Mitsubishi Ki-57, Japanese users

 

The Mitsubishi Ki-57 was a Japanese passenger and transport aircraft developed from the Ki-21 bomber.

Back in 1938 when the Ki-21 entered service with the Imperial Japanese Army Air Force (IJAAF) its capabilities attracted the attention of the Imperial Japanese Airways (often referred to with their Japanese acronym of DNKKK - Greater Japan Airways Co.). Therefore, a civilian version of the Ki-21 was developed. This had many aspects in common with its bomber counterpart, as it retained the Nakajima Ha-5 KAI radial engines rated at 950 hp each and some other details. It differed mainly in having the same wings moved down from a mid-wing to a low-wing configuration and the incorporation of a new fuselage which could accomodate up to 11 passengers. The civilian variant of this new version was called MC-20, while the military version was called Ki-57.

The first prototype of the Ki-57 flew for the first time in July 1940 and, in spite of a fatal crash suffered by the fourth prototype, it was ordered into production both for the IJAAF, the DNKKK and the Imperial Japanese Navy Air Force (IJNAF) which employed a small number of Ki-57-II, and was known as the L4M1. A total of 101 Ki-57 and MC-20s were manufactured between June 1940 and April 1942 at Mitsubishi's factory in Nagoya. 

The Ki-57-II was an improved variant powered by two Mitsubishi Ha-102 rated at 1.080 hp each, which also powered the Ki-21-II bomber. This variant also featured the revised engine nacelles that the bomber had. They were also 25 mph (40.23 km/h) faster than the Ki-21-I, had a higher service ceiling and could carry heavier loads. Production of the Ki-57-II began in May 1942 and it ran until January 1945 with a total of 306 machines completed (though, according to other sources, the total produced number was higher; 406).

The Ki-57 was, numerically speaking, the most important transport plane of the IJAAF, its main role the Ki-57 was employed in was communications and logistics, but it was also used in paratroop transport and saw service in every front where the Imperial Japanese Army was involved. Its biggest success came on 14th February 1942 when Ki-57s (together with same Kawasaki Ki-56s) of the 1st Raiding Air Regiment (Teisin Sentai) transported paratroopers to attack the oil refineries at Palembang, on Sumatra to prevent their destruction by the Allies before they fell into Japanese hands. 

As the war progressed, and the Allied increased their air superiority, the Ki-57 proved to be very vulnerable to enemy fighters. Dozens were lost when the Allies swept West, including many that encountered heavily armed American patrol bombers, which were not afraid to engage the defenseless transports. When the war ended, many surviving Ki-57s and L4M1s were repainted in white with green crosses painted over the Hinomaru (the Japanese roundel) and were used to ferry Japanese delegates to the surrender ceremonies. 

In 1942 every version of the Ki-57 received the Allied nickname of "Topsy".

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_Ki-57

2. http://www.historyofwar.org/articles/weapons_mitsubishi_ki-57.html

3. https://pacificeagles.net/mitsubishi-ki-57-type-100-topsy/

4. https://www.valka.cz/Micubisi-Ki-57-Topsy-t33121 (translated)

Mitsubishi Ki-57, foreign users

 

The Mitsubishi Ki-57 was a Japanese transport aircraft that was developed from the Ki-21 bomber. It was used by Japan but also by many other countries, like the following ones:

• People's Republic of China: After World War II and the subsequent follow-up of the Chinese Civil War, the Red Army of China took over many Ki-57 transports, left over by the Japanese, mostly in Manchuria, left overs at Changchun airfield. They were employed during the last part of the conflict in the mainland, mainly as trainers, in the flight academy that the Red Army of China (forerunner of the People's Liberation Army) had set in that region. After the war ended, in 1949, they were still being used as trainers until 1952, when they were written off due to their age.
• Republic of China: Just like their Communist foes, the Republic of China Air Force (ROCAF) used some captured MC-20s (the civilian version of the Ki-57 military transport) after the Japanese retreat in 1945. Those were captured mainly in the Mukden airfield, they were also used during the latest stages of the Chinese Civil War, however, they were mostly either destroyed or captured by the Red Army when the Nationalists retreated to Taiwan. 
• Reorganized National Government of the Republic of China: The Japanese collaborationist puppet government had, theoretically, one MC-20 in strength which was used as the presidential transport of Wang Jingwei (president of the collaborationist government). Further details are unknown and, as we couldn't find graphical information, the drawing should be considered as speculative.
• Dutch East Indies: In order to repatriate and liberate Allied civilian and soldiers prisoners of war the Rescue of Allied Prisoners of War and Internees (RAPWI) commission, set up a RAPWI-Air transport company. This was founded by Captain Arens, a former KNILM (the official airline of the Dutch East Indies) pilot and was composed of dozens of left-over Japanese airplanes, among them four Ki-57 machines as well as Japanese airmen. A number of those repatriation flights were conducted by Japanese pilots, often accompanied by Dutch soldiers. For example, one of those service repatriation flights was set up between the cities of Bali and Bandung.
• Manchukuo: The Manchukuo National Airways, more known by its Japanese acronym MKKK (a paramilitary organization working for the Japanese Kwantung Army), had in inventory a total of 20 MC-20 machines. These were supplied by Japan and were used as transport and VIP aircraft. During the last stages of World War II, they were taken over by the Manchukuo Imperial Air Force and flew with Japanese markings, though they kept their Manchurian numbers and pilots. Most of them were either destroyed during the Soviet Invasion of Manchuria or captured and given to the Chinese Red Army.
• Second Philippine Republic: The Japanese puppet government set up in the Philippines had one MC-20 which was used as the presidential transport of José P. Laurel (the president of that republic). As we couldn't find further info nor pics of this aircraft, the drawing should be considered as speculative.

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_Ki-57

2. http://cwlam2000.epizy.com/manchu_x.htm#6、三菱陸軍百式運輸機_/_MC-20_（1945）（Mitsubishi_Ki-57_,_MC-20）(M-600,_601,602,_603,_604,_605...) (translated as much as we could)

3. https://www.ipms.nl/artikelen/nedmil-luchtvaart/vliegtuigen-m/vliegtuigen-m-mitsubishi-ki57 (translated)

4. http://www.airhistory.org.uk/gy/reg_M-.html