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The Mitsubishi J8M/ Ki-200 was a rocket plane based on the German Me 163B but that was developed in Japan in less than a year despite the lack of any detailed plans of the German original.
The motive for the rapid development of the J8M was the appearance over Japan of the first B-29s, operating at an altitude that but them beyond the reach of most Japanese fighters. There was suddenly an urgent need for a fast-climbing interceptor capable of catching and engaging the giant American bombers. One possible solution was already being developed in Germany - the rocket powered Messerschmitt Me 163. The Japanese negotiated a licence to produce both the aircraft and the Walter HWK 109-509 rocket, and one aircraft and a set of blueprints were dispatched from Germany on a submarine. The entire programme suffered a massive setback when this submarine was sunk, but the Japanese did receive one rocket engine and an instruction manual for the aircraft.
Despite this disaster the Japanese decided to continue with the project. A 19-Shi specification was issued by the Navy, but the work was also supported by the Army. The Navy designated their version the J8M Shusui (Swinging Sword), while the Army called theirs the Ki-200. Work on the rocket was carried out by a joint Mitsubishi-Army-Navy team. The designer's job was to produce an aerodynamic copy of the Me 163 that could use the same rocket, but with a new interior layout. The team worked quickly. A mock-up was ready in September 1944 and was approved three weeks later.
At the same time the First Naval Air Technical Arsenal at Yokosuka was given the task of developing a glider to be used to train pilots to fly the radical tail-less aircraft. This glider, the MXY8 Akigusa (Autumn Grass) was ready by December 1944 and made a successful first flight soon afterwards. A heavier version, with ballast to give it the same weight as the J8M, was ordered as the Ku-13 Shusui Training Glider. Fifty to sixty of these heavier gliders were built. The Navy also wanted to build a powered version, the MXY9 Shuka (Autumnal Fire), powered by a 441lb thrust ducted fan engine, but none of these were built.
Meanwhile work on the first prototype of the J8M made rapid progress, and it was completed in June 1945. On 7 July 1945 the J8M made its maiden flight, with Lieutenant Commander Toyohiko Inuzuka at the controls. The test flight was short and disastrous. The aircraft took off successfully, but during the steep climb to altitude the engine failed and the aircraft crashing, killing the pilot. Six more prototypes were under construction at this time, but none of them flew before the end of the war.
The Navy and Army both had ambitious plans for the J8M/ Ki-200. The Navy ordered it into production in two versions - the J8M1 with two 30mm cannon and the J8M2 with one 30mm cannon and extra fuel. The Army ordered a more advanced version, the Ki-202, but none of these aircraft were ever produced.
Specifications (performance figures are estimates)
Engine: Toko Ro (KR10) bi-fuel liquid rocket
Power: 3,307lb thrust
Crew: 1
Wing span: 31ft 2in
Length: 19ft 10 3/14in
Height: 8ft 10 1/16in
Empty Weight: 3,318lb
Loaded Weight: 8,565lb
Max Speed: 559mph at 32,810ft
Service Ceiling: 39,370ft
Powered Endurance: 5 min 30 sec
Armament: Two 30mm Type 5 cannon.
Bomb-load: None