HISTORY

the Nakajima Ki-27, Kyunana-shiki sentoki, Type 97 Fighter) was the main fighter aircraft used by the Imperial Japanese Army Air Service up until 1940. Its Allied nickname was "Nate", although it was called "Abdul" in the "China Burma India" (CBI) theater by many post war sources; Allied Intelligence had reserved that name for the nonexistent Mitsubishi Navy Type 97 fighter, expected to be the successor to the carrier-borne Type 96 (Mitsubishi A5M) with retractable landing gear and an enclosed cockpit.

DESIGN AND DEVELOPMENT

in 1935, the Imperial Japanese Army held a competition between Nakajima, Mitsubishi, and Kawasaki to design a low-wing monoplane to replace the Kawasaki Ki-10 (Army Type 95 Fighter) biplane. The new fighter was to have also a better performance than the experimental Mitsubishi Ki-18.

The results were the Nakajima Ki-27, the Kawasaki Ki-28, and the Mitsubishi Ki-33 (a modification of the Mitsubishi A5M carrier-based fighter). The Nakajima design was based on its earlier Ki-11 monoplane fighter which lost to the Ki-10 in the Type 95 Fighter competition. When the follow-up Nakajima Ki-12 proposal with a liquid-cooled engine and retractable landing gear was deemed too complex by the Japanese officials, the Ki-27 was designed by Koyama Yasushi to have an air-cooled radial engine and fixed landing gear. The aircraft had the Nakajima trademark wing with a straight leading edge and tapered trailing edge which would reappear again on the Ki-43, Ki-44, and Ki-84.

The Ki-27 made its first flight on 15 October 1936. Although it had a slower top speed and worse climb performance than its competitors, the Army chose the Nakajima design for its outstanding turning ability granted by its remarkably low wing loading. The Army ordered 10 pre-production samples (Ki-27a) for further testing, which featured an enclosed cockpit with sliding canopy and larger wings.

The type was officially accepted into service in 1937 as the Army Type 97 Fighter. In addition to Nakajima, the Ki-27 was also manufactured by Tachikawa Aircraft Company Ltd and Manshukoku Hikoki Seizo KK, with a total of 3,368 built before production ended in 1942.