Searchers say they still expect to find three missing Canadians on a flight in Antarctica alive.
Fierce gales continue to hamper the search led by the New Zealand Rescue Coordination Centre and it has been suspended until Saturday morning.
Bob Heath, who has 25 years' experience polar flying and training pilots, and two passengers have been missing since Wednesday after setting out on a trip from the South Pole to the Italian base Terra Nova Bay in the Ross Sea.
Their Twin Otter's emergency locator beacon was activated at 10pm on Wednesday (NZ time) from the northern end of the Queen Alexandra mountain range.
It is not known whether the plane crashed or made an emergency landing, but the transmitter sent a clear position before its battery ran out.
A search plane flew over the area earlier on Friday, but could not get a clear view through cloud and had to turn back.
Two helicopters and an expert rescue team will fly to Beardmore Glacier, about 50km away from the site near the mountain range, to enable the search resume as soon as possible. The weather is expected to improve by Saturday morning.
Search and rescue mission coordinator Kevin Banaghan told Radio New Zealand's Checkpoint programme on Friday that because of the altitude, pilots will have about a 30-minute window to search for the plane once the weather clears.
"The actual position itself is at 13,000 feet, so it's quite high ... so they've got to get in, get the job done and get out as quickly as they can.
"This 30-minutes can obviously be extended with the use of oxygen, and I understand these guys have got these assets with them.
"We also understand that the people involved in the incident are very well trained, that they've got survival skills and they're very well equipped, so we are hopeful to get a positive result."
Tony Szekely, a friend of Mr Heath's and occasional co-pilot, also remains optimistic that the Canadians will be found alive.
Mr Szekely told Checkpoint on Friday that Mr Heath is one of the most experienced pilots he knows.
"Bob's been trained in Antarctic survival, is very knowledgeable. I'm optimistic because it is Bob and not somebody else. He's one of the best pilots I know."