French: Air France plane hit the sea belly first

LE BOURGET, France — An intact Air France Flight 447 slammed belly first into the Atlantic Ocean at a very high speed, a top French investigator said Thursday, adding that problems with the plane's speed sensors were not the direct cause of the crash.

Alain Bouillard, who is leading the investigation into the June 1 crash for the French accident agency BEA, says the speed sensors, called Pitot tubes, were "a factor but not the only one."

"It is an element but not the cause," Bouillard told a news conference in Le Bourget outside Paris. "Today we are very far from establishing the causes of the accident."

The Airbus A330-200 plane was flying from Rio de Janeiro to Paris when it went down with 228 people on board in a remote area of the Atlantic, 930 miles (1,500 kilometers) off Brazil's mainland and far from radar coverage.

The BEA released its first preliminary findings on the crash Thursday, calling it one of history's most challenging plane crash investigations. Yet the probe, which has operated without access to the plane's flight data and voice recorders, appears to have unveiled little about what really caused the accident.

"Between the surface of the water and 35,000 feet, we don't know what happened," Bouillard admitted. "In the absence of the flight recorders, it is extremely difficult to draw conclusions."

One of the automatic messages emitted by the Air France plane indicates it was receiving incorrect speed information from the external monitoring instruments, which could destabilize the plane's control systems. Experts have suggested those external instruments might have iced over.

The Pitots have not been "excluded form the chain that led to the accident," he said.

Bouillard said the plane "was not destroyed in flight" and appeared to have hit "belly first," gathering speed as it dropped thousands of feet through the air.

He said investigators have found "neither traces of fire nor traces of explosives."

Bouillard said life vests found among the wreckage were not inflated, suggesting that passengers were not prepared for a crash landing in the water. The pilots apparently also did not send any mayday calls.

He said there was "no information" suggesting a need to ground the world's fleet of more than 600 A330 planes as a result of the crash.

"As far as I'm concerned there's no problem flying these aircraft," he said.