Kawasaki Ki-10

The Kawasaki Ki-10 (九五式戦闘機) was the last biplane fighter used by the Imperial Japanese Army, entering service in 1935. Built by Kawasaki Kōkūki Kōgyō KK for the Imperial Japanese Army, it saw combat service in Manchukuo and in north China during the early stages of the Second Sino-Japanese War. Its reporting name given by the Allies was "Perry".

Design and development
The Ki-10 was designed by Japanese aeronautical engineer Takeo Doi, who had succeeded Richard Vogt as chief designer for Kawasaki. The design was in response to a requirement issued by the Imperial Japanese Army for a new fighter, and was the winner of a competition against Nakajima's Ki-11. Although the low-wing monoplane offered by Nakajima was more advanced, the Army preferred the more maneuverable biplane offered by Kawasaki. In order to overcome the speed disadvantage the Kawasaki team used a metal three-blade propeller in the third prototype, while flush-head rivets were used in an attempt to reduce drag.

The Kawasaki design had sesquiplane (unequal-span) wings, braced by struts, and with upper-wing ailerons. The structure was of all-metal construction, which was then fabric-covered. Armament consisted of two 7.7 mm (.303 in) Type 89 machine guns, synchronized to fire through the propeller. The initial production version was powered by a liquid-cooled 633 kW Kawasaki Ha-9-IIa V engine.

Operations
The Ki-10 was deployed in Manchukuo (Manchuria) and in the initial campaigns of the Second Sino-Japanese War in northern China. It proved an excellent dogfighter against the Chinese air force, including those active at the Battle of Wuhan. However, by the time of the Nomonhan Incident (Battles of Khalkhin Gol) in 1939, against the forces of Soviet Russia, it was largely obsolete.

At the beginning of the Pacific War, the Ki-10 was retired to training and secondary missions, but later returned to front-line service, performing short-range patrol and reconnaissance missions in Japan proper and China in January–February, 1942.

Variants
data from Japanese Aircraft of the Pacific War
 * Ki-10 : Prototype for Imperial Japanese Army Air Force (4 built in early 1935).
 * Ki-10-I (Army Fighter Type 95-I): Initial production version (300 built December 1935 - October 1937)
 * Ki-10-II : Prototype of modified Mark I, increased in length (1 built May 1936)
 * Ki-10-II  (Army Fighter Type 95-2): Improved production version (280 built June 1937 - December 1938)
 * Ki-10-I KAI : Prototype Ki-10-I with modifications to engine and radiator (1 built October 1936)
 * Ki-10-II KAI : Prototype - Aerodynamic modification of Ki-10-II, now designated Ki-10-I-KAI, with 634 kW Kawasaki Ha-9-IIb engine (2 built November 1937)

Total production: 588 units

Operators

 * 🇯🇵 Japan
 * Imperial Japanese Army Air Force
 * 1st Rentai IJAAF
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 * Akeno Fighter Training School