WELLINGTON, New Zealand — 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 U.S. station near the South Pole to an Italian research base in Terra Nova Bay.

New Zealand, U.S. and Italian authorities are working together to find the de Havilland Twin Otter plane, which they presume has crashed about 280 miles north of the pole.

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