Time and uncertainty make plane hunt uniquely hard

CANBERRA, Australia (AP) — Not one object has been recovered from the missing airliner that Malaysian officials are now convinced plunged into the southern Indian Ocean 17 days ago.

Some of the pieces are likely 3,500 meters (11,500 feet) underwater. Others are bobbing in a fickle system of currents that one oceanographer compares to a pinball machine.

And by now, they could easily be hundreds of kilometers (miles) away from each other.

The job of gathering this wreckage, and especially the black boxes that will help determine what happened to Malaysia Airlines Flight 370, is an unprecedented challenge. The crews who needed two years to find a black box from the Air France flight lost in the Atlantic in 2009 had much more information to go on.

"Even though that was the biggest and most complicated search for an aircraft in the ocean ever conducted, it was a relatively refined area compared with what we're talking about here," said U.S. underwater wreck hunter David Mearns, who advised both British and French investigators in the Air France case.

Malaysia said the latest search area had been narrowed to about 870,000 square kilometers (335,000 square miles, 470,000 square nautical miles), an area about as big as Texas and Oklahoma combined.