Robotic submarine launches 5th mission to locate missing plane

A remote-controlled mini-submarine deployed to find the crashed Malaysia Airlines plane embarked on a fifth mission today with still no sign of wreckage, as Malaysia vowed not to back down from searching for the jet.

Autonomous underwater vehicle Bluefin 21, a US Navy probe equipped with side-scan sonar, has focused the search on an area in the southern Indian Ocean where four acoustic signals were detected that led authorities to believe that the plane's black box may be located there.

"Overnight Bluefin-21 AUV completed another mission in the underwater search area and has commenced mission five," the Perth-based Joint Agency Coordination Centre (JAAC) said in a statement, as the search entered into the 42nd day.

"Bluefin-21 has searched approximately 110 square kms to date. Data analysis from the fourth mission did not provide any contacts of interest," it said.

Up to 11 military aircraft and 12 ships will assist in today's search for missing Malaysia Airlines flight MH370.

"Today the Australian Maritime Safety Authority has planned a visual search area totalling approximately 51,870 square kilometres, across three areas," the statement said.

Meanwhile, Malaysia's Acting Transport Minister Hishammuddin Hussein said his country will not back down from searching for the missing flight MH370, despite Australia announcing that the Bluefin-21 may cease scouring the Indian Ocean, if no trace of the aircraft is found within a week.

Hishammuddin said this message was conveyed by Australian Prime Minister Tony Abbott to Prime Minister Najib Razak.

The minister said there was no reason to call off the search as it took two years for a remotely operated vehicle to retrieve the flight data recorders of crashed Air France flight 447 from the bottom of the Atlantic Ocean in 2011.

"I clearly agree with Abbott. But this does not mean that the search and rescue effort will be called off. We will continue no matter what approach we use (to locate the missing aircraft)," he said yesterday.

He said any decision made concerning the search and recovery effort would take into consideration the views of the international team of investigators, via joint discussions.

The Beijing-bound Malaysia Airlines flight MH370 - carrying 239 people, including five Indians, an Indo-Canadian and 154 Chinese nationals - had mysteriously vanished on March 8 after taking off from Kuala Lumpur.

The mystery of the missing plane continued to baffle aviation and security authorities who have so far not succeeded in tracking the aircraft despite deploying hi-tech radar and other gadgets.