Aviation of World War II
In March 1942, the air headquarters of the Imperial Army issued the Tachikawa company a task to design and build a new heavy transport aircraft with two engines of increased power, capable of transporting manpower, light tanks and field artillery over long distances.
Shinjiro Shinagawa, who was in charge of the aircraft's development, began work in March 1943, and the first prototype was completed by September 1944. The Ki-92 had a sealed cargo compartment with double-glazed windows and a passenger capacity of 32 with 4 soldiers in each row (including two emergency seats). To reduce the need for oxygen, the plane was inflated with air taken from the engines. Due to the revealed defects and subsequent modifications, the aircraft made its first flight only in April 1945.
The test flight recorded a maximum speed of 426 km/h (according to other sources 466 km/h), but it was found that it was dangerous to fly the Ki-92 with the door open, although at these speeds the fuselage was stiff enough.
The all-metal wing consoles had a laminar profile, which is absolutely exceptional for an aircraft of this class. The wing mechanization included retractable Fowler flaps.
The power plant of the military transport aircraft consisted of two radial two-row 18-cylinder air-cooled Mitsubishi Ha-104 engines equipped with turbochargers and forced cooling by means of a fan installed between the propeller and the front row of engine cylinders. The takeoff power of each of the engines was 2000 hp. (1470 kW), at an altitude of 1700 meters, they developed 1870 hp each. (1375 kW). This made it possible to hope for a maximum speed of more than 400 km/h.
The main landing gear was retracted into the nacelle niches in the forward direction, the tail wheel was left non-retractable. The plumage was performed according to a single-fin scheme.
The first prototype of the Ki-92 was ready in September 1944, but due to constant improvements, its flight was postponed. Only in May 1945, the Ki-92 prototype was successfully lifted into the air. As it turned out, Shinjiro Shinagawa's calculations were generally correct. On tests, the prototype showed a maximum speed of 426 km / h (according to other sources - even 466 km / h) and a cruising speed of about 350 km/h. The nominal range was 3960 km, but the maximum was determined at 5000 km. It was assumed that the aircraft will be armed with one 12.7 mm machine gun No-103, but it was not on the prototype. Thus, in terms of the main performance characteristics, the aircraft was satisfied with the command of the Army Air Force, however, in conditions of constant bombing and dwindling sources of resources, the start of serial production remained a big question.
Due to the deteriorating military situation and the falling priority for transport aircraft, only one of ten planned prototypes of the Ki-92 was built, and their serial production was never started. Tachikawa hoped to receive an order for 114 aircraft, in which it was supposed to widely use wood materials to save aluminum, although the first prototype of the Ki-92 already had a tail made of wood. The Tachikawa company managed to start building two more experimental aircraft, but their construction was not completed until the end of the war in September 1945.
Allied intelligence organizations such as ATAIU SEA did not know anything about the existence of the Ki-92 and did not assign a codename to it.