The Aichi AC-1 was an experimental 250 kW (330 hp) nine-cylinder air-cooled radial engine. In 1929, it was used to power the newly designed Aichi AB-2, a catapult-launched reconnaissance seaplane. The AB-2 with its AC-1 engine is noted for being the first shipboard reconnaissance seaplane and engine combination designed and manufactured entirely in Japan, without foreign assistance. This was a major turning point, not only for Aichi, but for all of the other Japanese aircraft and engine manufacturers, as they no longer need rely on foreign designs.