A Twin Otter airplane, operated by Kenn Borek Air, Ltd., out of Calgary, Alberta, is used for transportation around the interior of Antarctica. This photo shows the plane landing at Amundsen-Scott South Pole Station on September 20, 2003, during a medical evacuation of an ill participant. The plane had flown from Punta Arenas, Chile, to the British Antarctic Survey Station Rothera on Adelaide Island near the Antarctic Peninsula and then to the South Pole when weather allowed. The participant had become ill during the long Antarctic winter when no regular flights occur to the South Pole. Due to the extremely cold temperatures, nearly minus 70 degrees Fahrenheit on this day, only planes with mechanical systems (as opposed to hydraulics) can operate.