PERTH, Australia — An air and sea hunt for the missing Malaysian jet resumed today in the same swath of the southern Indian Ocean where an underwater sensor made the fifth detection of a signal in recent days, raising hopes that searchers are closing in on what could be a flight recorder.
An Australian air force P-3 Orion, which has been dropping sonar buoys into the water near where four sounds were heard earlier, picked up a "possible signal" Thursday that may be from a man-made source, said Angus Houston, who is coordinating the search for Flight 370 off Australia's west coast.
The latest acoustic data would be analyzed, he said. If confirmed, the signal would further narrow the hunt for the Malaysia Airlines Boeing 777, which vanished March 8 while flying from Kuala Lumpur to Beijing with 239 people aboard.
The Australian ship Ocean Shield, which is towing a U.S. Navy device to detect signal beacons from a plane's flight data and cockpit voice recorders, picked up two underwater sounds Tuesday. Two sounds it detected Saturday were determined to be consistent with the pings emitted from the flight recorders, or "black boxes."
The searchers are trying to pinpoint the location of the source of the underwater signals so they can send down a robotic submersible to look for wreckage and the flight recorders from the Malaysian jet.
Houston's coordination center said the area to be searched for floating debris today had been narrowed to 18,036 square miles of ocean extending from 1,400 miles northwest of Perth. Up to 15 planes and 13 ships would join today's search.
Thursday's search of a 22,300 square mile area of ocean in a similar location reported no sightings of potential wreckage, the center said.