Nakajima C6N - Development and Design

Development and Design

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.