As each day passes and another theory emerges to explain the disappearance of Air France Flight 447, the urgency increases to find the flight data recorders -- or black boxes -- which hold critical and concrete clues to the mystery.
First speculation centered on lightning or turbulence as the cause. The latest centers on small speed sensors that may have iced up, causing the plane to register incorrect speeds. French investigators today confirmed that Air France had not replaced those sensors, called pitot tubes, despite a recommendation from the manufacturer.
But Paul-Louis Arslanian, who heads the French investigative agency, cautioned against jumping to conclusions. The A330-200 is designed to fly with multiple component failures, he says. And there were 24 error messages sent automatically from the plane to Air France headquarters in the flight’s last few minutes, including references to the aircraft's speed readings and autopilot.
Not enough information
Aviation experts say those messages do provide clues and may have relevance, but they have to be put into larger a context and there is nowhere near enough information to do that.
“The consensus among the true experts is that speculation at this point is unwarranted and dangerous in the sense that it can be misleading,” says Richard Healing, an aviation safety consultant and former member of the National Transportation Safety Board (NTSB).
“There is no concrete evidence that eliminates the possibility of a bomb. There is no concrete evidence that eliminates the possibility of…an on board electrical fire that caused a loss of control of the aircraft by burning through control mechanisms. And there’s no conclusive evidence that there was an in-flight break up -- and none that indicates there wasn’t an in-flight break up,” he says. “So we’re very much at the point where we need to recover the flight data recorders.”
The problem with speculation, says Mr. Healing, is that it can lead people to jump to wrong conclusions, which then leads to political pressure to investigate one possibility more than another.
Lessons from TWA Flight 800
For instance, when TWA Flight 800 exploded over Long Island in 1996, initial speculation centered on a terrorist attack or a missile strike. In part, that’s because of testimony from more than 700 witnesses, some of whom believed they saw what looked like a flare heading toward the plane before it broke apart.
That prompted the NTSB to focus a lot of attention on that question and the Federal Bureau of Investigation to open an investigation parallel to the NTSB’s. More than a year later, the FBI dropped it saying it had found no evidence of criminal activity.
“If you remember TWA Flight 800, a lot of people thought they saw a lot of different things,” Healing says. “And that turned out to be total speculation and misleading to some degree. There are still people who believe that it was a missile [that brought the plane down].”
Healing helped investigate the cause of that crash, among many others. In that case, he focused on the wiring. The NTSB ultimately determined in 2000 that the “probable cause” was indeed faulty wiring which ignited jet fuel fumes in the center wing fuel tank causing the explosion.
“Having been in and out of the wreckage numerous times I can tell you that it’s quite clear what happened,” he says. “The physical facts are very, very telling, and the confirmation of it came from careful reconstruction of virtually everything that could be reconstructed.”
Recovery of "black boxes" a top priority
That’s why Healing and French investigators believe the top priority now should be the recovery of the black boxes and whatever wreckage can be found.
A French nuclear submarine is now heading to the area already being searched by French and Brazilian Navy ships. [A Brazilian military official said Saturday afternoon that two male bodies and a suitcase from the flight had been picked up.] Experts say the next two to three weeks are critical to an underwater search because the black boxes send out a locator “ping” for at least 30 days.
But some aviation experts worry that even with that locator beacon, the chances are slim of finding the flight data recorders, which are actually painted bright orange despite being called “black boxes.”
“It’s critical but it may not be possible,” says Michael Boyd, president of the Boyd Group, aviation consultants in Evergreen, Colorado. “It’s not a nice sandy bottom down there, you have mountain ranges and valleys and all sorts of things down there. A three-by-two-foot orange box will be pretty hard to find.”
Preventing future accidents
But Healing says that even if searchers can’t find the black boxes, it will be crucial to continue the search for wreckage for many more months. That’s because current aviation safety is based in part on understanding the causes of accidents to help prevent similar ones in the future. While the A330 is about ten years old, it was made with some composite materials, which are expected to be used far more extensively in the future.
“We’re at the beginning of the next generation aircraft where more and more components of the aircraft are made of composite materials,” he says. “We need to know that it’s the right decision. We need to know if some of them failed [on Flight 447] whether they failed at a point that any other material would have failed.”