as transports and were redesignated L4M1. Operators Wartime Military operators Imperial Japanese Army Air Force Imperial Japanese Navy Air Service Manchukuo Imperial Air Force Civil operators Imperial Japanese Airways (Dai Nippon Koku KK) Asahi Shimbun Osaka Mainichi Shimbun Tyuka Koku Kaisya (in China) Manchukuo National Airways (in Manchuria) Reorganized National Government of China One MC-20 used as presidential transport One MC-20 used as presidential transport Post-war The last Ki-57 was used as a trainer and retired in 1952. Imperial Japanese Airways (till October 1945) Captured aircraft, used by the KNIL. Accidents and incidents On December 20, 1940, an Imperial Japanese Airways MC-20-I (J-BGON, Myuko) crashed into Tokyo Bay off Chiba during CAB's test flight, killing all 13 on board including 8 CAB inspectors. On June 21, 1941, a Manchurian Air Transport MC-20 (M-604) crashed into the Sea of Japan, killing all 18 on board. Specifications (Ki-57-II) See also References Bibliography Francillon, Ph.D., René J. The Mitsubishi Ki-21 (Aircraft in Profile number 172). Leatherhead, Surrey, UK: Profile Publications Ltd., 1967. (new edition 1987 by Putnam Aeronautical Books, ); 3rd edition 1987 by Putnam Aeronautical Books, 1987. ). External links Classic Airplane Museum MC-20 Japanese JCAL MC-20 Japanese Ki-057 1940s Japanese military transport aircraft Low-wing aircraft Ki-57, Mitsubishi Aircraft first flown in 1940 Twin piston-engined tractor aircraft