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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