Robotic sub should finish seabed search in focused area for missing Malaysia plane in 1 week

The search coordination center says an underwater robotic submarine is expected to finish searching a narrowed down area of the Indian Ocean seabed for the missing Malaysia Airlines plane within the next week, after completing six missions and so far coming up empty.

As the hunt for Flight 370 hit week six Saturday, the Bluefin 21 unmanned sub began its seventh trip into the depths off the coast of western Australia.

Its search area forms a 10-kilometer (6.2-mile) circle around an underwater signal detected April 8 that was believed to be coming from the aircraft's black boxes before their batteries died.

The sonar scan of the seafloor in that area is expected to be completed in five to seven days, the center said in an email to The Associated Press.