|MC-20-I, with a nickname Asagumo (morning cloud), used by Asahi Shimbun|
|Manufacturer||Mitsubishi Jukogyo Kabushiki Kaisha (Mitsubishi Heavy Industries Limited)|
|Designer||Mitsubishi Jukogyo KK Design Team|
|First flight||August 1940|
|Primary user||Imperial Japanese Army Air Force|
Imperial Japanese Navy Air Service
Imperial Japanese Airways
|Developed from||Mitsubishi Ki-21|
In 1938, when the Ki-21 heavy bomber began to enter service with the Imperial Japanese Army, its capability attracted the attention of the Imperial Japanese Airways. In consequence a civil version was developed and this, generally similar to the Ki-21-I and retaining its powerplant of two 708 kW (950 hp) Nakajima Ha-5 KAI radial engines, differed primarily by having the same wings transferred from a mid to low-wing configuration and the incorporation of a new fuselage to provide accommodation for up to 11 passengers. This transport version appealed also the navy, and following the flight of a prototype in August 1940 and subsequent testing, the type was ordered into production for both civil and military use.
This initial production Ki-57-I had the civil and military designations of MC-20-I and Army Type 100 Transport Model 1, respectively. A total of 100 production Ki-57-Is had been built by early 1942, and small numbers of them were transferred for use by the Japanese navy in a transport role, then becoming redesignated L4M1. After the last of the Ki-57s had been delivered production was switched to an improved Ki-57-II, which introduced more powerful 805 kW (1,080 hp) Mitsubishi Ha-l02 14-cylinder radial engines installed in redesigned nacelles and, at the same time, incorporated a number of detail refinements and minor equipment changes. Civil and military designations of this version were the MC-20-II and Army Type 100 Transport Model 2, respectively. Only 406 were built before production ended in January 1945. Both versions were covered by the Allied reporting name "Topsy".
- Ki-57-I Army Type 100 Transport Model 1: Powered by two 708 kW (950 hp) Nakajima Ha-5 KAI radial engines and a redesigned fuselage to accommodate 11 passengers. About 100 aircraft of this type were built including the civil version.
- MC-20-I: Same as above but built for civil use with Imperial Japanese Airways (Dai Nippon Koku KK).
- Ki-57-II Army Type 100 Transport Model 2:Powered by two 805 kW (1,080 hp) Mitsubishi Ha-l02 14-cylinder radial engines installed in redesigned nacelles. Minor equipment and detail refinements were also incorporated. 306 aircraft of this type were produced before the end of production in January 1945.
- MC-20-II: Same as above but built for civil use with Imperial Japanese Airways (Dai Nippon Koku KK).
- L4M1: A small number of Ki-57-Is were transferred for test by the Japanese navy as transports and were redesignated L4M1.
- Imperial Japanese Airways (Dai Nippon Koku KK)
- Asahi Shimbun
- Osaka Mainichi Shimbun
- Tyuka Koku Kaisya (in China)
- Manchukuo National Airways (in Manchuria)
- One MC-20 used as presidential transport
- One MC-20 used as presidential transport
- The last Ki-57 was used as a trainer and retired in 1952.
- Captured aircraft, used by the KNIL.
Accidents and incidentsEdit
- 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.
Data from Japanese AIrcraft of the Pacific War
- Crew: 4 (pilot, co-pilot, navigator and radio operator)
- Capacity: 11 passengers
- Length: 16.10 m (52 ft 9⅞ in)
- Wingspan: 22.60 m (74 ft 1¾ in)
- Height: 4.86 m (15 ft 11⅜ in)
- Wing area: 70.08 m2 (754.3 ft2)
- Empty weight: 5,585 kg (12,313 lb)
- Loaded weight: 8,173 kg (18,018 lb)
- Max. takeoff weight: 9,120 kg (20,106 lb)
- Powerplant: 2 × Mitsubishi Ha-102 Zuisei 14-cylinder air-cooled radial engine, 805 kW (1,080 hp)(at take-off) each
- Francillon, Ph.D., René J. The Mitsubishi Ki-21 (Aircraft in Profile number 172). Leatherhead, Surrey, UK: Profile Publications Ltd., 1967.
- Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970. ISBN 0-370-00033-1 (2nd edition 1979, ISBN 0-370-30251-6; 3rd edition 1987 by Putnam Aeronautical Books, 1987. ISBN 0-85177-801-1).