The Valentich disappearance refers to the unexplained disappearance at around 7:12 pm on 21 October 1978 of 20-year-old Frederick Valentich a young Australian, while piloting a Cessna 182 L light aircraft over Bass Strait in Australia. He intended to land at King Island and return to Moorabbin Airport.
During the 127-mile (235 km) flight, Valentich advised Melbourne air traffic control that he was being accompanied by an aircraft about 1,000 feet (300 m) above him. He described some unusual actions and features of the aircraft, saying that his engine had begun running roughly, and finally reported that the "strange aircraft is hovering on top of me again. It is hovering and it's not an aircraft."