There are growing fears for a West Australian FIFO worker who mysteriously disappeared after being dropped at Perth Airport over the weekend.

Bill Carter was scheduled to fly back to a mine site near Karratha on Saturday following a recent overseas break, but he never made it onto the plane.

His mother Jenny O’Byrne said she last saw her 25-year-old after they had breakfast in Kelmscott. She took a selfie with him just before driving him to Terminal 3.

“That photo was taken just as we left The Dome cafe in Kelmscott, I said ‘come on lets take a selfie for your sister’ because she’d asked me whether I was with him, and that was about 12.20pm on Saturday,” Ms O’Byrne told PerthNow.

Bill Carter was scheduled to fly back to a mine site near Karratha on Saturday following a recent overseas break, but he never made it onto the plane.

She said she dropped him at the terminal around 12.40pm ahead of his 2.15pm departure.

Bill was carrying only a small 5-litre bag, which his mother said was normal as most of his belongings remained onsite at the mine.

“I believe he may have had some phone contact with someone at 1.05pm, (but) since about 1.45pm on Saturday afternoon his phone has been switched off and nobody has seen or heard from Bill,” she said.

Fenner Dunlop, the company he works for in Cape Lambert on a 12-days-on, 9-days-off roster, confirmed on Monday that Carter did not check in for his flight.

The business has been assisting efforts to locate him.

Ms O’Byrne said she fears for her son’s wellbeing and is desperate for community help.

“There are serious concerns for his outlook on life at the moment, so the police now are taking the missing persons concerns very seriously. He’s not well, and he’s very vulnerable and at risk and we just need a lot of people to keep their eyes out,” she said.

She added that disappearing without contact is very unlike him, though he has previously battled mental-health difficulties and had recently ceased taking prescribed anxiety medication.

Bill Carter was scheduled to fly back to a mine site near Karratha on Saturday following a recent overseas break, but he never made it onto the plane.

“This is completely out of character for him, he has been displaying some quite bizarre behaviours, he does normally take anxiety medication but he’s been off that for about the last 5 months and that was a scheduled tailoring off. But I think there’s been some other things that have gone on in his life, a situational crisis, and that’s so often the case in the mental health field,” Ms O’Byrne said.

Bill studied at Bunbury Cathedral Grammar School before attending Murdoch University and later moving into FIFO work. His mother described him as softly spoken and well-liked.

“He’s a very quiet affable chap, he’s someone that everybody enjoys, he’s not loud and garish, he’s very quiet, he’s been going through some challenges recently and because he’s so quiet in nature, some of those challenges have been missed because he’s not very talkative,” she said.

Fenner Dunlop, the company employing Bill, has confirmed it is assisting the search.

“As a family we’re very supportive, I spoke to him a little bit on Saturday about what his concerns were, told him he has the full support of the family, we’re financially very solvent here and overseas, it’s just simply a case of when someone’s not well and they’re going through a situational crisis they don’t see the world as we would see it, they see it altered.”

WA Police have meanwhile put a call-out to the public.

“Bunbury Police have welfare concerns for 25-year-old man William Patrick Carter, who has not been seen or heard from since Saturday, 6 December 2025,” an official statement read.

“Mr Carter was last seen outside Perth Airport Terminal 3 about 12.40pm.

“He is described as being approximately 174cm tall, of slim build, with brown hair and blue eyes.

“Anyone with any information regarding the whereabouts of William Carter is urged to contact police immediately on 131 444.”