Paris: Investigators have narrowed down the zone in the Atlantic depths where the black box flight recorders of Air France Flight 447 are believed to be located, nearly a year after it crashed, officials said on Thursday.
Researchers have determined an area of 5 square kilometres (about 2 square miles), based on new analysis of data retrieved during the initial search efforts, when the recorders were still emitting signals, a French defence official said. The official was not authorised to be publicly named because of his agency`s policy.
The plane crashed en route from Brazil to France in June, killing all 228 people aboard.
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 wreckages 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-analysed and that researchers determined were pings from the black boxes, the official said.
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.
Defence Minister Herve Morin contacted Transport Minister Dominique Bussereau about the results of the new analysis this week, and it was sent to the French accident investigation agency BEA, which is leading the probe into what happened.
BEA spokeswoman Martine Del Bono said of Thursday`s announcement, "We are working on this information to check it and eventually validate it."