Military Wiki
Role High speed research aircraft
National origin Japan
Manufacturer Kawasaki Kokuki Kogyo K.K. (川崎航空工機業株式会社 - Kawasaki Aircraft Industries)
Design group Aeronautical Research Institute of the University of Tokyo
First flight 26 December 1942[1]
Number built 1 completed + 1x mock-up and the partially complete 2nd prototype[1]

The Kawasaki Ki-78, originally given the designation KEN III (Kensan III - research III), was a high speed research aircraft, also intended to attempt breaking the World Absolute speed record.[1]

Design and development

The Kawasaki Ki-78 was a high-speed research aircraft developed to investigate laminar profile wings with high wing loadings. Early in 1938 a high-speed research program was started at the Aeronautical Research Institute of the University of Tokyo for a small single-seat aircraft.[1] The Ki-78, designed at the Aeronautical Research Institute and built at Kawasaki Kokuki Kogyo K.K. to investigate flying behaviour at very high speed, featured a streamlined minimumcross section fuselage fitted with a licence-built Daimler-Benz DB 601A engine. For short duration power boost, methanol/water injection was used, and cooling was improved by a 45 kW (60 hp) turbine driven cooling fan for the radiators.[1] All-metal construction was used in combination with a small thin wing with a laminar flow profile and sharp leading edge.[1]

Operational history

By the outbreak of the war, the whole project was taken over by the Imperial Japanese Army, who gave it the military type designation Ki-78. Kawasaki received the order to build two prototypes of the Ki-78, construction of which was started in September 1941. The first was completed more than a year later and was flown for the first time on 26 December 1942. A feasibility study to improve the KI-78 flight performance showed that extensive airframe modifications were needed and consequently the project was officially terminated after the 32nd flight on 11 January 1944, the second Ki-78 was never completed.[1]

Specifications (KEN III / Ki-78)

Data from Japanese Aircraft of the Pacific War[1]

General characteristics

  • Crew: 1
  • Length: 8.1 m (26 ft 7 in)
  • Wingspan: 8 m (26 ft 3 in)
  • Height: 3.07 m (10 ft 1 in)
  • Wing area: 11 m2 (120 sq ft)
  • Empty weight: 1,930 kg (4,255 lb)
  • Gross weight: 2,300 kg (5,071 lb)
  • Powerplant: 1 × Daimler-Benz DB 601A V-12 inverted liquid-cooled piston engine rated at 1,160 kW (1,550 hp) with Water/Methanol injection for short durations


  • Maximum speed: 700 km/h (435 mph; 378 kn) at 3,500 m (11,500 ft)
  • Range: 600 km (373 mi; 324 nmi)
  • Service ceiling: 8,000 m (26,247 ft)
  • Wing loading: 209 kg/m2 (43 lb/sq ft)
  • Power/mass: 0.373 kW/kg (0.2273 hp/lb)

See also


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Francillon, Rene (1979). Japanese Aircraft of the Pacific War. London: Putnam & Compny Limited. ISBN 0 370 30251 6. 

Further reading

  • "Error: no |title= specified when using {{Cite web}}". December 1986. p. 489. 

External links

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