Sunday, July 31, 2011

Black Box

by  Jerry Adler

They were guarded by silent corpses, the passengers and crew of an Airbus A330 that plummeted to the bottom of the Atlantic in June 2009. For nearly two years, the boxes -- not black, actually, but bright orange -- had lain amid some of the most rugged undersea terrain in the world, 3,500-metre-high mountains rising from the ocean floor, covered with landslides and steep scarps.

Until May when an advanced robotic submersible, the Remora 6000, brought the two black boxes from Air France flight 447 to the surface, they were among the world's most sought-after artefacts, the keys to understanding why a state-of-the-art wide-body jet fell out of the sky on a routine flight from Rio de Janeiro to Paris, killing all 228 aboard. Since no one knew the exact coordinates of the crash, the searchers had to extrapolate their grid from the plane's last known location. It took a team led by the king of undersea searchers, Dave Gallo of the Woods Hole Oceanographic Institution in Massachusetts, to find the wreckage; Phoenix International, a deepwater recovery company, finally brought the recorders home. Why did it take so long? "You can find a needle in a haystack," Gallo says, "but you have to find the haystack first."

French accident investigators removed the memory cards, carefully dried them, plugged in the right cables, and soon announced that the boxes had preserved nearly all the data they had captured -- two hours of audio recorded from the cockpit and a complete record of thousands of measurements taken between takeoff and the moment the Airbus crashed. It was regarded, rightly, as a technological triumph. Although voice and data recorders are built to withstand the most extreme conditions of shock, fire and pressure -- they get fired from an air cannon as part of the testing regimen -- they are not designed to preserve data for so long at such depths. The black boxes, built by Honeywell, had greatly exceeded their specifications.

But this elaborate and expensive undersea search could have been avoided; the technology has long existed that could make the recorders obsolete. As the Bureau d'EnquĂȘtes et d'Analyses (BEA), the French agency that investigates air accidents, struggled to explain the crash in two inconclusive interim reports in 2009, the question was already being asked: if real-time stock quotes can be transmitted to anyone with a smartphone, why does the vital work of investigating an aeroplane crash still depend on reading physical memory chips that must be rescued from the wreckage?

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