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Mitsubishi Ki-51 (Sonia)

1940 WORLD WAR 2

Mitsubishi Ki-51 (Sonia) History

Not only did Mitsubishi provide the "Zeros" with considerable development and production talent during WWII, it also clashed with the Imperial Japanese Army (IJA) - especially during operations in China and Burma. Total production eventually reached 2,385 and the model remained in service until the final weeks of the Pacific War in August 1945. The Ki-51 was codenamed "Sonia" by the Allies.

Its official IJA designation is "Type 99 Assault Aircraft".

The series started with two prototypes, the first flight was recorded in 1939. As a result, 11 prototype aircraft came for evaluation. Its design included two crew members sitting side by side under a long greenhouse-like canopy, with the pilot in front and the gunner in the back. The cockpit is midship forward and above the monoplane wing, which itself is a straight protrusion with a rounded tip.

As usual, the large radial piston engine is housed in the forward compartment, and the fuselage tapers gracefully to a point just below the tail. A single circular vertical stabilizer is used in conjunction with a low-position horizontal stabilizer. The landing gear was in a trailing arrangement and had aerodynamic fairings on the main legs - typical of early fighters such as the Ki-51. Dimensions include a length of 9.2 meters, a wingspan of 12 meters and a height of 2.7 meters.

Curb weight is 4,130 lbs and maximum takeoff weight (MTOW) is 6,415 lbs.

Power comes from a 950 hp Mitsubishi Ha-26-II series air-cooled 14-cylinder radial piston engine. The engine drives a three-bladed propeller unit at the front of the aircraft, and is equipped with a large spinner for airflow.

Top speed reaches 265 mph, range is up to 660 miles, and service is capped at 27,130 feet.

Standard armament consists of two fixed forward-firing 7.7mm Type 89 machine guns. The rear operator mounts a 7.7mm Te-4 series machine gun on a trainable mount. As a light bomber dive bomber airframe, the Ki-51 can carry up to 440 pounds of bombs.

Both Mitsubishi and Tachikawa Army Air Corps contributed to mass production of the Ki-51. Mitsubishi ended up delivering 1,462, and Tachikawa added another 913. The Imperial Japanese Army Air Force (IJAAF) became its main user. All production models belong to the simple designation "Ki-51".

Initially, this aircraft was vital to Japan's expansion in the Pacific, especially against smaller enemies to which the Ki-51 could go with impunity. The Ki-51 serves a general light bombardment role, providing conventional throwing weapons when needed, while also serving as a dive bomb platform for more accurate engagement of enemy targets and positions. Machine guns can be used as a defensive measure or during strafing as needed.

The aircraft proved to be structurally strong enough to allow the Ki-51 to operate in impassable areas, extending the tactical flexibility of this Mitsubishi design for Japanese war planners. Later versions were upgraded by replacing the 7.7mm machine guns with 2 x 12.7mm Ho-103 series machine guns for better frontal "impact".

The success of the Ki-51 began to spawn another form, the tactical reconnaissance platform built by the Manchukuo Wanzhou Aircraft Manufacturing Company (a subsidiary of Nakajima). The aircraft included modern qualities such as retractable landing gear, and three prototypes were launched.

However, the design, known as the Mansyu Ki-71, was not used in mass production.

After the successful Allied advance towards Tokyo, the fortunes of Imperial Japan changed. In an effort to turn the tide of the waror at least get the Allies to accept favorable surrender termsstocks of Ki-51 aircraft were restored later in the war to be used against the kamikazes of Allied warships. For these suicide attempts, the aircraft carried a 550-pound ammunition load to maximize damage and carnage to the enemy.

This ended the Ki-51's wartime career when Japan surrendered in September 1945.

The Ki-51 existed in the postwar era through capture forms used in Indonesia, China, and North Korea. Indonesians were included in the war with the Dutch in their struggle for independence, and many lost their lives. The Chinese Ki-51 was in service until 1953.

North Korea's mounts were provided by the Soviet Union immediately after the war and helped build North Korea's air power.