Hunt for MH370 enters 'different phase'

The mystery surrounding missing Malaysia Airlines Flight MH370 has deepened as the autonomous underwater vehicle Bluefin-21 wraps up its search without finding any debris and the search area has been discounted as the final resting place of the ill-fated aircraft.

The Joint Agency of Coordination Center announced on Thursday that Bluefin-21 had completed its mission after covering over 850 square kilometers of ocean floor in an area some 1,600 km off the coast of Western Australia.

The area was defined based on the four acoustic signals detected by the towed pinger locator deployed by the Australian Defense Vessel Ocean Shield. The signals, or pings, were believed to be from a man-made device and have all the characteristics of the transmission from an emergency locator beacon.

Bluefin-21 started searching the sea floor in the area, looking for debris of the missing aircraft or the "black boxes", the aircraft's data and voice recorders.

After searching for more than 40 days, Bluefin-21 completed its last mission on Wednesday afternoon. The data collected on that mission has been analyzed and no signs of aircraft debris were found.

Hours after the Joint Agency of Coordination Center issued the statement, Australian Deputy Prime Minister Warren Truss told the Australian Parliament that the search for MH370 will continue in "a different phase". He said he still believes the resting place of the aircraft is in the Southern Indian Ocean.

The Australian Transport Safety Bureau said the search in the vicinity of the acoustic detections can now be considered complete, and, in its professional judgment, the area can be discounted as the final resting place of MH370.

The announcement came hours after the US navy's deputy director of ocean engineering Michael Dean told CNN that there was now broad agreement the signals came from some other man-made source unrelated to the jet that disappeared on March 8 carrying 239 people.

"Our best theory at this point is that (the pings were) likely some sound produced by the ship ... or within the electronics of the towed pinger locator," Dean said.

"Your fear anytime you put electronic equipment in the water is that if any water gets in and grounds or shorts something out, that you could start producing sound."

The US navy has since issued a statement calling Dean's comments "speculative and premature".

Xinhua