The Nakajima Ki-49 Donryu was a Japanese medium bomber of World War II. It was a twin-engine, mid-wing, cantilever monoplane of all-metal construction fitted with a retractable tailwheel undercarriage. During World War II, it was known to the Allies by the reporting name "Helen".
Going operational from autumn 1941, the Ki-49 first saw service in China. After the outbreak of the Pacific War it was also active in the New Guinea area and in raids on Australia. Like the prototype, these early versions were armed with five 7.7 mm (0.303 in) machine guns and one 20 mm cannon.
In the face of its increasing vulnerability to opposing fighter aircraft while performing its intended role, the Ki-49 was used in other roles towards the end of the Pacific War, including ASW patrol, troop transport and, ultimately, as kamikaze.
