Area of black boxes from 2009 Air France crash found

The location of black box recorders from a 2009 Air France crash that killed 228 people has been sharply narrowed down in the Atlantic Ocean, the French air accident investigation authority said Thursday.

France's BEA body, which looks into air crashes, said it made the breakthrough after a further analysis of sonar data from an initial search of the crash area last year.

"The BEA was told yesterday ... that the black box recorders have been tracked down by the defence ministry thanks to data from the first phase of the probe, and a further perimeter for searches has been set up," said a BEA spokeswoman.

French government spokesman Luc Chatel advised caution. "Now we must see if there's a possibility of recovering the black boxes and to see at what depth they are" he told France Info radio.

Two sophisticated salvage vessels, using miniature submarines, have been scouring a 3,000-square-km area to try to locate the flight recorders of the Airbus A330 plane.

France Info radio said that area was now reduced to just 3-5-square-km.

Air France Flight AF447 between Rio de Janeiro and Paris plunged into a remote corner of the Atlantic during a storm on June 1, killing everyone on board.

Earlier this week, the BEA said it would extend a deep-sea search for the wreck of the plane and that the new search would cover a broader expanse of ocean.

Speculation about the cause of the crash has focussed on possible icing of the aircraft's speed sensors, which appeared to give inconsistent readings seconds before the plane vanished.

However, investigators need to recover the flight recorders to confirm or deny that theory.