FIFO worker mysteriously disappears after failing to board flight

A 25-year-old FIFO worker has disappeared after failing to board a flight to a posting in Western Australia’s Pilbara region.

William Carter made the short travel from Kelmscott to Perth Airport to board a flight to Karratha on Saturday to start working at a mine site.

His mother, Jenny O’Byrne, last saw him outside terminal 3 about 12.40pm.

Jenny O’Byrne and her missing son, Bill, before he went missing. (Facebook)

But he never made the flight and has not been seen or heard from since.

O’Byrne said she has serious concerns for his health in a public appeal for information.

She shared a photo they took together at Kelmscott Dome before heading to Perth Airport, before he went missing.

Carter is described as about 174cm tall with a slim build, brown hair and blue eyes.

Anyone who has information on his whereabouts is urged to contact police on 131 444.