Ki-51 "Sonia", Japanese
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The Pacific War Online Encyclopedia | |
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MitsubishiKi-51 "Sonia"
| Crew | 2 in tandem cockpit |
|---|---|
| Dimensions | 39'8" by 30'3" by 8'11"12.09m by 9.22m by 2.72m |
| Wing area | 259 square feet24 square meters |
| Weight | 4129-6415 lbs18873-2910 kg |
| Maximum speed | 263 mph at 9845 feet423 km/h at 3000 meters |
| Climb rate | 28 feet per second8.5 meters per second |
| Ceiling | 27,130 feet8270 meters |
| Power plant | One 940 hp (700 kW) Type 99 Model 2 (Mitsubishi Ha-26-II) 14-cylinder radial engine driving a variable-pitch 3-bladed metal propeller |
| Armament | 2 12.7mm Type 1 machine guns (wings)1 7.7mm Type 89 machine gun(rear cockpit) |
| External stores | 441 lbs (200 kg) of bombs normal551 lbs (250 kg) of bombs as kamikaze |
| Range | 660 miles1060 km |
| Production | A total of 2385 aircraft as follows: |
| Mitsubishi Jukogyo K.K. (Nagoya): | |
| Tachikawa Dai-Ichi Rikugun Kokusho: | |
"Sonia" was a more successful design than "Helen", serving throughout the Pacific. Though somewhat slow, it was unusually well protected for a Japanese design, was easily maintained, and was well-liked by its crews. It had a good rough-fieldcapability.
The design originated in December 1937 with a specification issued to Mitsubishi for a ground attack aircraft based on the Ki-30 "Ann". The Japanese Army wanted a smaller aircraft capable of operating on short airstrips close to the front. The design team shortened the cockpit and gave the rear cockpit a limited set of instruments and controls. The bomb bay was eliminated and the wings were lowered to permit a sturdier undercarriage. A prototype was completed in June 1939 and, with modifications to improve handling and the addition of 6 mm armor plating around the cockpit and engine, the design went into production in January 1940.
The aircraft was designed so that the rear cockpit instruments and controls could be replaced with camera equipment for photoreconnaissance.
"Sonia" was so well liked by its crews that a new production line was set up as late as 1944 at Tachikawa First Air Arsenal (Tachikawa Dai-Ichi Rikugun Kokusho). The aircraft was assigned to kamikaze missions in the final months of the war, and a few relic aircraft were used by the Indonesian Air Force against Dutch forces postwar. An attempt to produce a more powerful version with retractable landing gear in Manchuria came to naught, but was discovered by Allied intelligence, who assigned the new aircraft the code name "Edna".
References
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