Airbus has a history of problem with A330

Airbus has faced problems with the speed sensors on its A330 aircraft dating back to at least 2001, forcing changes in equipment as well as the pilot's flight manual, according to regulatory documents. An automated error message from the flight deck pointing to discrepancies in airspeed data is among a handful of clues available so far to experts investigating last week's crash of an Air France A330 in an Atlantic storm that killed 228 people.

France's chief crash investigator said than an airspeed problems had arisen on the same type of plane before but stressed it was too soon to say if these were to blame for the crash of AF 447 and added the plane was still safe to fly.

Airbus confirmed on Saturday it had recommended before the crash that airlines change speed sensors called pilot probes. But it said it was an optional move based only on performance rather than concerns about safety, which would be mandatory.

Operators have however been warned in the past of unsafe conditions resulting from potential ice damage to the sensitive probes fixed to the fuselage, according to online filings.
In 2001, France reported several cases of sudden fluctuation of A330 or A340 airspeed data during severe icing conditions, according to the U.S. Federal Aviation Administration.
"Lost or erroneous airspeed indications could result in lack of sufficient information for the flight crew to safely operate the airplane, and consequent inadvertent excursions outside the normal flight envelope," the FAA wrote in a 2001 summary.

Airbus was ordered as a result to update the cockpit manual. Following the crash of AF 447, Airbus issued a reminder to pilots on procedures in the event of speed discrepancies.The plane which crashed was an A330-200, the newer of two variants of the A330 wide-body twinjet. It was built in 2005.In 2002, operators of the A330-300 sister model had been ordered to upgrade speed

AP contributed to this report