Introduction and Development
Introduction and Development
The Kawanishi N1K-J Shiden (Violet Lightning) was one of the best fighters to see service with the Imperial Japanese Navy, and in skilled hands was more than capable of holding its own against the American fighters that were increasingly dominating the Pacific skies.
The N1K1-J was developed from the N1K floatplane, although work on the land plane actually began before the first floatplane made its maiden flight. Kawanishi had been working on the N1K since late in 1940, but the idea of developing a land based version of the same aircraft wasn't considered until December 1941. The Kawanishi management agreed to fund development, and work on the N1K1-J began as a private venture.
The N1K was a mid-winged radial engined powered monoplane, with a large central float and wing tip stabilisers. The N1K1-J retained the basic mid-winged configuration, but the Kasei engine used in the floatplane was replaced with the eighteen cylinder Nakajima Homare radial engine. This was expected to produce 2,000hp, but needed a large four bladed propeller with a 10ft 9 29/32in diameter. This large propeller combined with the mid-wing layout meant that the new aircraft needed very long main undercarriage legs. In order to prevent the legs from taking up too much space when folded into the wings they were made telescopic, and were meant to shrink as they folded.
The first N1K1-J prototype, then known as the Model X-1 Experimental Land-based Fighter, made its maiden flight on 27 December 1942, just under eight months after the N1K floatplane. The new aircraft was very manoeuvrable, and it was clear that its overall performance would eventually be excellent, but both the engine and the undercarriage caused problems. The Homare 11 engine used in the prototype only produced 1,820hp, well down on the expected 2,000hp, while the complex undercarriage caused problems.
Even with the limited power, the prototype reached a top speed of 357mph, faster than the A6M5 Zero. The aircraft was slower than the Mitsubishi J2M2 land based fighter, but was more manoeuvrable and had a long range. In 1943, with their existing fighters suffering at the hands of American Hellcats and Corsairs, the Japanese Navy decided to support the development of the N1K1-J. Ironically Kawanishi were also working on a purpose-built land based fighter, the J6K1, and work on this project was now cancelled.
Work on the newly designated N1K1-J Shiden (Violet Lightning) Model 11 now moved ahead quickly. It was now powered by the 1,990hp Hakajima NK9H Homare 21 engine in an improved cowling. The prototype had been armed with two 7.7mm machine guns in the fuselage and two 20mm cannon in gondolas under the wings. Two extra 20mm machine guns were now added, mounted outside the gondolas. The aircraft entered full production during 1944, and in the same year was rushed into combat.
The N1K1-J's combat debut came over the Philippines. The 201st Kokutai was moved to Cebu during the period before the American invasion of the Philippines, and soon entered combat. The N1K1-J proved itself to be an excellent aircraft when in the air, and was able to hold its own against the American aircraft it encountered.
The picture on the ground was less rosy. A number of aircraft were destroyed on the ground, while others were lost when their engines or undercarriage failed. By 1944 the Japanese Navy had lost many of its best ground crews, and so the aircraft suffered from poor maintenance.
The N1K2-J was an even more successful aircraft. In one noteworthy incident in February 1945 one pilot, Warrant Officer Kinsuko Muto, fought off twelve Grumman Hellcats, shooting down four before the remaining aircraft retreated. This must have been a great relief for Japanese naval pilots, more used to the opposite happening when the manoeuvrable but lightly armoured Zero clashed with the sturdy American fighters.
The N1K-J saw service on the Philippines, in Formosa, during the battle of Okinawa, and during the defensive of Honshu against American air raids. It was successful against American fighters and medium bombers, but struggled to reach the operating altitude of the high flying B-29s.
N1K1-J Navy Interceptor Fighter Shiden Model 11
This was the first, and most numerous, version of the aircraft. It was armed with two 7.7mm machine guns and four 20mm cannon, and a total of 998 production aircraft were produced (including the minor variants detailed below).
N1K1-Ja Navy Interceptor Fighter Shiden Model 11a
The N1K1-Ja was armed with four 20mm cannon, all carried within the wings. The machine guns were removed.
N1K1-Jb Navy Interceptor Fighter Shiden Model 11b
The N1K1-Jb could carry two 551lb bombs under the wings. It had modified tail with square-tipped horizontal surfaces. Improved 20mm cannon were used.
N1K1-Jc Navy Interceptor Fighter Shiden Model 11c
The N1K1-Jc was a fighter-bomber version that could carry four 551lb bombs. It was otherwise identical to the N1K1-Jb.
N1K2-J Navy Interceptor Fighter Shiden Model 21
The N1K2-J was a major improvement on the N1K1-J. The wings were moved down to the lower part of the fuselage eliminating the need for the complex long undercarriage legs. The fuselage and tail were both redesigned, with the main aim being to simplify production and maintenance. The first prototype made its maiden flight on 31 December 1943, and was then handed over to the Navy for trials in April 1944. The only problem with the aircraft was the Homare 21 engine, which was still suffering from reliability problems, and it was soon ordered into production as the Navy Interceptor Fighter Shiden Kai Model 21. In theory the N1K2-J was produced by a large number of companies, but most of this effort was wasted and only Kawanishi produced any significant numbers, with 393 being produced by two of their factories. Omura produced ten aircraft, Mitsubishi nine, Aichi, Showa and the Dai-Juichi Kaigun Kokusho one each.
N1K2-Ja Model 21A
The N1K2-Ja was a fighter-bomber version of the aircraft, designed to carry four 551lb bombs.
The N1K2-K was a two-seat trainer produced in small numbers by adding a second cockpit behind the pilot's seat.
N1K3-J Model 31
The centre of gravity of the N1K2-J was a little too far back. In an attempt to solve this problem Kawanishi designed the N1K3-J, in which the engine was moved six inches forward. Two prototypes were built, and were armed with four 20mm cannon and two 13.2mm machine guns.
N1K3-A Shiden Kai 2 Model 41
The N1K3-A would have been a carrier borne fighter based on the N1K3-J. None were built.
N1K4-J Shiden Kai 2 Model 32
The N1K4-J was given a 2,000hp NK9H-S Homare 23 radial engine with a low-pressure fuel injection system. Two prototypes were built and were armed with four 20mm cannon and two 13.2mm machine guns.
N1K4-A Shiden Kai 4 Model 42
The N1K4-A was a carrier-borne version of the N1K4-J. One prototype was built.
N1K5-J Shiden Kai 5 Model 25
The entire N1K-J series suffered from poor performance at very high altitudes. At first this hadn't mattered too much, but when the high flying B-29 began to appear over Japan the Navy suddenly needed high-altitude interceptors. Kawanishi responded with two prototypes. The N1K5-J was to use a 2,200hp Mitsubishi MK9A eighteen-cylinder air-cooled radial. One prototype was under construction, but was destroyed by the very aircraft it was designed to intercept. The second proposal was for an aircraft powered by the Homare 44 engine with a mechanically drive three-speed supercharger.
Engine: Nakajima NK9B Homare 11 eighteen cylinder air-cooled radial
Power: 1,820hp at take off, 1,600hp at 6,560ft, 1,440hp at 18,700ft
Wing span: 39ft 4 7/16in
Length: 30ft 7 29/32in
Height: 12ft 11 29/32in
Empty Weight: 5,858lb
Loaded Weight: 8,818lb
Max Speed: 369mph at 18,375ft
Cruising Speed: 230mph at 9,845ft
Service Ceiling: 35,300ft
Range: 1,066 miles normal, 1,488 maximum
Armament: Four wing mounted 20mm cannon
Bomb-load: Two 551lb bombs