Disappearance of Frederick Valentich

On the evening of Saturday 21 October 1978, Frederick Valentich, a 20-year-old Australian pilot, disappeared while flying a Cessna 182L (registration VH-DSJ) on a planned 125-nautical-mile (232 km) flight across Bass Strait to King Island. Valentich had approximately 150 hours of total flying time and held a class-four instrument rating permitting night flight only in visual meteorological conditions. He had twice been rejected from the Royal Australian Air Force due to inadequate educational qualifications and had a poor record in his part-time commercial pilot studies, having failed all five commercial licence subjects twice, including three subjects the month before his disappearance. He gave differing and later-found-untrue explanations for his King Island trip, telling officials he was picking up friends and telling others he was collecting crayfish. He also failed to notify King Island Airport of his intended landing, contrary to standard procedure.

At 7:06 pm, Valentich radioed Melbourne Flight Service to report an unidentified aircraft following him at 4,500 feet, though air traffic control had no record of other traffic at that altitude. He described a large aircraft with four bright landing lights passing about 1,000 feet overhead at high speed, then approaching from the east, suggesting the other pilot might be "playing games" with him. He reported the aircraft was "orbiting" above him with a shiny metal surface and a green light, and that his own engine was running roughly. When asked to identify the aircraft, Valentich stated, "It's not an aircraft." The transmission was then interrupted by an unidentified metallic, scraping sound before contact was permanently lost.

A search and rescue operation involving ocean shipping, a RAAF Lockheed P-3 Orion, and eight civilian aircraft covered more than 1,000 square miles of Bass Strait but ended on 25 October 1978 without locating Valentich or the aircraft. The Australian Department of Transport's investigation could not determine a cause for the disappearance, formally presuming Valentich dead. In 1983, an engine cowl flap consistent with the serial number range of Valentich's Cessna 182 washed ashore on Flinders Island; the Bureau of Air Safety Investigation consulted the Royal Australian Navy Research Laboratory about whether the part could have drifted from the presumed crash site.

Multiple explanations have been proposed, none confirmed. Department of Transport officials suggested Valentich may have become disoriented while flying upside down and mistaken his own lights' reflection in the water for another craft. Others have proposed a staged disappearance, noting the aircraft had enough remaining fuel to travel much farther and was never confirmed on radar despite reportedly ideal conditions, alongside police reports of an unexplained light-aircraft landing near Cape Otway around the same time. Suicide has also been raised as a possibility, though UFOlogist Kieth Basterfield reported that interviews with doctors and colleagues who knew Valentich largely ruled this out. Researchers James McGaha and Joe Nickell proposed in 2013 that Valentich experienced a "graveyard spiral" due to spatial disorientation, misidentifying visible planets and a bright star as an accompanying craft. Ufologists have offered alternative interpretations involving an unidentified flying object, though photographic evidence cited in support has been disputed. The case remains unresolved.