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American Morning

Wreckage Pattern in Crash of American Airlines Flight 587 Offers Clues About Possible Cause of Crash

Aired December 19, 2001 - 07:19   ET

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
PAULA ZAHN, CNN ANCHOR: The wreckage pattern in the crash of American Airlines Flight 587 offers some clues about the possible cause of the crash. The vertical stabilizer, the tail, fell off first, followed by both engines. The National Transportation Safety Board is spending a lot of energy trying to understand why the tail came off in the first place. To that end, is has assembled a team of experts schooled in the high tech world of composite aircraft materials.

Leading the effort, the team at NASA's Langley Research Center in Hampton, Virginia, where the tail has been transported for analysis.

Our own Miles O'Brien is there.

(BEGIN VIDEOTAPE)

MILES O'BRIEN, CNN CORRESPONDENT (voice-over): The tale of the tail has yet to be told. But past these portals, there is little doubt the mystery will be solved. This is a place where they add pressure and tension for a crash course on the strong but light materials collectively called composites.

UNIDENTIFIED MALE: We hit the ground.

O'BRIEN: Here at NASA's Langley Research Center in Hampton, Virginia, they have been pushing the composite envelope for three decades to see how they work and how they fail. Graphite composite like the material in the tail fin of the doomed Air Bus A300, is made of carbon thread that is woven and then layer caked with an epoxy goo. It's the same idea as a sheet of plywood, but stronger and much lighter.

MARK SHUART, DIRECTOR, STRUCTURES AND MATERIALS: People can go a little faster. They can go a lot farther and cost effectively. So that's one of the reasons that composites are being looked at.

O'BRIEN: So it is no wonder the airlines are following the military's lead, using more and more composites in key components. The Air Bus that crashed in New York was about five percent composite. The newest planes from the European company that made the A300 have three times more carbon fiber material. But composites are still relatively new compared to good old-fashioned aluminum. So the aviation industry is still learning. Layers that come unglued, so- called delaminations, are not always obvious to the naked eye, as this ultrasound inspection reveals.

PATRICK JOHNSTON, NASA LANGLEY SCIENTIST: In this particular example, the impact was, I think, a 5/8 inch diameter steel ball. The surface has a small indentation which was just barely visible to the eye and just, you can just feel it with your finger.

O'BRIEN (on camera): The problem with ultrasound is it doesn't work through the air. It has to be transmitted through a fluid like this tank of water. Now clearly it's not practical for an airline to remove a tail fin, submerge it in water and inspect it this way. Instead, some airlines have this sort of equipment. It actually suction cups onto the side of a surface of the airplane. Water is pumped through this and that's the sensor there. And slowly but surely they can inspect a composite piece of an aircraft.

It's such a cumbersome process that the airlines don't do it unless they have reason to suspect there's a problem.

(voice-over): So serious defects in composites could go unnoticed.

SHUART: I don't think so. I think it's a matter of understanding what you're looking for and making sure that you understand that what you're looking for in composites is different than what you might look for in a metal.

O'BRIEN: The experts here say that does not mean these space age materials are inherently unsafe. But, they concede, the aviation industry may have to find new ways to look beneath the composite surface for trouble that may lie below.

(END VIDEOTAPE)

O'BRIEN: Live now at the structures and materials lab at NASA's Langley Research Center, let me give you a sense of scale and a sense of some of their handiwork here. This is a composite rudder that was built for the DC-10, the McDonnell Douglas DC-10, which NASA Langley got involved with. Just in putting this rudder on they saved 15 percent in weight. And if you're in the aviation industry, trimming weight is like a mantra. That's why these graphite composites are such an important thing.

Let me give you a sense of how this is made. You can see the braids. That is the carbon fiber and this is the portion that has been layered with epoxy. It's very stiff where it's been layered. It's also extremely light.

Now this is some of the equipment they used to conduct this investigation. They're being very tight-lipped about it. The National Transportation Safety Board is leading the way. But part of what they do here and part of what will go into all this investigation is a sense of close inspections, those ultrasound type inspections and in some cases they may actually try to break things like this.

This is one of the ways they test equipment and then test materials to see where the weak points are. A little bit later in the program we're going to do just that live. So stay tuned for that -- Paula.

ZAHN: All right, look forward to that Miles. Thanks.

The NTSB, as Miles mentioned, just announced there were some problems reported with parts of the rudder assembly before the American Airlines plane took off. But a mechanic reportedly corrected them.

For the very latest on that, let's turn to NTSB Chairman Marion Blakey, who joins us from Washington. Welcome back. Good to see you again.

MARION BLAKEY, CHAIRWOMAN, NTSB: Thank you, Paula. I'm glad to be here.

ZAHN: Thank you.

So let's talk a little bit about the maintenance records and what they show. Apparently a maintenance worker worked on what is called a yardamper (ph) and according to those reports, the computer said it was fixed. What exactly does that mean?

BLAKEY: Well, apparently the morning of the flight the yardamper control was found to be interactive. In other words, it needed to be reset. A mechanic came, set it again, tested it and as far as they determined, the yardamper was then working well.

Remember, this is the control for sort of the subtle movements, if you will, of the rudder that keep a plane stable in flight.

But it does pertain in the sense that we know that the rudder as well as the vertical stabilizer were the parts that separated before the flight crashed.

ZAHN: So does this suggest a computer failure that would have inaccurately shown that the yardamper was fixed when, in fact, it wasn't?

BLAKEY: We're looking to see if there was a problem with the electronic controls, with the computer control itself. We have to determine, of course, whether this was a mechanical problem or something more subtle. We don't know. And we don't know, of course, whether it contributed to the crash or not.

ZAHN: Right. We do know that that plane underwent several performance checks in the weeks leading up to the crash. Did they catch anything?

BLAKEY: The maintenance records we've been scrutinizing very carefully. To this point, it looks like the maintenance record of the plane was very normal, very average. The plane was well maintained. It was, it certainly had a lot of flight hours on it but by no means was it the oldest plane in the fleet and therefore I think at this point everything so far looks like a fairly normal history there. ZAHN: Now we know that there are a couple hundred other Air Buses with the same tail sections as American Flight 587 that are currently being used. They have been visually inspected, not with that same kind of ultrasound inspection that some are recommending.

BLAKEY: Yes.

ZAHN: Are you wholly comfortable with these planes being flown given the fact that they haven't been inspected by ultrasound?

BLAKEY: Well, you have to remember, they have a very safe track record and they have been very carefully inspected. They're also being very carefully watched.

At this point, though, what I think is the most constructive way to approach this is we're working with the scientists at NASA. We're looking at these very high technology approaches to testing. And when we determine that there is a reason to apply those more broadly to the fleet, you can bet we'll do it.

ZAHN: So you mean that...

BLAKEY: Or we will call for it.

ZAHN: ... it'll be visually inspected.

BLAKEY: We won't be doing it.

ZAHN: Yes. There will be a visual inspection until you think something's amiss and then you'd call for the ultrasound inspection?

BLAKEY: We would certainly recommend it if we feel that that's appropriate. Right now, though, we're looking at this as a proprietary approach with a number of other ways that we can also test composites.

ZAHN: Chairman Blakey, before we let you go this morning, do you have any doubt that this was an accident and not another terrorist attack?

BLAKEY: You know, Paula, we continue to look very, very carefully at all of the evidence, every piece of information that comes in with that question in mind because we know it's on the minds of the public. And it should be. These are tough times. We have not seen any evidence of criminal activity, any evidence of sabotage, any evidence that would point to a bad actor. This appears to be, everything points to an accident.

ZAHN: Well, we'd love to have you back as it becomes clearer as to what or what the yardamper might have contributed or maybe had no role in this at all.

BLAKEY: Thank you.

ZAHN: When you have more information will you come back and share that with us? BLAKEY: I'd be happy to.

ZAHN: All right, Chairman Blakey, have a great holiday and we hope it's a quiet one for your sake and all the rest of us.

BLAKEY: Thank you. I do, too.

ZAHN: All right, take care.

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