Disappearance of Frederick Valentich

Twenty-year-old pilot Frederick Valentich, flying a Cessna 182 to King Island, radioed Melbourne Flight Service at 7:06 pm that a large craft with four bright lights, a shiny metal surface and a green light was orbiting above him, then reported a rough-running engine and said 'it's not an aircraft' before a burst of metallic noise ended contact. The radio exchange was recorded and transcribed; a sea and air search over more than 1,000 square miles found nothing, and a cowl flap from a Cessna 182 washed up on Flinders Island five years later. The Department of Transport's summary report (1982) states only that the reason for the disappearance was not determined; officials speculated he became disoriented, possibly flying inverted and seeing his own lights reflected in the water. Valentich was a UFO believer with a poor flying record, and his stated reasons for the flight were found to be untrue.

Spatial disorientation and loss of control over the sea at night; no evidence of another craft

• Wikipedia: Disappearance of Frederick Valentichen.wikipedia.org
• Skeptoid 4385skeptoid.com