The Mitsubishi J2M Raiden (雷電, "Lightning Bolt") is a single-engined land-based fighter aircraft used by the Imperial Japanese Navy Air Service in World War II. The Allied reporting name was "Jack". Design and development 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 oversized Mitsubishi Kasei engine buried behind a long cowling, cooled by an intake fan and connected to the propeller with an extension shaft. Teething development problems stemming from the Kasei engine cooling system, and the main undercarriage members led to a slowdown in production. A continual set of modifications resulted in new variants being introduced with the ultimate high-altitude variant, the J2M4 Model 34 flying for the first time in August 1944. It had a 1,420 hp Kasei 23c engine equipped with a turbocharger (mounted in the side of the fuselage just behind the engine) that allowed the rated power to be maintained up to . Two upward-aimed, oblique-firing (aimed at seventy degrees) 20 mm cannons, mounted in the German Schräge Musik style, were fitted behind the cockpit with the four wing cannons retained. Unresolved difficulties with the turbo supercharger caused the project to be terminated after only two experimental J2M4s were built. Operational history The first few produced J2M2s were delivered to the development units in December 1942 but severe problems were encountered with the engines. Trials and improvements took almost a year and the first batch of the serial built J2M2 Model 11 was delivered to 381st Kōkūtai in December 1943. Parallel with the J2M2, production of the J2M3 Raiden Model 21 started. The first J2M3s appeared in October 1943 but deliveries to combat units started at the beginning of February 1944. The Raiden made its combat debut in June 1944 during the Battle of the Philippine Sea. Several J2Ms operated from Guam and Saipan and a small number of aircraft were deployed to the Philippines. Later, some J2Ms were based in Japanese airfields in Korea under Genzan Ku: Genzan (Wonsan); Ranan (Nanam); Funei (Nuren); Rashin (Najin); and Konan, for defense of these areas and fighting against