Nakajima Ki-4

The Nakajima Ki-4Kyūyon-shiki teisatsuki (九四式偵察機) was the last biplane reconnaissance aircraft of the Japanese Imperial Army. It saw combat service in Manchukuo and in north China during the early stages of the Second Sino-Japanese War.

Design and development

The Ki-4 was initially produced by Nakajima in response to a 1931 specification for a high-performance reconnaissance aircraft that could also be used in the light ground support role. After evaluating aircraft from Europe and the United States, the Imperial Japanese Army Air Force selected a new design by the domestic Nakajima Aircraft Company. The prototype was test flow in May 1934.

The Nakajima Ki-4 was a biplane design with staggered wings and fixed divided landing gear. It was powered by one 477 kW (640 hp) Nakajima Ha-8, nine-cylinder, air-cooled radial engine. Maximum speed was 300 km/h (190 mph) and maximum take-off weight 2,500 kg (5,510 lb). It was armed with up to four 7.7 mm (.303 in) machine guns, two fixed to fire forward, synchronized with the propeller, and one or two more mounted dorsally on a flexible mount. The maximum bomb load was 50 kg (110 lb).