The Nakajima Army Type 91 fighter was a Japanese fighter aircraft of the 1930s. It was a single-engine, single-seat parasol monoplane with a fixed, tailskid undercarriage.
Designed in response to an Army requirement of 1927, the Type 91 was developed from the NC series of fighter prototypes. The prototype was the sixth machine under that designation but was a fundamentally distinct airframe design. Compared to the earlier NC, the Type 91 had a smaller wing, relocated fuel tank and wing-bracing struts, Townend ring-type cowling, new design tail and undercarriage.[1] It first flew in 1931.
The Army ordered the new aircraft as the Nakajima Army Type 91 fighter and the first deliveries took place late in 1931. However, issues arose with both directional stability and centre of gravity, with the result that the type was delayed entering service.
Between 1931 and 1934, 420 aircraft were constructed (including 100 by Ishikawajima; 23 of the total were Type 91-2, powered by a 432 kW (580 hp) Nakajima Kotobuki 2 radial engine. This version first flew in July 1934.
The type was supplanted in service by the Kawasaki Army Type 95 fighter in 1936–1937.
The Tokorozawa Aviation Museum in Tokorozawa, Saitama has a fuselage on display. Also, at a gate of Yanagisawa Shrine in Yamatokōriyama in Nara Prefecture there is a propeller preserved.