 Though such air attacks throughout this campaign caused fearsome superficial damage and crew casualties to a great number of Allied vessels, no Pacific Fleet surface warships larger than a destroyer were sunk directly by this method during the spring of 1945.Meanwhile, he gathered even more aircraft and hid them to be used in the same fashion in defense of Kyūshū against the expected Allied invasion that was sure to come.Ugaki planned to hit the invasion forces with hundreds of aircraft and suicide boats in a few hours in Operation "Ketsu-Go" (Decisive Operation).