The was a trainer built by Mitsubishi which was used by the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrend ...

in an extremely wide variety of roles, including light transport, liaison aircraft,

utility aircraft A utility aircraft is a general-purpose light airplane or helicopter, usually used for transporting people, freight or other supplies, but is also used for other duties when more specialized aircraft are not required or available. The term can a ...

and occasionally light bomber. Its Allied reporting name was Pine.

Design & Development

The Mitsubishi K3M was designed by

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, ...

aeronautical engineer Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is sim ...

and aircraft designer Herbert Smith, from Sopwith working in Japan for Mitsubishi. The prototype, designated Mitsubishi 4MS1, made its maiden flight in 1930. The aircraft was strut-braced high-wing cabin

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 wide-track

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 ...

, and was powered by a single water-cooled radial piston engine. Pilot and gunner were located in separate open cockpits, with an instructor and two pupils in the enclosed cabin in 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 aircraf ...

. Later passenger variants seated five passengers in the cabin. Total production of all versions was around 625 aircraft, with production mostly undertaken by

Kyushu Hikoki K.K. The was a Japanese manufacturer of military aircraft during World War II. While it mainly manufactured other firms' designs, it was notable for the radical J7W "Shinden" fighter. Named after Kyushu island where the company was based. The compa ...

and

Aichi Kokuki was a Japanese aircraft manufacturer which produced several designs for the Imperial Japanese Navy. After the war, the company was reorganized as Aichi Machine Industry Co., Ltd (愛知機械工業) where they made small '' kei'' cars until ...

. Production continued until 1941, and examples pressed into service as liaison aircraft in the postwar period were found in a variety of

national markings Military aircraft insignia are insignia applied to military aircraft to identify the nation or branch of military service to which the aircraft belong. Many insignia are in the form of a circular roundel or modified roundel; other shapes such as ...

Operational history

The first version of the K3M offered to the Imperial Japanese Navy Air Service was prone to stability problems, and more importantly, problems with the water-cooled Mitsubishi-built

Hispano-Suiza 8A The Hispano-Suiza 8 was a water-cooled V8 SOHC aero engine introduced by Hispano-Suiza in 1914, and was the most commonly used liquid-cooled engine in the aircraft of the Entente Powers during the First World War. The original Hispano-Suiza 8A ...

eight-cylinder

liquid-cooled engine Radiators are heat exchangers used for cooling internal combustion engines, mainly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plant or any similar use of such an engine. In ...

. The improved K3M2 used a Hitachi Amakaze 11 nine-cylinder

air-cooled Air-cooled engines rely on the circulation of air directly over heat dissipation fins or hot areas of the engine to cool them in order to keep the engine within operating temperatures. In all combustion engines, a great percentage of the heat ge ...

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 ...

, rated at for take-off and at sea level. The first K3M2 production examples entered service in 1932 as the Navy Type 90 Crew Trainer. It was superseded in production with the K3M3, using a

Nakajima Kotobuki The Nakajima Ha1 Kotobuki (寿, "Longevity") was an aero-engine developed by Nakajima. It was a radial piston developed under licence from the Bristol Jupiter. Design and development In 1917, Chikuhei Nakajima set up the "Airplane Institute" a ...

air-cooled engine. The Navy Type 90 Crew Trainer was primarily a land-based aircraft although a few were fitted with floats. 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 ...

had an interest in the aircraft as part of its modernization program, and as a potential supplement to the Nakajima Ki-6. Two examples were acquired and tested, and the airframe was given the designation of Ki-7. One prototype used a Mitsubishi Type 92 nine-cylinder air-cooled radial engine and the other a

nine-cylinder air-cooled radial engine. The IJAAF did not order either version into production. The civil version was offered to commercial operators with a Nakajima-built Bristol Jupiter VI nine-cylinder air-cooled radial engine. The Mitsubishi K3M was used for both civil and military roles and some remained in operation until well after World War II.

Variants

;Mitsubishi K3M1 : Initial version ;Mitsubishi K3M2 ''(Japanese Navy Type 90 Crew Training Aircraft)'' : Initial production version for Imperial Japanese Navy ;Mitsubishi K3M3 ''(Japanese Navy Type 90 Crew Training Aircraft)'' : Final production version for Imperial Japanese Navy ; Mitsubishi K3M3-L : Military transport used by Imperial Japanese Navy ;Ki-7 : Version for Imperial Japanese Army, 2 built ;Mitsubishi MS-1 : Civil transport version

Operators

Military operators

; * Imperial Japanese Navy Air Service

Specifications (K3M3)

References

;Notes ;Bibliography * *

External links

Combined Fleet.com site
{{Allied reporting names K03M, Mitsubishi K03M High-wing aircraft Single-engined tractor aircraft