The Mitsubishi Ki-1, also known as Mitsubishi Army Type 93 Heavy Bomber, was a

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 air ...

built by Mitsubishi for the Imperial Japanese Army in the 1930s. The Ki-1 design was heavily based on the

Junkers K 37 The Junkers S 36 was a twin-engine mail plane developed in Germany in the late 1920s that was further developed in Sweden as a multi-role military aircraft, albeit unsuccessfully, under the designation K 37. The design itself was a low-wing canti ...

and a mockup was ready in August 1932, with the first prototype being finished in March 1933. Despite its antiquated appearance, the Ki-1 was used in Manchukuo and in north China during the early stages of the

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 and the Empire of Japan. The war made up the Chinese theater of the wider Pacific Th ...

, in areas where danger from enemy fighter aircraft was minimal.

Design and development

The Mitsubishi Ki-1 was a low-wing,

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 con ...

with fixed

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 ...

, twin

fins A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...

and

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...

s, and was powered by two

Mitsubishi Ha2 The is a group of autonomous Japanese multinational companies in a variety of industries. Founded by Yatarō Iwasaki in 1870, the Mitsubishi Group historically descended from the Mitsubishi zaibatsu, a unified company which existed from 1870 ...

-II water-cooled

V-12 engine A V12 engine is a twelve-cylinder piston engine where two banks of six cylinders are arranged in a V configuration around a common crankshaft. V12 engines are more common than V10 engines. However, they are less common than V8 engines. The fir ...

s, giving a maximum speed of . The pilot and co-pilot were seated in tandem under an enclosed

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 ...

, while gunners sat in semi-enclosed nose and dorsal

gun turret A gun turret (or simply turret) is a mounting platform from which weapons can be fired that affords protection, visibility and ability to turn and aim. A modern gun turret is generally a rotatable weapon mount that houses the crew or mechani ...

s, each armed with a single

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 rifles) ar ...

. The usable bomb load was up to . The Ki-1 shared a similar configuration with the Junkers S 36 first flown in 1927, militarized into the Junkers K37 by Junker's Swedish subsidiary AB Flygindustri at Limhamn near

Malmö Malmö (, ; da, Malmø ) is the largest city in the Swedish county (län) of Scania (Skåne). It is the third-largest city in Sweden, after Stockholm and Gothenburg, and the sixth-largest city in the Nordic region, with a municipal pop ...

. It was able to reach altitudes not reachable for the fighters of 1927. However, as soon as 1930 this advantage was lost due to

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

developments such as the

Bristol Bulldog The Bristol Bulldog is a British Royal Air Force single-seat biplane fighter designed during the 1920s by the Bristol Aeroplane Company. More than 400 Bulldogs were produced for the RAF and overseas customers, and it was one of the most fam ...

fighter, and Junkers was not successful in selling the design. In 1931 however representatives of Mitsubishi from Japan visited the Limhamn facilities to study some of the military conversions of Junkers aircraft. The sole K 37 prototype S-AABP (ex D-1252 - S 36-prototype), as well as all development papers were purchased in part by funds raised by donations in Japan. The aircraft got the name ''Aikoku No.1'' (patriotic gift). The K37 prototype was brought to Japan and tested in combat during the

Manchurian Incident The Mukden Incident, or Manchurian Incident, known in Chinese as the 9.18 Incident (九・一八), was a false flag event staged by Japanese military personnel as a pretext for the 1931 Japanese invasion of Manchuria. On September 18, 1931, L ...

of 1931, following which 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 Im ...

authorized Mitsubishi to produce both

heavy Heavy may refer to: Measures * Heavy (aeronautics), a term used by pilots and air traffic controllers to refer to aircraft capable of 300,000 lbs or more takeoff weight * Heavy, a characterization of objects with substantial weight * Heavy, ...

and light bomber variations. The heavy bomber Ki-1, was much larger than the original Junkers K37 and first flew in August 1932. A total of 118 aircraft were built in two versions between March 1933 and April 1936.

Operational history

The Mitsubishi Ki-1 was also designated Mitsubishi Army Type 93-I Heavy Bomber under the long aircraft nomenclature system used by the Japanese military. Already obsolete by the time of its introduction, it found use during the

counterinsurgency Counterinsurgency (COIN) is "the totality of actions aimed at defeating irregular forces". The Oxford English Dictionary defines counterinsurgency as any "military or political action taken against the activities of guerrillas or revolutionari ...

operations of the

Pacification of Manchukuo The Pacification of Manchukuo was a Japanese counterinsurgency campaign to suppress any armed resistance to the newly established puppet state of Manchukuo from various anti-Japanese volunteer armies in occupied Manchuria and later the Communis ...

, as well as limited use during the

. The design was upgraded to the Mitsubishi Ki-1-II (Mitsubishi Army Type 93-II Heavy Bomber) with a strengthened airframe and slightly more powerful

-III V-12 engines, which increased maximum speed to . However, even with the new engines, the Ki-1 was still underpowered, and was unable to maintain altitude during single engine flights, which proved to be a serious issue during the aircraft's operational service due to lack of reliability of the engines. It was replaced in 1937 by the

Fiat BR.20 The Fiat BR.20 ''Cicogna'' (Italian: " stork") was a low-wing twin-engine medium bomber that was developed and manufactured by Italian aircraft company Fiat. It holds the distinction of being the first all-metal Italian bomber to enter service;B ...

Variants

;Ki-1-I (Army Type 93-I Heavy Bomber):Initial production variant, powered by two

-II (Army Type 93-II 700 hp Water Cooled In-line)

s. ;Ki-1-II (Army Type 93-II Heavy Bomber):Improved version with more powerful engines, strengthened airframe, powered by two

-III (Army Type 93-III 700 hp Water Cooled In-line)

Operators

Military operators

; *

Specifications (Ki-1-I)

Notes

Bibliography

* * * *

External links

"Japan Matches War Planes of Other Powers" ''Popular Mechanics'', September 1937

{{Japanese Army Aircraft Designation System Ki-01, Mitsubishi Ki-001 Low-wing aircraft Aircraft first flown in 1932 Twin piston-engined tractor aircraft