Mitsubishi Ki-51

The Mitsubishi Ki-51 (Army designation "Type 99 Assault Plane". Allied nickname "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, they began to be used in kamikaze attacks. Total production was around 2,385 units.

On the day Hiroshima was destroyed by an atomic bomb, two Ki-51s scored the last Japanese victory against US submarines, and of which is confirmed as the 52nd USN submarine lost during the war; essentially, she would have been second to last, as USS Halibut (SS-232) was irreparably damaged in action months before Bullhead was lost, and was decommissioned in early 1945. Two depth charges hit USS Bullhead (SS-332), in which she later exploded and sank with all hands.

Charles Lindbergh, flying a P-38 Lightning shot down a Ki-51 after a vigorous dogfight in which the much slower Ki-51 utilized its low speed maneuverability and made a fight of it.

Versions

 * Prototypes: 2 built
 * Service trials: 11 built
 * Ki-51: 2,372 built (Manufacturers: Mitsubishi (1,462), Tachikawa Army Air Arsenal (913))
 * Mansyu Ki-71: 3 protoypes of a tactical reconnaissance variant built by Mansyu with a retractable landing gear, did not enter production.

Operators
captured a small number of aircraft at numerous Japanese air bases, including Bugis Air Base in Malang (repatriated 18 September 1945). Most aircraft were destroyed in military conflicts between the Netherlands and the newly proclaimed-Republic of Indonesia during the Indonesian National Revolution of 1945-1949.
 * Imperial Japanese Army Air Force
 * 🇮🇩 Indonesia
 * Indonesian Air Force - In 1945, Indonesian People's Security Force (IPSF) (Indonesian anti-Dutch Militia)
 * Indonesian Air Force - In 1945, Indonesian People's Security Force (IPSF) (Indonesian anti-Dutch Militia)
 * Communist Chinese (captured): The last 4 Ki-51s retired in 1953.
 * Communist Chinese (captured): The last 4 Ki-51s retired in 1953.