CORRECTED - UPDATE 2-Bodies, debris retrieved from Air France crash

(Corrects source for faulty speed readings in lead paragraph)

* Searchers retrieve two bodies, debris from Atlantic

* Airbus detected faulty speed readings on A330s

* Aircraft sent 24 system failure messages

(Recasts with bodies found, previous dateline PARIS)

By Fernando Exman and Tim Hepher

RECIFE, Brazil/PARIS, June 6 (Reuters) - Brazilian search crews on Saturday retrieved the first bodies from a crashed Air France plane in the Atlantic and air investigators said faulty speed readings had been detected on the same type of jets.

Navy ships found the bodies of two men and debris including a blue seat with a serial number matching Air France flight 447, a rucksack containing a vaccination card, and a briefcase with an Air France ticket inside, rescue officials said.

"This morning at 8:14 a.m., we confirmed the rescue from the water of pieces and bodies that belonged to the Air France flight," air force spokesman Jorge Amaral told reporters in the northeastern city of Recife.

Brazilian air force planes and navy ships have been scouring a swathe of the Atlantic about 1,100 km (683 miles) northeast of Brazil's coast since the Airbus (EAD.PA) A330-200 plane disappeared on Monday, killing all 228 people on board.

The crash of the flight from Rio de Janeiro to Paris was the world's deadliest air disaster since 2001 and the worst in Air France's (AIRF.PA) 75-year history. Fears have grown that many bodies sank or were devoured by sharks.

Theories about the crash have focused on the possibility that airspeed sensors malfunctioned, leading the pilots to set the wrong speed as the plane passed through storms.

French air investigators said on Saturday that Airbus had detected faulty speed readings on its A330 jets ahead of last week's crash and had recommended clients replace a sensor.

The head of France's air accident agency (BEA) said in a news conference that it was too soon to say if problems with the pressure-based speed sensors were in any way responsible for the disaster.

"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," BEA chief Paul-Louis Arslanian said.

Airbus confirmed it issued a bulletin asking the plane's 50 or so airline operators to consider changing the speed sensors, known as Pitot tubes, but it said it was an optional measure to improve performance and not related to safety.

The date of the bulletin was not immediately clear, and an Air France spokesman said he did not yet know whether the sensors had been changed on the stricken jet.

FLURRY OF MESSAGES

The doomed Air France plane sent 24 automated messages between 0210 GMT and 0214 GMT indicating a series of system failures before it vanished, Arslanian said.

In the middle of this stream of data was one message showing inconsistent speed readings from the A330's sensors.

The messages also showed that the autopilot was off, though it was impossible to say whether it had disengaged itself, as it is designed to do when it receives suspect data, or whether the pilot had decided to turn it off, Arslanian said.

"You have a plane which transmitted a message, and it is not an exceptional or unheard of message, particularly on the A330, which detected incoherent speed readings," he said.

"Problems had been detected (on A330s) and we are studying them," he said, adding that the plane was safe to fly.

Airbus also issued a reminder late Thursday that pilots should follow standard procedures -- to maintain flight speed and angle -- if they thought their speed indicators were faulty.

Meteorological experts said the jet crossed a storm zone but that the weather did not seem to pose a particular threat.

Investigators are not optimistic that they will be able to locate the plane's flight recorders.

"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 that 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), said Laurent Kerleguer, the French navy's deputy head of hydrography. (Writing by Stuart Grudgings and Crispian Balmer; Editing by Paul Simao)