Search continues despite days of ping silence

Latest developments:

• Black boxes silent for six days
   
• 12 aircraft, 15 ships scour 47,644 square kilometres

Follow us as we bring the latest updates and coverage for the search of Flight MH370:

Black box signals cold for six days

9.31am: As ADV Ocean Shield enters its sixth day without being able to reacquire the signals it picked up last week, optimism appears to drain from the Australian side.

Australian Prime Minister Tony Abbott (left in photo), who, just on Friday, said he was "confident" of the black box location now warns of a difficult task.

"There's still a lot more work to be done and I don't want anyone to think that we are certain of success, or that success, should it come, is going to happen in the next week or even month.

"There's a lot of difficulty and a lot of uncertainty left in this," he is quoted as saying by The Independent.

ADV Ocean Shield first picked up two signals on April 5 which were consistent with the presence of two black boxes - the flight data recorder and cockpit voice recorder and again picked up two more signals on April 8.

However, as the trail goes cold, fear is that the batteries powering the black boxes’ emergency beacon that allows them to emit the signals have died, paving way for an arduous inch-by-inch undersea search.

The black boxes have a certified battery life of 30 days but can at times last longer.

Search underway, with no new signals

8am: Searchers continue to narrow the search area for missing Malaysia Airlines Flight MH370 with today's operation covering only 47,644 square kilometres compared to 77,580 square kilometres when signals "consistent with black boxes" were first picked up.

Up to 11 military aircraft, one civil aircraft and 15 ships are joining the operation today at an area approximately 2,200 kilometres north west of Perth, says the Joint Agency Coordination Centre (JACC).

The oceanographic ship HMS Echo has arrived to assist Australian Defence Vessel (ADV) Ocean Shield, which has thus far failed to reacquire the "black box signals" picked up last week.

ADV Ocean Shield will also be assisted by AP-3C Orions which will conduct their acoustic search.

Weather today, like yesterday's search, is expected to see south easterly winds with possible showers with sea swells up to 1.5 metres and visibility of three to five kilometres.

Background:

• The Beijing-bound Boeing 777-200ER aircraft went missing not long after taking off from KL International Airport in the early hours of March 8, with 12 crew members and 227 passengers.
   
• Authorities have determined the plane intentionally turned back and altered its course shortly after cutting communications with tower controllers for unknown reasons.
   
• "Groundbreaking" data analysis on the six last 'pings' between MH370 and British company Inmarsat's communications satellite has yielded clues to the aircraft's position and heading, leading investigators to narrow down the search area to the south Indian Ocean.
   
• Australia leads the search in the south Indian Ocean. As of March 30, the Joint Agency Coordination Centre (JACC) is tasked with overseeing the operations, led by retired air marshal and former defence chief Angus Houston.