The Nakajima Ki-27 was the main fighter aircraft used by the Imperial Japanese Army Air Force up until 1940. Its Allied code name was Nate, although it was also called Abdul in the China Burma India Theater. When placed into combat service over northern China in March 1938, the Ki-27 enjoyed air superiority until the introduction of the faster Soviet-built Polikarpov I-16 fighters by the Chinese. The Ki-27 also saw extensive action against the American Volunteer Group; outclassed the Ki-27 was replaced in frontline service by the Ki-43, with surviving examples continued to serve as a trainer during World War II. Near the end of the Second World War, a few Ki-27 were equipped with up to 500 kg (1100 lb) of explosives for a Kamikaze role.