish Moranes were scrapped