Kawanishi N1K Shiden
The Kawanishi N1K began as the Kyofu, a floatplane fighter first flown in 1942, and was converted into the land-based N1K1-J Shiden and the redesigned N1K2-J Shiden Kai. Powered by the powerful but troublesome Nakajima Homare engine, the Shiden Kai is regarded as the best Japanese naval fighter produced in quantity, but it entered operational service only in 1944 and about 1,500 of all models were built. Four Shiden Kais survive in museums in the United States and Japan.
Why It Mattered
Japan alone built and fielded fighters on floats in the Second World War, and the Kawanishi N1K1 Kyofu was its purpose-built example, meant to win air superiority above invasion beachheads where no carrier or land-based fighter could operate. The design's lasting importance came ashore: converted to a landplane, it produced the Shiden and the Shiden Kai, regarded as the best Japanese naval fighters produced in quantity during the war. They reached operational service only in 1944, in the war's final year, and in numbers too small to affect its outcome.
Design Notes
The Kyofu carried its single pilot on a ventral float steadied by two outrigger floats. Even so, its speed came close to the Zero's, and it was almost as maneuverable as its land-based cousin. For the landplane, Kawanishi replaced the floats with retractable landing gear and the floatplane's Kasei 13 engine with the new 18-cylinder Homare. The bigger propeller the Homare needed demanded long gear legs to keep its tips off the ground, and the landing gear functioned poorly in service. The Shiden Kai redesign moved the wing to the bottom of the fuselage, which permitted a shorter, conventional undercarriage, and it lengthened the fuselage, redesigned the tail and made the aircraft approximately 250 kg lighter. Armament was heavy for a Japanese fighter: four 20mm cannons in the wings. The landing flaps doubled as combat flaps, deployed automatically through a mercury switch in hard maneuvering; no other fighter during World War II used a similar system.
Operational History
The Kyofu prototype flew on 6 May 1942, and production aircraft were first delivered to the Navy in early 1943. By then Japan was firmly on the defensive, and the Kyofu only saw limited service, mostly in Southeast Asia. Kawanishi developed the land-based version as a private venture, and the first N1K1-J Shiden flew on 27 December 1942. The Homare failed to deliver the expected power and the Shiden fell short of its projected speed, but it was still faster than the Zero, and the Navy ordered it into production; about 70 aircraft were delivered by the end of 1943, used for pilot familiarization and training. The first Shiden unit was sent to Cebu to oppose the Allied invasion of the Philippines in October 1944, but engine, landing gear, logistics and maintenance problems plagued the Shiden units. The Shiden Kai reached squadrons in 1944 and was concentrated in elite units, above all the 343rd Kokutai, constituted on 25 December 1944 from a group of experienced fighter pilots and commanded by Minoru Genda. Over the Inland Sea in March 1945, 343rd pilots fought Hellcats of VBF-17, and on 2 June 1945 they battled Corsairs of VBF-85 over Kagoshima Bay. Against B-29s above the home islands the type was less successful, limited by inadequate climb and power loss at high altitudes. According to the Smithsonian's account, in February 1945 Warrant Officer Muto single-handedly engaged 12 Hellcats and shot down four of them before the remainder disengaged.
Afterlife
Production of all N1K models totalled 1,532 aircraft. The standard breakdown credits 97 Kyofu floatplanes, 1,007 N1K1-J Shidens and 423 N1K2-J Shiden Kais, with a handful of prototypes of later variants making up the rest. Four Shiden Kais remain today: at the National Museum of the U.S. Air Force in Dayton, at the National Naval Aviation Museum in Pensacola, at Misho Park in Ehime Prefecture, Japan, and the Smithsonian's example. The Ehime aircraft was recovered from the seabed on 14 July 1979, decades after its pilot ditched it following a battle; the pilot was never identified. The Smithsonian's example deteriorated outdoors for decades, until 1983 when the Smithsonian Institution acquired it; restored by the Champlin Fighter Museum in the early 1990s, it now wears the markings of the 343rd Kokutai at the Udvar-Hazy Center.