Military Wiki
The sole prototype of the Kawasaki Ki-28
Role Experimental Fighter Aircraft
Manufacturer Kawasaki Kōkūki Kogyo KK
Designer Takeo Doi
First flight 1936
Primary user IJA Air Force
Number built 1

The Kawasaki Ki-28 (キ28 Ki-Nijuhachi?), World War II Allied reporting name "Bob",[1] was an experimental fighter aircraft designed for the Imperial Japanese Army and meant as a replacement for the Kawasaki Ki-10. It flew in 1936, but was never produced for actual use as the Army choose the Nakajima Ki-27.

Design & Development

The Ki-28 was initially produced by Kawasaki Kōkūki Kōgyō KK in response to Japanese army specifications for a fighter to replace the existing Kawasaki Ki-10. In mid-1935, Kawasaki, Mitsubishi and Nakajima were instructed to build competitive prototypes. The Kawasaki design was based on its earlier, but unsuccessful Ki-5. It was a low-wing cantilever monoplane of all-metal construction, except for fabric-covered control surfaces, with a conventional tail unit, fixed tailskid landing gear and powered by a 596 kW (800 hp) Kawasaki Ha 9-II-Ko liquid-cooled inline V12 engine.[2]

Service trials proved that the Kawasaki Ki-28 was the fastest of the three contenders, but the Nakajima Ki-27 was by far the most maneuverable and had the lowest wing-loading, and on this basis was selected by the Imperial Japanese Army Air Force.[3] Despite losing to the Ki-27, the Ki-28 provided Kawasaki with valuable experience which would later help with development of the Kawasaki Ki-60 and Kawasaki Ki-61 fighters.[2]

Mistakenly believing the Ki-28 to have entered production in Japan as the Army Type 97 Fighter, the Allies assigned it the reporting name "Bob" during World War II.[1]


Military operators



Data from Famous Aircraft of the World, no.76: Japanese Army Experimental Fighters (1);[4] Japanese Aircraft, 1910-1941[5]

General characteristics

  • Crew: 1
  • Length: 7.9 m (25.92 ft)
  • Wingspan: 12 m (39.37 ft)
  • Height: 2.60 m (8.53 ft)
  • Wing area: 19 m² (204.52 ft²)
  • Empty weight: 1,420 kg (3,130 lb)
  • Loaded weight: 1,760 kg (3,880 lb)
  • Useful load: 340 kg (750 lb)
  • Powerplant: 1 × Kawasaki Ha-9-II-Ko liquid-cooled in-line piston V-12 engine, 800 hp (597 kW)
  • Propellers: 1 propeller
    • Propeller diameter: 2.90 m (10 ft)


  • Maximum speed: 485 km/h (262 kn, 301 mph)
  • Range: 1,000 km (540 nmi, 620 mi)
  • Service ceiling: 11,000 m (36,000 ft)
  • Wing loading: 92.6 kg/m² (18.97 lb/ft²)
  • Power/mass: 0.33 kW/kg (0.45 hp/kg; 0.20 hp/lb)
  • Time to altitude: 5 min. 10 sec. to 5,000 metres (16,000 ft)Armament

    See also


    1. 1.0 1.1 Francillon, p. 566.
    2. 2.0 2.1 Mikesh and ABe 1990, p. 157.
    3. Wieliczko and Szeremeta 2004, pp. 17–19.
    4. FAOW 1976, p. 2.
    5. Mikesh and Abe 1990, p. 158.
    • Francillon, René J. Japanese Aircraft of the Pacific War Annapolis, Maryland: Naval Institute Press, 1979, ISBN 0-87021-313-X.
    • Mikesh, Robert C.; Shorzoe Abe (1990). Japanese Aircraft, 1910-1941. Annapolis, MD: Naval Institute Press. ISBN 1-55750-563-2. 
    • Unknown Author(s). Famous Aircraft of the World, no.76: Japanese Army Experimental Fighters (1). Tokyo, Japan: Bunrin-Do Co. Ltd., August 1976.
    • Wieliczko, Leszek A. and Zygmunt Szeremeta. Nakajima Ki 27 Nate (bilingual Polish/English). Lublin, Poland: Kagero, 2004. ISBN 83-89088-51-7.

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