Many people know the Mitsubishi Zero fighter that Japanese pilots flew throughout World War II. Less well-known is that Japan developed another exceptionally good fighter airplane: the N1K2-J Shiden Kai (‘sheeden-kie’ or Violet Lightning Modified; Allied codename GEORGE). This fighter did not enter operational service until 1944, but its superb abilities helped make it a notable part of Japanese aerial history.

Development

The Shiden Kai story begins in December 1941 when a team of designers at the Kawanishi Aircraft Company proposed a land-based version of the float-equipped fighter called the Kawanishi N1K1 Kyofu (Mighty Wind, Allied codename REX).

A few of the major changes made to transform the floatplane to fly from land bases include:

• Removing the main float and two wingtip floats
• Upgrading the 14-cylinder Kasei engine to an 18-cylinder Homare
• Installing a bigger propeller to absorb the extra power from the more powerful engine
• Installing retractable landing gear with long gear legs to keep the propeller off the ground

The Japanese navy named the new fighter N1K1-J Shiden, and a test pilot made the first flight on December 27, 1942. Kawanishi spent the next year resolving various problems with the design before navy pilots took the first Shidens into combat early in 1944. The factory delivered a total of 1,007. Meanwhile, Kawanishi had begun revising the design less than a week after the first Shiden flew. Designers moved the wing to the bottom of the fuselage, shortened the landing gear, lengthened the fuselage, redesigned the tail, and removed 550 lb (250 kg) of superfluous weight. They kept the powerful but temperamental 2,050 hp (1,529 kW) Homare engine and named the new aircraft Shiden Kai (Violet Lightning Modified). A test pilot made the first flight on January 1, 1944, and the navy rushed the fighter to operational squadrons less than four months later.

This new fighter’s impressive capabilities motivated the navy to get the aircraft into combat as soon as possible. Capable of rolling at 82° per second at 240 mph (386 km/h) and having a maximum speed of about 370 mph (595 km/h) at 18,000 ft (5,480 m), the Shiden Kai was maneuverable and fast and mounted a formidable array of four 20mm cannons in the wings. Japanese pilots with skill and experience could hold their own in combat with American pilots flying F6F Hellcats and F4U Corsairs.

One system unique to the Shiden Kai enhanced its maneuverability: The landing flaps doubled as combat flaps that automatically deployed up to 30 degrees when triggered by a tube holding a mercury switch linked to the aircraft’s pitot-static air system. The system detected the amount of G-force and airspeed, for example during a tight loop or steep turn, and deployed the flaps without pilot intervention. The flaps increased lift and lowered the fighter’s stall speed. Once the pilot stopped turning, the system automatically retracted the flaps, easing workload on the pilot. No other fighter during World War II used a similar system.

Operational History

The Japanese navy gathered a group of experienced fighter pilots, formed them into the 343rd Kokutai (air group), and assigned them to fly Shiden Kai fighters. The group was led by Minoru Genda, who helped Admiral Yamamoto plan the Pearl Harbor attack in December 1941. Over the Inland Sea in March 1945, 343rd pilots fought U. S. Navy pilots of Fighter-Bomber Squadron VBF-17 flying Grumman F6F Hellcats. 

On June 2, 1945, over Kagoshima Bay, 343rd pilots battled pilots of VBF-85 flying Vought F4U Corsairs from the aircraft carrier USS Shangri La. Visitors can see a part of this history firsthand, as the National Air and Space Museum displays an F6F and a Corsair at the Steven F. Udvar-Hazy Center.

The Museum’s Shiden Kai is one of four on display at museums in the United States and Japan. Staff at the Champlin Fighter Museum painted the fighter in the color and markings of an airplane assigned to the 343rd Kokutai when they restored the airplane for the Museum in 1991.