PERTH, Australia (RNN) - With no new pings detected, it's "time to go underwater," search coordinator Angus Houston said in a news conference Monday.
The searchers for Malaysia Airlines Flight 370 have concluded that the batteries for the source of the pings have likely died, as no new pings have been detected since Tuesday. As a result, the pinger locator will no longer be deployed.
It is hoped that the four signals heard last week came from the flight's black box.
With the four pings heard by the searchers, the search team has enough information to launch the submersible, Houston said.
Though no debris has been found, Houston said that the search team found an oil slick in the search area in the southern Indian Ocean. A two-liter sample of the oil has been taken and is being tested.
"I stress the source of the oil is yet to be determined but the oil slick is approximately 5, 500 meters downwind and downsea from the vicinity of the detections picked up by the towed pinger locator on the Ocean Shield," the search coordinator said.
The Bluefin 21 will be deployed Monday evening from the Ocean Shield, Houston said. However, he warned that it will be "a slow and painstaking process."
It will take six weeks to two months to canvassing the ocean in the search area. Each mission of the Bluefin 21 takes one day, including two hours to dive and four hours to download data.
The Bluefin 21 takes a sonar scan of the ocean floor, and thus can detect possible debris there.
"As I have said before, wreckage needs to be visually identified before we can say with certainty this is the final resting place of MH370," Houston said.
Flight 370, has been missing since March 8, when it took off from Kuala Lumpur, Malaysia, en route to Beijing with 239 aboard, mostly Chinese.
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