Weather may have triggered malfunctions

THE lightning and turbulence that may have hit an Air France jet flying from Rio de Janeiro to Paris are rarely the cause of plane crashes, analysts say.

But they note that rough weather may have triggered a series of malfunctions that led to the disappearance of the jetliner.

Chief Air France spokesman Francois Brousse suggested the plane could have been struck by lightning.

But most experts say lightning doesn’t usually bring down a modern airliner, unless it coincides with other factors that contribute to the accident. “Planes are built with lightning strikes in mind and are struck reasonably frequently,” said Patrick Smith, a US commercial pilot and aviation writer.

Aviation safety statistics indicate that each large passenger jet – such as the Airbus A330 – is struck by lightning about once every three years on average.

About four hours after taking off, the pilots of the Air France Airbus reported they had encountered an area of intense cumulonimbus activity, part of the massive thunderstorms that regularly batter the world’s equatorial belt.

To avoid structural damage, military and civilian pilots use standard onboard radar to manoeuvre around the thunderheads, which are characterised by electrical discharges, hail and high winds.

The mid-Atlantic region is where most hurricanes that hit the Western Hemisphere originate, and this is the beginning of the storm season. Thunderheads in the area can tower up to 18,000m, making it impossible for airliners to climb over them and forcing them to make long diversions.

Air France reported that the aircraft’s Aircraft Communications and Addressing System – a digital datalink that transmits service messages from the aircraft to ground stations – messaged the company’s headquarters regarding a problem with the aircraft’s electrical and pressurisation systems.

Although aviation experts stressed it was too early to speculate about the causes of the disappearance, they noted that the incident was most likely caused by various factors that combined to cause a catastrophic chain of events. “It sounds like something that evolved into a problem, not something that happened instantly,” said Bill Voss, president and CEO of Flight Safety Foundation, in Alexandria, Virginia.

“It would appear that their systems were degrading, but we don’t know why they were degrading.”