US Navy: Without New Leads, Malaysia Airlines Jet 'Pinger' Search to End in a 'Few More Days'

April 12, 2014— -- Search teams looking for missing Malaysia Airlines Flight 370 will abandon use of the U.S. Navy’s underwater black box locator in the next few days unless credible new signals are picked up from possible emergency beacons, a U.S. Navy captain said today.

“When the time is right, we’ll say ‘Yes, the beacons have probably stopped transmitting’ and it’s time to shift,” Capt. Mark Matthews told ABC News.

That time, he said, is coming in a “few more days.”

“As long as we have a chance to receive another signal from the beacon, we’re going to try. But eventually we’re going to shift to the autonomous underwater vehicle,” Matthews said.

Read more: Malaysia Airlines Flight 370: What Happens Now?

Matthews is in charge of the TPL-25 (the Towed Pinger Locator) and the Bluefin-21 underwater autonomous vehicle currently on board the Royal Australian Navy ship Ocean Shield. Last Saturday, the TPL-25 detected “pings” consistent with beacons attached to black boxes - aircraft flight data and cockpit voice recorders. Two more sets of pings were heard Tuesday.

Later in the week, floating sonobuoys dropped from search aircraft also reported hearing signals underwater, but officials said they were unlikely to be coming from a black box beacon.

No credible signals have been heard since, Matthews said. While acknowledging the pinger locator search will soon end without new leads, he said the team wants a few more days to try and narrow the underwater search area down from its current size of approximately 500 square miles. Ocean Shield, along with a British ship and submarine, is operating in deep-ocean waters about 1,400 miles northwest of Perth, Australia.

The Bluefin-21 will pick up the search from the TPM-25 by using sonar to map the ocean floor for any sign of wreckage. It travels slower than the TPM-25 - up to about 5 mph - and scans about 12 square miles a day, Matthews said.

“We’re not going to be convinced we’ve found the aircraft until we can actually take a look at a picture and say, ‘Yes, that is Malaysia 370,” he said.

Matthews - who earlier in the week was “shocked” at the news that pings had been detected in such a massive search area - said the operation is actually making rapid progress.

“It is abnormal for things to proceed as quickly as they have. Normally these things are done over months and months,” he said. “We are in a much better position than we could really hope for in one of these searches.”

On Saturday, ten planes and 14 ships continued the search for debris on the surface of the Indian Ocean, an area of about 16,000 square miles.

Ships recovered a small number of items from the water on Friday, officials said, but nothing appeared associated with the missing airliner.