"We would expect them to be with the plane, " Rendle said of the crew.

CNN: STORY HIGHLIGHTS

By then, rescuers had pinpointed the location, but harsh weather has made visual sightings impossible, Rendle said.

CNN: STORY HIGHLIGHTS

"We've got a reasonably positive forecast for that site, " Rendle said from Wellington.

CNN: STORY HIGHLIGHTS

"It is difficult to think of a more difficult environment, " said Steve Rendle, spokesman for Rescue Coordination Centre New Zealand.

CNN: STORY HIGHLIGHTS

"If the beacon is operating... that's a good sign as a heavy landing can tend to prevent the beacon working, " Steve Rendle from the Rescue Co-ordination Centre New Zealand (RCCNZ), told Radio New Zealand.

BBC: Antarctic search for missing plane carrying Canadians