Medium Transport Aircraft
Ki-57 Topsy began its flight life as an airliner in the Japanese airline Nippon Koku with a simple rearrangement of the fuselage space of twelve Ki-21 bombers undergoing repair for passenger seats. However, the appearance of a dozen civilian vehicles, created on the basis of a bomber, was only the beginning of the history of perhaps the most successful Japanese transport aircraft of the Second World War.
The aircraft was developed on the basis of the outstanding Ki-21 bomber, which interested the airline with its ability to carry a significant combat load over long distances. The new passenger airliner, civilly designated MC-20, impressed the Japanese army in turn, and it placed orders for a military version called the Ki-57 or the Type 100 transport aircraft.
Most of the Ki-57's design was taken directly from the Ki-21 - the wing, tail, cockpit, landing gear and powerplant were identical to the Ki-21. To optimize the fuselage space for accommodating passengers, the aircraft has changed from a mid-wing to a low-wing aircraft.
The first flight of the prototype took place in August 1939. Flight tests, even despite the crash of the fourth prototype, were recognized as successful, and before the end of the year, both versions were launched into series.
• Ki-57-I - in total, from 1940 to 1942, Mitsubishi produced 101 production vehicles for the army. They were officially designated Type 100 Model 1 Army Transport Aircraft (Ki-57-I). A small number of transport workers were transferred to the fleet, where they were assigned the L4M1 index.
• Ki-57-II - in May 1942, an improved modification of the Ki-57-II (MC-20-II) aircraft was created. The cars of this version, built before January 1945 in the amount of 406 units, differed from their predecessors by the more powerful Mitsubishi Ha-102 engines (1080 hp) and the composition of the onboard equipment.