(CNN) Fresh hope fueled the search for the missing Malaysia Airlines plane Thursday after a plane detected a possible underwater signal.
The crew of an Australian P-3 Orion dropped dozens of buoys equipped with underwater sensors into the ocean, and they heard something.
The signal -- the fifth picked up by search teams so far -- may be from one of the so-called black boxes aboard Flight 370, the Australian agency coordinating the search announced.
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The acoustic data show "potential of being from a man-made source," said retired Air Chief Marshal Angus Houston, the agency's chief coordinator.