had a crew of two, eliminating the navigator position. Like the KAI, it had twin 20 mm Type 99 Model 1 cannon firing upward in a 30° upward angle, but added a second pair firing downward at a forward 30° angle, allowing attacks from above or below. This arrangement was effective against B-17 Flying Fortress bombers and B-24 Liberators, which usually had Sperry ball turrets for ventral defense. The Gekkō's existence was not quickly understood by the Allies, who assumed the Japanese did not have the technology for night fighter designs. Early versions had nose searchlights in place of radar. Later models, the J1N1-Sa Model 11a, omitted the two downward-firing guns and added another 20 mm cannon to face upward as with the other two. Other variants without nose antennae or searchlight added a 20 mm cannon to the nose. The J1N1-S was used against B-29 Superfortresses in Japan, though the lack of good radar and insufficient high-altitude performance handicapped it, since usually only one pass could be made against the higher-speed B-29s. However, some skillful pilots had spectacular successes, such as Lieutenant Sachio Endo, who was credited with destroying eight B-29s and damaging another eight before he was shot down by a B-29 crew, Shigetoshi Kudo (nine victories), Shiro Kurotori (six victories), and Juzo Kuramoto (eight victories); the last two claimed five B-29s during the night of 25–26 May 1945. Another Gekkō crew shot down five B-29's in one night, but these successes were rare. Many Gekkō's were also shot down or destroyed on the ground. Variants J1N1 : Three seaters long-range fighter. Two of prototypes and seven of supplementary prototypes. J1N1 KAI : Night Fighter converted from J1N1. J1N1-C : Long-range reconnaissance aircraft. Later re-designated J1N1-R. J1N1-C KAI : Night Fighter converted from J1N1-C. J1N1-R : Long-range reconnaissance aircraft. J1N1-F : Observation aircraft. A little number of prototypes only. Equipped G5N2 turret or G4M2 turret. J1N1-S : Night fighter aircraft. Armed with 2 × 20 mm forward up-firing Type 99 cannons and 2 × 20 mm forward under-firing Type 99 cannons. J1N1-Sa : Night Fighter same as above, armed with 3 × 20 mm forward up-firing Type 99 cannons. Surviving aircraft Only one J1N1-S Gekkō survives today. Following the occupation of the home islands, U.S. forces gathered 145 interesting Japanese aircraft and sent them to the United States aboard three aircraft carriers. Four Gekkō's were in this group: