Air France flight AF 447, travelling from Rio de Janeiro to Charles De Gaulle in Paris has disappeared over the Atlantic Ocean, with 228 people on board.
The Airbus 330-200 was expected to arrive in Paris at 09.10 GMT, but instead an automatic message reporting a short circuit caused by turbulence was sent four hours after leaving Rio.
Airline officials believe the airplane to have been over the sea at the time and have singled out a lightning strike as a possible cause, the BBC website reports.
Flight AF 477 left Rio at 22.00 GMT on Sunday carrying 216 passengers and 12 crew onboard. The passengers included seven children, 82 women and 126 men.
The French Government has reported that most passengers were Brazilian, however at least 40 French and 20 German people were on board as well as a smaller number of British and Italian passengers.
The plane last made contact at 01.33 GMT, 565km off Brazil's north-eastern coast according to the Brazilian Air Force. Conditions were reported as normal.
At 02.20, Brazilian air traffic controllers noticed the plane had not made its required radio call to declare its movement into Senegalese airspace. Air traffic control in the Senegalese capital were contacted immediately.
At 05.30 GMT, the Brazilian Air Force launched a search-and-rescue mission, sending out a coastguard patrol plane and a specialised air force rescue aircraft.
According to the BBC website France's minister for transportation, Jean-Louis Borloo has ruled out hijacking as a cause of the plane's loss.
Air France has opened a telephone hotline for friends and relatives of people on the plane - +33 157 021 055 for callers outside France and 0800 800 812 for inside France.