PERTH, Australia (AP) -- A robotic submarine looking for the missing Malaysian jet has returned to the water for its second mission.
Yesterday's planned 16-hour search lasted just six hours. It was cut short by a built-in safety feature that returned the U.S. Navy sub to the surface after it went deeper than its limit of about 15,000 feet.
None of the data gathered by the sub yesterday offered any clues to the whereabouts of the plane.
Before starting today's mission, crews shifted the search zone away from the deepest water in the area.
The sub is programmed to hover about 100 feet above the seabed. It can create a three-dimensional sonar map of any debris on the ocean floor. But the search is taking place in an area where the seabed is covered in silt that could potentially hide part of the plane.
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