Mitsubishi Ki-21

Ki-21
Mitsubishi Ki-21
Role	Heavy bomber Type of aircraft
Manufacturer	Mitsubishi Heavy Industries
First flight	18 December 1936
Introduction	1938
Retired	1945
Primary users	Imperial Japanese Army Air Service Royal Thai Air Force
Number built	2,064 units (excluding Ki-57)
Variants	Mitsubishi Ki-57

The Mitsubishi Ki-21, formal designation "Type 97 Heavy Bomber" (九七式重爆撃機, Kyūnana-shiki jūbakugekiki) was a Japanese heavy bomber during World War II. It began operations during the Second Sino-Japanese War 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 it under the reporting names "Sally" /"Gwen".