Robotic mini-sub on 2nd search mission to locate plane debris

The underwater drone being used to locate the crashed Malaysian jet's wreckage was back in the waters scouring the seabed today after its first attempt ended prematurely due to challenging depths of the Indian Ocean.

Bluefin 21, a US Navy probe equipped with side-scan sonar, was again deployed last night from Australian Navy ship Ocean Shield to locate the debris of the Malaysia Airlines Flight MH370.

The Bluefin-21 was about four hours into its second dive mission, a source close to the operation told CNN.

"The data from Bluefin-21's first mission has been downloaded and analysed. No objects of interest were found," Australia's Joint Agency Coordination Centre said on the 40th day of the search for the plane.

The mini-submarine's mission was aborted yesterday after it encountered water deeper than its operating limits of 4.5 km.

"After completing around six hours of its mission, Bluefin-21 exceeded its operating depth limit of 4,500 metres and its built in safety feature returned it to the surface," the JACC said yesterday.

US Navy Captain Mark Mathews of the Bluefin search team said the initial launch on Monday night took place "in the very far corner of the area it's searching, so they are just shifting the search box a little bit away from that deep water and proceeding with the search."

The search for the missing plane could take up to two months as the underwater vehicle takes six times longer to cover the same area as the towed pinger locater, officials said.

"It is estimated that it will take the AUV anywhere from six weeks to two months to scan the entire search area," lt J G Daniel S Marciniak, a spokesman for the US Seventh Fleet, said in a statement yesterday.

Meanwhile, the aerial and sea search for the plane continued with up to 11 military aircraft, three civil aircraft and 11 ships taking part in today's search for the plane.

Finding the black box and the wreckage are crucial to know what happened on March 8 before the Beijing-bound plane with 239 people, including five Indians, an Indo-Canadian and 154 Chinese nationals, mysteriously vanished on March 8 after taking off from Kuala lumpur.