Description

      The Nakajima C6N1 Saiun was a high-speed reconnaissance aircraft of the Imperial Japanese Navy.

      In 1940, the Navy formulated a plan for the production of practical aircraft prototypes and
notified various manufacturers of its plans. Among the several notifications received by the Nakajima Air Group was one for a carrier-based high-speed reconnaissance aircraft.

      This project, known as N-50, had extremely demanding performance requirements. The maximum speed was 350 knots (650 km/h), and the maximum range was 2,500 nautical miles (4,630 km), the distance between Osaka and Bangkok. Therefore, it was estimated that a 2,000-horsepower engine would be necessary. For this reason, Nakajima devised a twin-engine design with two 1,000-horsepower engines mounted inside the fuselage, driving the propellers on both wings via shafts and gears.

      However, around this time, prototype development of a high-horsepower, small-diameter engine called "Homare" was progressing smoothly, so the Navy instructed them to consider using "Homare" in the N-50 project. "Homare" was an engine that was undergoing practical testing by the Ginga at the time, and it was a high-performance engine with a diameter of 1,180 mm and a takeoff output of 1,830 horsepower.

      In June 1942, Nakajima decided to abandon the twin-engine design with its complex mechanism and proceed with a single-engine design equipped with the "Homare" engine, and reported this to the Navy. It was discovered that the 1,830-horsepower "Homare" engine would only produce 1,600 horsepower at an altitude of 6,000 meters, which was 400 horsepower short of the initial planned 2,000 horsepower. Therefore, it was decided to compensate for this by modifying the aircraft's shape.

      This involved reducing the frontal fuselage area and the wing area. Reducing the wing area would increase the landing speed, making carrier landings difficult, so slats and Fowler flaps were adopted to generate high lift. Because the aircraft had to carry a large amount of fuel and launch from the cramped space of an aircraft carrier , a large-diameter propeller with a diameter of 3.5m was used.

      The first prototype, built with a completely new and state-of-the-art design, was completed in April 1943 and underwent evaluation by the Navy. Mass production of this aircraft began in April 1944, and in September 1944, it was officially adopted as the Saiun Type 11 (C6N1).

      The mass-produced Saiun had a maximum speed of 609 km/h, a decrease from the prototype's 635 km/h, but it was still able to outrun the Grumman F6F. Some of the mass-produced aircraft were also modified as night fighters due to their speed and range, and were equipped with either two 20mm oblique cannons or one 30mm oblique cannon, playing an active role in homeland air defense.

Specifications

• Crew: 3
  
• Overall width: 12.50m
  
• Overall length: 11.15m
  
• Overall height: 3.96m
  
• Engine: Nakajima Homare 21 (air-cooled twin radial 18-cylinder)
  
• Takeoff power: 1,990 hp
  
• Maximum speed: 609 km/h (altitude 6,100 m)
  
• Armament: 7.9mm swivel machine gun x 1 (rear upper)