This Article is From Apr 08, 2014

Search for Malaysian plane's black boxes will continue, officials vow

Search for Malaysian plane's black boxes will continue, officials vow

An Australian Orion aircraft (C) arrives back at Pearce Airbase in Bullsbrook, 35 km north of Perth on April 8, 2014 after assisting in the search for the missing Malaysia Airlines jet.

Sydney: Australian officials on Tuesday pledged to scour the ocean for the black boxes of Malaysia Airlines Flight 370 until they were certain that the pingers from the devices were no longer working, describing the task of locating them on the ocean bed as "herculean."

"There have been no further contacts with any transmission, and we need to continue that for several days, right up to the point at which there's absolutely no doubt that the pinger batteries will have expired," retired Air Chief Marshal Angus Houston, the Australian coordinating the search, said from Pearce Air Force Base.

In recent days, pings were picked up by the Australian navy vessel Ocean Shield and the Chinese ship Haixun 01, which were searching about 1,400 miles northwest of Perth. But since those initial detections, the first on April 5, no subsequent sounds have been picked up.

Houston said a submarine would not be deployed unless further sounds were detected. Ocean Shield is at the northern end of the defined search area, and Haixun 01 is in the south. The search zone, about 30,000 square miles, has been reduced from the 90,000 square miles being searched Monday. Commanders try to maintain a distance between the vessels to ensure a quiet environment that limits the chances of false feedback.

David Johnston, the Australian defence minister, described the challenging task ahead.

"This is an herculean task," Johnston said. "It is over a very, very wide area. The water is extremely deep."

The plane disappeared March 8 on a routine flight from Kuala Lumpur, Malaysia, to Beijing with 239 passengers and crew members on board.

On Monday, Houston reported that the Ocean Shield had detected signals on two distinct occasions, one lasting two hours and 20 minutes and the second lasting 13 minutes, using a towed ping locator. The sounds were consistent with flight data and cockpit voice recorders and were described as the best lead that searchers had had as to where Malaysia Airlines plane may have disappeared. There has been no confirmation that the signals were from the jet, and no debris identified as being from Flight 370 has been collected from the sea.

Finding debris on the ocean surface, or detecting new acoustic transmissions, would allow searchers to significantly narrow the area on the ocean floor where wreckage might be found. Houston described the small submersible they would use as having a very narrow field of vision, adding, "It's literally crawling along the bottom of the ocean."

"If we go down there now and do the visual search, it will take many, many, many days, because it's very slow, very painstaking work to scour the ocean floor, and of course the depths are very deep, and it's very challenging," Houston said. The joint agency coordination centre estimates the water depth to be about 16,000 feet.

Cmdr. William J. Marks, a spokesman for the U.S. Navy's 7th Fleet, said Australian and U.S. crews were "working around the clock in a deliberate and methodical manner" to reacquire the signal, which would be emitted continuously if it came from a black box. He said that with a single pass, the signal could be located within a 2-mile zone, but that with several passes, and a continuous signal, the beacon could be triangulated to within a couple of hundred yards.

Searchers are also concerned that the locator devices may soon stop emitting noises. The search is now at Day 32, Johnston said, adding that the life of the batteries in the devices - normally around 30 days - could be expected to fade at any time. But signal frequency did not point to life expectancy. Other factors, including water pressure, could affect the signal.

Houston expressed hope that progress was being made with the detection of the pings.

"They sounded like, as I said yesterday, an emergency locator beacon," he said. "That's why we're so excited about it. We're very hopeful that we will find further evidence which will confirm the aircraft is in that location."

But he added that without the discovery of any wreckage, there remains a long way to go.

© 2014, The New York Times News Service
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