The Mitsubishi Ki-51 (Army designation "Type 99 Assault Plane"; Allied reporting name "Sonia") was a light bomber/dive bomber in service with the Imperial Japanese Army during World War II. It first flew in mid-1939. Initially deployed against Chinese forces, it proved to be too slow to hold up against the fighter aircraft of the other Allied powers. However, it performed a useful ground-attack role in the China-Burma-India theater, notably from airfields too rough for many other aircraft. As the war drew to a close, the Japanese began using them in kamikaze attacks. Total production was around 2,385.
The only complete survivor of Ki-51 is part of the collection of the Dirgantara Mandala Museum in Indonesia. The aircraft was found abandoned at the Babo Airfield in West Papua province. The aircraft was likely stripped for spare parts and later abandoned. Before the aircraft was recovered, its propeller blade was cut off, with its engine cowling and cockpit canopy was missing. The aircraft was recovered from Babo airfield in 1987, was restored and then displayed with Indonesian Air Force markings at the Dirgantara Mandala Museum.[4][5]
Green, William & Swanborough, Gordon (n.d.). "Pentagon Over the Islands: The Thirty-Year History of Indonesian Military Aviation". Air Enthusiast Quarterly (2): 154–162. ISSN0143-5450.
Soumille, Jean-Claude (September 1999). "Les avions japonais aux couleurs françaises" [Japanese Aircraft in French Colors]. Avions: Toute l'Aéronautique et Son Histoire (in French) (78): 6–17. ISSN1243-8650.
