By — Miriam Firestone, Gil Aegerter and Eric Baculinao, NBC News
Two ships looking for the Malaysian Airlines jet now have picked up faint acoustic signals, but it’s still very uncertain whether those came from the missing aircraft’s black boxes, a leader of the search effort said Sunday.
The Australian ship Ocean Shield reported on Sunday detecting an acoustic signal that bears investigating, and the Chinese ship Haixun 01 reported that it had heard two sets of signals about 24 hours apart, said retired Australian Air Marshal Angus Houston, who is coordinating the massive international search effort.
“This is an important and encouraging lead,” Houston told a briefing in Perth, noting the huge size of the area that was being searched in the southern Indian Ocean.
Meanwhile almost all Chinese family members of those on board were planning to leave Kuala Lumpur for Beijing, a spokesman for the families said Sunday.
Jiang Hui added that only two or three would remain behind in Malaysia's capital, where many have gathered for weeks in order to hear the latest updates about the fate of their loved ones and the doomed jet.
The Ocean Shield will further investigate the "acoustic event" that it detected, and if it’s determined to be nothing, the ship will be redirected to the area where the Haixun 01 is operating, Houston said.
Houston said the Haixun 01 first detected a signal on Friday Australian time, then when it was not far away about 24 hours later heard a “second acoustic event” lasting about 90 seconds. “In an ocean that size, two kilometers is not a huge distance,” he said.
The acoustic event detected by the Ocean Shield came on Sunday about 300 miles from the Haixun 01’s position, Houston said.
He said that if the Ocean Shield’s contact is determined to be nothing, it will take the ship more than 24 hours to recover its detection equipment, move to the area where the Haixun 01 is looking, then redeploy its gear. He said the HMS Echo was en route to the Haixun 01’s position and would be there in about 14 hours.
He said that the Ocean Shield was the best-equipped ship to resolve whether the signals are coming from lost Flight 370, which disappeared March 8 with 239 people aboard.
He cautioned that the data that searchers have received was not enough for verifying that the signals came from the black boxes. He also said that as the result of new satellite information, the search area was being refined.
Searchers are racing against time to find the black boxes before their power supplies are drained.