In the search for Malaysia Airlines Flight 370, a plane has detected a possible signal from the locator beacons on the so-called black boxes from the missing aircraft, the Australian agency coordinating the search announced Thursday.
“The acoustic data will require further analysis overnight but shows potential of being from a man-made source,” said retired Air Chief Marshal Angus Houston, the agency’s chief coordinator.
The possible signal, which was picked up through sonar buoys equipped to receive such electronic data, was detected near the Australian ship Ocean Shield, said the Joint Agency Coordination Centre.
Crews have been narrowing the search area in the Indian Ocean.
Up to 10 military aircraft, four civil aircraft and 13 ships were to assist in Thursday’s search for the Boeing 777-200ER, which was carrying 239 people when it vanished March 8 on a fight from Kuala Lumpur, Malaysia, to Beijing.
Three of the vessels — the Ocean Shield to the north, and the British HMS Echo and Chinese Haixun 01 to the south — were focusing underwater.
Aircraft and ships spotted a number of objects during Wednesday’s search, but could recover only a small number, none of which appeared linked to MH370, the JACC said.
Thursday’s search area is about 22,400 square miles (58,000 square kilometers), centered some 1,417 miles (2,280 kilometers) northwest of Perth. That’s roughly the size of West Virginia.
But the latest search area is about three quarters of the size of the area that teams combed the day before and far smaller than what it was a few weeks ago.
Thursday’s underwater search area was bracketed by the Ocean Shield at the northern end of the search area and the Chinese ship Haixun 01 and HMS Echo at the southern end.
The Ocean Shield first picked up two sets of underwater pulses on Saturday that were of a frequency close to that used by the locator beacons. It heard nothing more until Tuesday, when it reacquired the signals twice. The four signals were within 17 miles of one another.
“I believe we are searching in the right area, but we need to visually identify wreckage before we can confirm with certainty that this is the final resting place of MH370,” Houston said Wednesday.
In another piece of encouraging news, authorities analyzed the signals picked up over the weekend and concluded that they probably came from specific electronic equipment rather than from marine life, which can make similar sounds.
“They believe the signals to be consistent with the specification and description of a flight data recorder,” Houston said. “I’m now optimistic that we will find the aircraft or what’s left of the aircraft in the not too distant future.”
Thursday is Day 34 in the search. Time is of the essence: The batteries powering the flight recorders’ locator beacons are certified to emit high-pitched signals for only 30 days after they get wet.
“The signals are getting weaker,” Houston said Wednesday, “which means we’re either moving away from the search area or the pinger batteries are dying.”
As the searchers appeared to make progress, new details emerged Thursday about events in the cockpit prior to the plane’s disappearance. MH370’s pilot, Capt. Zaharie Ahmad Shah, was the last person to speak to air traffic controllers with the words “Good night Malaysian three-seven-zero,” sources told CNN.
The Malaysian sources told CNN there was nothing unusual about the voice and there was no indication of stress.
One of the sources, an official involved in the investigation, told CNN that police played the recording to five other Malaysia Airlines pilots who knew the pilot and co-pilot.
“There were no third party voices,” the source said.