The search for wreckage related to the missing Malaysia Airlines Boeing 777-200ER aircraft is set to enter a new phase as authorities switch its focus to an underwater search, amid concerns that batteries on the aircraft's flight recorders are expiring.

Joint Agency Coordination Centre chief Angus Houston said at a press conference on the evening of 14 April that an underwater autonomous vehicle - the Bluefin-21- will soon be deployed. Ocean Shield meanwhile will pull up the towed pinger locater it has been relying on for signals from the recorders.

The decision was made to switch the focus to an underwater search after four pings consistent with those from an aircraft's cockpit voice recorder or flight data recorder were detected by Ocean Shield using the towed pinger locater. No further pings have been detected, which Houston says is likely due to batteries in the recorders expiring.

“The four signals previously acquired taken together constitute the most promising lead we have in the search for MH370,” he adds.

Bluefin-21 will be able to search an area of approximately 40 square kilometres per deployment, and will use sidescan sonar to deliver high definition pictures of the ocean floor. Each mission will take 24 hours, with the vehicle taking two hours to sink to a depth of 4,500m and rise again, 16 searching, and four hours to download the imagery once it is back on the ship.

Houston also revealed that Ocean Shield has spotted an oil slick in the search area, and has taken samples for further analysis. Analysis work will however take some days, as it cannot be conducted at sea.

He adds that with the search now focusing underwater, aerial and surface searches will continue over the next two to three days, but are likely to be scaled back thereafter.

“The chances of any floating material will have seriously diminished,” Houston says.

Flight MH370 went missing in the early hours of 8 March while enroute from Kuala Lumpur to Beijing. Satellite data later concluded that it ended its flight over the southern Indian Ocean, thousands of kilometres off course from its intended flight path. There were 239 passengers and crew on board the flight.

Source: Cirium Dashboard