Searchers attempting to track down Malaysia Airlines flight MH370 are focusing their efforts on a remote stretch of the Indian Ocean thousands of miles off the coast of Western Australia ever since satellite imagery showed what appeared to be large metal debris churning on the ocean's surface.
Vessels and aircraft from Australia, China and the UK are combing the seas some 2000 km off the coast of Perth, WA are reportedly tracking down the most promising lead on the missing airliner since the Malaysia Airlines 777 vanished from radar tracking a month ago. Over the weekend, searchers have confirmed they've detected an unidentified 'Ping' that is reportedly consistent with a plane's black box.
Angus Houston, who is coordinating the multinational search, said an Australian navy ship had detected two sets of pulse signals which sounded "just like an emergency locator beacon". The development was, he said, a "promising lead".
The first set was heard on Saturday and lasted for two hours and twenty minutes. The Ocean Shield ship then lost contact with the "pings" but turned around and later heard further signals for 13 minutes. It has since lost contact again and was last night trying to relocate the signals.
Significantly, Mr Houston said, the second set included two distinct sounds which would be consistent with transmissions from separate pingers attached to the black box's flight data recorder and cockpit voice recorder.
The new signals are not believed to be related to those detected by a Chinese ship about 345 miles to the south.
Adding to the urgency of the search, the black box pinger has passed the 30 day point at which its battery life is expected to end – though it could last a further two weeks. The aircraft and its 239 people on board disappeared on March 8.
"We're already one day past the advertised shelf life," said Mr Houston. "We hope that it keeps going for a little bit longer."
Mr Houston said it would probably take days to confirm whether the plane has been found and a potential recovery of the aircraft would take a "long time", possibly months.
"What I'd like to see now is us find some wreckage because that will basically help solve the mystery."
Mr Houston said the area in the Indian Ocean where the plane is believed to be located is 14,800 feet deep. An underwater autonomous vehicle will be dispatched to comb the ocean bed for possible wreckage but its depth limit is also 14,800 feet.
Relatives of some of the passengers as well as investigators have been critical of Malaysia's handling of the missing airliner with officials alternately withholding information from searchers or issuing contradictory statements. Recently, one Malaysian official speaking on the condition of anonymity speculated that the aircraft may have deliberately avoided Indonesian airspace after Indonesian military officials told him the missing airliner was never detected on Indonesia's military or civilian radar.