Mitsubishi played a prominent role as a primary defense contractor for the Empire of Japan during World War 2. To fulfill an Imperial Japanese Army Air Force (IJAAF) charge for a light bomber to succeed the outmoded Kawasaki Ki-3 biplane series, Mitsubishi squared off against its rival in Kawasaki when developing an all-modern design beginning in 1936. Each company was called to provide two viable prototypes by the end of the year in which the prototypes would have to fulfill very specific program goals including a maximum speed of 250 miles per hour and the ability to operate without restrictions up to 13,000 feet. Three aero engines - one from Mitsubishi, another from Nakajima and a third from Kawasaki - were selected as potential powerplants for the new aircraft.
In the coming year, Mitsubishi was able to unveil their submission which first took to the skies on February 28th, 1937 while fitted with a Mitsubishi Ha-6 series radial piston engine. A second prototype, this fitted with a Nakajima Ha-5 engine, proved the most promising of the two designs when trialed and earned Mitsubishi the production order. The Japanese Army required sixteen initial evaluation models and these were then thoroughly tested beginning January of 1938. Formal approval of the type followed in March. To Mitsubishi, the model was recognized as the "Ki-30" while the IJAAF assigned it the more formal name of "Army Type 97 Light Bomber". During World War 2, the Allies gave the aircraft the codename of "Ann".
Outwardly, the Ki-30 was a conventional aircraft design for the period. The vehicle featured a standard operating crew of two made up of the pilot and bombardier/radio-operator/rear gunner seated in tandem under a long-running "greenhouse" style framed canopy. The large radial pistol engine was fitted to a forward compartment and powered a three-bladed propeller assembly behind a rounded spinner. Wings were mid-mounted appendages along the rounded fuselage sides with an internal bomb bay featured under the fuselage. While the original prototype sported a retractable undercarriage, finalized Ki-30s were fielded with fixed spatted (shrouded) legs when it was found that the retractable versions offered little performance gain and complicated production and maintenance. Each leg held a single wheel with a tail wheel fitted at the rear of the fuselage. The empennage was traditional with a single vertical tail fin and a pair of low-set horizontal planes. Power was served through the Nakajima Ha-5-kai series 14-cylinder, double-row, air-cooled, radial piston engine developing 950 horsepower. The Ha-5 was Japan's first twin-row radial engine fitted to an aircraft. The powerplant allowed for a top listed speed of 263 miles per hour with a cruise speed of 236 miles per hour. The maximum service ceiling was 28,100 feet with optimal performance in the required 6,500 foot to 13,000 foot altitude range. On internal fuel stores, the aircraft managed an operational range out to 1,060 miles. Self defense was through 1 x 7.7mm Type 89 machine gun fitted to the wing in a fixed, forward-firing position and 1 x 7.7mm Type 89 machine gun on a trainable mounting at the rear cockpit managed by the rear crewman. The aircraft was cleared to carry up to 880lbs of internal stores.
One in service, the Ki-30 formed the No. 82 and 87 Dokuritsu Hiko Chutai and No. 6, 16, 31, 32, 35 and 90 Hiko Sentai aircraft groups of the Imperial Japanese Army Air Force. Their baptism of fire proved to be during the Second Sino-Japanese War ongoing between Japan and China since 1931. The Ki-30 made its debut in the early portion of 1938. There, against a limited foe, the type proved an excellent light bombing platform and certainly made itself a viable tactical tool in the Japanese Army arsenal - particularly when under the protection of Japanese Army fighters. As the standalone attack craft, the Ki-30 held limited capabilities and armament which would make it fodder to a more determined foe. With Japanese expansion in the Pacific continuing into 1941, the Ki-30 remained in service while the Japanese military held the initiative through land, sea and air. However, its fortunes turned for the worse when the Imperial Japanese Navy headed the surprise attack of Pearl Harbor, Hawaii, to officially involve the United States in World War 2.
The Ki-30 proved serviceable in the months that followed the attack but it was quickly regressing into an obsolete design. When American engineering, tactics and training finally caught up to the war effort, the Ki-30 was no longer deemed a useable frontline implement - advanced Allied fighters could engage Ki-30s with ease particularly when IJA flights were left without fighter protection. Losses grew to unacceptable levels which forced the hand of the IJAAF to reduce frontline Ki-30 operations. Instead, the stock of aircraft were used as trainers where they served out the rest of their days. The Ki-30 was formally withdrawn from frontline service by the beginning of 1943. It was utilized briefly during the kamikaze suicide attacks period during the final defense of Japan and its holdings, bringing an end to the tenure of the Ki-30 as a conventional bombing aircraft.
Beyond its use by the Japanese Army in World War 2, the Ki-30 series was also in play with the Royal Thai Air Force when it went to war against the French beginning in January of 1941. The French-Thai War lasted from October 1940 into May of 1941 before ending in a ceasefire (arranged by the Japanese). Thailand received several territories from the French as part of the cease fire. Considering France's weakened position in Europe following the German conquest, the nation was in no position to defend its colonial interests half a world away.
Production of Ki-30 aircraft spanned from 1938 until 1941 to which 704 total units were delivered. No known variants were listed. Post-war operators included the Chinese Air Force and Indonesian Air Force, both operating the type in relatively limited quantities.
China (post-war); Imperial Japan; Indonesia; Thailand
(OPERATORS list includes past, present, and future operators when applicable)
✓Ground Attack (Bombing, Strafing)
Ability to conduct aerial bombing of ground targets by way of (but not limited to) guns, bombs, missiles, rockets, and the like.
✓Intelligence-Surveillance-Reconnaissance (ISR), Scout
Surveil ground targets / target areas to assess environmental threat levels, enemy strength, or enemy movement.
Developed ability to be used as a dedicated trainer for student pilots (typically under the supervision of an instructor).
34.0 ft (10.35 m)
47.7 ft (14.55 m)
12.0 ft (3.65 m)
4,916 lb (2,230 kg)
7,319 lb (3,320 kg)
+2,403 lb (+1,090 kg)
(Showcased structural values pertain to the base Mitsubishi Ki-30 (Ann) production variant)
1 x Nakajima Ha-5 KAI radial piston engine developing 950 horsepower.
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