Mitsubishi Ki-57


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 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 eleven passengers. This transport version appealed also to 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 one-hundred 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 Mitsubishi Ha-102 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.

Variants

;Ki-57-I Army Type 100 Transport Model 1
;MC-20-I
;Ki-57-II Army Type 100 Transport Model 2
;MC-20-II: Same as above but built for civil use with Imperial Japanese Airways.
;L4M1

Operators

Wartime

Military operators
Civil operators
; Reorganized National Government of China
  • One MC-20 used as presidential transport
  • One MC-20 used as presidential transport

Post-war

Accidents and incidents