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."There were belated reports of a UFO sighting in Australia on the night of the disappearance; however, the Associated Press reported that the Department of Transport was sceptical a UFO was behind Valentich's disappearance, and that some of their officials speculated that "Valentich became disoriented and saw his own lights reflected in the water, or lights from a nearby island, while flying upside down."