The Mitsubishi Ha-43, known as the Ha-211 by the Imperial Japanese Army Air Force (IJAAF) and MK9 by the Imperial Japanese Navy Air Service (IJNAS)), was a Japanese 18-cylinder, twin-row air-cooled radial engine developed during World War II. It was a more powerful derivative of Mitsubishi's 14-cylinder Kinsei. While planned for use in several promising aircraft, only prototypes were made and the engine never saw combat.