A forecasted break in the weather could be the best opportunity for searchers to find a group of Canadians missing in Antarctica.
Steve Rendle of New Zealand's Rescue Coordination Centre said skies were expected to clear in the area Saturday morning local time -- Friday afternoon in Alberta -- which could allow rescue teams to fly over where the plane owned by Calgary-based Kenn Borek Air is believed to have gone down.
The Twin Otter began transmitting signals from its emergency locator beacon early Wednesday. Aircraft tried twice to spot it in the mountainous area where it went down but failed due to heavy, low cloud.
If the weather clears, Rendle said they hope to establish a base of operations at a runway and fuel depot located at the Beardmore Glacier, about 50 kilometres from the presumed crash site.
From there, helicopters would be dispatched to search for the craft.
Rendle said the signal from the locator beacon is no longer being received.
"But that's to be expected as the battery life is limited," he explained, adding it's not a problem, as rescue teams have a fix on the beacon's coordinates.
Rendle wouldn't say if it's a concern that there have been no communications with the plane's crew, saying there are a number of scenarios that could explain the silence.
"But we don't speculate on what we haven't been able to see," he said. "There's no point in it."
Those who know the pilot of the downed craft say that if anyone would know how to get through, it would be Bob Heath.
"He's a bit of a living legend up (North)," said friend and fellow pilot Sebastien Seykora. "He's been flying down there for at least a decade. If somebody had a question about how to do things, especially about going down there, he would be the guy they would ask."
Heath, who lives in Inuvik, N.W.T., has logged thousands of hours teaching young flyers in regions from the Maritimes to northern Ontario and administers tests to other pilots, said Roger Townsend, who was a co-pilot with Heath out of Red Lake, Ont. Flying with Heath was always a learning experience, Townsend said.
"He used it as an opportunity to impart knowledge. He's a true instructor with an extraordinary passion for teaching and training."
The Twin Otter was well-equipped with survival equipment, including mountain tents and supplies which could last five days.
The missing plane's signal came from the north end of Antarctica's Queen Alexandra range -- about halfway between the South Pole and McMurdo Station. The site is roughly four hours by helicopter from an American base at McMurdo Station. It's a two-hour flight with a DC-3.
Authorities in Canada have been in contact with officials organizing the search in New Zealand. Canada's Department of Foreign Affairs said officials from the Canadian High Commission in Wellington are working closely with local authorities.
"Search and rescue operations are currently underway. Consular officials stand ready to provide consular services as required," said spokeswoman Barbara Harvey.
Kenn Borek Air, which is experienced in Antarctic aviation, did not provide any details on the three crew members on board the missing twin-engine propeller aircraft.
A spokesman for the U.S. National Science Foundation -- which operates an Antarctic research station helping in the search -- said they were thought to be a pilot, a co-pilot and a flight engineer.
The plane was flying from the South Pole to an Italian base in Antarctica's Terra Nova Bay. The region is in New Zealand's area of responsibility and that country's rescue crews have been working with U.S., Canadian and Italian authorities.
Kenn Borek Air has been in operation since 1970. According to the company's website, 14 aircraft participated in its 2012 Antarctic season.
The company, which is also a fixture in Canada's North, has been sending planes to Antarctica for the past 28 years.
In 2001, its pilots and planes were involved in the daring rescue of an ailing American doctor from the Amundsen-Scott South Pole Station.
In 2009, the company was commissioned to recover an aircraft that had been involved in an accident nearly a year earlier. A 12-person Kenn Borek recovery crew spent 25 days at a remote field camp on the eastern side of the Antarctic Plateau to carry out the operation.
