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American Morning
Research Center Tests Aviation Material
Aired December 19, 2001 - 09:50 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: Some important aviation news to talk about this morning. The National Transportation Safety Board is reporting that right before American Airlines Flight 587 took off and then crashed, two components that help pilots control the rudder of the airplane didn't work in a preflight check, but a mechanic reportedly fixed the problem. The rudder was part of a tail section which, apparently, broke off just before the plane plunged into a New York neighborhood.
The wreckage is now being analyzed by a team of experts at NASA's Langley Research Center, in Virginia. Right now, they are focussing in on some relatively new composite aircraft materials.
And that's exactly where we find our man Miles O'Brien, who understands this better than just about anybody.
Good morning, Miles.
MILES O'BRIEN, CNN CORRESPONDENT: Good morning, Paula. I guess you could literally say this is very cool stuff here. This is liquid nitrogen, minus-350 degrees. Phil Robertson (ph) is controlling the pressure there. Some of the tests here have involved extreme temperatures, both high and low. Obviously, the liquid nitrogen is used for some of the lower temperature stuff. In just a second, Phil is going to help us out on show us how they conduct some of the testing on composites here.
This particular device is designed to break things. If you ever wonder where the kids go who spend all their childhood tearing apart their toys, seeing how they work, well, they work here, at Langley Research Center, in Hampton, Virginia, NASA's center which focuses primarily, among other things, on composite materials used in aircraft.
The director of structures and materials here is Mark Shuart. He joins us live this morning.
Mark, good to have you with us.
MARK SHUART, NASA LANGLEY RESEARCH CENTER: Nice to see you, Miles.
O'BRIEN: As Phil puts this into -- first of all, what do you call this device that we're looking at now? SHUART: This is a tension test machine. We can also do a little bit of fatigue testing in it. But we use it for smaller specimens, to get the sort of properties we need to design structures.
O'BRIEN: As we look at this, you get a sense of the honeycomb structure inside and the woven exterior of it. These graphite materials, very strong and very light. How much do we know about them?
SHUART: We know an awful lot about them. We have been working in composites here at the Langley Research Center for about 30 years. We have worked with a lot of folks across the country, including airplane manufacturers, actually to make these things work very effectively in service.
O'BRIEN: Before we get this live test going, let's tale a look at some of the tests which have occurred in recent history here in Langley. This is a place with they deliberately break things, quite frequently. What we are looking at here is a test on a big piece of a wing, some crashes of some aircraft here. What is learned by doing this?
SHUART: Certainly, we're after the true limits of performance. That's why we test things all the way it failure. In some of those tests that you saw, the crash tests, we are trying to design these smaller vehicles to be much safer.
The wing test that you see is a test where we really are trying to understand exactly how these large structures behave under flight loads.
O'BRIEN: Let's take a look really quickly -- I'm sorry to duck in front of you that way -- and give people a sense of what these composites are all about. We have heard an awful lot about them since the crash of American Airlines 587. It begins with a spool of this thread, and that is made of carbon fiber. That, in and of itself, is not very strong. I guess you can pull on it.
SHUART: It's very strong in tension, but you can't push too much.
O'BRIEN: You can't push too much. What makes it a stiff item is that it sandwiched, woven together, and then sandwiched with an epoxy. This is very light and very stiff. How is this developed, and how frequently is it used now?
SHUART: It is used a lot on the airlines for very small secondary structures.
O'BRIEN: Phil Robinson (ph) here is going to start this test. And to give you a sense of how much they know about composites here, yesterday we did a practice run: It took 1.07 minutes for this to break under about 2,500 lbs. of pressure. So if everything goes well, I think we can predict that will probably break right about at the one-minute point, which tells you that these are very predictable materials. How strong are they, though? Are they stronger than aluminum?
SHUART: It depends on the design, obviously. When one looks at the strength and then looks at how light they are, that sort of stiffness strength-to-weight ratio is much higher than aluminums. Stiffness-to-weight ratio, same thing. But we designed these materials to have certain strengths and stiffness that they need.
O'BRIEN: How far along are we, Phil, as we wait for this to break here, live on CNN.
UNIDENTIFIED MALE: We're about there.
O'BRIEN: We're just about there. We're going to watch and see.
There you have it. As if on schedule, it took 1.94 minutes.
This is exactly the kind of thing that is underway here in the lab right now. This American Airlines tail fin is here. Some of these types of testing will be used to determine exactly what happened there. This is the place to do it -- Paula.
ZAHN: Fascinating. And what a view we all have this morning. Thanks so much, Miles.
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