SYDNEY, April 25 (Reuters) - The search for missing Malaysia  Airlines Flight MH370 is likely to drag on for years, a senior  U.S. defense official told Reuters on Friday, as an underwater  search for any trace of the plane's wreckage off west Australia  appeared to have failed.                
The official, speaking under condition of anonymity because  he was not authorized to comment on the search effort, said two  weeks of scouring the Indian Ocean floor with a U.S. Navy  submersible drone had turned up no wreckage.                
He said the search for the jetliner, which vanished on March  8 with 239 people on board, would now enter a much harder phase  of scouring broader areas of the ocean near where the plane is  believed to have crashed.                
"We went all in on this small area and didn't find anything.  Now you've got to go back to the big area," the official said.  "And now you're talking years."                
On Frida!   y, the undersea drone Bluefin-21 is expected to  finish what may be the last of its 16-hour trips to depths of  more than 4.5km (2.8 miles) searching a 10 square km (6.2 square   mile) stretch of seabed about 2,000 miles northwest of Perth.                
Authorities had identified the area as their strongest lead  in determining the plane's final resting place after detecting  what they suspected was a signal, or "ping", from the plane's  black box recorder on April 4.                
But the U.S. official said Malaysia would have to decide how  to proceed with the search, including whether to bring in more  underwater drones, even with the understanding that the search  could continue for years without a refined search area.     (Reporting by Matt Siegel; Editing by Paul Tait)
Source : http://www.huffingtonpost.com/2014/04/25/malaysia-airlines-missing-plane-search_n_5210240.html?utm_hp_ref=business&ir=Business
