Nakajima Ki-87

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Nakajima Ki-87
Nakajima Ki-87.jpg
Role High-altitude fighter-interceptor
Manufacturer Nakajima Aircraft Company
Designer Kunihiro Aoki
First flight April 1945
Status Prototype
Primary user Imperial Japanese Army Air Force
Number built 1

The Nakajima Ki-87 was a Japanese high-altitude fighter-interceptor of World War II. It was a single seat, exhaust-driven turbo-supercharged engined, low-wing monoplane with a conventional undercarriage.

Design and development[edit]

The Ki-87 was developed in response to American B-29 Superfortress raids on the Home Islands. It followed up on earlier research by Nakajima and the Technical Division of Imperial Army Headquarters into boosting a large radial engine with an exhaust-driven turbo-supercharger, which had begun in 1942, well before the B-29 raids began.[1] The efforts of the Technical Division of Imperial Army Headquarters eventually culminated into the Tachikawa Ki-94-I, while the Ki-87 was developed as a fall-back project, using less stringent requirements.[2][3] Nakajima started in July 1943 with the construction of three prototypes, to be completed between November 1944 and January 1945, and seven pre-production aircraft, to be delivered by April 1945.[3] The Technical Division of Imperial Army Headquarters made itself felt during the development of the Ki-87 prototype when they insisted upon placing the turbo-supercharger in the rear-fuselage, and from the sixth prototype the Nakajima fighter was to have that arrangement.[4][5] The Ki-87 had a rearward folding undercarriage to accommodate the storage of ammunition for the cannons, which were mounted in the wing.[1][6]

Construction was delayed due to problems with the electrical undercarriage and the turbo-supercharger, and the first prototype was not completed until February 1945; it first flew in April, but only five test flights were completed, all with the undercarriage in the extended position.[6][7]

A further variant, the Ki-87-II, powered by a 3,000 hp Nakajima Ha217 (Ha-46) engine and with the turbo-supercharger in the same position as the P-47 Thunderbolt, never went further than the drawing board.

Operational history[edit]

Production of 500 aircraft was planned, but the war ended before any more than the single prototype were built.

Aircraft markings[edit]

The sole completed prototype was in natural metal finish; some paintings show a black anti-glare area in front of the cockpit, but this is not seen on any of the known photographs of the plane.[1][8][9]

Specifications (Ki-87 prototype)[edit]

Another photograph of the first Ki-87 prototype, showing to advantage the turbo supercharger.

Data from Japanese Aircraft of the Pacific War;[6] Japanese Army Fighters, Part 2;[7] Famous Aircraft of the World, first series, no.76: Japanese Army Experimental Fighters (1)[10]

General characteristics

  • Crew: 1
  • Length: 11.82 m (38 ft 9 in)
  • Wingspan: 13.423 m (44 ft 0 in)
  • Height: 4.503 m (14 ft 9 in)
  • Wing area: 26 m2 (280 sq ft)
  • Empty weight: 4,387 kg (9,672 lb)
  • Gross weight: 5,632 kg (12,416 lb)
  • Max takeoff weight: 6,100 kg (13,448 lb)
  • Powerplant: 1 × Nakajima Ha219 Ru (Ha-44 Model 11) 18-cylinder air-cooled radial piston engine, 1,800 kW (2,400 hp) for take-off
1,641 kW (2,200 hp) at 1,500 m (4,921 ft)
1,529 kW (2,050 hp) at 6,000 m (19,685 ft)
1,380 kW (1,850 hp) at 10,500 m (34,449 ft)
  • Propellers: 4-bladed constant-speed metal propeller


  • Maximum speed: 706 km/h (439 mph, 381 kn) at 11,000 m (36,089 ft)
  • Endurance: 2 hours
  • Service ceiling: 12,855 m (42,175 ft)
  • Time to altitude: 10,000 m (32,808 ft) in 14 minutes 12 seconds
  • Wing loading: 216.6 kg/m2 (44.4 lb/sq ft)
  • Power/mass: 0.3161 kW/kg (0.1923 hp/lb)


See also[edit]

Aircraft of comparable role, configuration and era


  1. ^ a b c Green 1973, p. 90.
  2. ^ Francillon 1979, p. 238 and 265.
  3. ^ a b Green and Swanborough 1977, p. 62.
  4. ^ Green and Swanborough 1977, p. 63.
  5. ^ Francillon 1979, p. 239.
  6. ^ a b c Francillon 1979, p. 240.
  7. ^ a b Green and Swanborough 1977, p. 64.
  8. ^ FAOW 1976, pp. 59–61 and front cover.
  9. ^ Green and Swanborough 1977, pp. 62–64.
  10. ^ FAOW 1976, p. 67.
  • Francillon, René J. Japanese Aircraft of the Pacific War. London, Putnam & Company, 1970 (Second edition 1979). ISBN 0-370-30251-6.
  • Green, William. War Planes of the Second World War, Volume Three: Fighters. London: Macdonald, 1961 (Seventh impression 1973). ISBN 0-356-01447-9.
  • Green, William and Swanborough, Gordon. WW2 Aircraft Fact Files: Japanese Army Fighters, part 2. London, Macdonald & Jane's, 1977. ISBN 0-354-01068-9.
  • Unknown Author Famous Aircraft of the World, first series, no.76: Japanese Army Experimental Fighters (1). Japan: Bunrin-Do Co. Ltd., August 1976.

External links[edit]