The first prototype was ready by August 1945. Lieutenant Commander Susumu Takaoka made the first flight on August 7. He made a second attempt four days later but aborted the takeoff and crashed into Tokyo Bay, tearing off the landing gear. Technicians had mounted the two takeoff-assist rockets at the wrong angle. Development of the Kikka ended four days with the Japanese surrender. Another prototype was almost ready for flight and about 25 other Kikkas sat in the Nakajima factory in various stages of assembly.