The black boxes were sitting on the ocean floor in what would have been plain sight, if there were any light at a depth of 12,800 feet. 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, 11,500-foot mountains rising from the ocean floor, covered with landslides and steep scarps. Until the days in 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 artifacts, the keys to understanding why a state-of-the-art widebody 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, 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 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 airplane crash still depend on reading physical memory chips that must be rescued from the wreckage?

The tragedy of Air France 447 might have been on the minds of executives from Bombardier, the Canadian aircraft manufacturer, when they announced in 2010 that their new CSeries narrow-body jets, scheduled to come to market in 2013, would be the first commercial airliners built with the capability to transmit telemetry data instead of merely recording it. The idea—to stream black box data in real time, either directly to a ground station or by satellite relay—isn’t new, even though there remains no consensus on whether to call it an uplink, which is conceptually accurate, or a downlink, which expresses the physical relationship of an airplane to the ground.

Bombardier is advertising the innovation not as a way to improve crash investigation—survivability of data after a crash isn’t something airplane manufacturers like to boast about—but as a way to give airlines a central database for routine information on airplane operations and mechanical performance. At a minimum, the data could be stored securely as a backup to black boxes in the event of an accident. One company, Calgary-based FLYHT AeroMechanical Services, already provides this service as an aftermarket retrofit; so far, smaller carriers and charters have been the main customers.

But until the Air France crash, streaming data was mostly considered a solution in search of a problem. Black boxes were almost always found: The last US or European accident from which onboard data recorders were not recovered was the World Trade Center attacks, in which both planes were essentially vaporized. When planes crash into the ocean, locator beacons on the black boxes send out an ultrasonic ping designed to be heard through the water at distances of up to several miles. “Approach and landing accidents are half the crashes in a given year,” says Bill Voss, president and CEO of the Flight Safety Foundation, “and then you just walk over and pick it up.” Even in the more difficult cases, black boxes usually survive. Data was retrieved from the recorders aboard the hijacked United Airlines flight 93, which nosed into a Pennsylvania field on 9/11 at an estimated speed of over 550 miles an hour, gouging a crater 8 feet deep.

Invented in the 1950s after a spate of accidents involving the de Havilland Comet, the first commercial jet, flight data recorders have become standard equipment on all but the smallest aircraft. The earliest models recorded data with a moving stylus on a roll of foil; as recently as 1994, when USAir flight 427 rolled over and crashed on approach to Pittsburgh, the flight data recorder on the Boeing 737 measured only 13 parameters, such as altitude, airspeed, heading, pitch and roll, and whether the pilots were pulling or pushing on the control column. It did not, for instance, record the position of the rudder or of the rudder pedals in the cockpit—information that turned out to be crucial in the investigation, which took five years before probable cause was ascribed to a malfunction in the rudder’s hydraulic control valve.

As a result, the latest black boxes are far more sophisticated. The FAA requires most planes flying today to monitor only 88 parameters, generally once or twice per second, but data recorders on modern commercial jetliners may track as many as 3,000 data points, including the status of every system on the aircraft, the positions of cockpit controls, and pressure and temperature readings from fuel tanks and hydraulic systems. Sensors monitor every point in the engines from intake to exhaust. And starting next year, new rules will require that critical measurements such as the positions of flaps, ailerons, and rudders get sampled eight times per second. Some airlines use this data for routine purposes like scheduling engine maintenance, but you never know what might turn out to be important in a crash investigation. It is, of course, far more information than is available to pilots in the cockpit—or that they could possibly absorb during a crisis. When something goes wrong at 550 miles an hour, it can go wrong very quickly.

Pages: Previous 1234 | Full Page | Next