Valentich has been presumed dead since October 21, 1978, when he disappeared while manning a small plane to King Island in Australia. Shortly before his disappearance, he asked Australian authorities to verify if other aircraft were in his vicinity after seeing a strange aircraft with green lights. Valentich's eerie last words were, "That strange aircraft is hovering on top of me again. It is hovering and it's not an aircraft." Valentich and his plane haven't been seen since.