The aerial search for the missing Malaysia Airlines jet was called off Monday, and the underwater hunt will be expanded to include a vast swath of ocean floor that may take at least eight months to thoroughly search, Australian officials said.
Not a single piece of confirmed debris from Malaysia Airlines Flight 370 has been recovered by a massive multinational hunt that began after it disappeared March 8 with 239 people on board.
"It is highly unlikely at this stage that we will find any aircraft debris on the ocean surface. By this stage, 52 days into the search, most material would have become waterlogged and sunk," Prime Minister Tony Abbott said.
"Therefore, we are moving from the current phase to a phase which is focused on searching the ocean floor over a much larger area," he said.
The U.S. Navy's Bluefin 21 robotic submarine has spent weeks scouring the initial search area for the plane in the remote Indian Ocean far off Australia's west coast, but has found no trace of the missing aircraft. Officials are now looking to bring in new equipment that can search a larger patch of seabed for the plane, Abbott said.
The aerial search officially ended Monday, the search coordination center confirmed.
Radar and satellite data show the jet veered far off course for unknown reasons during a flight from Kuala Lumpur, Malaysia, to Beijing. Analyses indicate it would have run out of fuel in the remote section of ocean where the search has been focused.
The unmanned sub has been creating a three-dimensional sonar map of the ocean floor for more than two weeks near where signals consistent with airplane black boxes were heard on April 8. The sub has searched a nearly 400-square kilometer (150-square mile) area.
Crews will now begin searching the plane's entire probable impact zone, an area 700 kilometers (430 miles) long and 80 kilometers (50 miles) wide, Abbott said.