The Shiden Kai (known to the Allies by the codename “George”) was a marked improvement over the Japanese Zero, but came too late in the war to have any effect.
“Icons of Aviation History” is a diary series that explores significant and historic aircraft.
Shiden Kai on display at the US Air Force Museum in Ohio
In December 1941, the Japanese looked unbeatable. The US Navy in Hawaii had been crippled, and Imperial Army troops were swarming across the Pacific. To the Kawanishi company in Japan, it looked like the military advance might soon outrun the ability of the Japanese to construct new airfields to keep up, and it seemed likely that there would be a need for fighter aircraft that could operate from water, without any landing strips.
The Imperial Navy already had a floatplane version of its famed Zero fighter, known as the Rufe, but Kawanishi, who specialized in seaplanes and flying boats, thought they could do better. The design they came up with was based on the Mitsubishi MK4C Kasei 13 engine, driving an 11-foot four-bladed propeller. It would be faster than the Rufe, and, equipped with the company’s new automatic flap system, it would be more maneuverable as well. Large floats would allow it to take off and land in water. And with two machine guns and two 20mm cannons, it would carry the same armament as the Zero. It was designated the N1K1.
But only six months later, as production of the new floatplane was just beginning to come together, the situation was entirely different. Japan was in retreat, and there was no need for forward-based floatplanes that could operate without airfields: instead, Japan needed fighters that could effectively defend its existing bases.
Kawanishi now thought that their seaplane could still provide a solution. With the floats removed, the N1K1 would still be a formidable fighter and an improvement over the Zero. The modification was pretty simple, although the large propeller blades presented a difficulty: they required long landing gear to hold the prop off the ground, and this would make the gear too weak for rough carrier landings. Kawanishi’s solution was to make telescoping landing gear. They also upgraded the engine to use the Nakajima NK9A Homare 11. The resulting fighter was designated the N1K1-J (the “J” indicating that it was a modified seaplane) and named the Shiden (“Purple Lightning”).
But when the first prototypes flew in December 1942, there were problems with the engine and with the landing gear, and within a week Kawanishi decided to make major modifications. The two machine guns were replaced with two additional 20mm cannons, making four in all—enough firepower to bring down a B-29. The wings were lowered from mid-body to the bottom of the fuselage, which allowed for shorter and sturdier landing gear. The engine was also upgraded yet again to the more reliable 18-cylinder Nakajima Homare NK9H model with 2,000 horsepower, and the overall weight was decreased by about 500 pounds, producing speeds up to 370mph. The new version was designated N1K2-J, and became known as the Shiden Kai (“Purple Lightning—Improved”). After it was deployed in May 1944, the Allies gave both of the N1K type fighters the codename “George”.
The Shiden Kai was a formidable fighter. It was as fast as a Mustang or Hellcat, more maneuverable, and packed heavy firepower. For the first time since 1942, Japanese pilots had an aircraft that could take on the Americans on equal terms, and in the hands of a trained and experienced pilot, it was lethal. But by this time in the war, Japan had very few experienced pilots left: they had been steadily worn away by years of war. Unlike the Americans, who had their flyers serve a fixed tour of duty and then sent them home to help train new pilots, the Japanese kept flying until they were wounded, captured or killed. So although the George was a superb fighter plane, there were no longer enough suitable pilots to fly them.
Nor were there ever planes in sufficient numbers. By this time, the Japanese merchant fleet had been destroyed by American submarines, and Japanese industry was at a virtual standstill because of raw materials shortages and constant B-29 raids. In the end, then, the George was simply a case of too little, too late. Less than 1500 were produced, and most of these were the inferior Model N1K1-J Shiden. Only 400 Shiden Kais were made, and most of them never got to the frontlines.
Only four Shiden Kai fighters survive today. One is on display at Miho Park in Tokyo. After the war, the US sent four captured Georges to the US for flight testing: three of these are now on display. One is at the US Naval Aviation Museum in Pensacola FL, another is at the Smithsonian’s Udvar-Hazy Center, and the third is at the US Air Force Museum in Dayton.
NOTE: As some of you already know, all of my diaries here are draft chapters for a number of books I am working on. So I welcome any corrections you may have, whether it's typos or places that are unclear or factual errors. I think of y'all as my pre-publication editors and proofreaders. ;)
