Australia on Sunday sent planes and ships to investigate signals detected by a Chinese ship in the hunt for a missing Malaysian jet, saying they matched black box beacons and were an “important and encouraging lead”.
Angus Houston, the Australian head of the mission, said a second “ping” was also being scrutinised 300 nautical miles away in the Indian Ocean, as the one-month lifespan of batteries powering the beacons loomed.
He said China’s Haixun 01 has twice detected an underwater signal on a frequency used for flight data and cockpit voice recorders – once for 90 seconds on Saturday and another more fleeting “ping” on Friday a short distance away.
“This is an important and encouraging lead but one which I urge you to continue to treat carefully, we are working in a very big ocean and within a very large search area,” Houston told reporters.
“Speculation and unconfirmed reports can see the loved ones of the passengers put through terrible stress and I don’t want to put them under any further emotional distress at this very difficult time.”
Britain’s HMS Echo and the Australian ship Ocean Shield – both also equipped with black box locators – and Australian air force planes were being diverted to the area to help discount or confirm the signals, Houston said.
Ocean Shield was also investigating a signal it detected on Sunday in its current location, about 300 nautical miles north of Haixun 01, in waters far off Australia’s west coast.
Houston said the mission was taking both detections “very seriously” as time ticked down on the beacons’ battery life, though he described the Chinese finding as the most promising.
“I think the fact that we’ve had two detections, two acoustic events in that location, provides some promise which requires a full investigation,” he said.
– Time ‘running out’ –
The hunt for the jet, which vanished on a flight between Kuala Lumpur and Beijing on March 8, was refocused on the southern end of the search zone Sunday after corrected satellite data showed it was more likely the plane entered the water there.
Houston said the Haixun 01 was already operating in that more southerly zone.
Some analysts greeted the acoustic detections with optimism, saying a 37.5kHz signal can only be transmitted by an emergency beacon. But others were sceptical and said it was vital to find supporting evidence.
Houston said Haixun 01 was in waters about 4.5 kilometres (nearly three miles) deep, meaning “any recovery operation is going to be incredibly challenging and very demanding and will take a long period of time” if the plane is found there.
The Malaysia Airlines mystery has been compared with Air France Flight 447, which crashed into the Atlantic in 2009. Debris was located within a week but it took two years for undersea drones to recover the black box.