The was a

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese dia ...

light bomber A light bomber is a relatively small and fast type of military bomber aircraft that was primarily employed before the 1950s. Such aircraft would typically not carry more than one ton of ordnance. The earliest light bombers were intended to d ...

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

. It was a single-engine,

mid-wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

cantilever A cantilever is a rigid structural element that extends horizontally and is supported at only one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cant ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing conf ...

of stressed-skin construction with a fixed

tailwheel undercarriage Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...

and a long transparent

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the controls that e ...

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an a ...

. The type had significance in being the first Japanese aircraft to be powered by a modern two-row

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

. During the war, it was known by the Allies by the name Ann.

Design and development

The Ki-30 was developed in response to a May 1936

Imperial Japanese Army The was the official ground-based armed force of the Empire of Japan from 1868 to 1945. It was controlled by the Imperial Japanese Army General Staff Office and the Ministry of the Army, both of which were nominally subordinate to the Emperor o ...

specification to replace the Kawasaki Ki-3 light

bomber A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped from an aircraf ...

with a completely indigenously designed and built aircraft. Mitsubishi and Kawasaki were requested to build two

prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and software programming. A prototype is generally used ...

s each by December 1936. The specification called for a top speed of at 3,000 m (9,840 ft); normal operating altitude from 2,000 m (6,560 ft) to 4,000 m (13,130 ft), the ability to climb to 3,000 m (9,840 ft) within eight minutes and an engine to be selected from the Mitsubishi Ha-6 radial, Nakajima Ha-5 radial, or Kawasaki Ha-9-IIb liquid-cooled inline engines, a normal bomb load of and a maximum of , one forward-firing

machine gun A machine gun is a fully automatic, rifled autoloading firearm designed for sustained direct fire with rifle cartridges. Other automatic firearms such as automatic shotguns and automatic rifles (including assault rifles and battle ri ...

and one flexible rearward-firing machine gun, the ability to perform 60° dives for

dive bombing A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact througho ...

, and a loaded weight less than . The first Mitsubishi

flew on 28 February 1937 powered by a Mitsubishi Ha-6 radial. Originally, designed with a retractable main

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Martin ...

wind tunnel Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...

tests indicated that the gain in speed was minimal due to the landing gear's extra weight and complexity and a fixed arrangement with " spatted" main wheels was chosen instead. The wing was mounted at a point above the line of the aircraft's belly in order to fully enclose the

bomb bay The bomb bay or weapons bay on some military aircraft is a compartment to carry bombs, usually in the aircraft's fuselage, with "bomb bay doors" which open at the bottom. The bomb bay doors are opened and the bombs are dropped when over th ...

within the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft ...

. The pilot sat just above the

leading edge The leading edge of an airfoil surface such as a wing is its foremost edge and is therefore the part which first meets the oncoming air.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 305. Aviation Supplies & Academics, ...

of the wing, and the rear-gunner/radio-operator just behind the wing

trailing edge The trailing edge of an aerodynamic surface such as a wing is its rear edge, where the airflow separated by the leading edge meets.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 521. Aviation Supplies & Academics, 1997. ...

, in a long "greenhouse"

which gave both crewmen excellent all-around vision. The Ha-6 engine drove a three-blade variable-pitch

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

. A second prototype, fitted with the slightly more powerful Nakajima Ha-5 engine, was completed the same month. Although two months behind schedule and overweight, both prototypes met or exceeded every other requirement. The second prototype's top speed of at 4,000 m (13,130 ft) led the

Imperial Japanese Army Air Force The Imperial Japanese Army Air Service (IJAAS) or Imperial Japanese Army Air Force (IJAAF; ja, 大日本帝國陸軍航空部隊, Dainippon Teikoku Rikugun Kōkūbutai, lit=Greater Japan Empire Army Air Corps) was the aviation force of the I ...

to place an order for 16 service trials machines. These were delivered in January 1938 and the result of the trials was that the Army ordered the Ki-30 into production in March under the designation Army Type 97 Light bomber. Mitsubishi built 618 production machines through April 1940, and the 1st Army Air Arsenal (Tachikawa Dai-Ichi Rikugun Kokusho) built 68 more by the time production ceased in September 1941. Including prototypes, a total of 704 Ki-30s were built.

Operational history

The Ki-30s were first used in combat in

Second Sino-Japanese War The Second Sino-Japanese War (1937–1945) or War of Resistance (Chinese term) was a military conflict that was primarily waged between the Republic of China (1912–1949), Republic of China and the Empire of Japan. The war made up the Chinese ...

from spring 1938. It proved to be reliable in rough field operations, and highly effective while operating with fighter escort. This success continued in the early stages of the

Pacific War The Pacific War, sometimes called the Asia–Pacific War, was the Theater (warfare), theater of World War II that was fought in Asia, the Pacific Ocean, the Indian Ocean, and Oceania. It was geographically the largest theater of the war, ...

, and the Ki-30s participated extensively in operations in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. However, once unescorted Ki-30s met Allied fighters, losses mounted rapidly and the type was soon withdrawn to second-line duties. By the end of 1942, most Ki-30s were relegated to a

training Training is teaching, or developing in oneself or others, any skills and knowledge or fitness that relate to specific useful competencies. Training has specific goals of improving one's capability, capacity, productivity and performance. It ...

role. Many aircraft were expended in ''

kamikaze , officially , were a part of the Japanese Special Attack Units of military aviators who flew suicide attacks for the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, intending ...

'' attacks towards the end of the war. From late 1940, the Ki-30 was in service with the

Royal Thai Air Force "Royal Thai Air Force March" , mascot = , anniversaries = 9 April 1937 (Royal Thai Air Force Day) , equipment = , equipment_label = , battles ...

, and saw combat in January 1941 against the French in

French Indochina French Indochina (previously spelled as French Indo-China),; vi, Đông Dương thuộc Pháp, , lit. 'East Ocean under French Control; km, ឥណ្ឌូចិនបារាំង, ; th, อินโดจีนฝรั่งเศส, ...

in the French-Thai War. 24 aircraft were delivered, and were nicknamed ''Nagoya'' by the crews.Garlicki, Jarosław (2001). ''Historia lotnictwa wojskowego Królestwa Tajlandii w latach 1912 – 1945. Część 3. Wojna tajsko-francuska.'' "Militaria i Fakty". 4/2001, p. 37 Additional Ki-30s were transferred from Japan in 1942.

Operators

World War II

; *

**No. 82 Dokuritsu Hikō Chutai IJAAF **No. 87 Dokuritsu Hikō Chutai IJAAF **No. 6 Hikō Sentai IJAAF **No. 16 Hikō Sentai IJAAF **No. 31 Hikō Sentai IJAAF **No. 32 Hikō Sentai IJAAF **No. 35 Hikō Sentai IJAAF **No. 90 Hikō Sentai IJAAF ; *

Royal Thai Air Force "Royal Thai Air Force March" , mascot = , anniversaries = 9 April 1937 (Royal Thai Air Force Day) , equipment = , equipment_label = , battles ...

Post-war

; * Chinese Communist Air Force – Operated three captured Ki-30s used as trainers until the early 1950s. ; *

Indonesian Air Force The Indonesian Air Force ( id, Tentara Nasional Indonesia Angkatan Udara (TNI-AU), literally "''Indonesian National Military-Air Force''") sometimes shortened as IDAF / IdAF, is the Air force, aerial branch of the Indonesian National Armed For ...

Specifications (Ki-30)

Notes

Bibliography

* * * * * * *

External links

Ki-30 on www.warbirdsresourcegroup.org

A photograph of Ki-30 in Royal Thai Air Force service
{{Thai attack aircraft designations Ki-030 Ki-30, Mitsubishi Single-engined tractor aircraft Ki-30, Mitsubishi Aircraft first flown in 1937 Mid-wing aircraft