Mitsubishi Ki-51

The Mitsubishi Ki‑51, nicknamed “Sonia” by Allied pilots, was a two‑seat light bomber and dive‑bomber built by Mitsubishi Heavy Industries for the Imperial Japanese Army Air Service during World War II. First flown in August 1939, it entered service in 1940 and saw extensive action in the early campaigns of the Pacific War, including the Battle of China, Burma, the Philippines and the Dutch East Indies. The aircraft featured a low‑wing monoplane layout, fixed split‑type landing gear, and was powered by a 14‑cylinder Mitsubishi Ha‑26 radial engine delivering roughly 850 horsepower, giving a top speed of about 430 km/h (270 mph). Its internal bomb bay could accommodate up to 500 kg of ordnance, while external racks allowed additional fuel or small bombs. The Ki‑51’s rugged construction, short take‑off distance and ability to operate from rough forward airstrips made it valuable for close‑support and anti‑shipping strikes. Although increasingly outclassed by newer Allied fighters, the Ki‑51 continued in service with the Japanese and several post‑war air forces, illustrating the adaptability of a modest design that bridged the gap between tactical reconnaissance and ground‑attack roles in mid‑century aviation.

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