Most of the aircraft used in kamikaze attacks were converted obsolete fighters and dive-bombers. Supported Allied invasion of Okinawa by attacking airfields that served as bases for kamikaze pilots. Allied gunners had begun to develop techniques to negate "kamikaze" attacks. The Japanese defense relied heavily on "kamikaze" planes. "Ralph Talbot" later received a "kamikaze" hit off Okinawa. Henceforward attacks were mostly confined to kamikaze. The landing forces faced strong opposition from Japanese "kamikaze" aircraft. They said that the commander of a "kamikaze" attack should engage in the task first. The smaller ships were least able to withstand damage from "kamikaze" attacks. The US Navy also started missile research to deal with the Kamikaze threat. The first use of "kamikaze" aircraft took place following the Leyte landings. Critics have accused the film of misrepresenting Kamikaze pilots. This contrasts markedly with the relative success by kill-ratio of the Kamikaze pilots. A "kamikaze" hit the Australian heavy cruiser on 21 October. He described his government as being on a "kamikaze" mission.