What Caused The Miami Plane Crash?

CBS News correspondent Bob Orr explores the possible explanations for the recent airplane crash in Miami Beach, Fla., in which 20 people died aboard a seaplane that broke apart in midair.

It's rare for an airplane to break up in midair. And it's rarer still for such a catastrophe to be captured on videotape. But that's what happened off Miami Beach, and now investigators have a huge head start towards piecing together what went wrong.

By now, you've likely seen the tape. It shows most of the Chalk's Ocean Airways seaplane hitting the water in a nose-down position. Trailing the plane is a large piece of flaming debris that appears to be one of its wings.

So there is no doubt the airplane came apart in the air. But why? There are two primary suspects and a third extremely remote possibility that investigators are considering as they begin to raise the wreckage.

First, did the plane simply "unzip?" That is, did the structure fail due to some kind of stress or metal fatigue? It could be. This was an old airplane, built just after World War II, a plane subjected to thousands of takeoffs and landings as well as thousands of hours of rocky vibrations.

Even if the aircraft was meticulously maintained (and that's something investigators will check), we know metal structures don't last forever. How many people remember the Aloha Airlines jet which landed with its fuselage peeled open like a can of sardines?

Investigators will look for signs of hairline cracks, missing rivets, or corrosion in the metal to determine if the plane suffered some kind of sneaky, long-term deterioration. Very small problems that go undetected for a very long time can add up to a catastrophic failure.

A second and equally plausible suspect is the engine attached to the wing that appeared to break off in flight. Investigators should be able to tell fairly quickly if that engine blew apart in the air, causing the wing to fall off. A so-called uncontained engine failure can be devastating. It can send shrapnel flying through the fuselage and the fuel lines, and can fatally damage a wing.

In any case, the fire seen on the videotape is strong evidence that a fuel line was ruptured, exposing a mist of combustible vapors to a hot engine. (That's a little like spraying charcoal starter on an smoldering ember in your backyard grill.) Investigators don't yet know if the broken fuel line and fire were part of the initial failure which caused the crash or simply the result of the wing breaking away. The wreckage will help clear this up.

If, for example, investigators find heavy charring on the wings but no burn marks on the plane, that would suggest the fire was the result, not the cause, of the crash.

And now to that extremely remote possibility. Investigators cannot absolutely rule out that the crash was caused deliberately. Terrorism seems highly unlikely, but sabotage is not completely off the table. Crash experts and the FBI will talk to everyone who had recent contact with the plane to ensure that no one — say, a person with a grudge — took any actions to compromise the airplane. But there is nothing whatsoever to suggest sabotage played any role.

There is, however, an abundance of evidence pointing the National Transportation Safety Board to what did happen. Investigators, who are cautious and deliberate by nature, won't say so out loud, but they will solve this one. As one veteran investigator puts it, "the wreckage being pulled from the water will talk to us." Sounds captured by the cockpit voice recorder may help fill in the blanks.

I have no doubt investigators will eventually determine which part of the seaplane failed first. Ideally, they'll also be able to tell us why. The videotape, as difficult as it is to watch, has already revealed a lot about what happened so unexpectedly Monday in the skies just off the shores of Miami Beach.
By Bob Orr