MH370 search on hold after trouble with mini-sub

SYDNEY - The hunt for the missing Malaysian passenger jet in the Indian Ocean was put on hold Thursday after technical issues with a US Navy mini-submarine that require spare parts to be sent from Britain.

Australia's Joint Agency Coordination Agency (JACC), which is leading the search, revealed Wednesday that the Bluefin-21 submersible lasted only two hours in the water this week before it had to be raised.

The JACC blamed "communications problems" for the aborted mission and after a more thorough examination, announced that spare parts will be needed before the sophisticated mini-sub can be used again.

Malaysia Airlines flight MH370 vanished on March 8 with 239 people on board.

It is believed to have crashed far off Australia's west coast after mysteriously diverting from its Kuala Lumpur-Beijing route. No wreckage has been found, despite a massive international search operation.

The mini-sub had only arrived back in the remote southern Indian Ocean search zone on Tuesday following a port visit to Perth onboard the Australian vessel Ocean Shield.

The problems with the mini-sub mean Ocean Shield is once more steaming for land in order to pick up the spare parts, which are due to arrive in Australia on Sunday.

"Examination of the communications problem has established that a hardware defect exists in the transponder mounted on the Ocean Shield and a defect may also exist in the transponder mounted on the Bluefin-21," JACC said.

"This inhibits the ability of the two devices to communicate with each other."

"As a consequence, spare parts for both defects will be dispatched from the United Kingdom. The parts are expected to arrive in Western Australia on Sunday."

Ocean Shield is now en route to Dampier in Western Australia to pick up the transponder parts, with the journey "anticipated to take a number of days". The JACC also revealed that the Bluefin-21 was damaged as it was being hauled out of the water, but said it had been repaired with spare parts already on board Ocean Shield.

The intensive air and sea search for the Boeing 777 was drastically scaled back at the end of last month.

Officials have said an intensified undersea mission, to complement the Bluefin-21 operation, will begin once new and more sophisticated equipment can be obtained to search at depths of more than 4,500 metres (15,000 feet).

The ocean bed in the search zone is not just deep but largely unmapped, meaning specialist sonar equipment and other autonomous vehicles are needed.

Preparations to map the ocean floor are underway, with a Chinese ship in the search area to assist.

International experts are meanwhile continuing to examine satellite imagery and all the data collated so far to try to pinpoint a more precise location for the search.

The Bluefin had previously been scouring a 314-square kilometre zone centred around one of the transmissions believed to have come from the plane's black box flight recorders before their batteries died.