Perth, Australia (AP) -- The hunt for the missing Malaysian airliner is continuing to focus on a search for weakening radio signals from deep beneath the waves despite mounting evidence that the batteries in the plane's all-important black boxes may finally have died.
Following four strong underwater signals earlier this month, all has gone quiet in the hunt for the missing Malaysia Airlines Boeing 777.
The search coordination center says no new electronic pings have been detected since Tuesday by an Australian ship dragging a U.S. Navy device that listens for flight recorder signals. Once officials are confident that no more sounds will be heard, a robotic submersible will be sent down to the floor of the southern Indian Ocean to scour for wreckage.
But the center says the Australian ship will continue the signal hunt Monday, along with a British warship and Australian air force P-3 Orion plane.
A visual search for debris is also planned for Monday over 18,400 square miles of ocean centered 1,400 miles northwest of the west coast city of Perth. A total of 12 planes and 15 ships are joining the two searches.