Kyūshū J7W Shinden

[Rheged]

You kindly offered the chance for  another whiffer to produce a backstory for your excellent piece of work.   Here is my offering:- 

The Kyūshū J7W Shinden, its origin and service

In early 1943, Lieutenant Commander Masayoshi Tsuruno of the Imperial Japanese Navy technical development staff proposed a rear winged interceptor aircraft with nose canards and a pusher propellor.  His interim proposal was for a radial engine, preferably the Nakajima Homare or similar  with the  airframe being easily modified to take the  Ne-20 turbojet engine then under development by  Ishikawajima-Harima Heavy Industries.  Technical data exchanges between  the German Reichs Luft Ministerium and the Japanese Dai-Ichi Kaigun Koku Gijitsushi  regarding    Junkers and  BMW turbojet developments  suggested that the basic airframe was easily adaptable to the  new form of propulsion.

An initial concept-proving study resulted in the building of a trio of  Yokosuka MYX6 gliders, one of which was eventually fitted with a 22 hp air cooled engine. These aircraft so impressed the IJN that  Tsuruno and his team were seconded to the Kyushu Aircraft company to develop an interceptor using the canard format. Detailed design work proceeded apace, with two prototypes being available for flight testing by April 1945. The eventual engine choice being the 2130 hp Mitsubishi Mk 9D radial. Ground testing showed some problems with engine cooling whilst ground running: mainly due to the conformation of the long, narrow air intakes in the fuselage sides. Flight  tests indicated vibration difficulties with the extended shaft drive, some flutter in the six bladed propellor and a very marked torque pull to starboard from the radial engine.  Despite these concerns, Kyushu and Nakajima factories placed the aircraft into full production, with over a thousand units anticipated in service by early 1947. 

Following the partial failure of the "special weapon" dropped on Hiroshima, the ground invasion of Japan became inevitable.  Boeing B29 raids operating from Guam, Tinian and Saipan found themselves under attack by this unusually configured interceptor. The four nose mounted  30mm cannon did considerable damage to lower level B29s, and a ceiling of 38000 feet allowed interception of higher flying aircraft. A partial response to this was the introduction of Fleet Air Arm Sea Hornet aircraft operating from Royal Navy fleet carriers sailing somewhat closer  to the Japanese coastline than really prudent. Their speed and range allowed early interception of  climbing Shindens and short range and scarcity of aviation fuel  reduced the  effectiveness of the Shindens. Research work in the UK by Sir William Penney  and development of his discoveries by the Manhattan Project teams resulted in a more successful detonation of a second "Special Weapon"  on Nagasaki , dropped from 'Silver Plate' B29 "Bock's Car" This finally broke Japanese resistance and the third bomb, designed to be released by an ultra-long range Lancaster IV of Tiger Force was not necessary.  An unexpected difficulty experienced by Shinden pilots was the propensity of Japanese army anti-aircraft gunners to shoot at everything in the air during raids. . Despite huge Hinomaru red discs on each wing, many friendly fire incidents occurred.

The Shinden can be assessed an a potentially very  good interceptor fighter, despite its unusual configuration.   Had it not been for the conclusion of hostilities, its development into a turbojet aircraft would have caused considerable difficulties for the invading forces.