The Kawanishi N1K, designated Kyōfū (強風), was a floatplane designed to operate from water bases where no airstrips were available. While the Kawanishi N1K-J, designated Shiden (紫電), was a land-based repurpose of the N1K, which was considered one of the finest land-based fighters flown by the Japanese and could match the best Allied fighters.
Nicknames:
- N1K Kyōfū (強風, Strong Wind), Allied Codename: Rex
- N1K-J Shiden (紫電, Violet Lightning), Allied Codename: George
History
N1K Kyōfū
Development
With the start of the Sino-Japanese war, the navy required a new line of planes for the southern expansion. One of these required planes by the navy was a fighter seaplane. Before World War I, seaplanes were not uncommon to play a central role in combat missions, but closing into World War II seaplanes were usually only used for observation and reconnaissance missions.
This plane was thought to be needed as some islands simply didn't have enough place for an airfield and were too trivial to send aircraft carriers towards. Which at the time of the Japanese situation seemed like a proper investment.
In September of 1940, the Imperial Japanese Navy instructed Kawanishi, who were quite experienced in developing seaplanes, to make a prototype plane under the name of 15-Shi Seaplane Fighter, the specifications of the 15-Shi were as followed:
Speed ≥ 310 kn at 5,000 m
Cruising range ≥ 6 hours at cruising speed.
Armament = 2 x 20 mm & 2 x 7.7 mm OR 2 x 13.2 mm & 2 x 7.7 mm OR 4 x 7.7 mm
Bombs ≥ 2 x 30 kg
The chief design engineer appointed for this specification was Shizuo Kikuhara, who also worked on the H8K2. Kikuhara and his team were up to quite a task as comparing this specification to the A6M2 mod. 11 that was just put into service in China. The speed was exceeded by 30 knots, cruising range was two-thirds, and armament was equal.
Simply put, the team was required to make a seaplane with the same performance as the new main fighter, and particularly the speed requirement was almost unrealizable for a seaplane (in 1940), let alone an interceptor like the Raiden whose prototype (J2M1) barely had a top speed of 578 km/h.
The maximum speed of the first completed prototype N1K missed the requirement by nearly 100 km/h, but Shizuo Kikuhara and his team put all their technical efforts into achieving the requirement.
Nakajima also made a seaplane fighter of their own as a temporary bridge for the N1K until it entered service. This seaplane was simply making use of the new A6M2 mod. 11, making it more waterproof and adding pontoons to it. The A6M2-N would be adopted as the Type 2 seaplane fighter on July 6, 1942.
After much development and trial time, the N1K1 with a Kasei 13 engine would finally be adopted as the Kyōfū on December 21, 1943.
But during its adoption, the Americans were already waging a victory in the Solomon Islands. The need for a seaplane fighter was no longer needed as Japan was on the defensive now.
Usage
Some Kyōfū's were based in Indonesia and were used as an interceptor of bombers with the use of aerial bombs that would detonate after a short time attempting to bomb American bombers such as B-24/PB4Y's and B-29s.
Other Kyōfū's were stationed in the mainland, primarily at Sasebo Air Group and the Otsu Air Group but have almost no battle record.
In the end, the Kyōfū was a little too late as its stopgap replacement, the A6M2-N, primarily filled its role. However, this indirectly opened the way to evolve in the Shiden.
As the navy knew the Kyōfū would be simply too late for its order, they scrapped most of the orders on the N1K and, with concerns of Kawanishi losing a lot of money on developing a plane that wouldn't be used anymore, promoted the repurposing of the N1K as a land-based fighter instead which would result in the much stronger and fearsome Shiden which would see service till the very last bitter end.
N1K-J Shiden
Development
In late 1941, as the 15-shi was still in development, some engineers were already concerned and proposed it would also be the basis of a formidable land-based fighter, and a land-based version was produced as a private venture by the company. This version flew on 27 December 1942, powered by a Nakajima NK9A Homare 11 18-cylinder radial engine, replacing the less powerful Mitsubishi MK4C Kasei 13 of the N1K1.
As the navy cancelled its orders on the Kyōfū, Kawanishi came to 3 choices:
- Repurpose the H8K, Type 2 Flying Boat as a land-based bomber
- Repurpose the 15-shi (N1K, Kyōfū) as a land-based fighter
- Create a new carrier-based fighter
Kawanishi decided to further promote the development of the land-based fighter version. Even though some Navy engineers showed concern that Kawanishi wouldn't be a suited designer of land-based planes due to the little experience they have on land, the plane still showed great potential and was quickly evaluated by the Navy. Aside from engine problems stemming from rushed engine development and some landing gear issues, the Navy was thoroughly impressed as its speed was far faster than the A6M and its maximum range was beyond that of the Raiden and ordered its production as the N1K1-J, Shiden.
A complete redesign was begun only four days after the Shiden's first test flight. 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 was redesigned. The production of the entire aircraft was simplified; it was lighter by 250 kg, faster and more reliable than its predecessor. Although engine issues were still a problem, the Homare couldn't be replaced as there was simply no alternative. The first test flight of this new plane was flown on the 1st of January 1944, completed its Navy trials in April, and was rushed into production as the N1K2-J, Shiden Kai (Improved)
Usage
The N1K2-J Shiden Kai offered a formidable if demanding aircraft in limited quantities. As a result, the planes were distributed to elite naval fighter units such as 343rd Kōkūtai, constituted on 25 December 1944 and commanded by Minoru Genda. The new Kōkūtai included some of Japan's finest fighter pilots, such as Muto and Genda. The unit was issued the best available equipment and a new Nakajima C6N Saiun.
In every encounter with enemy fighters, the Shiden, especially the Kai version, proved to be a capable dogfighter with a potent combination of firepower, agility, and rugged structure. The premier unit flying the Shiden, 343rd Kōkūtai, remained operational until overwhelming unit losses obliged the group to stand down. The 343rd was disbanded on 14 August 1945 when the Emperor ordered surrender.
Media
The intended float-plane fighter to support the Japanese Pacific offensive across the many remote Islands. However, due to the required engine power and development, it came too late and was replaced by its stop-gap replacement, the A6M2-N.
The first result of remodelling the N1K1 to a land-based fighter, removing the floating pontoons and replacing them with a rather long landing gear.
Shortly after equipping previous N1K1s with landing gear, newly built N1K2-Js featured a redesigned fuselage and lower positioned wing to allow for a more sturdy landing gear construction and overall aerodynamic benefits.
The last of the mass-produced variants, the N1K2-Ja was a relatively small modification allowing for a heavier bomb load and redesigning the tail to further increase aerodynamic stability.