PARIS – The head of the French agency leading the probe into the crash of Flight 447 says Air France had not replaced instruments that measure air speed on the plane, which the manufacturer had recommended.
Agency head Paul-Louis Arslanian says some problems had been detected with the instruments on the Airbus A330, the model that disappeared over the Atlantic Ocean on May 31.
Arslanian says Airbus had recommended that airlines replace the instruments on the A330. The head of the crash investigation says Air France had not changed the instruments known as Pitot tubes on the plane that crashed.
Arslanian warned on Saturday against jumping to conclusions.
He says planes can be flown safely "with damaged systems."
An Air France memo Friday said it is replacing Pitot tubes on all medium- and long-haul Airbus jets.
Plane manufacturer Airbus says the probe found the flight received inconsistent readings from different instruments as it struggled in a massive thunderstorm.
Probe chief Alain Bouillard says "we also saw messages that show the automatic pilot wasn't working."
Arslanian says investigators are searching a zone of several hundred square miles for the debris.
France's transportation minister said Friday that French forces have found no signs of the doomed plane.
Dominique Bussereau said he regretted that an announcement by Brazilian teams that they had recovered plane debris from Air France flight 447 turned out to be false.
The Brazilian air force announced Thursday afternoon that a helicopter plucked an airplane cargo pallet from the sea that came the Air France flight, but then said six hours later that it was not from the Airbus.
"French authorities have been saying for several days that we have to be extremely prudent," Bussereau told France's RTL radio. "Our planes and naval ships have seen nothing."
Bussereau said the search must continue and stressed that the priority was finding the flight recorders. The plane went down Sunday night with 228 people on board in the world's worst aviation disaster since 2001.
France's defense minister and the Pentagon have said there were no signs that terrorism was involved. Brazil's defense minister said the possibility was never considered.
French Foreign Minister Bernard Kouchner, speaking Thursday in Rio de Janeiro where he attended a Mass honoring the crash victims, said experts had not found signs that would back up a "terrorism theory."
"But we cannot discard that for now," he told reporters. "Nothing leads us to believe that there was an explosion, but that doesn't mean there wasn't one."
"All the paths are open and we will not give priority to a single premise because that would be immoral," he added.
But investigators will have little to go on until they recover the plane's "black box" flight data and voice recorders, now likely on the ocean floor miles beneath the surface.