The latest signal reported in the search for a missing Malaysia Airlines jet in the Indian Ocean probably did not come from the plane, the body coordinating the hunt said on Friday.
“The signal reported in the vicinity of the Australian Defence vessel Ocean Shield is unlikely to be related to the aircraft black boxes,” Search leader Angus Houston told reporters in Perth.
The statement came after analysis of the data from sound-locating buoys dropped by a Australian patrol plane on Thursday near where a navy ship had monitored a possible signal from the missing Boeing 777.
“On the information I have available to me, there has been no major breakthrough in the search for MH370,” Houston said.
The Ocean Shield first heard a promising signal on Saturday, then on Tuesday again picked up acoustic signals on the pinger locator it is towing.
On Thursday, there were early reports that the buoys dropped from the plane in the same spot had confirmed the acoustic signal, raising hopes that the batteries in the black box were holding out beyond their one-month life span.
But this was not borne out by an analysis of the data overnight, Houston said on Friday, without giving further details.
Prime Minister Tony Abbott, speaking in China, said he was still confident that signals picked up this week were transmitted from MH370.
“We have very much narrowed down the search area and we are very confident the signals are from the black box,” Abbott said.
MH370 went missing more than a month ago an hour into a night flight from Kuala Lumpur to Beijing with 239 people on board.
Worries about the life of the black box batteries had brought a new urgency, with expectations a probe would be sent down with either sonar or a camera if the signal was confirmed.
The underwater drone aboard the Ocean Shield is not capable of retrieving the black boxes and at 4,500 metres depth would be operating at the limit of its capability.
“A decision as to when to deploy the autonomous underwater vehicle will be made on advice from experts on board the Ocean Shield and could be some days away,” Houston said.
Ships and planes have yet to sight a debris field or pick up items that could be linked to MH370.
Speaking earlier this week, Houston warned the families of those aboard MH370 that the best they might be able to hope for was a photograph of wreckage.
“I’m informed by experts that there’s a lot of silt down there,” Houston said. “That could complicate the search because the silt on the bottom of the ocean can be very thick and things disappear into it and it makes a visual search underwater very difficult.” Preparations are being made to ferry the bereaved out to the spot where MH370 is likely to have gone down.
Malaysia Airlines has offered families free flights and Australia has waived visa fees. Most of those aboard were Chinese nationals.