See also:
I.J.N. Mitsubishi B2M1 Type-89 torpedo bomber, c. 1930.
Mitsubishi A6M2 “Zero”, c. 1940.
Mitsubishi 1MT, c. 1922.
“The Mitsubishi Ki-21 (formal designation ‘Type 97 Heavy Bomber’, Kyūnana-shiki jūbakugekiki) was a Japanese heavy bomber first introduced into service in 1938 with production ended with the Pacific War in 1945.
“It began operations during the Second Sino-Japanese War (1937-1945) participating in the Nomonhan Incident, and in the first stages of the Pacific War, including the Malayan, Burmese, Dutch East Indies and New Guinea Campaigns. It was also used to attack targets as far-flung as western China, India and northern Australia. The Allies designated the bomber under the reporting names ‘Sally’ or ‘Gwen’.
“The bomber was initially conceived and specified during 1936 as a means of dealing with the vast distances posed by Japan’s newly-seized territories in Manchuria, and a potential war against that other military power who shared these borders, the Soviet Union. The intent was to provide the Army with an aircraft which could carry large tactical bomb loads over these largely uninhabited distances and attack targets at the front line, the frontier between the nations’ spheres of influence. This limitation in its military applicability would haunt the design later.
“The Ki-21-Ia was used in combat in the war with China by the 60th Sentai [‘Wing’] from autumn 1938, carrying out long-range unescorted bombing missions in conjunction with the Fiat BR.20-equipped 12th and 98th Sentai. Two more sentai, the 58th and 61st deployed to Manchuria in the summer of 1939 for operations against China, with aircraft from the 61st also being heavily used against Russian and Mongolian Forces during the Nomonhan Incident in June–July 1939.
“A number of Ki-21-Ia were modified to serve as military transports for use by Greater Japan Airways, which was under contract by the Japanese Army in China for transportation. Designated ‘MC-21’, these aircraft had all armament and military equipment removed. Used primarily as cargo transports, each could also seat nine paratroopers.
“The Ki-21 had more than one Allied codename. Initially called ‘Jane’, the name was quickly changed to ‘Sally’ when General Douglas MacArthur objected that the name was the same as that of his wife.”
– Wikipedia
Performance
Cruise speed: 380 km/h (240 mph, 210 kn)
Range: 2,700 km (1,700 mi, 1,500 nmi)
Service ceiling: 10,000 m (33,000 ft)