World War II Vehicles, Tanks and Airplanes, picture of P-51 Mustang
World War II Vehicles, Tanks and Airplanes, picture of T-34/85
World War II Vehicles, Tanks and Airplanes, picture of Fw-190
World War II Vehicles, Tanks and Airplanes, picture of Churchill
wwiivehicles.com ©2016
Search:
Japan's Imperial Army flag

Japan's Mitsubishi Ki-51 ground attack; Army Type 99
Allied code name: Sonia

Photos

  • 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.1,2,3 The Ki-51 was designed by Kawano, Ohki, and Mizuno.2,4

Requirements:

  • Speed: 260 mph at 6,500'2, 261 mph at 6,560'4, 420 kph at 2,000 m4
  • Weight: 5,952 lb4, ~6,000 lb2, 2,700 kg4
  • Bombs: 440 lbs2 , twelve 33 lb / 15 kg4 or four 110 lb / 50 kg4
  • Armament: three machine guns2, two MG in wings4, one MG in rear cockpit4
  • Engine: Mitsubishi Ha-26-II radial4

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 The were placed close together to allow for better communication.4

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.1,2,3

Production

Mitsubishi produced Ki-51s until March 1944 and Tachikawa until July 1945.1

  • Prototypes: 21,2,3,4
    • Production: June - August 19394
  • Service trials: 111,2,3,4
    • Production: September - December 19394
  • Mitsubishi Ki-51: 2,3721
    • Manufacturers: Mitsubishi (1,4594, 1,4621), Tachikawa Army Air Arsenal (913)1,4
    • Production: June 1940 - March 1944 (Mitsubishi)4, July 1941 - July 1945 (Tachikawa)4
  • Total: 2,3851,2,4
    • Manufacturer: Mitsubishi Jukogyo K.K.2 at Nagoya4, Tachikawa Dai-Ichi Rikugun Kokusho (Tachikawa Army Air Force Arsenal)2 at Tachikawa4
    • Production: 1940 - July 19452
  • Mitsubishi Ki-71 Prototypes: 31,4
    • Manufacturer: Tachikawa Army Air Arsenal1,4

Variants

  • Mitsubishi Ki-51:
  • Mitsubishi Ki-51a, Army Type 99 Tactical Reconnaissance: Service trial aircraft with cameras for reconnaissance.1,3,4
  • Mitsubishi Ki-71, "Edna"4: Prototype.1,2,3,4 Reconnaissance.1,3,4 Undercarriage was retractable.1,2,3 Had a Mitsubishi Ha-112-II engine (1,500 HP).1,2,3,4 Was to have two 20 mm Ho-5 cannons in the wings.3,4

Usage

Even though the Ki-51 never excelled in its classification it was well liked for its ability to withstand punishment, reliability, and manauverability.2,3,4

Units

  • Sentais: 6th, 27th, 32nd, 44th, 65th, 66th, 67th, 83rd4
  • Kokuritsu Hiko Chutais: 41st, 45th, 47th, 48th, 49th, 52nd, 53rd, 71st, 73rd, 83rd, 89th, 90th, 91st4
  • 4th Kokugun Shireibu Hikodan4
  • Koku Shikan Gakko (Army Air Academy)4

Sino-Japanese War

The Ki-51 was first used in China.1,3

Suicide

Towards the end, the Ki-51 was used as a suicide plane.2,3

Dutch Post World War II

The Dutch confiscated some abandoned Ki-51s and used them in the Indonesian Air Force.1,4

Specifications

  Mitsubishi Ki-51
Type Attack2, Ground attack1,3,4, Reconnaissance1,3,4
Crew 21,2,3,4
Engine (Type) Mitsubishi Ha-26-II1,2,3,4
Cylinders Radial3, Radial 141,2,4
Cooling Air2
Net HP 9402,3,4, 9501
Propeller blades 31, 3 metal variable pitch2,4
Dimensions  
Span 39' 8"2, 39' 8.375"4, 39' 8.4"3, 39' 8.5"1
12.1 m1,3,4
Length 30' 2"2, 30' 2.2"3, 30' 2.5"1, 30' 2.59"4
9.2 m3, 9.21 m1,4
Height 8' 11"2, 8' 11.5"1,3,4
2.73 m1,3,4
Wing area 258.548 sq ft4, 258.56 sq ft3
24.02 sq m3,4
Weight  
Empty 4,129 lb1,3,4
1,873 kg1,3,4
Loaded 6,169 lb1,2,4
2,798 kg1,4
Maximum loaded 6,415 lb1,4, 6,437 lb3
2,910 kg1, 2,920 kg3,4
Performance  
Speed at 9,845' / 3,000 m 263 mph1,2,4, 264 mph3
423 kph1, 424 kph4, 425 kph3
Climb to 16,405' / 5,000 m 9.9 minutes1, 9 minutes 55 seconds4
Service ceiling 27,130'1,2,3,4
8,270 m1,3,4
Range 659 miles3, 660 miles1,2,4
1,060 km3,4, 1,062 km1
Armament 3: MG2
Wings - early aircraft 2: 7.7 mm Type 89 MG1,2,3,4
Wings - later aircraft 2: 12.7 mm Type 1 MG1,2,3,4
Rear cockpit 1: 7.7 mm Type 89 MG1,2,3,4
Bombs 440 lb2, 441 lb1,3,4
200 kg1,3,4
Bombs - suicide mission 551 lb1,3,4
250 kg1,3,4

Sources:

  1. Aircraft of WWII, Stewart Wilson, 1998
  2. World War II Airplanes Volume 2, Enzo Angelucci, Paolo Matricardi, 1976
  3. The Encyclopedia of Weapons of World War II, Chris Bishop, 1998
  4. Japanese Aircraft of the Pacific War, René J Francillon, 1970
20th Century American Military History Crucial Site