Extra powerful sonar equipment needed to plumb depths in MH370 search

Australia may use more powerful sonar equipment that can delve deeper beneath the Indian Ocean in the hunt for the missing Malaysia Airlines jet as the prime minister said on Wednesday that failure to find any clue in the most likely crash site would not spell the end of the search.

The search coordination centre said on Wednesday a robotic submarine, the US Navy’s Bluefin 21, had so far covered more than 80 per cent of the 310-square-kilometre seabed search zone off the Australian west coast, creating a three-dimensional sonar map of the ocean floor. Nothing of interest had been found.

The 4.5-kilometre deep search area is a circle 20 kilometres wide around an area where sonar equipment picked up a signal on April 8 consistent with a plane’s black boxes. But the batteries powering those signals are now dead.

Defence Minister David Johnston said Australia was consulting with Malaysia, China and the United States on the next phase of the search for the plane that went missing on March 8, which is likely to be announced next week.

Johnston said more powerful towed side-scan commercial sonar equipment would probably be deployed, similar to the remote-controlled subs that found RMS Titanic 3,800 metres under the Atlantic Ocean in 1985 and the Australian WWII wreck HMAS Sydney in the Indian Ocean off the Australian coast, north of the current search area, in 2008.