Forty-two years ago in 1978, an experienced Australian pilot Frederick Valentich disappeared under strange circumstances.

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 the Bass Strait on the evening of October 21, 1978. A 20-year-old Australian Pilot Frederick Valentich disappeared over the Bass Strait while flying from Melbourne`s Moorabbin Airport to King Island.

Frederick Valentich had about 150 total hours' flying time and held a class-four instrument rating, which authorized him to fly at night, but only "in visual meteorological conditions." He had twice applied to enlist in the Royal Australian Air Force (RAAF) but was rejected because of inadequate educational qualifications.

He was a member of the RAAF Air Training Corps, determined to have a career in aviation. Valentich was studying part-time to become a commercial pilot but had a poor achievement record, having twice failed all five commercial license examination subjects, and as recently as the month before his disappearance had failed three more commercial license subjects.

Frederick had been involved in flying incidents, for example, straying into a controlled zone in Sydney, for which he received a warning, and twice deliberately flying into a cloud, for which prosecution was being considered. According to his father, Guido, Valentich was an ardent believer in UFOs and had been worried about being attacked by them.

The destination of Valentich's final flight was King Island, but his motivation for the flight is unknown. He told flight officials that he was going to King Island to pick up some friends, while he told others that he was going to pick up crayfish. Later investigations found both stated reasons to be untrue.

Valentich had also failed to inform King Island Airport of his intention to land there, going against "standard procedure".

Valentich radioed Melbourne air traffic control at 7:06 pm to report that an unidentified aircraft was following him at 4,500 feet (1,400 m). He was told there was no known traffic at that level.

Valentich said he could see a large unknown aircraft that appeared to be illuminated by four bright landing lights. He was unable to confirm its type but said it had passed about 1,000 feet (300 m) overhead and was moving at high speed. Valentich then reported that the aircraft was approaching him from the east and said the other pilot might be purposely toying with him.

Valentich said the aircraft was "orbiting" above him and that it had a shiny metal surface and a green light on it. Valentich further reported that he was experiencing engine problems. Asked to identify the aircraft, Valentich radioed, "It's not an aircraft." His transmission was then interrupted by unidentified noise described as being "metallic, scraping sounds" before all contact was lost.

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 skeptical a UFO was behind Valentich's disappearance and that some of their officials speculated that "Valentich became disoriented and saw his lights reflected in the water, or lights from a nearby island while flying upside down."