Nakajima Ki-87 high altitude fighter 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. Production of 500 aircraft was planned, but the war ended before any more than one was built . The first prototype flew in April 1945.