Kawanishi's
N1K was originally built as a single pontoon floatplane fighter to support forward offensive operations where no airstrips were available, but by 1943 when the aircraft entered service, Japan was firmly on the defensive, and there was no longer a need for a fighter to fulfill this role. The Navy's requirements for this fighter were nearly impossible to achieve for a float plane, and the expected protracted development period led Nakajima to develop an interim float plane fighter based on the Zero, the
Nakajima A6M2-N. In the end, the
Kyofu only saw limited service, mostly in Southeast Asia. A number were flown out of
Ambon and the
Aru Islands in the Moluccas, while some were stationed at
Penang Island, off the Malayan peninsula. They were also used in the
Battle of Okinawa. Towards the end of the war,
Kyōfū were also used in the homeland defense role, operating from
Lake Biwa by the Sasebo Air Corps and the Ōtsu Air Corps. The N1K was powered by the
Mitsubishi MK4C Kasei 13 14-cylinder radial engine. Top speed was ; falling short of the Navy's specified requirement of requirement.
Land-based version The requirement to carry a bulky, heavy float essentially crippled the N1K against contemporary American fighters. However, in late 1941 Kawanishi engineers had proposed that the N1K could serve as a basis for a fighter variant. A land-based version was produced as a private venture. This version flew on 27 December 1942, powered by a
Nakajima NK9A Homare 11 18-cylinder
radial engine, replacing the less powerful MK4C
Kasei 13 of the N1K-1. The aircraft retained the mid-mounted wing of the floatplane; combined with the large propeller, this necessitated a long, stalky main
landing gear. A unique feature was the aircraft's combat
flaps that automatically adjusted in response to acceleration, freeing up the pilot's concentration, and reducing the chance of stalling in combat. However, the N1K did have temperamental flight characteristics that required an experienced touch at the controls. The Nakajima
Homare was powerful but had been rushed into production before it was sufficiently developed and proved troublesome. Another problem was landing gear failure due to poor heat treatment of the wheels. Apart from engine problems and the landing gear, the flight test program showed that the aircraft was promising. Prototypes were evaluated by the Navy, and since the aircraft was faster than the Zero and had a much longer range than the
Mitsubishi J2M Raiden, it was ordered into production as the
N1K1-J, the -J indicating a land-based fighter modification of the original floatplane fighter. Only four days after the
Shidens first test flight, a complete redesign began. The
N1K2-J addressed the N1K1-J's major defects, primarily the mid-mounted wing and long landing gear. The wings were moved to a low position, which permitted the use of a shorter, conventional undercarriage. The fuselage was lengthened and the tail redesigned. The production of the entire aircraft was simplified: over a third of the parts used in the previous
Shiden could still be used in its successor, while construction used fewer critical materials. The N1K2-J was approximately lighter, while faster and more reliable than its predecessor. The
Homare engine was retained, even though reliability problems persisted, as no alternative was available. A prototype of the new version flew on 1 January 1944. After completing Navy trials in April, the N1K2-J was rushed into production. This variant was named the " with
Kai meaning
modified. ==Operational history==