The Mitsubishi A6M Zero was a long-range fighter aircraft operated by the IJN (Imperial Japanese Navy) from 1940 to 1945. The A6M was designated as the Mitsubishi Navy Type 0 Carrier Fighter, and also designated as the Mitsubishi A6M Rei-sen and Mitsubishi Navy 12-shi Carrier Fighter. The A6M was usually referred to by the Allies as the "Zero", from 1940 the year in which the aircraft entered service with the Imperial Navy. The official Allied reporting name was "Zeke".The J2M was designed by Jiro Horikoshi, creator of the A6M Zero to meet the 14-Shi (14th year of the Showa reign, or 1939) official specification. It was to be a strictly local-defense interceptor, intended to counter the threat of high-altitude bomber raids, and thus relied on speed, climb performance, and armament at the expense of manoeuvrability. The J2M was a sleek, but stubby craft with its over-sized Mitsubishi Kasei engine buried behind a long cowling, cooled by an intake fan and connected to the propeller with an extension shaft. Pilot visibility was poor, but a domed canopy introduced later in production partially alleviated this concern.