Tachikawa Ki-92

The Tachikawa Ki-92 was an experimental Japanese heavy transport aircraft of World War II. It was a low-wing monoplane with a pressurized fuselage, twin piston engines and a tailwheel undercarriage.

Development
In March 1942 the Imperial Japanese Army Air Force chose Tachikawa to design and build a new heavy twin engine transport aircraft with a focus on increased range, power and speed to carry light tanks, field artillery and troops.

Shinjiro Shinagawa was in charge of the development and began work in March 1943 and the first prototype was completed by September 1944. Due to various repairs and modifications, the first flight did not occur until April 1945. The test flight recorded a maximum speed to 426 km/h but it was found to be dangerous to fly with the cargo door open at these speeds though fuselage rigidity was not a problem. Like Tachikawa's Ki-77 it featured a laminar flow wing, a sealed cabin with double glazed windows seating 34 troops in 4 rows (including two emergency seats) to reduce the need for oxygen, and forced draught cooling in low drag engine nacelles.

Due to the deteriorating war situation, and resulting reduction in priority for transport aircraft, only one of between three and 10 prototypes planned for and no production aircraft were built before the war ended. Orders included 114 built extensively from wood to conserve on aluminium use though the prototype already featured a tail made from wood. Tachikawa had planned for their use as commercial transports during the design phase.

Allied intelligence organizations such as ATAIU SEA were unaware of the existence of the Ki-92 and did not assign a code name to it.