Nakajima C6N1-S Saiun (Myrt)
Saiun (彩雲) means "Glowing Cloud". Code named Myrt by the Allies. Soon after Japan attacked Pearl Harbor, Japanese naval leaders acknowledged that standard torpedo bombers made poor reconnaissance aircraft. A new, fast airplane designed and built specifically to conduct long-range scouting missions was needed. Nakajima completed the first prototype in March 1943 and flew it first on May 15. From the start, the Homare engine failed to generate the specified power at altitude and suffered other problems endemic to most new engines. While the aircraft handled well, the power loss meant that the speed requirements could not be met. The speed that was achieved, 639 kph (397 mph), was still far better than any other similar airplane. The Navy ordered the Saiun into production in the spring of 1944.
Myrt first saw combat during the battles for the Marianas. By carrying a torpedo-shaped gas tank of 730 liters (193 gal), the C6N1 fly more than 4,830 km (3,000 mi). Range of this magnitude, combined with high speed, generally kept them safe from interception. Myrt crews could shadow the U.S. fleet with impunity. Its speed was exemplified by a famous telegraph sent after a successful mission: "No Grummans can catch us."
Nakajima also worked on a torpedo-carrying variant, the C6N1-B, but this model was not needed after Japan lost most of its carriers. As Allied forces closed in on the home islands, there arose a critical need for good night fighters. Nakajima created the C6N1-S by eliminating the observer and installing two oblique-firing 20mm cannon instead. These weapons weighed about the same as the observer, so performance suffered little. The C6N1-S was the fastest Japanese night interceptor but it had no air-to-air radar equipment. Only a few of the type were built. Other designs C6N variants were contemplated but none left the drafting boards. A Myrt was the last aircraft shot down in World War II, on August 15, 1945 at 5:40 am, five minutes before hostilities ended.
Nakajima had built 463 C6N aircraft at the company's two factories in Koizuma and Handa.