Frederick Valentich disappeared from air traffic control following contact with an unidentified aircraft.
Frederick Valentich was an Australian pilot who disappeared while on a 125-nautical-mile (232 km) training flight in a Cessna 182L light aircraft, registered VH-DSJ, over Bass Strait on the evening of Saturday 21 October 1978. Described as a "flying saucer enthusiast", twenty-year-old Valentich informed Melbourne air traffic control that he was being accompanied by an aircraft about 1,000 feet (300 m) above him and that his engine had begun running roughly, before finally reporting, "It's not an aircraft." An investigation into Valentich's disappearance by the Australian Department of Transport was unable to determine the cause but it was "presumed fatal" for Valentich. 
