In May 1936 the Imperial Japanese Army issued its specification for a light bomber required to supersede the Mitsubishi Ki-2 and Kawasaki Ki-3 then in service. The Mitsubishi Ki-30 prototype that resulted was of cantilever mid-wing monoplane configuration with fixed tailwheel landing gear, the mam units faired and spatted, and powered by a 850-hp / 615kW Mitsubishi Ha-6 radial engine. The engine drove a three-bladed variable-pitch metal propeller. The Ki-30's two-man crew were housed beneath a long raised glazed canopy. Arma-ment comprised a wing mounted forward-firing 7.7-mm (0.303-in) Type 89 machine-gun with a similar weapon on a flexible mounting in the rear cockpit operated by the observer. The normal bombload of 300 kg (660 lb) was carried internally in the bomb bay. The Ki-30 was characterized by its fixed undercarriage with single cantilever-strut main units fitted with open-sided wheel spats.
The first prototype made its initial flight at the army's Kagamigahara experimen-tal airfield on February 28, 1937. The army specification had called for a maximum speed of 400 km/h (248 mph) and this was easily exceeded. All other requirements were met except that the weight was slightly more than the specified maximum of 3300 kg (7275 lb). The second prototype had a more powerful Nakajima Ha-5 KAI radial engine. This aircraft showed some slight improvement in performance but, in any case, exceeded the army's original specification, so there was no hesitation in ordering 16 service trials aircraft. These were delivered in January 1938 and, two months later, the Ki-30 was ordered into production.
Production at Mitsubishi's Nagoya plant started at the beginning of 1938, utilizing an alternative engine, the 960hp Nakajima Ha-5 Kai. Mitsubishi built 636 aircraft up to April 1940, supplemented by 68 completed at the Tachikawa army arsenal workshops between 1939-1941.
In service with six Sentais (groups) and several independent Chutais (squadrons) as the Army Type 97 Light Bomber, first used operationally in China during 1938.
A number were.supplied to Thailand who used them against the French in Indo-China during early 1941. When war was declared on Britain and the United States, Ki-30 units operated in the Philippines, but were from then on gradually transferred to training schools from where a number flew kamikaze missions in the sum-mer of 1945. The Allied codename 'Ann' was allocated to the Ki-30, but few were seen operationally after the opening phases of the war.
A total of 704 had been built when production ended in 1941, 68 manufactured by the First Army Air Arsenal at Tachikawa.
Engine: 1 x Mitsubisi Ha-6, 710kW
Max take-off weight: 3322 kg / 7324 lb
Empty weight: 2230 kg / 4916 lb
Wingspan: 14.55 m / 47 ft 9 in
Length: 10.34 m / 33 ft 11 in
Height: 3.65 m / 11 ft 12 in
Wing area: 30.58 sq.m / 329.16 sq ft
Max. speed: 432 km/h / 268 mph
Cruise speed: 380 km/h / 236 mph
Ceiling: 8570 m / 28100 ft
Range: 1700 km / 1056 miles
Armament: 2 x 7.7mm machine-guns, 300-450kg of bombs
Mitsubishi Ki-30 ANN