A military transport plane carrying 38 people has disappeared en route to Antarctica.
Chile’s air force said the military had declared an alert and activated search and rescue teams.
The personnel were flying to check on a floating fuel supply line and other equipment at the Chilean base.
General Eduardo Mosqueira, of the Fourth Air Brigade, told local media that a search was underway and a ship was in the area where the plane should have been when contact was lost.
Mr Mosqueira said the aircraft would have been about halfway to the Antarctic base when it lost contact.
No emergency signals had been activated, he said.
He said the plane, whose pilot had extensive experience, had been scheduled to return on Monday night.