Flutter in Plane's Tail Eyed as Cause of Crash

New York Daily News ^ | 11/15/01 | RUSS BUETTNER

[Movemout]

Flutter is a potentially destructive oscillation that can occur at any speed. It is likely to be more destructive at high speeds but if a composite structure is damaged for any reason then benign oscillations, as defined by design engineers, could become structurally endangering oscillations in real life operations.

[Wm Bach]

There is such thing as wake turbulance. You can takeoff right on the tail of another plane in a crosswind, but where there is no wind, or the wind corresponds directly with the flight path, you will run into the previous plane's wake. If there is any prevailing wind, there is little chance that you are going to encounter the previous plane's wake however. And if you DO run into the previous plane's wake, your own plane is going to be buffeted out of the wake the second it becomes strong enough to change your flight attitude. The pilot would have to fight to keep his plane in the wake.

The CNN video demonstration by the T6 Texan pilots was very bad propoganda on their part, if the object was to build a case for miles-apart wake shake, as anyone could see that the chase plane was mere yards behind in the wake of the plane in front, and the rear pilot was struggling mightily to get his plane back into the wake every time he was tossed out of it.

On a still day, you do not want to follow a C5A Galaxy up until it clears the horizon. It would be useful to see what the prevailing winds were on the day of the crash and compare them to the two plane's flight paths. It would be a minor miracle if this crash were the result of wake turbulance, and an indictment against Airbus for building such a flimsy machine. Why are they not grounded?

If they are now suggesting that the Airbus suffers from "flutter", then why are they not grounded?

The NTSB has the soul of Clinton, and should be trusted just as much.

[DB]

This plane is controlled by computer. A sensor failure in a critical feedback loop could cause oscillations that could destroy the plane at any flying speed.

Just one of many possible theories.

[DB]

I'm not saying that was the cause. I am just saying that it sounds like a viable theory thus far.

And thank you for the informative link.

[spokeshave]

Composite structures are well understood but not as well understood as metal structures

Remember some years ago the failure of marine helicopter blades due to de-lamination....eventually traced to a worker using nail polish....ALSO one of the top plane home builders was killed when his plane de-laminated...he used the wrong solvent to attach the cloth on the control surfaces which came off in flight.

[Snowy]

I think it was terrorism. I think most people probably think it was terrorism. However, I can see why the government would want us to believe otherwise. If they were to come out and say, "it was an act of terrorism", then our economy, the airline industry, etc would be worse off than they are now. We were told the airlines are safe, but this would prove otherwise. Our government probably wants to sweep this under the rug and quietly increase security even more. Is this the right thing to do? I don't know - I can see both sides of this issue.

~Snowy

P.S. My husband flew last night on flight 452 (4+5+2=11) and was delayed because the altimeter was broken. I was a little nervous, but life must go on.

[mlocher]

...someone leaving the bolts loose on the tail...

the report i saw said that the bolts were in-tact and tight. the material that broken in two is apparently not a metal or alloy (fiberglass?) it is beginning to sound like an accident due to material failure to this naive mind, but i still have suspicions...

[Ben Hecks]

Is there a prize?

To: jlogajan

**The whole turbulance issue is bogus unless there is a pre existing mechanical condition.**

Here's another wacko theory: Is it possible that the control system failed (while trying to compensate for wake turbulence) which allowed uncontrolled movement by the rudder? If uncontrolled, a "flapping" rudder could exert substantial stress on the VS. Obviously, this scenario would also have to end with the rudder locked in a 10 degree left positon. 60 posted on 11/14/01 1:42 PM Pacific by Ben Hecks

[NY.SS-Bar9]

I know what flutter, resonance and harmonics are.

It just seems to me that everyone is trying awfully hard to find an explanation leading anywhere but terrorism with only minimal investigation. We are being subjected to the "theory du jour" by "experts" and politicians with NO knowledge of aviation or airframe design.

[Dog Gone]

Hear this, Bullsh!t. Again, this is Bullsh!t. Like I just wrote to Joe Farah, over at WND, 9-11..., what about 11-12?This is just like Flight 800 in that the government doesn't want to report the truth because if they do, the masses would get hysterical.

Calm down, okay? Read the story again. This isn't something that the government has even suggested. This is speculation being reported as a possibility by the press. Nothing more.

It seems that every theory spoken by anyone is automatically being attributed to the Department of Official Cover-ups. So what if Pataki was wrong? He's not part of the investigation.

Let the people do their work.

[dawn53]

It just seems to me that everyone is trying awfully hard to find an explanation leading anywhere but terrorism

Seems like that to me too. Seems they could be coming up with just as many bizarre explanations of how the terrorists managed to sabotage a plane.

Six of one, half dozen of the other.

But that bit about flutter being the cause,(when it's never happened before in a commercial crash, then happening on a flight out of JFK, crashing into New York, on an American Airlines plane, at the same time in the morning as other attacks when we've just had terrorist activity in our nation and threats to the airline industry), has about the same odds as the proverbial monkeys running across the typewriter and producing Webster's dictionary.

[6ppc]

I deal with atrial flutter, but have never heard of a tail flutter.

Now come on doc! Surely you've heard of flatulence!

[Denver Ditdat]

I deal with atrial flutter, but have never heard of a tail flutter.

A link to some videos illustrating flutter as applied to airframes:

Smithsonian Air & Space Magazine - Flutter video clips

You'll need the Quicktime plugin to view the videos.

[KQQL]

Unless a small explosive was placed in the tail section, this crash sounds like an accident.

[mlocher]

agreed.