Designed by Nihon Kokusai in 1937 as a twin-engined commercial feeder-liner transport for domestic routes, the Ki-59 was known originally as the Teradakoken TK-3, and was flown for the first time in June 1938. The two civil prototypes were followed in mid-1939 by additional development aircraft to army air force standard, with lower-powered (510-hp Hitachi Ha-13a) nine-cylinder radial engines and internal changes. Although performance was far from outstanding, it entered production at Hiratsuka for the army air force in 1941 as the Army Type 1 Transport. However, Nihon Kokusai completed only 59 Ki-59s before production was ended, and their wartime use was very limited.
Of utilitarian appearance, the high-wing, fixed-undercarriage Ki-59, codenamed Theresa, was of mixed construction, and accommodated up to eight passengers in addition to two or three crew. One example became the original prototype for the Ku-8 troop transport glider.
Span: 17 m (55 ft 9 in)
Length: 12.5 m (41 ft)
Gross weight: 4240 kg (9347 1 b)
Cruising speed 300 km/h (186 mph).