| Ki-57 | |
|---|---|
![]()  | |
| MC-20-I, with a nickname Asagumo (morning cloud), used by Asahi Shimbun | |
| Role | Transport aircraft Paratroop transport Passenger aircraft  | 
| Manufacturer | Mitsubishi Heavy Industries | 
| First flight | August 1940 | 
| Introduction | 1942 | 
| Primary users | Imperial Japanese Army Air Force Imperial Japanese Navy Air Service Imperial Japanese Airways  | 
| Produced | 1940–1945 | 
| Number built | 406 | 
| Developed from | Mitsubishi Ki-21 | 
The Mitsubishi Ki-57 was a Japanese passenger transport aircraft, developed from the Ki-21 bomber, during the early 1940s.
Development
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.[1]
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".[2]
Variants

- Ki-57-I Army Type 100 Transport Model 1: Powered by two 708 kW (949 hp) Nakajima Ha5 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-102 Zuisei 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.
 
Operators

Wartime
Military operators
Civil operators
- 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
 
Post-war
- The last Ki-57 was used as a trainer and retired in 1952.
 
- Imperial Japanese Airways (till October 1945)[3]
 
- 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)

Data from Japanese Aircraft of the Pacific War [4]
General characteristics
- Crew: 4 (pilot, co-pilot, navigator and radio operator)
 - Capacity: 11 passengers
 - Length: 16.1 m (52 ft 10 in)
 - Wingspan: 22.6 m (74 ft 2 in)
 - Height: 4.86 m (15 ft 11 in)
 - Wing area: 70.08 m2 (754.3 sq ft)
 - Empty weight: 5,585 kg (12,313 lb)
 - Gross 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) each for take-off
 - Propellers: 3-bladed variable-pitch propellers
 
Performance
- Maximum speed: 470 km/h (290 mph, 250 kn) at 5,800 m (19,000 ft)
 - Range: 3,000 km (1,900 mi, 1,600 nmi)
 - Service ceiling: 8,000 m (26,000 ft)
 - Time to altitude: 5,000 m (16,000 ft) 15 minutes 45 seconds
 - Wing loading: 116.6 kg/m2 (23.9 lb/sq ft)
 
See also
Related development
Related lists
References
- ↑ Francillon 1979, pp. 182–183.
 - ↑ Francillon 1979, pp. 183–184.
 - ↑ Francillon 1979, p. 184.
 - ↑ Francillon 1979, pp. 184–185.
 
- Bibliography
 
- Francillon, Ph.D., René J. The Mitsubishi Ki-21 (Aircraft in Profile number 172). Leatherhead, Surrey, UK: Profile Publications Ltd., 1967.
 - Francillon, René J. (1979). Japanese aircraft of the Pacific War. London: Putnam. ISBN 0-370-30251-6. OCLC 6124909. (new edition 1987 by Putnam Aeronautical Books, ISBN 0-85177-801-1); 3rd edition 1987 by Putnam Aeronautical Books, 1987. ISBN 0-85177-801-1).
 
External links
- Classic Airplane Museum MC-20 Japanese
 - JCAL MC-20 Archived 2015-02-14 at the Wayback Machine Japanese
 
