Malaysia Airlines Flight 370: Australian Ship Picks Up Signals

The naval ship Ocean Shield—fitted with U.S. Navy black-box detector equipment that is able to pick up signals far beneath the ocean surface—has been searching an area of the southern Indian Ocean off the coast of Western Australia that investigators believe is the most likely spot where the plane could have crashed into the ocean when it ran out of fuel after disappearing from civilian radar on March 8.

The first of two signals, consistent with the pings emitted by an aircraft’s “black box” flight recorders, was held for more than two hours, Air Chief Marshal Angus Houston, who is leading the multinational search, said Monday. A second signal was picked up on a return trip along the same path of ocean and held for around 13 minutes, he said.

“Significantly this would be consistent with transmission from both the flight data recorder and the cockpit voice recorder,” he said. “Clearly this is a most promising lead and probably in the search so far, it’s probably the best information that we have had.”

Authorities still needed to fix on a precise location before sending an underwater vehicle to investigate the finding, in an area of ocean some 4,500 meters (14,764 feet) deep. Those depths are at the absolute limit of capability for such vehicles, Mr. Houston said.

Locator beacons on two flight recorders aboard the plane have an estimated battery life of about 30 days before they stop emitting signals. Monday marks the 30th day since the Boeing 777 200 jetliner vanished from civilian radar on a flight from Kuala Lumpur to Beijing on March 8 with 239 people on board. The devices, if found, could provide vital clues to what occurred on the ill-fated flight.

Nine military and three civilian aircraft were set to join 14 ships scouring a stretch of roughly 234,000 square kilometers (90,000 square miles) in the southern Indian Ocean for the black boxes and debris from the jetliner, Australia’s Joint Agency Coordination Centre, which is coordinating the multinational search, said Monday.

Good weather was expected throughout the day, with rain showers forecast for the afternoon unlikely to affect the search, the agency said.

The U.K. Royal Navy ship HMS Echo is on its way to assist the Chinese vessel Haixun 01, which reported detecting several “acoustic pings” on Friday and Saturday about 2 kilometers (1.2 miles) apart. The signals were thought to be consistent with frequencies belonging to the missing aircraft’s flight recorders.

The Chinese listening device was designed to identify sounds at depths of less than 1,000 feet, according to one person briefed on the Flight 370 probe, while the ocean bottom in parts of the search area exceeds 13,000 feet.

The search area where Flight 370 is thought to have hit the ocean continues to be refined based on technical analysis by air crash investigators from Malaysia, the U.S., the U.K., China and Australia. Authorities are now focusing on the southern part of the designated search zone, which has been divided into three dispersed blocks, based on the latest analysis that suggests the missing flight traveled slightly farther south than previously thought.

“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,” Air Chief Marshal Houston said Sunday. When it detected the pings, Haixun 01 had been searching in an area of the southern Indian Ocean close to but still outside three designated search zones. 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 the agency was “very satisfied” with the “consultation and coordination” it was receiving from China, which lost 153 citizens aboard the missing plane.

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.

Now in its fifth week, the hunt for Flight 370 so far has yielded only unrelated scraps of junk. 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 also be used to search for aircraft wreckage along the largely undisturbed seabed.