He was 20 years old and flying alone over Bass Strait when he radioed Melbourne to ask if anyone else was out there. Nobody was. But something was following him. Over 6 minutes he described it. >> [music] >> Four bright lights moving fast then hovering above his plane. Metallic, shiny, a green light. His engine started failing. Whatever it was, it was sitting directly [music] on top of his plane. Melbourne asked him to identify it. He said four words. >> It is not an aircraft. >> 17 seconds [music] of metallic scraping over the open frequency. Then, silence. Eight planes [music] searched the strait. Fishing vessels swept the water. No wreckage, no signal, no body. Not a single piece of his Cessna has ever been found. The Australian government investigated [music] for 4 years. Their conclusion, one sentence. The reason for the disappearance has not been determined. [music] Not pilot error, not weather, not anything. Not determined. 47 years. One [music] pilot, one radio call, and four words nobody has ever [music] explained. >> It is not an aircraft. >> What was it? Like and subscribe, [music] Grave File TV. New file every day.