Nakajima Ki-87

Artwork by KoikeShigeo

Name: Ki-87
Manufacturer: Nakajima (Japan)

Background

The Nakajima Ki-87 was a Japanese high-altitude fighter-interceptor of World War II. It was a single, exhaust-driven turbo-supercharged engined, low-wing monoplane with a conventional undercarriage.
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. 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. 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. 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. The Ki-87 had a Curtiss P-40 Warhawk-like undercarriage, as space in the wing was needed for ammunition for the wing-mounted cannon. The 90° rearwards retracting undercarriage was to provide that needed space.
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.
A further variant, the Ki-87-II, powered by a 3,000 hp Nakajima Ha.217 (Ha.46) engine and with the turbo-supercharger in the same position as the P-47 Thunderbolt, never went further than the drawing board.

Dimensions

Wing Span: 44.03 ft. / 13.42 M
Length: 38.78 ft. / 11.82 M
Height: 14.76 ft. / 4.50 M
Wing Area: 279.86 Sq ft. / 26.00 Sq M
Aspect Ratio: ---
Weight Empty: 9,672 lb. / 4,387 Kg
Weight Takeoff: 12,416 lb. / 5,632 Kg
Max. Takeoff Weight: 13,448 lb. / 6,100 Kg

Power & Performance

Powerplant(s): 1x Nakajima Ha-44 18 cylinder radial engine
Engine Power: 1800 kilowatts / engine
Fuel Fraction: ---

Max. Thrust/Weight Loading: ---
Combat Thrust/Weight Loading: ---

Maximum Wing Loading: 48.05 lb. per Sq. ft.; 234.62 Kg / Sq. M
Takeoff weight Wing Loading: 44.37 lb. per Sq. ft.; 216.62 Kg / Sq. M

VMax High Altitude / VMax Low Altitude: -- / --
Max Speed: 378 knots, 434.7 mph, 700.056 km/h
Operational Ceiling: 42,175 ft. / 12,855 M

Armament

2 x 20mm cannon, 2 x 30mm cannon, 1 x 551 lb bomb

Users

Japan