Mitsubishi J8M
| Mitsubishi J8M | |
|---|---|
 J8M-3 Shusui Model 22 |
|
| Type: | Interceptor |
| Design country: | |
| Manufacturer: | |
| First flight: |
1945 |
| Number of pieces: |
7th |
The Mitsubishi J8m Shusui ( Japanese :三菱J8M秋水- Sharp Sword ) was a Japanese interceptors with rocket propulsion from the final phase of World War II , which on the German Messerschmitt Me 163 Komet based. The designation "J8M" was given by the Japanese Navy for this aircraft, while the Air Force of the Japanese Army used the designation "Ki-200". The J8M was tested shortly before the end of the war, but was no longer used.
history
construction
The J8M was supposed to be a license- built copy of the Messerschmitt Me 163. The project was a direct response to the imminent deployment of the heavy four-engine Boeing B-29 "Superfortress" bomber in 1943. The development of this bomber was known in Japan, and it was correctly assumed that it would be used over the domestic market Japanese islands should be intended. Japanese military attachés in the German Reich found out about the Me 163 and negotiated the contract for a license production of the aircraft and its engine after a visit to the test command 16, where the aircraft were being tested at that time.
Like the Me 163, the Shusui was supposed to soar very quickly to great heights with a rocket engine. The fuel supply was used up in a short time, the aircraft had to go into gliding flight and finally land that way.
In Germany two deliveries were put together, one of which consisted of technical documentation and samples of mechanical parts. These were sent to Japan in two submarines . One of these boats was sunk on the way, the other ended up as far as Singapore , from where the responsible naval officer Eiichi Iwaya brought parts of the documents to Japan in advance by plane. Most of the detailed technical documents, however, remained on board and were also sunk with this submarine near the Philippines . Thus only a small part of the papers actually made it to Japan.
Since attacks with B-29 had already taken place in the meantime , the reconstruction of the aircraft began with the existing material - the technical operating instructions and a rocket engine of the type Walter KWK 109-509 - instead of waiting for a replacement. The Imperial Japanese Navy named the aircraft "J8M1" while the Imperial Japanese Army used the designation "Ki-200".
Both differed only in small details, most clearly in the choice of the type of 30 mm cannon. The Army Air Force's Ki-200 was armed with two Ho-105s ( cadence 450 rounds / min, muzzle velocity 716.280 m / s), while the J8M1 of the Navy Air Force had two Type 5 cannons (cadence 400 rounds / min, muzzle velocity 749.808 m / s) s). The Ho-105 was also the lighter of the two and both offered a higher initial speed but a lower cadence than the MK 108 of the original Me 163 (650 rounds / min, muzzle velocity 519.684 m / s).
The aircraft itself was developed by Mitsubishi with the participation of partner companies Nissan and Fuji , the engine for the machine based on the Walter HWK 109-509 and a school glider ( Yokosuka MXY-8 , Army designation: Ku-13) were designed and manufactured by Yokosuka .
Meanwhile the German Reich tried to send another "Komet" on board U 864 to Japan in February 1945 , but U-864 was sunk by the British submarine HMS Venturer near Bergen / Norway .
testing
Since the engines were not yet completed, the first attempts at gliding were made on January 8, 1945 . With the ballast built in as an alternative, the flight performance was very similar to that of a planing Me 163. The first of the " Toku Ro.2 " (KR10) called rocket engines was delivered in June when the war in Europe had already ended and the Allies had captured numerous Me 163 there.
After the last attempts at gliding with a built-in engine, the first powered flight was carried out on July 7, 1945 from the Oppama airfield near Yokosuka . Takeoff was normal and the plane rose quickly and steeply. However, at about 400 meters above sea level, it abruptly turned upside down and crashed straight into the ground, killing test pilot Toyohiko Inuzuka .
A subsequent investigation revealed that the design of the fuel tanks was unsuitable for such steep climbs and that the fuel pump only sucked in air instead of fuel. During the flight, an air bubble formed in a fuel line, causing the engine to stop abruptly, causing the crash. No further flight attempts were made while appropriate changes were being made. In the meantime, Mitsubishi had started mass production of aircraft components for this type.
The rocket engine of the Toku Ro.2 type continued to use the German fuels T-Stoff as an oxidizer and C-Stoff as fuel (methanol-hydrazine hydrate-water mixture), known in Japan as Ko and Otsu . The replica engine did not offer quite the same thrust as the original, with Mitsubishi calculating that a lighter version of the J8M1 could compensate for this. The flight performance in the first version was therefore not quite as high as that of the "Komet", but was only slightly inferior to the original, so that the operational requirements were met in every case.
However, before further trials began, Japan surrendered on August 15, 1945 .
variants
- J8M-2 Shusui Model 21 (?): Long-range version for the Navy, equivalent to J8M1, but armament reduced to a single 30 mm cannon
- J8M-3 Shusui Model 22 (Army type designation Ki-202 Shusui-kai): Long-range version with extended fuselage (7.10 m) and larger wingspan (9.75 m), with the Tokuro-3 engine with 19.6 kN should be used; projected maximum speed: 900 km / h
- Yokosuka MXY-8 "Akigusa" (Army type designation Yokoi Ku-13): school glider from the J8M fuselage
- Yokosuka MXY-9 "Shuka": School version made of J8M fuselage with a Tsu-11 - Thermojet engine (no longer built)
Total production
Operational version with rocket engine:
by Mitsubishi :
- J8M1 / Ki-200 (7 machines)
School version as a glider :
by Yokosuka , Yokoi and Maeda :
- MXY-8 / Ku-13 (approx. 60 machines)
Planned school version with Thermojet engine:
This school version with the designation MXY-9 / Ki-13 was no longer built due to the war.
Preserved machines
A total of seven J8M machines were built. Like some of their German predecessors, the Me 163, two of these machines were brought to the USA for evaluation after the end of the war . One of these machines is on display today in the Planes of Fame Museum . In the 1960s, an almost complete (but badly damaged) hull was discovered in a Japanese cave. This was initially exhibited at the Japanese air force base at Gifu until 1999 and then restored to be shown in Mitsubishi's own museum.
"Sword Stroke"
Numerous sources incorrectly translate the name "Shusui" as "sword stroke". Apparently this name comes from the work of Robert C. Mikesh in the 1950s and was subsequently adopted by many other authors. More precisely translated, 秋水 means “clear autumn water”, which is a common poetic metaphor in Japan for a well-sharpened sword. This is probably due to the fact that the clarity of the sword with its wavy line-like pattern is reminiscent of clear water.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 1 |
| length | 6.05 m |
| span | 9.50 m |
| height | 2.70 m |
| Wing area | 17.73 m² |
| Empty mass | 1,505 kg |
| Max. Takeoff mass | 3,885 kg |
| Top speed | 900 km / h in 10,000 m |
| Flight time (powered) | 5:30 min |
| Service ceiling | 12,000 m |
| Rate of climb | 2,858 m / min |
| Engine | Toku Ro.2 rocket engine |
| Thrust | 14.7 kN |
| Armament | two 30 mm MK type 5 Ki-200: two 30 mm MK Ho-105 |
Similar developments
See also
literature
- 「秋水」 と 日本 陸海軍 ジ ェ ッ ト 、 ロ ケ ッ ト 機, Model Art Co. Ltd., 1998. Edited by Takeo Yamashita
