Updated

A small plane carrying three Canadians disappeared while flying over an Antarctic mountain range, and bad weather Thursday was hampering a search.

The flight was going from a station near the South Pole to an Italian research base in Terra Nova Bay. Its emergency locator started transmitting about 10 p.m. Wednesday in a mountainous area about 280 miles north of the pole.

New Zealand, U.S. and Italian authorities are working together to find the de Havilland Twin Otter plane, which they presume has crashed. It was carrying survival equipment including tents and food, according to New Zealand Search and Rescue Mission Coordinator John Ashby.

New Zealand authorities said a Hercules C130 aircraft flew to the Queen Alexandra mountain range early Thursday but was unable to see the aircraft.

Ashby said in a statement Thursday afternoon that a DC3 aircraft flew over the area where the beacon was transmitting but heavy cloud prevented the rescuers from seeing the ground or any sign of the plane.

"Weather conditions are extremely challenging," Ashby said.

He said that winds had reached 90 knots (104 miles) per hour and heavy snow was predicted.

He said several planes and helicopters were standing by in Antarctica, waiting until conditions improved so they could travel to the site.

The plane is owned and operated by Kenn Borek Air Ltd., a Canadian firm based in Calgary that charters aircraft to the U.S. Antarctic program.