Air France said on Saturday it was speeding up replacement of faulty speed sensors on all of its Airbus A330s which problem was feared to have possibly downed its Flight 447 with 228 people on board.

In a statement, Air France said that in May last year it began noticing "incidents of loss of airspeed information during cruise flight" on its twin-engine A330s and four-engine A340s.

The company said it had begun changing all speed monitors, or pitot tubes, on both aircraft types in its fleet on April 27 -- five weeks before Flight 447 went down.

French investigators said Airbus had recommended to all its airline customers that they replace speed-measuring instruments on the A330.

"They hadn't yet been replaced" on the plane that crashed, said Paul-Louis Arslanian, the head of the French accident investigation agency, BEA.

According to Arslanian, it was inappropriate to swiftly tie the pitot tubes to the crash, saying that "it does not mean that without replacing the pitots that the A330 was dangerous."

The Air France Airbus 330 vanished over the Atlantic Ocean early on Monday after leaving Rio de Janeiro for Paris. Debris and two male bodies have been found.

Arslanian said signals from the missing Air France jetliner suggest that its autopilot was not on before it vanished.

The plane sent 24 failure signals in the five minutes before contact was lost, suggesting that the aircraft experienced multiple systems failures before it plunged into the sea, he said.

(Xinhua News Agency June 7, 2009)