Mystery over the Atlantic

Did lightning alone bring down Air France 447? Or were there complicating factors?

Solving the mystery surrounding the jet's trans-Atlantic disappearance is more challenging because there's no radar, no witnesses, no easy-to-find debris field.

But similar mysteries have been solved over the past couple of decades, thanks to some heavy-duty underwater sleuthing.

The four-year-old Airbus A330 jet and its 228 passengers and crew members were lost over the Atlantic Ocean during a Rio-to-Paris flight on Sunday night, in the midst of a towering storm. No distress call was heard. The only hint of trouble was an automated notification of an electrical failure and loss of cabin pressure, radioed to a monitoring station.

Satellite imagery indicates that vigorous thunderstorms were swirling through the tropical zone where the plane was flying - storms that the plane just couldn't go around. The jet could have been felled by a lightning strike, or by extreme turbulence and wind shear, or icing, or equipment failure, or a combination of those factors.

Although lightning has been listed as the likeliest suspect, no one really knows for sure, because authorities haven't yet located the wreckage - let alone the flight voice and data recorders that could tell the tale.

Bill Voss, president and chief executive officer of the Virginia-based Flight Safety Foundation, said the jet was designed to withstand the jolt. "Lightning strikes are really not that uncommon ... but I can't remember the last time lightning brought an airplane down," Voss told me. Such occurrences are few and far between.

Can the mystery be solved? Voss thinks so. "There's a good chance we're going to be able to find that thing," Voss said.

But it won't be easy. Based on the plane's telemetry, they surmise that the jet was downed over deep ocean 745 miles northeast of the Brazilian coast. Assuming that recovery teams spot the wreckage or detect the "ping" emitted by the flight recorders, someone ... or something ... will have to bring up the black boxes, plane debris and any remains that could be reclaimed from the sea.

"There's only a handful of companies that can do this kind of deep-water work," Voss said. Remotely operated vehicles will likely play a big role.

The authority in charge of the investigation is France's air safety agency - the BEA (which is short for Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation Civile, or Bureau of Inquiry and Analysis for Civil Aviation Safety). "That's a very serious accident [investigation] agency," Voss said.

Because the plane is assumed to have gone down in international waters, the BEA is already working with Brazilian searchers and has asked for assistance from the U.S. National Transportation Safety Board. In turn, the NTSB is asking all federal agencies, civilian and military, to provide any information that could help with the search. That could include military or spy satellite data, or radar readings.

Private companies will most likely be brought in to help with the recovery as well.

If the history of at-sea air crashes is any guide, cracking the case could take months or years, and there could be some surprises along the way. Here are four examples:

• Air India 182: The Boeing 747 crashed into the Atlantic off the coast of Ireland in 1985, leading to 389 deaths. Remotely operated vehicles recovered the flight recorders about two weeks after the crash, and international investigations concluded that the downing was caused by a bomb planted by Sikh separatists.
• TWA 800: The Boeing 747 went down into the Atlantic near Long Island during a New York-Paris flight in 1996, killing 230. Navy divers made nearly 700 dives to assist in the investigation. After three years of analysis, the NTSB blamed a wiring problem that sparked an explosion in one of the jet's fuel tanks (although conspiracy theorists still suspected foul play). The report led to design modifications in the 747.
• Swissair 111: The McDonnell Douglas MD-11 was lost during a New York-Geneva flight in 1998 over the Atlantic near Nova Scotia, killing 229. A sonar-equipped sub quickly located the flight recorders, and divers brought them up less than two weeks after the crash. Canadian investigators determined that faulty wiring, perhaps inside the in-flight entertainment system, caused an electrical fire that spread through flammable material so quickly the crew couldn't stop it.
• Adam Air KI-574: The Indonesian Boeing 737 went down in 2007, killing 102, and it took almost eight months to retrieve the flight recorders from the Makassar Strait. Indonesian investigators concluded that the plane crashed because pilots inadvertently disconnected the autopilot.

One of the biggest challenges for searchers has been the fact that the Air France plane couldn't show up on radar tracking as it passed over the Atlantic. "The problem with radar is, you can't put a radar station over water," said Paul Takamoto, a spokesman for the Federal Aviation Administration. You can get radar readings from orbiting satellites, but not from land-based installations.

That situation is changing, however, thanks to the Global Positioning Satellite system. The FAA is phasing in a GPS-based air traffic monitoring system known as ADS-B (that is, Automatic Dependent Surveillance-Broadcast). The system was pioneered by the FAA's Canadian counterpart, Nav Canada, and it's now being used in Alaska and south Florida.

Takamoto said ADS-B was introduced in Alaska first "because large parts of that state do not have radar coverage because of the rugged terrain." The satellite navigation system led to a 47 percent reduction in fatal air accidents in the state, he said.

ADS-B is slated to go nationwide by 2013, and if it takes hold internationally, the system will likely lead to safer and far more efficient air travel over the Atlantic, the Pacific and the Gulf of Mexico, Takamoto said. Here's why: Today, airplanes making their way across those radar dead zones have to be spaced roughly 10 minutes or 100 miles apart, to reduce the risk of collision. When the new system is phased in, pilots and controllers will be able to watch every move, even in places too remote for radar.

And that should make the skies a lot friendlier for planes passing over the sea.

Update for 8:50 p.m. ET: A big shout-out to NBC News' Tom Costello for sending facts my way. Here's his video report for "Nightly News."

Update for 10:30 p.m. ET: Spaceflight Now's Craig Covault reports that readings from the U.S. Air Force's Defense Support Program satellites are being analyzed for any signs of a flash from the jet's breakup or impact. As Costello has reported, authorities are checking other military satellite data as well.

Correction for 5 p.m. ET June 3: The TWA Flight 800 crash occurred in 1996, not 1997. I've corrected the reference above. Apologies for the error.

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