The Nakajima C6N Saiun was a carrier-based reconnaissance aircraft used by the Imperial Japanese Navy in World War II. Advanced for its time, it was the fastest carrier-based aircraft put into service by Japan during the war. The Allied codename was Myrt. Although designed for carrier use, by the time it entered service in September 1944, there were few carriers left for it to operate from, so most were used from land bases.The C6N originated from a 1942 Imperial Japanese Navy specification for a carrier-based reconnaissance plane with a top speed of 350 knots (650 km/h) at 6,000 m and range of 2,500 Nautical miles (4,960 km). Nakajima's initial proposal, designated N-50, was for a craft with two 1,000 hp engines housed in tandem in the fuselage, driving two propellers mounted on the wings. With the development of the 2,000 hp class Nakajima Homare engine though, this configuration was abandoned and Nakajima decided on a more conventional single-engine layout. However, the Homare's output turned out to be less than initially expected, so the design had to be optimized in other areas. The resulting aircraft was designed around a long and extremely narrow cylindrical fuselage, just large enough in diameter to accommodate the engine. The crew of three sat in tandem under a single canopy, while equipment was similarly arranged in a line along the fuselage. The C6N's low mounted laminar flow wing housed fuel tanks and was fitted with both Fowler and slit flaps and leading edge slats to lower the aircraft's landing speed to ease use aboard aircraft carriers. Like Nakajima's earlier B6N "Tenzan" torpedo bomber, the rudder was angled slightly forward to enable tighter packing on aircraft carriers.
The first flight was on 15 May 1943, with the prototype demonstrating a speed of 639 km/h (345 kt, 397 mph). Performance of the Homare engine was disappointing, especially power at altitude, and a series of 18 further prototypes and pre-production aircraft were built, before the Sauin was finally ordered into production in February 1944.
- C6N1 Experimental Type 17 carrier reconnaissance plane (17??????, 17-Shi Kanjo Teisatsuki)
- C6N1 Saiun Model 11 (??11?, Saiun 11-gata)
- C6N1-B Saiun Model 21 (??21?, Saiun 21-gata)
- C6N1 Saiun Model 11 night-fighter variant (??11?????, Saiun 11-gata Kaizo yasen)
- C6N2 Test production Saiun Kai/Saiun Model 12 (?????/??12?, Shisei Saiun Kai/Saiun 12-gata)
- C6N3 Test production Saiun Kai 1 (?????1, Shisei Saiun Kai 1)
- C6N4 Test production Saiun Kai 2 (?????2, Shisei Saiun Kai 2)
- C6N5 Test production Saiun Kai 3 (?????3, Shisei Saiun Kai 3)
- C6N6 Test production Saiun Kai 4 (?????4, Shisei Saiun Kai 4)