N1K2-J Shiden Kai (Violet Lightning Modified)
Although the N1K1-J was an outstanding fighter, it did have some serious defects. Its Homare 21 engine was notoriously unreliable, and the complex doubly-retracting landing gear was subject to frequent failures. Even before the N1J1-J entered production, work had already begun at Kawanishi on correcting some of its more glaring defects, in particular its long and complex landing gear.
The result of these changes was the Shiden-Kai (Violet Lightning--Modified). Given the designation N1K2-J, the aircraft was completely redesigned so as to use fewer components in order to simplify its construction. More non-critical materials were to be used. Another step towards simplification involved the use of pre-formed sheet construction. Perhaps the most easily-noted innovation was the use of a low-mounted wing in place of the original mid-mounted wing. This permitted a shorter set of landing gear legs to be used, and the complex double-retraction system which had caused so many problems could be eliminated. In addition, the fuselage was lengthened and the tail surfaces were redesigned. The result was a virtually new aircraft, although the unreliable 1990 hp Homare 21 engine of the N1K1-J was retained. Armament was four 20-mm cannon, all mounted internally to the wing.
The first N1K2-J prototype took off on its maiden flight on December 31, 1943. It was handed over to the Japanese Navy for trials in April of 1944. Although the Homare 21 engine was still mechanically unreliable, the Navy liked the aircraft so much that they authorized quantity production of the N1K2-J to be its standard land-based fighter and fighter-bomber even before the service trials were completed. Production aircraft were designated Navy Interceptor Fighter Shiden Kai (Violet Lightning Modified) Model 21. In addition to the Kawanishi plant at Naruo, the Shiden Kai was ordered into production at the Himeji works of Kawanishi. Shiden Kai fighter aircraft were also ordered into production from the Dai-Nana Kokuki Seisakusho (7th Airframe Works) of the Mitsubishi Jukogyo K. K. at Tsurashima, from the Aichi Kokuki K. K. at Eitoku, from the Showa Hikoki K. K. at Shinonoi, and from the Naval Air Arsenals at Hiro, Omura, and Koza.
A further seven prototypes had been completed by June of 1944, However, the prototypes began to experience a long series of teething troubles, which proved difficult to correct. The Shiden-Kai program began to slip its schedules, and by the autumn of 1944 the N1K2-J production lines were beginning to experience shortages of vital components due to B-29 attacks against the factories of Kawanishi's subcontractors. By the end of 1944, only 60 Shiden Kais had been delivered by the Naruo factory, and production at Himeji did not begin until March of 1945. The other manufacturers in the Shiden Kai pool were never able to produce more than a handful of aircraft.
The Shiden Kai was to become the best all-round fighter to be operational in the Pacific theatre. It was fast, powerful, and maneuverable, and was well-armed and armored. In the hands of an experienced pilot, the Shiden-Kai was the equal of any Allied fighter, even the later models of the P-51 Mustang which began to appear over Japan in the spring of 1945. In one notable action, on February 16 1945 over Yokohama, Warrant Officer Kinsuke Muto of the 343rd Kokutai in an N1K2-J single-handedly battled a dozen F6F Hellcats. He shot down four of them before the rest were forced to break off combat and return to their carrier.
However, against the B-29, the N1K2-J was less successful, since its climbing speed was insufficient and the power of the Homare 21 engine fell off rather rapidly at higher altitudes.
Only 415 production examples of the outstanding N1K2-J fighter were built, owing primarily to construction snags and delays resulting from the continuous B-29 raids on the Japanese homeland in the last year of the war. With the exception of Kawanishi's Naruo and Himeji plants, the other companies involved in the production pool were late in getting started and delivered only a token number of machines before the war ended. It is fortunate for the Allies that this outstanding aircraft was not available in greater quantity.
After the war in the Pacific was over, several N1K2-J fighters were discovered intact at Japanese airfields and were brought back to the United States for study. These aircraft were compared to all the available Allied fighters and found to be superior in all around superiorty. In mock dogfighting, several American aviators complemented the aircraft and its performance. They went so far as to say that had the Japanese been able to mass produce this aircraft earlier in the War, the loss of pilots would have been unacceptable.
Specification of the Kawanishi N1K2-J Shiden Kai:
One Nakajima NK9H Homare 21 eighteen-cylinder air-cooled radial rated at 1990 hp for takeoff, 1825 hp at 5740 feet, 1625 hp at 20,015 feet. Performance: Maximum speed 369 mph at 19,355 feet, 359 mph at 9840 feet. Cruising speed 230 mph at 9845 feet, service ceiling 35,300 feet cruising speed 230 mph at 6600 feet. Climb to 19,685 feet in 7 minutes 22 seconds. Normal range 1066 miles at 219 mph at 9840 feet, maximum range 1488 miles with 88 Imp. gall. drop tank.
Weights: 5858 pounds empty, 8818 pounds loaded, 10,714 pounds maximum loaded.
Dimensions: wingspan 39 feet 4 7/16 inches, length 30 feet 7 29/32 inches, height 12 feet 11 29/32 inches, wing area 252.95 square feet.
Armament: Four 20-mm Type 99 Model 2 cannon in the wings. Two 551-pound bombs or one 88 Imp. gall. drop tank could be carried externally.
