PERTH, Australia — For the fifth time in recent days, an underwater sensor detected a signal Thursday in the same swath of the southern Indian Ocean, raising hopes that searchers are closing in on what could be a flight recorder from the missing Malaysian jet.
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” 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.
The sonar buoys are being dropped by the Australian air force to maximize the sound-detectors operating in the search zone. Royal Australian Navy Commodore Peter Leavy said each buoy is dangling a hydrophone listening device about 1,000 feet below the surface and transmits its data via radio back to a search plane.
The underwater search zone is a 500-square-mile patch of the ocean floor — about the size of the city of Los Angeles — and narrowing the area as much as possible is crucial before the submersible is sent to create a sonar map of a potential debris field on the seabed.
The Bluefin 21 submersible takes six times longer to cover the same area as the ping locator towed by the Ocean Shield and would take six weeks to two months to canvass the current underwater search zone. That’s why the acoustic equipment is still being used to get a more precise location, U.S. Navy Capt. Mark Matthews said.
Houston has expressed optimism about the sounds, saying Wednesday that he was hopeful crews would find the aircraft — or what’s left of it — in the “not-too-distant future.”
