The Nakajima Ha219, (also known as the Ha-44 under the unified designation system, BH by the company and NK11A by the Imperial Japanese Navy Air Service (IJNAS)), was a late war Imperial Japanese Army Air Force (IJAAF) 2461 horsepower 18-cylinder air-cooled radial engine, used on the Tachikawa Ki-94-II, Nakajima Ki-84-N and Nakajima Ki-87.