Ki-49 Donryu. When designing its new medium bomber, Nakajima focused on ensuring good aircraft controllability. Structurally, the aircraft was a midwing with a very low aspect ratio wing of an unusual shape. The large volume of the center section made it possible to accommodate six protected fuel tanks with an overall low air resistance, as well as to provide good controllability and maneuverability at medium and low altitudes. To reduce the speed during takeoff and landing, the wing was equipped with Fowler flaps of a large area.
Ki-49II armament - one 20 mm Ho-1 cannon in the upper turret and five 12.7 mm Ho-103 machine guns on mobile units in the tail turret, in the nose, under the fuselage and in the side windows. Normal bomb load - 750 kg, maximum - 1000 kg.
The first flight of the prototype took place in August 1939 with 950 hp engines. with., the second and third already with 1250-horsepower Ha-41 engines. The next seven machines of the installation batch had automatic pitch propellers.
Combat use. During the fighting, it turned out that the much-publicized new bomber, designed to "end the war and bring victory to Japan," suffered heavy casualties. The speed, the main trump card before the Ki-21, was not enough to get away from the modern Spitfires and Supermarines. The pilots only spoke positively about the armor protection and the relatively powerful defensive armament of the Ki-49. Saved in some cases, and the presence of protection of fuel tanks. But this was not enough, so the new Ki-49s in parts did not completely replace the old . In addition, compared to the Ki-21, the aircraft required significantly more complex maintenance.
At the final stage of the war, the few Ki-49 survivors after the battles for the Philippines were used by kamikaze pilots against large enemy ships. At the same time, all weapons were removed from the Ki-49, the crew was reduced to two pilots, and the bomb load increased to 1600 kg. The aircraft entered the history of Japanese aviation only as a bomber, for the first time equipped with a tail gun turret, and, perhaps, as a bomber with one of the shortest combat careers among the main bombers of World War II. The Allied aircraft was codenamed "Helen", after the wife of one of the intelligence officers in the Pacific Southwest.