Transcript for Flight 370 Search to Go Underwater
Now to the latest on the intense search for flight 370. In its sixth week and entering a new phase officials fear the batteries in the black boxes are no longer working. And are now deploying a high-tech deep sea explorer to search for clues and David Kerley is in Washington for the latest. Good morning, David. Reporter: Good morning. It is time to stop listening and time to start looking, say the searchers so they have selected a 15-square-mile area here around these pings to start looking. To give you an idea how big it is, it is about two-thirds the size of Manhattan and another clue this morning, they have found an oil slick about three miles to the northwest from this area. This morning, crews are putting this towed pinger locator out of the water. It did hear those four pings. Reporter: But its job now done. We haven't had a single detection in six days. So I guess it's time to go underwater. Reporter: And this is the robot, the bluefin-21 that will go underwater. Its job to map the bottom. It accepts out sonar signals that return and produce a 3D map. Those four pings from the black boxes and some of those sonar buoys have allowed searchers to make a good guess as to where to look. We've identified some areas we prioritized to go evaluate with the sonar search and see if there's debris there. Reporter: They did find an oil slick three miles away. That oil is being tested but this morning they're concentrating on an area 15,000 feet under the water right on the edge of the bluefin's capability. A dark and forbidding place. I think this is an area new to man. It's not sharply mountainous or anything. It's more flat and almost rolling. Reporter: Mapping this 15 square miles will take days and the bluepin returns to the surface every 24 hours and they have to actually download the data and look at it. Because they can't see it from down there and get it back on board. How about planes? Will they still be searching from the air? Reporter: They're going back up in the air again today. But this is about the end. The head of the search says another two or three days. They searched everything so looks like the aerial search will come to an end before the week is out. Thanks so much.
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