Japan's Mitsubishi Ki-51 ground attack; Army Type 99
Allied code name: Sonia
Photos
Mitsubishi Ki-51, "Sonia" ground attack: |
Mitsubishi Ki-51, "Sonia" ground attack1: |
Mitsubishi Ki-51, "Sonia" ground attack: |
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Mitsubishi Ki-51, "Sonia" ground attack: |
Design
The Mitsubishi Ki-51 met a 1937 requirement for an aircraft that could take off from short strips near the front lines.1,2 The plane was required to have a speed of 260 mph at 6,500', weigh around 6,000 lb, carry 440 lbs of bombs, and have three machine guns.2 The Ki-51 was designed by Kawano, Ohki, and Mizuno.2
The Ki-51 was of all metal construction.2
Wings
The wings were mounted low in the fuselage.1,2
Main Armament
The early production aircraft had 7.7 mm MG in the wings and these were later replaced by 12.7 mm MGs.1 At the same time additional fuel tanks were added to the wing leading edges.1
Landing Gear
The landing gear on the Ki-51 were fixed.2
Cockpit
The pilot and navigator/bombardier were located in an all glass cockpit.2
Field Modifications
In the field the Ki-51 could be modified for either ground attack or reconnaissance.1
Prototype
In June and August 1939 the two prototypes were first flown.1,2
Production
Mitsubishi produced Ki-51s until March 1944 and Tachikawa until July 1945.1
- Prototypes: 21,2
- Service trials: 111,2
- Mitsubishi Ki-51: 2,3721
- Manufacturers: Mitsubishi (1,462)1, Tachikawa Army Air Arsenal (913)1
- Total: 2,3851,2
- Manufacturer: Mitsubishi Jukogyo K.K.2 , Tachikawa Dai-Ichi Rikugun Kokusho (Tachikawa Army Air Force Arsenal)2
- Production: 1940 - July 19452
- Mitsubishi Ki-71 Prototypes: 31
- Manufacturer: Tachikawa Army Air Arsenal1
Variants
- Mitsubishi Ki-51:
- Mitsubishi Ki-51a: Service trial aircraft with cameras.1
- Mitsubishi Ki-71: Prototype.1,2 Reconnaissance.1 Undercarriage was retractable.1,2 Had a Mitsubishi Ha-112-II engine (1,500 HP).1,2
Usage
Even though the Ki-51 never excelled in its classification it was well liked for its ability to withstand punishment, reliability, and manauverability.2
Sino-Japanese War
The Ki-51 was first used in China.1
Suicide
Towards the end, the Ki-51 was used as a suicide plane.2
Dutch Post World War II
The Dutch confiscated some abandoned Ki-51s and used them in the Indonesian Air Force.1
Specifications
| Mitsubishi Ki-511,2 | |
|---|---|
| Type | Attack2, Ground attack1, Reconnaissance1 |
| Crew | 21,2 |
| Engine (Type) | Mitsubishi Ha-26-II1,2 |
| Cylinders | Radial 141,2 |
| Cooling | Air2 |
| Net HP | 9402, 9501 |
| Propeller blades | 31, 3 metal variable pitch2 |
| Dimensions | |
| Span | 39' 8"2, 39' 8.5"1 12.1 m1 |
| Length | 30' 2"2, 30' 2.5"1 9.21 m1 |
| Height | 8' 11"2, 8' 11.5"1 2.73 m1 |
| Wing area | |
| Weight | |
| Empty | 4,129 lb1 1,873 kg1 |
| Loaded | 6,169 lb1,2 2,798 kg1 |
| Maximum loaded | 6,415 lb1 2,910 kg1 |
| Performance | |
| Speed @ 9,845' / 3,000 m |
263 mph1,2 423 kph1 |
| Cruising speed | |
| Climb to 16,405' / 5,000 m |
9.9 minutes1 |
| Service ceiling | 27,130'1,2 8,270 m1 |
| Range | 660 miles1,2 1,062 km1 |
| Armament | 3: MG2 |
| Wings - early aircraft | 2: 7.7 mm MG1,2 |
| Wings - later aircraft | 2: 12.7 mm MG1,2 |
| Rear cockpit | 1: 7.7 mm MG1,2 |
| Bombs | 440 lb2, 441 lb1 200 kg1 |
| Bombs - suicide mission | 551 lb1 250 kg1 |
Sources:
- Aircraft of WWII, Stewart Wilson, 1998
- World War II Airplanes Volume 2, Enzo Angelucci, Paolo Matricardi, 1976
