Yesterday the Joint Agency Coordination Centre in Canberra said the navy ship Ocean Shield was returning to Perth after failing to locate any signs of debris. "The Australian Transport Safety Bureau has advised that the search in the vicinity of the acoustic detections can now be considered complete and in its professional judgment, the area can now be discounted as the final resting place of MH370."
Although not addressing the claims directly, the centre's statement appeared to back comments by the United States Navy's deputy director of ocean engineering Michael Dean, who told CNN there was now "broad agreement" that the acoustic "pings" were from another source unrelated to MH370.
The pings prompted Prime Minister Tony Abbott to say last month that search officials were confident they knew the position of the black box flight recorder "to within some kilometres".
But Dean told CNN: "Our best theory at this point is that they were likely some sound produced by a ship ... or within the electronics of the Towed Pinger Locator. Your fear any time 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 hosed down Dean's remarks. "Mike Dean's comments today were speculative and premature, as we continue to work with our partners to more thoroughly understand the data acquired by the towed pinger locator. As such, we would defer to the Australians, as the lead in the search effort, to make additional information known at the appropriate time."
Dean's comments followed earlier criticism of the search by a group of underwater acoustic experts who told News Corp Australia that the search was a "debacle". They said the frequencies and spacing of the pings were incorrect for black box signals. Other critics have questioned the Inmarsat interpretation of satellite data that triggered the Indian Ocean search. Raw satellite data released by the Malaysian Government this week could take weeks to fully analyse. Australian search officials say an independent review of the Inmarsat data by a number of British and US organisations supported the conclusion that MH370 crashed off Western Australia.
But new reviews have been ordered by the co-ordination centre, which said: "The expert satellite working group continues to review and refine complex analyses of radar and satellite data and aircraft performance data to determine where the aircraft most likely entered the water. The findings of the review will be made public in due course."
Experts will review all data to define a search zone of up to 60,000 sq km, press ahead with a bathymetric survey to map the ocean floor, and recruit more specialist services. Chinese survey ship Zhu Kezhen has begun conducting the bathymetric survey, supported by another Chinese vessel, Haixun 01 and Malaysian ship Bunga Mas 6. They will be joined by another vessel next month. The survey is expected to take three months, followed by a new underwater search from August lasting for up to 12 months.
Out of contention
"The Australian Transport Safety Bureau has advised that the search in the vicinity of the acoustic detections can now be considered complete and in its professional judgment, the area can now be discounted as the final resting place of MH370."
- statement by the Joint Agency Co-ordination Centre
The search
April 7: JACC announced that a pinger locator towed from Ocean Shield had picked up two acoustic signals, with one held for more than two hours. At the time, it described the signals as consistent with flight data or cockpit voice recorders, the most promising lead yet and likely from a man-made source.
April 9: Two more signals were detected, holding for about five and seven minutes.
April 14: The Bluefin-21 underwater drone begins scanning the sea floor off the West Australian coast. It has scoured more than 850sq km.
