The Tachikawa Ki-92 was an experimental Japanese heavy transport aircraft developed during World War II. It was a low-wing monoplane with a pressurized fuselage, twin piston engines, and a tailwheel undercarriage. Only one prototype was built.
Development
In March 1942, the Imperial Japanese Army Air Service selected the Tachikawa Aircraft Company to design and build a new heavy twin-engine transport aircraft with an emphasis on increased range, power, and speed, intended to carry light tanks, field artillery, and troops.
Design work was led by Shinjiro Shinagawa, beginning in March 1943. The first prototype was completed by September 1944. Like Tachikawa's earlier Ki-77, the Ki-92 featured a laminar flow airfoil. The aircraft had a sealed (pressurized) cabin with double-glazed windows, seating 34 troops in four rows (including two emergency seats), which reduced the need for supplemental oxygen. It also employed forced-draught cooling in low-drag engine nacelles.
Due to various repairs and modifications, the first flight did not occur until April 1945. The test flight recorded a maximum speed of 426 km/h, but the Ki-92 was found to be dangerous to fly with the cargo door open at these speeds, although fuselage rigidity was not a problem.
Production and Cancellation
Because of the deteriorating war situation and the resulting reduction in priority for transport aircraft, only one prototype was built. Between three and ten prototypes had been planned. Orders had been placed for 114 production aircraft, which were to be constructed extensively from wood to conserve aluminium (the Ki-92 prototype already featured a tail made from wood). No production aircraft were completed before the war ended. Tachikawa had also planned for potential use of the design as a commercial transport during the design phase.
Allied intelligence organizations, such as the Air Technical Intelligence Unit South East Asia (ATAIU SEA), were unaware of the Ki-92's existence and did not assign it a code name.
Operators
- Imperial Japanese Army Air Service (evaluation only)
Specifications (Tachikawa Ki-92)
Data from Japanese Aircraft of the Pacific War
General characteristics
- Crew: 5
- Capacity: 34 troops
- Length: 22 m (72 ft 2 in)
- Wingspan: 32 m (105 ft 0 in)
- Height: 5.95 m (19 ft 6 in)
- Wing area: 122 m² (1,310 sq ft)
- Empty weight: 11,175 kg (24,637 lb)
- Gross weight: 17,600 kg (38,801 lb)
- Powerplant: 2 × Mitsubishi Ha104 (Army Type 4 1,900 hp Air Cooled Radial) 18-cylinder air-cooled radial piston engines, 1,390 kW (1,870 hp) each
- Propellers: 4-bladed constant-speed propellers
Performance
- Maximum speed: 466 km/h (290 mph, 252 kn)
- Range: 3,960–5,000 km (2,460–3,110 mi, 2,140–2,700 nmi) (estimated)
- Service ceiling: 10,100 m (33,100 ft)
- Time to altitude: 7,000 m (23,000 ft) in 18 minutes 20 seconds
Armament
- Guns: 1 × 12.7 mm (0.50 in) Ho-103 machine gun (not fitted to prototype)
