Airman 1st Class Masaaki Shimakawa, Formosa, October 1941. The Mitsubishi A6M Zero was a lightweight fighter aircraft operated by the Imperial Japanese Navy Air Service (IJNAS) from 1940 to 1945. The origin of its official designation was that "A" signified a carrier-based fighter, "6" for the sixth such model built for the Imperial Navy, and "M" for the manufacturer, Mitsubishi. The A6M was usually referred to by the Allies as the "Zero"Ì´Ì_ÌÎÌàÌ´Ì_Ì´ÌÏa name that was frequently misapplied to other Japanese fighters, such as the Nakajima Ki-43Ì´Ì_ÌÎÌàÌ´Ì_Ì´ÌÏas well as other codenames and nicknames, including "Zeke", "Hamp" and "Hap".