Nakajima Ki-4

The Nakajima Ki-4, officially the Army Type 94 Reconnaissance Aircraft, was the last biplane reconnaissance aircraft of the Imperial Japanese Army. Nakajima built it in response to a 1931 specification for a high-performance reconnaissance machine that could also serve in light ground support, and the prototype flew in May 1934. It was a staggered-wing biplane with fixed, divided landing gear, powered by a single Nakajima Ha-8 nine-cylinder air-cooled radial engine of about 640 horsepower and armed with up to four 7.7 mm machine guns. A total of 516 were built, 333 by Nakajima, 57 under licence by Tachikawa and 126 by Manshu in Manchukuo. It saw combat in Manchukuo and North China in the Second Sino-Japanese War, was obsolete by 1941, and all had left active service by 1943.