For the third time ever, rescue workers have successfully evacuated someone from the South Pole during the brutal Antarctic winter, the National Science Foundation (NSF) said yesterday.

A plane carrying two sick workers from the Amundsen-Scott research station arrived on the Antarctic Coast yesterday and then flew to Chile, following a harrowing 10-hour flight across the continent. Both workers require medical attention not available at the station, prompting the rare rescue effort.

Typically, none of the 50 or so people who stay over winter at Amundsen-Scott can leave between February and October. One former worker even described the South Pole as more inaccessible than the International Space Station.

During the six-month polar night, when the sun never rises and the wind chill regularly dips below -80C, flight to the station is all but impossible. Fuel freezes to an unuseable jelly at those temperatures, and it's unsafe for planes to fly over terrain they can't see. In the past, a winter worker with cancer and another who suffered a stroke have remained at the station until October, when flights to the pole resume.


But this time the NSF, which runs the South Pole station, decided that the circumstances at the pole demanded an evacuation. For privacy reasons, the foundation couldn't provide further information about the workers' medical conditions.

The two sick patients then flew to Punta Arenas, the capital city of Chile's southernmost region and the nearest mainland airport. They were then taken to a hospital in the city.

The plane that rescued them - a hardy Twin Otter operated by the Canadian firm Kenn Borek Air - is one of the only aircraft capable of flying at the low temperatures at the pole.

Kenn Borek pilots carried out the two previous evacuation missions: one in 2001 to rescue a doctor with pancreatitis and a second in 2003 for an environmental health and safety officer who developed a serious gallbladder infection.

"You're the only plane flying on an entire continent," said Sean Loutitt, the chief pilot for Kenn Borek on both those missions. "You have to be prepared to be totally self-reliant if something goes wrong."