A French investigator says Air France Flight 447 did not break up in flight but plunged vertically into the Atlantic Ocean at a very high speed.

Alain Bouillard, leading the investigation into the June 1 crash for the French accident investigation agency BEA, also says life vests found among the wreckage of the plane were not inflated.

All 228 people aboard the plane were killed when it plunged into the ocean en route from Rio de Janeiro to Paris.

Bouillard said at a news conference outside Paris on Thursday that the search for the plane's black boxes has been extended by 10 days and will continue through July 10.

Sensors not cause of crash

Alain Bouillard says the sensors, called Pitot tubes, were not the only factor.

He says "it is an element but not the cause."

One of the automatic messages emitted by the 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.

Source: chinadaily.com.cn/Agencies