Mitsubishi Ki-21
| Mitsubishi Ki-21 | |
|---|---|
 Mitsubishi Ki-21-2 |
|
| Type: | Bomb plane |
| Design country: | |
| Manufacturer: | |
| First flight: |
1936 |
| Commissioning: |
1938 |
| Production time: |
1936-1944 |
| Number of pieces: |
2564 |
The Mitsubishi Ki-21 was the main long-range bomber in the Imperial Army of Japan at the start of World War II. Her allied code name was 'Sally'.
history
Development began in 1936 when the Japanese Army Ministry requested a long-range bomber for use in China and Manchuria . The bomber was intended for the second Sino-Japanese War , which the Japanese military was already planning intensively. Mitsubishi designed an all-metal mid-decker with radial engines, retractable landing gear and bomb bay.
In a comparison with the competing model Ki-19 from Nakajima Hikōki , the Ki-21 asserted itself.
The production version was equipped with a modified conical bow and an enlarged cockpit roof instead of the originally built-in machine gun tower. Instead of the Mitsubishi Kinsei Ha-6, the more modern 850 hp Nakajima Ha-5-Kai engines were used as engines. The top speed increased to 432 km / h thanks to the improved aerodynamics. The Polikarpow I-16 and Curtiss P-36 fighter planes used by the Chinese were hardly faster.
In the spring of 1938, the Ki-21-Ia, also known as the Type 97, entered service with the 60th Sentai and proved itself to be a reliable and frequently used aircraft. At the same time, the production of the Ki-21 also started at the previous competitor Nakajima. The Ki-21 was tough enough against the weakly armed Chinese (Russian and American) fighters to hold its own until the early 1940s. Further versions followed on the basis of operational experience: The 1-b with stronger armor and defensive armament as well as an improved bomb bay, then the 1c with an extended fuel tank and increased range and finally the Ki-21-IIa (allied code designation erroneously initially "Gwen", until it was recognized that it was only a variant of the already known "Sally") with a larger horizontal stabilizer and 1490 hp Ha-101 engines. The final point was the Ki-21-IIb with a machine-gun turret.
The planned version Ki-21-III was no longer implemented, because despite all the improvements it soon became apparent that the Ki-21, which was used on all fronts of the Pacific War as the Japanese standard bomber, was already out of date for front-line use. Many older types of Ki-21s were converted into training or transport aircraft ( MC-21 ). When the Americans appeared in the Pacific with more heavily armed and much faster fighters, the losses of the Ki-21 increased enormously, despite constantly improved armament and armor. Escort protection in the form of fighters was of little help either, as these generally had shorter ranges, so that the Ki-21 was completely out of date in its role as a long-range bomber by 1942.
The successor model Nakajima Ki-49 showed such serious defects that the Ki-21 was only replaced by the Mitsubishi Ki-67 in 1944 . By that year, 1,713 Mitsubishi and 351 Nakajima aircraft had been built. In addition, there were around 500 civil and military transport aircraft MC-20 and Ki-57 (allied code designation "Topsy"). By then, however, Japan had almost completely lost the possibilities for offensive warfare and long-range bombers turned out to be superfluous in this war situation.
Technical specifications
| Parameter | Data (Ki-21-I Ko) |
|---|---|
| crew | |
| length | 16.50 m |
| span | 22.50 m |
| height | 4.35 m |
| Wing area | 69.60 m² |
| Wing extension | |
| payload | |
| Empty mass | 5105 kg |
| Max. Takeoff mass | 8412 kg |
| Cruising speed | |
| Top speed | 432 km / h |
| Service ceiling | 8600 m |
| Range | |
| Use radius | 1500 km |
| Engines | two radial engines Nakajima Ha-5 Kai, each 708 kW (963 PS) |
| Armament | three 7.7 mm Type-89 machine guns , 1000 kg bombs |
literature
- Olaf Groehler : History of the Air War 1910 to 1980 , Military Publishing House of the German Democratic Republic, Berlin 1981, p. 191
- Kenneth Munson: Bomber, Patrol and Transport Aircraft 1939–45 , Orell Füssli Verlag, Zurich, 3rd edition 1977
Web links
Individual evidence
- ↑ According to Olaf Groehler: History of the Air War 1910 to 1980 , Military Publishing House of the German Democratic Republic, Berlin 1981, p. 191, the first delivery took place from 1936
- ↑ cf. Olaf Groehler: History of the Air War 1910 to 1980 , Military Publishing House of the German Democratic Republic, Berlin 1981, p. 191