HONG KONG -- The search area in the Indian Ocean that recovery teams have been scouring for more than a month is probably not the final resting place of a missing Malaysia Airlines jetliner, the Australian task force in charge of the operation said Thursday.
A U.S. Navy underwater vehicle has been searching the ocean floor in an area west of the Australian continent since early April, after the detection of pings from what was then believed to be the black box recorders of Malaysia Airlines Flight 370.
The announcement followed comments made Wednesday to CNN by Michael Dean, a U.S. Navy official, who said the pings detected in early April were probably not from the black boxes and, in fact, could been from the search ships themselves or the underwater craft. Mr. Dean, the Navy's deputy director of ocean engineering, told CNN that the search team's best theory was that the pings "were likely some sound produced by the ship" or "within the electronics of the towed pinger locator."
The Boeing 777-200 vanished in the early hours of March 8 on a flight to Beijing from the Malaysian capital, Kuala Lumpur. Raw satellite transmission data indicated that the plane had veered sharply off course and had headed south over the Indian Ocean.
The Australian Transport Safety Bureau, the country's transportation safety investigator, determined that the search in the vicinity of the pings "can now be considered complete, and, in its professional judgment, the area can now be discounted as the final resting place of MH370," the task force, the Australian Joint Agency Coordination Center, said Thursday in a statement.
The area has been the focus of the search since April 5, when an Australian ship, the Ocean Shield, detected a signal emitting a frequency suggesting that it was from one of the black boxes, which record flight data and voice transmissions. At the time, Angus Houston, a retired Australian air chief marshal in charge of the operation, urged caution.
But four days later, after more signals were detected, Mr. Houston told reporters, "I'm now optimistic that we will find the aircraft, or what is left of the aircraft, in the not-too-distant future." No more signals were detected in subsequent weeks, consistent with the battery life span of the recorders.
Thursday's announcement means that the search will now cover a much larger section of ocean, encompassing as much as 23,166 square miles, than the area that the Navy's Bluefin-21 submersible vehicle has searched since April. The unmanned, torpedo-shaped vehicle has searched more than 328 square miles of the ocean floor, looking for traces of the missing aircraft with its specialized sonar, the Australian statement said. Searchers are also mapping the ocean floor in the area.
An international team of experts still believes that the plane, carrying 239 people, turned sharply off course early March 8, then went west across the Malay Peninsula and over the Indian Ocean before turning south. Data released Tuesday by the Malaysian government provided further evidence that the plane headed over the Indian Ocean and ran out of fuel. That conclusion was based on an analysis of "electronic handshakes" that the aircraft had been making with a satellite.
An Australian Transport Safety Bureau spokesman said an international team would continue to analyze data from the satellite handshakes. He said the search would remain "along the arc of the seventh ping," or the last signal picked up before the jet is thought to have hit the water.
"We won't be searching the area where the acoustic pings were detected again," the spokesman said in a phone interview, citing government policy in declining to be identified by name. "We are confident that that search has been completed."
The Australian Transport Safety Bureau said Monday that the mapping of the ocean floor, which is underway, would take at least three months to complete. Once the bathymetric survey has been completed, the bureau said, it could take another year to finish the search. "The search will be a major undertaking," said Martin Dolan, the bureau's chief commissioner.