Nakajima's C6N Saiun was among the finest carrier-based reconnaissance aircraft to operate during World War II. Soon after Japan attacked Pearl Harbor, Japanese naval leaders acknowledged that standard torpedo bombers made poor reconnaissance aircraft. They needed a new, fast airplane designed and built specifically to conduct long-range scouting missions. In the spring of 1942, Nakajima Hikoki K. K. received a new specification from the Naval Staff. It described a 3-seat aircraft with a maximum speed of 648 kph (403 mph), a normal range of 2,780 km (1,727 mi), and a maximum range of 4,956 km (3,078 mi). Landing speed must not exceed 130 kph (81 mph), and the airplane must climb from sea level to 6000 m (19,685 ft) in less than 8 minutes.
Engineers Yasuo Fukuda and Yoshizo Yamamoto originally envisioned a pair of 1,000 horsepower engines buried in the fuselage of the new design and driving propellers mounted on the leading edge of the wings, via extension shafts. Thankfully, Nakajima was about to introduce the Homare engine. Its relatively small diameter coupled with a high power rating, allowed Fukuda and Yamamoto to meet the specified speed and range goals using a single engine. The original power arrangement would probably have been unreliable and a maintenance nightmare. They also canted the vertical stabilizer forward to keep the overall length of the aircraft within the dimensions of existing carrier deck elevators. The two Nakajima engineers used both Fowler flaps and split flaps to keep the landing speed low. The 3-man crew (pilot, observer, and radioman/gunner) sat beneath a long canopy. In flight, the observer viewed the earth below through windows in the bottom and sides of the fuselage.
Nakajima completed the first prototype in March 1943 and flew it 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, but the power loss meant that the firm could not meet the speed requirements. The actual speed of the airplane, 639 kph (397 mph), was still far better than any other similar aircraft. The Navy ordered the Saiun into production in the spring of 1944. By war's end, Nakajima had built 463 C6N aircraft at the company's two factories in Koizuma and Handa.
Nakajima's slender, elegant design saw its first combat during the battles for the Marianas. By carrying a torpedo-shaped gas tank of 730 liters (193 gal), the C6N1 Saiuns (or MYRT as the Allies called them) could fly more than 4,830 km (3,000 mi). Range of this magnitude, combined with high speed, generally kept them safe from intercepting U. S. Navy Grumman Hellcat fighters (see NASM collection). MYRT crews could shadow the U.S. fleet with impunity.
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, 20 mm cannon in his place. 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 and Nakajima built only a few of the type. The firm contemplated other C6N variants but none left the drafting boards. A MYRT was one of the last aircraft shot down during World War II, at 5:40 a.m. on August 15, 1945, five minutes before the hostilities ended.
The NASM Saiun is the last example remaining of this fine aircraft. It is a C6N1-S night-fighter variant armed with oblique-firing 20 mm cannon and crewed by two men. The aircraft was part of the shipment of 145 Japanese aircraft sent to the U.S. for technical evaluation. It transited the Pacific aboard the escort carrier USS "Barnes" and arrived at Langley Field, Virginia on December 8, 1945. We do not know why the Navy transferred this airplane to the Army Air Forces (AAF), but Army personnel overhauled the MYRT at the air depot at Middletown, Pennsylvania, then flight-tested the airplane. Details about the test flights remain unknown. On August 22, 1946, an AAF pilot flew the Saiun to the foreign aircraft storage area at Orchard Place Airport, Park Ridge, Illinois. The Air Force turned over the MYRT and all other assets at Park Ridge to the National Air Museum in 1949.