Jetliners such as Air France's Airbus 330, which was lost over the Atlantic after penetrating a violent tropical thunderstorm, are designed to withstand a storm's lightning and turbulence, aviation experts said Monday.
And because pilots are trained to fly over or around thunderstorms, such crashes are very rare, they said.
Air France Flight 447 early Monday was headed from Rio de Janeiro to Paris through a notorious stormy patch that shifts around the equator, where rapidly developing thunderstorms can tower up to 50,000 feet.
It is not clear why the pilot, with access to weather radar, did not avoid the storm, said Bill Voss, chief executive of Flight Safety Foundation, a nonprofit organization that conducts research on aviation safety.
Photos: Missing Air France plane
"This system would have been clearly visible," he said. "It may have developed quickly and the pilot wasn't able to outclimb it or turn."
Aviation experts stressed Monday that a lightning strike - a common occurrence - was unlikely to have caused the crash.
Planes constructed of metal, such as the Airbus 330, are designed to deflect the electrical current toward earth while protecting passengers and the aircraft's electrical system.
Though aircraft wings are designed to withstand a storm, buffeting by very strong winds can cause structural damage to a plane, loosening components or even tearing the craft apart, experts said.
There is a limit to the stresses a wing can withstand, said Harro Ranter, president of Netherlands-based Aviation Safety Network, which tracks aviation accidents. In 1981, a Fokker F28 - a smaller, Dutch-made jet - crashed in the Netherlands when a tornado folded one of its wings, Ranter said.
Early Monday, 14 minutes after Air France Flight 447 "crossed through a thunderous zone with strong turbulence," the plane sent an automatic message reporting electrical failure and a loss of cabin pressure, said company spokeswoman Brigitte Barrand.
The Airbus has multiple backup electrical systems and it is unlikely that the plane had lost all power, Voss said. But the message indicated a serious problem - one that would have required an immediate emergency descent to 10,000 feet, where passengers could breathe without temporary oxygen masks.
- With AP