An Air France plane with 228 people on board was presumed to have crashed into the Atlantic Ocean on Monday after hitting heavy turbulence on a flight from Rio de Janeiro to Paris.
Air France said the Airbus flew into stormy weather four hours after its scheduled take-off from the Brazilian city and shortly afterwards sent an automatic message reporting electrical faults.
Company spokesman Francois Brousse said several of the plane's mechanisms had malfunctioned, preventing it from making contact with air traffic controllers.
"It is probably a combination of circumstances that could have led to the crash," he said.
The airliner might have been hit by lightning, he said. The Brazilian air force said the plane was far out over the sea when it went missing. Military planes took off from both Brazil and Africa to hunt for it.
Flight AF 447 left Rio de Janeiro on Sunday at 7 p.m. (11 p.m. British time) and had been expected to land at Paris's Roissy Charles de Gaulle airport on Monday at 11:15 a.m. (10:15 a.m. British time).
The carrier said 216 passengers were on board, including seven children and one baby, and 12 crew members. Air France said the pilots were highly experienced.
Tearful relatives and friends were led away by airport staff after they arrived at Roissy expecting to greet the passengers.
About 20 relatives of passengers on board the flight arrived at Rio's Galeao airport on Monday morning seeking information after hearing news of its disappearance.
