Drone diving to record level in Malaysian plane search

Operators aboard the Australian Defense Vessel Ocean Shield move the US Navy's Bluefin 21 autonomous underwater vehicle into position for deployment in the Southern Indian Ocean, as the search continues for the missing Malaysia Airlines Flight 370, o
Operators aboard the Australian Defense Vessel Ocean Shield move the US Navy's Bluefin 21 autonomous underwater vehicle into position for deployment in the Southern Indian Ocean, as the search continues for the missing Malaysia Airlines Flight 370, on April 14, 2014. -- FILE PHOTO: REUTERS

PERTH (REUTERS) - A US Navy deep-sea drone is diving to unprecedented depths to scour a remote stretch of the Indian Ocean floor for a missing Malaysian jetliner as the Malaysian government said it may use more remote control submarines to help with the search.

The Bluefin-21 and its "side scan" sonar has become the focal point of the search 2,000 km west of the Australian city of Perth, where authorities believe Malaysia Airlines Flight MH370 hit the ocean after disappearing from radars on March 8 with 239 people on board.

Now in its seventh week, the search has centred on a city-sized area where a series of "pings" led authorities to believe the plane's black box may be located. But after almost two weeks without a signal, and long past the black box battery's 30-day life expectancy, authorities have turned to the Bluefin-21.

After the Bluefin-21's searches were frustrated by an automatic safety mechanism which returns it to the surface when it exceeds a depth of 4.5 km, authorities have adjusted the mechanism and have sent it as deep as 4,695 metres, a record.

But hopes that the Bluefin might soon guide searchers to wreckage are dwindling with no sign of the plane after six deployments spanning 133 square kilometres. Footage from the Bluefin's sixth mission was still being analysed, the Joint Agency Coordination Centre said on Saturday.

Malaysian acting Transport Minister Datuk Seri Hishammuddin Hussein said in a Twitter post that the government's Deployment of Assets Committee was considering using more autonomous underwater vehicles. He did not elaborate.

On Monday, the search coordinator, retired Air Chief Marshal Angus Houston, said the air and surface search for debris would likely end by midweek as the operation shifted its focus to the ocean floor.

But the air and surface searches have continued daily, and on Saturday the Joint Agency Coordination Centre said up to 11 military aircraft and 12 ships would help with the day's search covering about 50,200 square kilometres across three areas.