New Theory and Speculation On AA A300 Crash In New York
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Two words, bull-sh*t.
The rudder swung 11 degrees to the right for a half a second, 10.5 to the left for 0.3 seconds, between 11 and 10.5 to the right for 2 seconds, 10 left for a second, and 9.5 to the right before the data became unreliable (till the tail fell off).
The crew must have been tap-dancing on that rudder to make it move like that. It seems like the pilots did one thing and the rudder did it's own thing <img src="eek.gif" border="0"> .I could physically do that if I was hell-bent on it as I'm in pretty good shape, well coordinated and have strong-legs. But why the hell would I *WANT* to do that!? Who in their right mind would be flinging the rudder to the left, the right, the left, and the right like that? I think it's a malfunction. Didn't they find a bent-actuator rod in the wreckage?
My opinion, it's a defect in the composites that caused the tail to get overstressed like that and a mechanical problem, not pilot-error, that caused the rudder to behave erratically before failing. No tail should fail... even with full-rudder deflection. In fact rudder-harddovers have happened before. Remember those two 737 crashes? In either event the rudder went hard-over, and despite this, the tail stayed intact. They crashed, but the tail stayed on that plane until it hit the ground. I could understand the breakup happening if they were above maneuvering speed, but they were about 18 knots below it.
Composites have not been as tested and tried as have metals. Does this mean we give up on composites? No, it means we learn from our mistakes and re-design the composites until that rudder can take a full-deflection and not fly off the plane!
I started taking flying lessons when I was 15, which means I've been flying almost 21 years (almost 15 as an airline pilot (3 with Comair, almost 12 with Delta), I've flown aircraft ranging in size from a Cessna-152 all the way up to a 767-300ER (I'm now on the 757/767 -200's out of CVG) post 9/11), and *yes* there have been times where I've had to give it full-rudder (mostly with the props) to keep it flying straight, and no, the tail didn't come off. If it did, I'd be in a grave-yard, resting in pieces.
What Blakey is doing is very low. Blame the dead guys, they ain't gonna object <img src="mad.gif" border="0"> .
Anyone remember USAir 427? They claimed the F/O (the pilot flying) had a seizure, then they claimed he panicked and stepped on the wrong rudder peddle and for some stupid reason held it until they hit the ground "in a panic", and then they claimed this and that! It took 3 years before they finally got to the bottom of it.
You know, after awhile you begin to get a sixth-sense for detecting crap. Thank God for my BS repelling shoes though, when I'm about to step in a load of crap, it moves it out of the way so I don't get it on my shoes <img src="tongue.gif" border="0"> .
-Nikki
The rudder swung 11 degrees to the right for a half a second, 10.5 to the left for 0.3 seconds, between 11 and 10.5 to the right for 2 seconds, 10 left for a second, and 9.5 to the right before the data became unreliable (till the tail fell off).
The crew must have been tap-dancing on that rudder to make it move like that. It seems like the pilots did one thing and the rudder did it's own thing <img src="eek.gif" border="0"> .I could physically do that if I was hell-bent on it as I'm in pretty good shape, well coordinated and have strong-legs. But why the hell would I *WANT* to do that!? Who in their right mind would be flinging the rudder to the left, the right, the left, and the right like that? I think it's a malfunction. Didn't they find a bent-actuator rod in the wreckage?
My opinion, it's a defect in the composites that caused the tail to get overstressed like that and a mechanical problem, not pilot-error, that caused the rudder to behave erratically before failing. No tail should fail... even with full-rudder deflection. In fact rudder-harddovers have happened before. Remember those two 737 crashes? In either event the rudder went hard-over, and despite this, the tail stayed intact. They crashed, but the tail stayed on that plane until it hit the ground. I could understand the breakup happening if they were above maneuvering speed, but they were about 18 knots below it.
Composites have not been as tested and tried as have metals. Does this mean we give up on composites? No, it means we learn from our mistakes and re-design the composites until that rudder can take a full-deflection and not fly off the plane!
I started taking flying lessons when I was 15, which means I've been flying almost 21 years (almost 15 as an airline pilot (3 with Comair, almost 12 with Delta), I've flown aircraft ranging in size from a Cessna-152 all the way up to a 767-300ER (I'm now on the 757/767 -200's out of CVG) post 9/11), and *yes* there have been times where I've had to give it full-rudder (mostly with the props) to keep it flying straight, and no, the tail didn't come off. If it did, I'd be in a grave-yard, resting in pieces.
What Blakey is doing is very low. Blame the dead guys, they ain't gonna object <img src="mad.gif" border="0"> .
Anyone remember USAir 427? They claimed the F/O (the pilot flying) had a seizure, then they claimed he panicked and stepped on the wrong rudder peddle and for some stupid reason held it until they hit the ground "in a panic", and then they claimed this and that! It took 3 years before they finally got to the bottom of it.
You know, after awhile you begin to get a sixth-sense for detecting crap. Thank God for my BS repelling shoes though, when I'm about to step in a load of crap, it moves it out of the way so I don't get it on my shoes <img src="tongue.gif" border="0"> .
-Nikki
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I step into this discussion with much trepidation <img src="confused.gif" border="0"> so be gentle on me if I'm wrong, but...
I can remember getting a phenomina called "Fin-Stall" when I've mis-handled the rudder during aero's or, I think, E/O exercises in a twin turbo-prop. With me so far?
At the speed these guys were flying SURELY the fin would have stalled out before the side-loading exceeded the permissable or sensible structural limit and prevented the seperation.
At higher speeds Boeings (some) have rudder limiters to prevent excessive loading on the fin from over-exuberant application of rudder.
Any comments?
If Deadflyer's report about the oscillations is correct then look for component failure, 5 full cycles in less than 5 seconds is mishandling even I'm incapable off!!
I can remember getting a phenomina called "Fin-Stall" when I've mis-handled the rudder during aero's or, I think, E/O exercises in a twin turbo-prop. With me so far?
At the speed these guys were flying SURELY the fin would have stalled out before the side-loading exceeded the permissable or sensible structural limit and prevented the seperation.
At higher speeds Boeings (some) have rudder limiters to prevent excessive loading on the fin from over-exuberant application of rudder.
Any comments?
If Deadflyer's report about the oscillations is correct then look for component failure, 5 full cycles in less than 5 seconds is mishandling even I'm incapable off!!
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Regarding fin stall.. .Interesting thought, but V2 on that airplane when it's heavy would be around 155kts. Perhaps I'm missing your point here but if you lose an engine at max thrust and fly at V2 or V2+10 to clean up you are going to have very close to full rudder fed in until you can accelerate and power down. If the rudder doesn't "stall" then, why would it stall at 250knots?. .The investigation is ongoing but I will wager my 401K (such as it is) that those pilots had nothing to do with the rudder going crazy. The powers that be will try their best to blame the crew because of political expediancy and it will be up to us and our unions to keep the "bull**** filter" up.
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Can anyone, or has anyone, briefly described the A300 rudder load-limiter system? What are the degrees of travel above and below the crossover point? What is the crossover point (airspeed)?
In addition, how does the limit system limit travel? Are there mechanical stops or hydraulic restrictors? What are the signals and parameters that affect the system?
Thanks!
In addition, how does the limit system limit travel? Are there mechanical stops or hydraulic restrictors? What are the signals and parameters that affect the system?
Thanks!
See <a href="http:////http://www.pprune.org/ubb/NonCGI/ultimatebb.php?ubb=get_topic&f=1&t=017746" target="_blank">NTSB and Rudders</a>
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It looks like the answer to the crash will be pilot error, either from mis-applying AA procedures or because AA was teaching the wrong drill. Sures looks to me like that this is where it is going.
But, after reading these threads it still doesnt rest my concern.
Now, could any of you work on the model that a bomb caused the violent side to side sway on 587. Work on the model in terms of how much force is required and placed where on the AC to get the necessary side ways force to rip the rudder off, to explain the "tap dancing" on the pedals and the quandry you all seem to be wrestling with up above. Try to proof such a model not to solve a conspiracy theorey or to please the nuts, but rather to see if it is impossible to work with the bomb as a model. If it cannot explain the forces and movements that ripped AA 587 rudder/tail off, so be it - but it is starting to appear that the bomb model is not as whacky as a AA pilot suddenly breaking into a deadly Fred Astaire routine on the pedals. (Since we have discared the material and material fatigue as most here were convinced of)
I would start with Reid shoe bomb placed in the stern, being basically a shaped charge to the side acting as a thruster swinging the tail hard to one side.
See if it can be done.
I do not have the engineering ability or flight knowledge, obviously, top be effective here. But many here do.
You might want to start working on it, for otherwise 587 will likely go down as pilot error. Does that result satisfy you? A senior pilot for AA would be so incompetent?
Baiting I am, but I bet a "bomb model" will have less back flips in logic than the rather bizarre twists and turns folks are making trying to explain how pilot error could rip the rudder off what appears to be a functional and air worthy plane.
But, after reading these threads it still doesnt rest my concern.
Now, could any of you work on the model that a bomb caused the violent side to side sway on 587. Work on the model in terms of how much force is required and placed where on the AC to get the necessary side ways force to rip the rudder off, to explain the "tap dancing" on the pedals and the quandry you all seem to be wrestling with up above. Try to proof such a model not to solve a conspiracy theorey or to please the nuts, but rather to see if it is impossible to work with the bomb as a model. If it cannot explain the forces and movements that ripped AA 587 rudder/tail off, so be it - but it is starting to appear that the bomb model is not as whacky as a AA pilot suddenly breaking into a deadly Fred Astaire routine on the pedals. (Since we have discared the material and material fatigue as most here were convinced of)
I would start with Reid shoe bomb placed in the stern, being basically a shaped charge to the side acting as a thruster swinging the tail hard to one side.
See if it can be done.
I do not have the engineering ability or flight knowledge, obviously, top be effective here. But many here do.
You might want to start working on it, for otherwise 587 will likely go down as pilot error. Does that result satisfy you? A senior pilot for AA would be so incompetent?
Baiting I am, but I bet a "bomb model" will have less back flips in logic than the rather bizarre twists and turns folks are making trying to explain how pilot error could rip the rudder off what appears to be a functional and air worthy plane.
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Iom, and you should change your name to "pig to a slaughter" as it seems the professional pilot class is willing to accept the fact that a brethren inexplicable decided to do a tap dance on the pedals. Why? The logic here is bizarre and incredible contortions of very very talented people's models first accomodated geese, then wake, then material failure, and now the pilot just inexplicably paniced over the wake and started doing a tap dance on the pedals.
Any engineers wish to answer what sideways thrust in terms of whatever was required to rip the tail off of 587? How many G's? Semtex on the side of the cabin shaped to explode out produces how much thrust per ounce? Can a shoe bomb be large enough? Does this make sense?
It completely confuses me that after Reid someone with the skill set hasnt at least seen if enough force is in a shoe bomb to provide the sideways spin. I am amazed how completely gullible the professional airline set has been in first accepting the adminstrations dealing with Reid as the mere "shoe bomber", as if it weer a M80 he had on the craft. I doubt few of you would question that he had enough to bring the plane down. If he had, then would we not have another AC down as mysteriously done as 587?
But methinks you all will go back to geese before you try out this thought experiment/model first.
It is an incredibly bizarre pysche that refuses to consider the obvious first so as at least it is eliminated from obfiscating the discovery.
Any engineers wish to answer what sideways thrust in terms of whatever was required to rip the tail off of 587? How many G's? Semtex on the side of the cabin shaped to explode out produces how much thrust per ounce? Can a shoe bomb be large enough? Does this make sense?
It completely confuses me that after Reid someone with the skill set hasnt at least seen if enough force is in a shoe bomb to provide the sideways spin. I am amazed how completely gullible the professional airline set has been in first accepting the adminstrations dealing with Reid as the mere "shoe bomber", as if it weer a M80 he had on the craft. I doubt few of you would question that he had enough to bring the plane down. If he had, then would we not have another AC down as mysteriously done as 587?
But methinks you all will go back to geese before you try out this thought experiment/model first.
It is an incredibly bizarre pysche that refuses to consider the obvious first so as at least it is eliminated from obfiscating the discovery.
Iconoclast
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Here is something to consider providing it hasn’t already been covered. Perchance there was undetected damage within the fin that caused the separation or worked in concert with the excessive rudder movement.
Here is a case in point. During the production of the 767, which also has a composite fin an operator of an overhead gantry crane was moving a production jig. He noted that the jig made a very small contact with the fin with that contact being concentrated in a very small area.
He notified the production manager and they sent a technician up to check the contact spot. He returned to ground level and told the production manager that the damage could be worked out with wet and dry sandpaper. They were ready to let it pass when a production technician who specialized in composite repair walked up and indicated that he would go up inside the fin and check it out. What he found were several skin stiffeners that were debonded indicating that the skin oil canned inward about twelve inches and popped out again. They had to remove the fin in an out of position operation and replace it with a newly minted fin assembly. Had the technician not gone up inside the fin then perchance there would have been a 767 that would have lost its’ rudder and fin.
Composite material is very difficult to verify that repairs have been effected properly because in many cases the repair material is opaque to X-ray inspection.
Here is a case in point. During the production of the 767, which also has a composite fin an operator of an overhead gantry crane was moving a production jig. He noted that the jig made a very small contact with the fin with that contact being concentrated in a very small area.
He notified the production manager and they sent a technician up to check the contact spot. He returned to ground level and told the production manager that the damage could be worked out with wet and dry sandpaper. They were ready to let it pass when a production technician who specialized in composite repair walked up and indicated that he would go up inside the fin and check it out. What he found were several skin stiffeners that were debonded indicating that the skin oil canned inward about twelve inches and popped out again. They had to remove the fin in an out of position operation and replace it with a newly minted fin assembly. Had the technician not gone up inside the fin then perchance there would have been a 767 that would have lost its’ rudder and fin.
Composite material is very difficult to verify that repairs have been effected properly because in many cases the repair material is opaque to X-ray inspection.
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Interesting comments from the latest issue of Aviation Week & Space Technology (18 February 2002, page 44..."As one pilot quipped, "Don't tell me not to kick the rudder around until the facts are in".. .Clearly, these guys have NOT been in civil jet TRANSPORT aircraft for very long...otherwise, they would know better.. .I wonder if these types are ex-USAF and expect the aircraft they now fly to respond like a fighter?. .If so, God help the flying public...AKA, the passenger.. .Any pilot in civil jet transport aircraft who does a tap-dance on the rudder (especially at higher speeds) needs to be REPLACED without delay.. .The lessons from the past are there for all to see. Wonder where the training departments stand? Have ALL the old guys retired, or what?
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411A - this is where it is going to go, gross pilot error. Doesnt make sense considering the pilots for 587 were not raw but experienced and that the speed of the rudder movements was, as recounted above, impossible to have been implimented from the pedals. Now what else could whip a rudder around liek that? Geese? Lightening (nope blue sky)? 747 wake? The force has to be monstrous, sudden, and invite a reflex snap back.
I just find it very hard that for all these decades professional pilots have been flying the Airbus using skills that are grossly negligent. First it is not the habit of the industry and second more Airbus' would have fallen from the sky by now - consider all the rudder use during bad conditions to date.
So, if it isnt the 747 wake, if the weather was pristine, if it wasnt large birds, if it wasnt a material failure - why dont we start to be brave enough to consider what else could produce such force rather than shoot down the old rabbit hole "pilot error".
I just find it very hard that for all these decades professional pilots have been flying the Airbus using skills that are grossly negligent. First it is not the habit of the industry and second more Airbus' would have fallen from the sky by now - consider all the rudder use during bad conditions to date.
So, if it isnt the 747 wake, if the weather was pristine, if it wasnt large birds, if it wasnt a material failure - why dont we start to be brave enough to consider what else could produce such force rather than shoot down the old rabbit hole "pilot error".
