The Kyūshū J7W1 Shinden fighter (震 電, "Magnificent Lightning") was a prototype aircraft powered by Japanese propeller from World War II that was built in a canard design. The wings were attached to the tail section and the outriggers were in the front. The propeller was also in the back, in a thrust configuration.
Developed by the Imperial Japanese Navy (IJN) as a short-range ground interceptor, the J7W was a response to the B-29 Superfortress raids on the islands of Japanese origin. For intercepting missions, the J7W was to be armed with four 30mm guns firing forward in the nose.
The Shinden was expected to be a highly maneuverable interceptor, but only two prototypes were completed before the end of the war. The construction of a version with a gas turbine engine was considered, but the drawing table was never reached.
Design and development Edit
The designation "J-" referred to the ground fighters of the IJN and the "-W-" to Watanabe Tekkōjo, the company that oversaw the initial design; Watanabe changed his name in 1943 to Kyūshū Hikōki KK.
The idea of a design based on the canard originated with Lieutenant Commander Masayoshi Tsuruno, from the IJN's technical staff in early 1943. Tsuruno believed that the design could be easily modified with a turbojet engine, when the proper engines were available. His ideas were resolved by the Technical Arsenal of First Naval Air (Dai-Ichi Kaigun Koku Gijitsusho), which designed three gliders designated as Yokosuka MXY6, with canards. These were built by Chigasaki Seizo KK and one was equipped with a Semi 11 (Ha-90) 4-cylinder air-cooled engine with 22 hp.
The feasibility of the canard design was tested by both the motorized and non-motorized versions of the MXY6 at the end of 1943, and the Navy was so impressed by the flight tests that they instructed Kyushu Aircraft Company to design a canard interceptor around the concept of Tsuruno. Kyushu was chosen because both his design team and production facilities were relatively free of charge, and Tsuruno was chosen to lead a team of Dai-Ichi Kaigun Koku Gijitsusho to help Kyushu design works.
The construction of the first two prototypes began in earnest in June 1944, the effort calculations ended in January 1945 and the first prototype was completed in April 1945. The Mitsubishi MK9D radial engine (Ha-43) of 2,130 hp and its Supercharger was installed behind the cabin and drove a six-bladed propeller through an extension shaft. The cooling of the engine was to be provided by long, narrow sockets, mounted obliquely on the side of the fuselage. It was this configuration that caused cooling problems while the engine was running while it was still on the ground. This, along with the lack of availability of some parts of the team postponed the first flight of the Shinden.
Even before the first prototype went on the air, the Navy had already ordered the production of J7W1, with quotas of 30 Shinden monthly for the Kyushu Zasshonokuma factory and 120 for the Handa plant in Nakajima. It was estimated that 1,086 Shinden could occur between April 1946 and March 1947.
On August 3, 1945, the prototype first took off, with Tsuruno at the controls, from the Itazuke air base. Two other short flights were made, a total of 45 minutes in the air, by the end of the war. The flights were successful, but showed a marked torsion torque to starboard (due to the powerful engine), a little flutter of the propeller blades and vibration on the extended transmission shaft.