PARIS: French investigators said on Saturday that the Air France jet which plunged into the Atlantic suffered multiple systems failures in its final moments and had speed monitors that had failed on other planes.

Automatic error messages broadcast by the Airbus A330 just prior to the crash on Monday showed that its autopilot had cut out after it received conflicting speed readings, the head of the French air accident investigation agency said. “We have seen a certain number of these types of faults on the A330,” BEA director Paul-Louis Arslanian told reporters, confirming the missing jet had had a problem calculating its speed on the flight from Rio de Janiero to Paris.

“There is a programme of replacement, of improvement,” he said, adding that planes that have not yet had replacement speed monitors are not necessarily dangerous, and that in other cases pilots had been able to regain control. Arslanian said the plane sent 24 automatic error messages in its final moments as its systems — including the autopilot — shut down.

It was impossible to tell from the signals whether the doomed crew had shut off the autopilot or whether it cut out, he added. On Friday, Airbus urged all pilots of its jets to review a warning issued in July 2001 on the procedures to follow if speed indicators give conflicting readings and force the autopilot to cut out.

Investigators seeking clues to what had caused flight AF 447 to crash with 228 people on board have so far had to rely on the automatic messages as salvage crews have been unable to locate the wreckage in deep Atlantic waters. Brazilian air force spotters believe they have identified floating debris, but no

surface vessel has been

able to recover any, and a French nuclear sub and a research ship equipped with ini-submarines are steaming to the scene.

Early speculation as to the cause of the accident focused on foul weather, as the jet was flying through a thunderstorm, but Arslanian said the conditions had not been exceptional for the region.

He also played down the idea that a terrorist bomb might have destroyed the plane, saying the 24 error messages showed the onboard electronic systems including the autopilot had shut down one by one.

But he did not formally rule out an attack:

“Really, that would be

truly astonishing, but that’s not to say it is 100 per cent impossible.”

Meanwhile, intense search operations continued 1,000 km off Brazil’s northeast coast, as salvage teams attempted to locate the black box flight recorders which might solve the mystery.

Five more Brazilian navy vessels were already in the area, which was being overflown by 12 Brazilian and French aircraft, and the French submarines and research vessel were heading to the area.