Search teams looking for the missing Malaysian airliner have begun a new phase of the operation - hunting underwater for signals from its flight recorder.
Flight MH370 disappeared about an hour into a flight from Kuala Lumpur to Beijing and inexplicably diverted far off course on 8 March with 239 people on board, including two New Zealanders.
Malaysian authorities say that based on satellite data, they have concluded that it crashed into the southern Indian Ocean.
Australian officials leading the search say two ships with electronic survey devices will cover a 240km track underwater on Friday.
Air Chief Marshal Angus Houston told reporters at the search headquarters in Perth that they still believe they can find debris from the Boeing 777 on the surface of the ocean.
Ten military planes, four civil jets and nine ships would take part in the search, with two vessels looking specifically for signals from the plane, he said.
"Using the towed pinger locater from the United States Navy on Australian defence vessel Ocean Shield and a similar capability on HMS Echo, the two ships will search a single 240- kilometre track converging on each othe
However, Air Chief Marshal Houston warned that the operation faces many difficulties and it is one of the most demanding and challenging search and rescue missions he has ever seen.
The Australian Maritime Safety Authority has determined a search area of 217,000 square kilometres. Weather conditions on Friday were fair, with a visibility of about 10km, he said.
Some of the world's most sophisticated military aircraft and technology are being used in the search, including a British Royal Navy nuclear submarine to find the flight recorder, the BBC reports.
But they had the same kit when they searched for the missing Air France plane that crashed in the Atlantic in 2009. Back then, searchers knew roughly where the plane came down and it still took nearly two years to find it.
This time, they have no idea where Flight MH370 hit the water. Without concrete evidence, families of those on board the Malaysian jet say they still hold hope that their loved-ones are still alive.