The Mitsubishi J8M1 Shusui, meaning “Swinging Sword,” was Japan’s answer to the sudden strategic threat posed by the arrival of the B-29 Superfortress over Japanese skies during World War II. This advanced bomber highlighted the lack of a fast-climbing interceptor in the Japanese arsenal, an oversight that needed urgent correction. The solution was inspired by the German Messerschmitt Me 163B, a revolutionary rocket-powered interceptor that impressed Japan’s military attachés in Germany.
Japan secured the rights to manufacture the Me 163B and its Walter HWK 109-509 engine, but the shipment carrying blueprints and a prototype was sunk en route. What reached Japan was only the rocket engine and a basic instruction manual, transported by Eiichi Iwatani, an attaché. Despite this setback, Japan pressed forward, driven by necessity and technical ambition.
In July 1944, the Japanese Navy issued the 19-Shi specification for the development of a rocket-powered interceptor, assigning the task to Mitsubishi. The project rapidly evolved into a joint venture with the Army, which had plans for its own version. Mitsubishi, led by Otsujiro Takahashi, completed a mock-up by September 1944, which was approved for prototype construction.
To gather data on handling the tailless design and train future pilots, the Navy initiated development of a glider version, the MXY8 Akigusa (Autumn Grass), at the Dai-Ichi Kaigun Koku Gijitsusho in Yokosuka. The MXY8 was first flown in December 1944 at Hyakurigahara Airfield by Lieut-Cdr Toyohiko Inuzuka, the J8M1 project pilot. The glider demonstrated satisfactory handling, which bolstered confidence in the upcoming powered variant. Additionally, heavier training gliders, designated Ku-13 Shusui, were developed with water ballast to replicate the J8M1’s weight.
Mitsubishi began construction of powered prototypes, designated J8M1 for the Navy and Ki-200 for the Army. The first prototype was completed in June 1945 and underwent checks at Yokosuka. The maiden flight took place on July 7, 1945, but the engine failed during a steep climb, leading to a crash and the death of Lieut-Cdr Inuzuka. The investigation identified fuel system flaws that were being addressed in subsequent prototypes when the war ended, halting further tests.
Despite the limited success, the production of J8M1s was underway at Mitsubishi, Nissan, and Fuji. The Navy intended to arm the J8M1 with two 30 mm Type 5 cannons, while the J8M2 Shusui-Kai was designed to replace one cannon with extra fuel tanks for longer range. The Army prioritized an advanced variant, the Ki-202, as their top interceptor project, but none of these plans came to fruition before Japan’s surrender in August 1945.
The J8M1’s development showcased Japan’s resourcefulness in adapting foreign technology to address critical wartime needs. While the program ultimately did not achieve operational success, it marked an ambitious attempt to match the cutting-edge rocket fighter technology of the era. The story of the Shusui reflects both the ingenuity and desperation of Japan’s wartime aviation industry during its final phase.
Difference J8M1 and Ki-200
The Ki-200 was equipped with 2x30 mm Ho-105 cannons, while the J8M1 was equipped with 2x30 mm Type 5 cannons. As stated in sections “Statistics of the vehicle”.
This results the J8M1 being at a lower br which could really boost their lineups and overall uniqueness of the TT.
Statistics of the vehicle:
Spoiler
More pictures
Sources:
- Mitsubishi J8M - Wikipedia
- https://www.militair.net/wapens/vliegtuigen/mitsubishi-j8m-shusui/
- https://mei1940.org/mitsubishi-j8m-shusui/
- IJNAF Mitsubishi J8M Shusui
- Japanese Aircraft of the Pacific War: Francillon, Rene J.: 9780870213137: Amazon.com: Books
- Уголок неба ¦ Mitsubishi J8M Shusui
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