Airbus had detected faulty speed readings on its A330 jets ahead of last week's crash of an Air France airliner, and had advised clients to replace a part, French air investigators said on Saturday.
But the head of France's air accident agency (BEA) said it was too soon to say if problems with speed sensors were in any way responsible for the disaster over the Atlantic Ocean, which cost the lives of all 228 passengers and crew.
"Some of the sensors (on the A330) were earmarked to be changed ... but that does not mean that without these replacement parts, the (Air France) plane would have been defective," said BEA chief Paul Louis Arslanian.
Airbus, maker of the A330 jet that crashed on Monday, also issued a second advisory late on Thursday that pilots should follow standard procedures -- to maintain flight speed and angle -- if they thought their speed indicators were faulty.
"Problems had been detected (on A330s) and we are studying them," said Arslanian, adding the plane was safe to fly.
Airbus said it had no immediate comment.
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 heavy turbulence over the Atlantic.
Search crews have failed to recover any wreckage so far and French and Brazilian aircrews are scouring a stretch of ocean some 1,100 km (680 miles) northeast of Brazil's coast where experts believe the plane might have come down.
Arslanian said the doomed Air France plane sent a series of 24 automated messages between 0210 GMT and 0214 GMT indicatating a series of system failures before it vanished.
In the middle of this stream of data was one message showing inconsistent speed readings from the A330's sensors.
"You have a plane which transmitted a message, and it is not an exceptional or unheard of message, particulary on the A330, which detected incoherent speed readings," Arslanian said.
Investigators are anxious to locate the plane's flight recorders to try and gleen more information on what went wrong, but are not optimistic that the black boxes will be retreived.
"This is what we are looking for in the middle of the Atlantic Ocean," Arslanian said, holding up a small, cylindrical canister which is attached to the flight recorders and designed to send homing signals for up to 30 days.
"We have absolutely no guarantee that it is still attached to the recorders. They can get detached," he said.
The search zone is a relatively uncharted patch of ocean which has deep ravines and a fine, muddy sediment.
France is sending a nuclear-powered submarine to try to locate the two flight recorders, which could be at a depth of anywhere between 864 and 4,000 metres (2,835-13,120 ft).
Shifting currents meant that in a worst case scenario searchers would have to be right above the beacon to hear it.
Aviation analysts have speculated that a combination of severe turbulence and mechanical problems caused the crash.
Meterological experts have said the plane did cross a storm zone, but that it did not pose an apparent threat.
"Nothing would indicate (that the plane) hit a storm mass of exceptional intensity," Alain Ratier, deputy head of Meteo France told a news conference on Saturday.