Malaysia Airlines Flight 370: Chinese, Australian Ships Detect Unidentified Signals; Chinese Vessel Picked Up Second Signal Within Two Kilometers of First Ping

The Wall Street Journal

By  Ross Kelly and Shani Raja

Updated April 6, 2014 5:45 a.m. ET

PERTH, Australia—The agency leading the hunt for Malaysia Airlines Flight 370 said Chinese and Australian ships had separately reported detecting pulse signals that could have come from the missing airline's black-box flight recorders.

News of the signals, which was cautiously welcomed by authorities heading up the search, came as "corrected" satellite data shifted the geographical focus of the search, with further analysis of the data suggesting the missing flight could have traveled further south than previously thought.

Australia's Joint Agency Coordination Centre, or JACC, said Sunday that a Chinese naval ship involved in the search, Haixun 01, had detected several "acoustic pings" on Friday and Saturday about 2 kilometers (1.2 miles) apart.

The signals, which on Saturday lasted for about 90 seconds, are thought to be consistent with frequencies belonging to the missing airliner's black-box flight recorders.

HMS Echo, a U.K. Royal Navy ship involved in the multinational search in the southern Indian Ocean, and a number of military aircraft have been sent to help investigate the signals.

About 300 nautical miles away, an Australian naval ship, Ocean Shield, picked up pulse signals on Sunday, which the vessel is now investigating.

JACC said it was cautiously treating Haixun 01's report as the more promising one for now.

"This is an important and encouraging lead but one which I urge you to continue to treat carefully," Air Chief Marshal Angus Houston, who heads up JACC, told reporters. "We will follow up and exhaust every credible lead we receive."

Earlier Sunday, Australia's Prime Minister Tony Abbott, in Japan for trade talks, said it was important not to rush to conclusions during a still difficult and complex search operation.

The leads comes as the search for the aircraft, which was carrying 227 passengers and 12 crew from Kuala Lumpur to Beijing, enters its fifth week.

Chief Marshal Houston said that if the Australian vessel's probe proved fruitless the ship would likely be redirected to help investigate the Chinese reports. If that happened, Ocean Shield would probably arrive at the new spot no earlier than midafternoon on Monday because of the time required to change direction with U.S. black-box detector equipment on tow.

 Williams, a visiting professor at the Australian National University and former military-intelligence officer, said the locator carried by the Ocean Shield would be a lot more effective than the less sophisticated technology used by China.

"If they picked it up with the U.S. equipment that's being towed behind the Australian vessel they'd have a better idea because it's got a direction assessment capability," he said. "The Chinese one is just picking up underwater sounds." Ocean Shield is also carrying an underwater unmanned vehicle-known as a Bluefin 21-to help search for any wreckage.

Separately, Chief Marshal Houston said satellite data used to determine the latest search zone had been reanalyzed and suggested the missing flight may have traveled slightly further south than previously thought. He said greater priority was thus being given to the southern part of the existing designated search zone, which has been divided into three dispersed blocks.

"The search area doesn't change so it's not a big change—not the sort of changes we had early in the operation," Chief Marshal Houston said. "But the area of highest probability we think is now probably in the southern part of the area pretty close to where Haixun 01 is operating."

The focus of the search for Flight 370 swung abruptly to the southern Indian Ocean on March 20, based on satellite images of possible plane debris. It later shifted around 700 miles to the north of the first search zone in the ocean after further calculations were made to radar data.

When it detected the pings, Haixun 01 had been searching in an area of the southern Indian Ocean close to but still outside of three designated search zones that JACC had demarcated. Air Marshal Houston dismissed the idea that China was acting unilaterally.

"China's sharing everything that's relevant to this search," he said, adding that JACC was "very satisfied" with the "consultation and coordination" it were receiving from the country where most of the 239 people aboard the missing Malaysian airliner were from.

It is far from certain that the pings detected are from the missing airline. Air-safety experts said other maritime locating devices also use similar frequencies. Following a signal that search teams detected on April 3 but later discounted, JACC warned that biological sources, such as whales, and shipping could lead to false alerts.

A further problem search teams face is that the pulse signals being received are patchy. "It's not a continuous transmission," said Air Marshal Houston—adding that the closer investigators got to any black-box recorders the clearer the signals should become.

The missing plane's flight recorders are running low on batteries, with signals from their beacons possibly falling silent this weekend. The detection range of the signal, which is emitted every second, is about one nautical mile.

"A word of caution," Air Marshal Houston told reporters. "In the days, weeks and possibly months ahead there may be leads such as the one I am reporting to you this morning, on a regular basis." He asked the media not to get carried away with speculation that may end up causing undue stress to relatives of the missing passengers.

China is among the countries that have stepped up undersea efforts to find the missing Malaysia Airlines jet, which set out from Kuala Lumpur to land in Beijing. Two navy vessels from Australia and the U.K. began an undersea probe on Friday even though investigators remain uncertain about the exact location where the plane is believed to have crashed.

Now entering its fifth week, the hunt for Flight 370 has yielded only unrelated scraps of junk. The current search area is in a part of the ocean where currents frequently bring together floating garbage.

Last week, the search was joined by a U.K. military submarine equipped to detect signals from the flight-data and cockpit-voice recorders. The nuclear-powered HMS Tireless, built for the Royal Navy as a Cold War attack vehicle, has equipment on board that may also help pinpoint signals from Flight 370's recorders. It could additionally be used to search for aircraft wreckage along the largely undisturbed seabed.

Source:   http://online.wsj.com