06.01.09

Did Lightning Bring Down Flight 447?

The 228 people on an Air France flight that disappeared over the Atlantic this morning are now presumed dead—possibly the victim of a lightning strike. Aviation expert Clive Irving on why that’s the most troubling theory of all.

Reports that before it disappeared, Air France Flight 447 encountered a severe electrical storm should not in themselves be ominous. These storms are a familiar hazard. In a plane with the exemplary safety record of the Airbus A330, lightning strikes should not be critical.

However, safety experts will be looking at one slender clue. Around 50 minutes after making its last contact with Brazilian radar, the Airbus sent an automated message that it had an “electrical circuit malfunction.” The airplane was relatively young: It went into service in April 2005. To save maintenance time on the ground, airliners of this generation have vigilant computer monitoring of all systems. Any faults are automatically reported to their destination so that engineers are ready to check them on landing.

In this case, that was the last communication sent. After that, silence.

No airline crash has been caused by lightning in more than 40 years. And before this, no passenger has ever been lost on an Airbus A330. And so if in some way Flight 447 became a victim of an unsuspected vulnerability to electrical storms, this will present investigators with a challenge unlike any before. The hope must be that since the flight path over the Atlantic is known, searchers can find floating wreckage that will provide an answer.

There is another major issue raised by this mystery.

The Boeing 787 Dreamliner, which is about to make its first flight, is the first airliner to be built entirely of composite materials, based on carbon-fiber, not metal. A metal airframe is designed to work as its own lightning conductor. Lightning bolts are dispersed with little more than a flash and a bang.

The 787, however, has no similar capacity to deal with lightning strikes through its major structures. How Boeing has solved this problem is a trade secret, although it is known that wire mesh has been embedded in the composites forming the fuselage, and that metal foils are used in other vulnerable parts of the airframe.

For this reason, the FAA subjected the 787 to a “special condition” examination before it was certified to make its first test flight, due later this month. Because no airliner has ever been built this way before, the 787’s ability to demonstrate a level of lightning protection at least equal to a conventional all-metal airplane is crucial.

The fate of Air France Flight 447 may well, therefore, have urgent implications for both Airbus and Boeing.

Xtra Insight: Read 7 theories on what happened to Flight 447

Clive Irving is senior consulting editor of Conde Nast Traveler.