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AMR 587 Airbus Crash (merged)

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AMR 587 Airbus Crash (merged)

Old 20th Nov 2004, 05:39
  #421 (permalink)  
swh

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Would one of you geniuses like to tell me how vortices that trail off an airplane and head straight for the ground engaged this aircraft?
How many contrails have you seen 747focal that "head straight for the ground " ?

Would you care to rephrase your question, and then maybe someone could give you and answer.

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Old 20th Nov 2004, 15:45
  #422 (permalink)  
 
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>No pilot would kick the rudder back and forth as recorded! No >pilot could induce an 0.8 G force on the rudder and shear off >both engines from their support structures, through pilot control >inputs alone!

Do you mean intentionally or accidentally. It sounds like these rudders are awfully sensitive and perhaps more input happened than was intended. How do you know that no pilot would do this . I bet most professional pilots on this board have come across someone in their career who who either wanted to or did do something that was ridiculous.


<However, a 200 mph rotating vortices striking the 27' tall <vertical stabilizer, BROADSIDE can! (NASA says that the rotating <forces in an aircraft wake vortex can reach 300'/sec., a virtual <horizontal tornado!)

I don't doubt what NASA has said but is this in the immediate vicinity of the airplane or is it still this strong after 90 seconds.
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Old 20th Nov 2004, 19:15
  #423 (permalink)  
 
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Ignition Overide,

Your comments,

"And if those rudder incidents were NOT caused by their pilots, caused by strong, opposite rudder "kicks" as alleged onboard AA flight 587, THEN, what is the common denominator here?"

When your flying a virtual "Weather Vane", (A300-600), you must expect some rough rides in weather and aircraft wake induced wind shear forces. Especialy if your flyinmg in the center of a virtual horizontal tornado! (AA 587 in the B 747's left wing tip vortex)
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Old 21st Nov 2004, 01:03
  #424 (permalink)  
 
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Arrow

Yes, wsherif1, by excluding the pilots as the cause of several incidents (because the AA 587 pilot can not defend himself, and those at the other airlines are not accused of violently pushing their rudder pedals), my point therefore was to solicit comments about the alleged over-sensitive characteristics of the A-300's rudder system.
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Old 21st Nov 2004, 05:21
  #425 (permalink)  
 
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Ignition Overide,

Your comment,

"my point therefore was to solicit comments about the alleged over-sensitive characteristics of the A-300's rudder system."

Whether the rudder was over-sensitive or not has little to do with the accident! The large, total flat plate surface area of the 27' tall, vertical stabilizer and the rudder combined, when struck broadside by the 0.8 G force of the rotating vortices of the B 747's wake, induced an instantaneous left YAW maneuver. The resultant, tremendous inertia force sheared off both of the massive engines from their support structure, and tossed the right engine to the left of the aircraft's track and the left engine to the right of the track, as indicated in the engine ground location graphic! This same left YAW motion induced the abrupt, left "Dutch Roll" into the ground!
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Old 22nd Nov 2004, 01:11
  #426 (permalink)  
 
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wsherif1,
While I find your thought refreshing and theoreticly plausable, trying to convince us all that this "tornado" effect is what brought down the aircraft is irresponsible - as this is your own theory, and not entirley based on fact. Yes I know that you are a sort of conspiricy theroist, but you are not an investigator. Please stop trying to force this on us. You are entitled to your own opinion, but I prefer to deal with facts.

Your repeated statements are not dealing with facts - but theories. Case in point....
The large, total flat plate surface area of the 27' tall, vertical stabilizer and the rudder combined, when struck broadside by the 0.8 G force of the rotating vortices of the B 747's wake, induced an instantaneous left YAW maneuver. The resultant, tremendous inertia force sheared off both of the massive engines from their support structure, and tossed the right engine to the left of the aircraft's track and the left engine to the right of the track, as indicated in the engine ground location graphic! This same left YAW motion induced the abrupt, left "Dutch Roll" into the ground!
I suppose you've run the computer simulations and can tell me exactly how much force was applied? And how much force is required or applied in order to rip the engines off in this type of manouver? And how you can predict what the engines will do after they have come off the aircraft? What about aerodynamic forces on an engineless and V/stab less A-310 - how does it react? I'm also sure it's wacked out C of G plays a big part. What was it's c of g and what were those consiquences?

There are too many questions that need to be answered before you or anyone could say that this IS what happened.
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Old 22nd Nov 2004, 06:11
  #427 (permalink)  
 
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74tweaker,

Your comment,

"And how much force is required or applied in order to rip the engines off in this type of manouver? And how you can predict what the engines will do after they have come off the aircraft?"

Obviously more than enough force was applied to tear the engines from their support structure. This is a fact! If you can't figure out in what direction the engines would be tossed, from a left YAW motion of 10 degrees/second, as reported, you have a problem. The physical location of the engines is a matter of record, and is illustrated by the engine location graphic. This is a fact!

NASA states that the rotational forces in an aircrft wake vortex can attain 300'/sec. I trust you have seen many pictures of wake vortices and are aware of their structure, and will admit that they are quite similiar to the structure of a tornado, except that they lie in a horizontal plane.

If the total left surface area of the vertical stabilizer and rudder are struck, broadside by a force of 0.8 G the aircraft is going to move into a left YAW (10 degrees/second, as reported, a fact!

A left instantaneous YAW will induce an immediate left "Dutch Roll", another fact!

.

Last edited by wsherif1; 22nd Nov 2004 at 06:33.
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Old 22nd Nov 2004, 08:00
  #428 (permalink)  
 
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People keep refering to the over-sensitive rudder, perhaps it is more sensetive than other aircraft, however the pilots were trained to fly this aircraft and were therefore used to the "feel" of this aircraft.

In addition, the NTSB report states that 140lbs of force were applied to the rudder pedals which would have given full deflection no matter whether the aircraft was an A300 or B767.
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Old 22nd Nov 2004, 09:27
  #429 (permalink)  
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True

And whan we talk facts, can anybody give data,

how close was that 747, in what position, direction etc
 
Old 24th Nov 2004, 00:43
  #430 (permalink)  
 
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<NASA states that the rotational forces in an aircrft wake vortex can attain 300'/sec.

Someone conveniently didn't respond to my last post on this thread.
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Old 25th Nov 2004, 16:53
  #431 (permalink)  
 
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Green Guard,

Your question,

"how close was that 747, in what position, direction etc"

The NTSB claims that AA 587 was at the legal four miles in trail.

Look up USRead's web page and there are graphics of the actual positions of both aircraft.
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Old 25th Nov 2004, 18:54
  #432 (permalink)  
 
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punkalouver,

Your comment, below

Text, (NASA says that the rotating forces in an aircraft wake vortex can reach 300'/sec., a virtual <horizontal tornado!)

Your quote, "I don't doubt what NASA has said but is this in the immediate vicinity of the airplane or is it still this strong after 90 seconds."

I experienced severe wake turbulence 45 miles, (5 minutes time wise), in trail of another B707. (distance reported by ATC) This happened in a completely stable air mass. The ride was smooth as glass, until the point I penetrated his wake, 500' below our assigned cruising altitude of 37,000'.

Last edited by wsherif1; 26th Nov 2004 at 19:17.
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Old 25th Nov 2004, 23:56
  #433 (permalink)  
 
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How can you be sure it was wake turbulence and not something that was in the atmosphere to begin with. We have all hit unexplained sudden bumps in smooth air. Don't you think five minutes in trail is a bit long to be getting severe wake turbulence from an aircraft not even in a high lift configuration. How many airplanes have followed 707's on final approach less than five minutes in trail without experiencing severe wake turbulence

Last edited by punkalouver; 27th Jan 2006 at 03:51.
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Old 26th Nov 2004, 00:02
  #434 (permalink)  
 
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I really do think that wsherif1 has lost the plot, punkalouver, but hey, at least he is entertaining with the ...horizontal tornados'.
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Old 26th Nov 2004, 00:31
  #435 (permalink)  
 
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wsherif1: In many of your posts you quote NASA as saying that the wake vortex can reach 300ft/sec.

Can you post a link to the page which will show:
1. which aircraft this refers to ?
2. the configuration and weight of that aircraft ?
3. at what range behind the aircraft the reading was taken ?
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Old 26th Nov 2004, 01:42
  #436 (permalink)  
 
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Dumb pilot asking. Did the pilot use Rudder to correct his 'course'. I have 12,000 hrs, of which are about 4,000 in Command on various types
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Old 26th Nov 2004, 05:13
  #437 (permalink)  
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No,
The pilot attempted to use coordinated rudder, something that is difficult (actually impossible) to do in the A300 because of a design deficiency.

The A300 had VERY poor roll response in certain regimes (when they went from the B4 to the 600r model that AA has they deleted the ouboard ailerons and went to just about spoilers only for roll, in the quest for aerodynamic clean up of the aircraft)

The airplane crossed one wake rolling the aircaft one way, then another one rolling the aircraft in the other direction, the second wake caught the copilot by suprise and he attempted coordinated rudder.

It just so happens that in the A300 though, breakout force is about the same as the force required to reach the stop. so the rudder pedals at 250 knots are really full left and right toggle switches. Something you would never know because to need rudder at 250 knots is a once in a career sort of thing.

Cheers
WIno
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Old 26th Nov 2004, 06:00
  #438 (permalink)  
 
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henry crun:

Your comment,

"In many of your posts you quote NASA as saying that the wake vortex can reach 300ft/sec."

Can you post a link to the page which will show:
1. which aircraft this refers to ?
2. the configuration and weight of that aircraft ?
3. at what range behind the aircraft the reading was taken ?

I would refer you to NASA , they issued the statement.

Last edited by wsherif1; 26th Nov 2004 at 18:44.
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Old 26th Nov 2004, 19:01
  #439 (permalink)  
 
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411A,

Your comment,

"I really do think that wsherif1 has lost the plot, punkalouver, but hey, at least he is entertaining with the ...horizontal tornados'"

What is your name for the 0.8 G rotating force recorded by the FDR?
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Old 27th Nov 2004, 05:20
  #440 (permalink)  
swh

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wsherif1,

You prob already know this, 0.8G is not a force its and acceleration.

As previously posted, the FDR recorded acceleration corresponding with a series of rudder movements, to the limit of those rudder movements.

There is no suggestion by any party to say the aircraft experienced 0.8g acceleration in yaw without any movement of the rudder.

The wake vortex figure you mention (300 ft/sec) would not be the figure 4-5 nm behind the lead 747, due to mixing with the atmosphere the vortex would be significantly weaker.

The wake vortex from the preceeding 747 was reduced as the aircraft gained distance from the departure point, induced drag (hence vortex) reduced with an increase in speed, stowing of high lift devices, and burn off of fuel.

Many aircraft have experienced this level or greater vortex passing esp in the north west pacific where the sub tropical jet stream is the strongest when flying through any of the jet streams.

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