BEIJING (USA TODAY) – Searchers will send a high-tech robotic sub to probe the sea floor for missing Malaysia Airlines jet MH370 after failing to pick up additional signals from what is believed to be the plane's data recorder.
Surface ships searching for acoustic signals last picked up a "ping" from the so-called "black box" six days ago.
"It is time to go underwater," and end the surface search, the Australian official leading the search said Monday.
Searchers will deploy Bluefin 21, the slow-moving robotic submersible, or "autonomous underwater vehicle" Monday night local time in the southern Indian Ocean to map the ocean floor, said Angus Houston, who leads the Joint Agency Coordination Centre responsible for the search and recovery effort. The Bluefin-21 is a little yellow submarine made in Quincy, Mass., fitted with sonar equipment that can map the ocean floor
Malaysia Airlines flight MH370 from Kuala Lumpur to Beijing, with 239 people on board, disappeared soon after take-off on March 8, sparking a massive, multi-national search effort including planes and vessels from the USA and China.
Australia's Ocean Shield ship will stop searching for acoustic signals, given the strong likelihood that the batteries of the black box recorders have now expired and will no longer transmit signals.
The air and surface search for debris will also be completed in the next two to three days as chances of finding wreckage "have greatly diminished," Houston said.
Authorities are also exploring an oil slick found Sunday in the area where four strong underwater signals were detected last week, he said. A two-liter sample was collected and is being analyzed, Houston said.
That oil slick, and the four earlier transmissions, are "the only leads" authorities currently have, Houston said. An earlier signal detected by a Chinese vessel is no longer considered credible, he said.
The four signals detected by the towed pinger locator on the Ocean Shield represent "the most promising lead in the entire search," said Houston, who spoke in Perth, Australia, at JACC's first news conference in five days. "We (will) start where we think the best location is, then go out from there," he said. "If we don't find anything, we go further out and look a bit further afield."
The search area for the first mission will cover 15.4 square miles of the ocean floor, Houston said. Each Bluefin mission will take 24 hours to descend, search, resurface, share its data and recharge.
The sub will take two hours to descend 15,000 feet, the very limits of its operating ability. After 16 hours probing the ocean bed, it will resurface and then deliver its data. Analysts will get no indication of its progress until that daily download, Houston said.
Houston, a former Air Chief Marshal of Australia, cautioned against raising hopes
"Don't be over optimistic, be realistic," he said. The ocean floor that will be mapped by side-scan sonar is "new to man," and the search may be complicated by heavy silt that could be "quite layered and quite deep," he said.
The majority of passengers aboard MH370 were from China, where many relatives still await evidence before they will accept
To meet the strong interest in China, Houston held a separate press conference Monday for Chinese media, with Mandarin translation.
Many relatives remain in Beijing at the Lido Hotel, where Malaysia Airlines has provided rooms for families of MH370 passengers. The families gather in daily meetings, sometimes with representatives from the airline and Malaysian or Chinese governments, and occasional prayer sessions.
For better co-ordination, the relatives recently set up a voting structure, with one voting member per passenger. The group will decide on media releases, legal and other matters.
"The new structure is working," said Ma Tong, 29, a Beijing actuary whose mother Ma Wenzhi, 57, was on the plane. "The relatives are too numerous and loosely-organized, and we want to be more efficient, so we established this smaller group with 154 people," he said.
After agonizing weeks of waiting and many false leads, "we are more calm now, we don't care so much about the latest updates," Ma said.
"Even if they find the black boxes later, if no bodies of our relatives are found, most of us won't go to Australia," he said. "We doubt the plane is there, our relatives could be in another place. We don't believe any news now."
Contributing: Sunny Yang