Mitsubishi K3M - Operational History

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 340 hp (250 kW) Mitsubishi-built Hispano-Suiza eight-cylinder liquid-cooled engine driving a two-blade wooden propeller.

The improved K3M2 used a Hitachi Amakaze 11 nine-cylinder air-cooled radial engine, rated at 340 hp (250 kW) for take-off and 300 hp (220 kW) at sea level, driving a two-blade wooden propeller. The first K3M2 production version entered service in 1932 as the Navy Type 90 Crew Trainer. It was superseded in production with the K3M3, using a Nakajima Kotobuki 460 hp (340 kW) air-cooled engine.

The Navy Type 90 Crew Trainer was primarily a land-based aircraft; however, a few were converted with floats for use as seaplanes.

The Imperial Japanese Army Air Force 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 475 hp (350 kW) Mitsubishi Type 92 nine-cylinder air-cooled radial engine and the other a 450 hp (340 kW) Nakajima Kotobuki nine-cylinder air-cooled radial engine. However, the IJAAF opted not to go into production with either version.

The civil version offered to commercial operators was with a 420 hp (310 kW) Nakajima-built Bristol Jupiter VI nine-cylinder air-cooled radial engine. The Mitsubishi K3M was used for both civil and military roles with some remaining in operation until well after World War II.