PARIS, June 5 (Reuters) - Airbus
has warned airline crews to follow standard procedures if they suspect speed indicators are faulty, suggesting that technical malfunction may have played a role in this week's Air France
Investigators know from the aircraft's final batch of automated messages, which were sent over a three minute period, that there was an inconsistency between the different measured airspeeds shortly after the plane entered a storm zone.
The Airbus telex was sent to customers of its A330s late on Thursday. An industry official said such warnings are only sent if accident investigators have established facts that they consider important enough to pass on immediately to airlines.
The recommendation was authorised by the French air accident investigation agency (BEA) looking into the disaster. It has said the speed levels registered by the slew of messages from the plane showed "incoherence".
Airbus said its message to clients did not imply that the doomed pilots did anything wrong or that a design fault was in any way responsible for the crash.
"This Aircraft Information Telex is an information document that in no way implicates any blame," Justin Dubon, a spokesman for Airbus, said on Friday.
The Air France A330-200 was en route from Rio de Janeiro to Paris when it suffered a rapid succession of technical problems after hitting turbulence early on Monday and almost certainly plunged into the Atlantic. All 228 people on board died.
Brazilian authorities hunting for the plane said on Thursday that flotsam scooped from the sea about 1,100 km (680 miles) northeast of Brazil's coast, was not from the Airbus A330, as previously reported.
Searchers have found several debris sites spread out over a 90 km (56 miles) zone and boats in the area are trying to pick it up to ascertain if the plane really did come down there.
More than 300 aircraft similar to the missing Air France
jet -- an Airbus A330-200 -- are in service worldwide.
Investigators do not know if Flight AF 447 was travelling at an incorrect speed as it crossed a storm cluster.
An aviation expert, who declined to be named, said the plane's airspeed sensors, called pitot tubes, work on air pressure and might provide incorrect readings if they get obstructed by objects such as ice.
The tubes are heated to prevent icing at high altitude and there was no immediate information on what went wrong.
If pilots believe the flawed readings are right, they might mistakenly alter their speed, jeopardising their plane.
Airbus said the correct procedure when confronted by unreliable speed indications was to maintain thrust and pitch and start trouble shooting.
The Airbus telex has revived a long-standing debate among pilots over whether the Airbus planes are overly complex.
"This is a plane that is conceived by engineers for engineers and not always for pilots," Jean-Pierre Albran, a veteran pilot of Boeing 747s, told Le Parisien newspaper.
"For example on a 747, the throttle is pushed by hand. You feel it move in turbulence. On recent Airbuses, this throttle is fixed. You look at the dials. You don't feel anything."
Aviation experts have speculated that the Air France plane was brought down by a chain of problems, with strong turbulence and stormy weather almost certainly a factor. Officials have played down any suggestion of terrorism. (Additional reporting by Fernando Exman and Brian Ellsworth in Brazil; Editing by Louise Ireland)
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