PARIS – PARIS (AP) — Investigators using new computer calculations believe they have narrowed their search for the flight recorders of Air France Flight 447, which crashed into the depths of the Atlantic Ocean nearly a year ago, officials said Thursday.
Researchers have determined an area about the size of Paris, based on new analysis of data retrieved during the initial search efforts, when the black box recorders were still emitting "pinging" signals, French Defense Ministry spokesman Gen. Christian Baptiste said.
That is much smaller than the 2,000-square-kilometer (770-square-mile) zone targeted in a search effort last month.
"Does this mean we will find the black boxes? We are far from certainty," Baptiste told a news conference.
He said investigators will still be facing the prospect of searching for recorders the size of a shoe box in a large area of Andes-like undersea terrain.
BEA, the French accident investigation agency that is leading the probe, said it is extending its search to the area. Searches will start Friday in the new zone, which is two hours sailing time south of where teams are currently exploring.
All 228 people were killed when the plane crashed en route from Brazil to France in June 1 into a distant area of the mid-Atlantic. The voice and data recorders are believed to rest on a mountainous area of seabed, perhaps as much as 13,100 feet (4,000 meters) deep.
Without the black boxes, investigators have been unable to determine the cause of the crash.
A series of automatic messages emitted by the plane indicated faults in the speed measuring equipment as the plane crossed a zone of heavy turbulence, but investigators have insisted they don't have enough information to assess why the plane went down.
International search teams scoured the area for weeks immediately after the crash, pulling up pieces of wreckage and dozens of bodies, but did not find the black boxes.
A French submarine, the Emeraude, picked up signals at the time that have since been re-analyzed and that researchers determined were pings from the black boxes, the official said.
After the Emeraude returned to port last year, sonar specialists from French company Thales continued to study the data it brought back from the search zone. They then developed a new algorithm to study the signals picked up by the submarine July 1, and applied them last week for the first time with defense officials in a French laboratory.
Baptiste said they think the signals "probably" came from the black boxes.
Officials urged caution about the announcement.
Government spokesman Luc Chatel said "we should remain extremely prudent for the moment." Speaking on France-Info radio, he said, "We must see if there is a possibility to recover the black boxes, what depth they are located in."
"It would obviously be very good news for everyone, first for the families of the victims of the flight, and then for all of us, because it has been one year that we have been waiting with impatience to find out what really happened on the Rio-Paris flight," he said.
Defense Minister Herve Morin contacted Transport Minister Dominique Bussereau this week about the results of the new analysis, which were sent to the BEA.
Air France said in a statement that it had been informed of the new calculation, and that although the information must still be verified, it is "excellent news" in the search to determine what happened. The calculation will be used to "orient the new search effort that has just begun," Air France said.
A third phase of search efforts, costing an unprecedented $10 million, was carried out in a 2,000-square-kilometer (770-square-mile) zone in March and April, but failed to find the black boxes.
Earlier this week, the BEA announced that search would be continued through late May, but with fewer resources. Air France and Airbus, the maker of the aircraft, will each pay €1.5 million ($1.9 million) to finance the search's continuation.
The devices contain recordings of cockpit conversations and various data readings from the aircraft.
The zone is 200 kilometers (125 miles) northwest of the Saint Peter and Saint Paul Archipelago, off the coast of Northeast Brazil.