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-   -   He stepped on the Rudder and redefined Va (https://www.pprune.org/tech-log/524238-he-stepped-rudder-redefined-va.html)

DozyWannabe 4th October 2013 20:55

IIRC, it came to light many years later that if certain electrical systems were damaged and the ground crew shut the power down then the CVR would automatically erase the tape.

flarepilot 4th October 2013 21:02

how off course are we now?

Famous Hoot Gibson maneuver...well boys the plane went through hell and they all came out alive. Good for the plane

Anyone remember the 60 minute Hoot Gibson interview? I do..he said straight to the camera..."every CFI out there thinks I did it, well I didn't...it was the rudder".

Has anyone posted the dissenting opinion of one of the NTSB members on the airbus thing?

Do consider one thing ...on the preceding page one of the posters says the FO did the correct thing on the first wake encounter...and did something different during the second...why would he?

Lots of graphs, reports and other things...but very little on the human side.

If you do something right the first time, why change? Did he panic? Did he have itchy feet?

Interviews with other pilots? Sorry, I've seen too many pilots say different things because it helps their own "six".

DozyWannabe 4th October 2013 21:12


Originally Posted by flarepilot (Post 8082378)
Has anyone posted the dissenting opinion of one of the NTSB members on the airbus thing?

I haven't heard of such a thing existing - can you find it?

HazelNuts39 4th October 2013 21:21


Originally Posted by flarepilot
the FO did the correct thing on the first wake encounter...and did something different during the second...why would he?

That question has been asked so many times on this thread that I'm wondering if anyone has read the NTSB's report. It discusses that very question in some detail and provides an explanation that satisfies me.

DozyWannabe 4th October 2013 21:31

For the sake of argument


Originally Posted by NTSB
The Safety Board considered why the first officer responded differently to the second wake turbulence encounter than he did to the first encounter. One possibility is the difference in the bank angle at the beginning of the two encounters. For the first encounter, the airplane was approximately wings level. Before the second encounter, the airplane was already in a 23º left bank, and, according to the Board’s simulations, the rolling moment generated by the second wake would have acted to roll the airplane (in the absence of countering control inputs) about 10º farther to the left and would have resulted in no significant yaw. However, if the first officer sensed a roll acceleration to the left while already in a left bank, he may have been prompted to react with a more aggressive control response.

The Safety Board emphasizes that the second wake encounter did not place flight 587 in an upset condition, and the airplane’s response to the wake did not indicate that an upset was imminent.197 Therefore, the Safety Board concludes that the first officer’s initial control wheel input in response to the second wake turbulence encounter was too aggressive, and his initial rudder pedal input response was unnecessary to control the airplane.


misd-agin 4th October 2013 22:09


That question has been asked so many times on this thread that I'm wondering if anyone has read the NTSB's report. It discusses that very question in some detail and provides an explanation that satisfies me.
Why read the report? It's much easier to accuse the NTSB of incompetence if you don't read the report OR understand the subject matter. :ugh:

HazelNuts39 4th October 2013 22:22

Dozy,

you omit the link to training exercises presented as a wake encounter, where the simulator was manipulated so that it did not respond to pilot inputs while the simulated airplane banked to 90 degrees.

DozyWannabe 4th October 2013 22:52

I didn't omit them as an act of commission - feel free to add them!

HazelNuts39 4th October 2013 23:01

Dozy,

rather than picking pieces out of the NTSB's reasoning, I'd prefer that thread participants read it for themselves.

DozyWannabe 4th October 2013 23:07


Originally Posted by HazelNuts39 (Post 8082527)
rather than picking pieces out of the NTSB's reasoning, I'd prefer that thread participants read it for themselves.

Agreed, but for those that can't be bothered, surely it's worth laying the basics out?

For those that want to read the report in full:
http://www.ntsb.gov/doclib/reports/2004/AAR0404.pdf

AirRabbit 4th October 2013 23:23


The Safety Board considered why the first officer responded differently to the second wake turbulence encounter than he did to the first encounter. One possibility is the difference in the bank angle at the beginning of the two encounters. For the first encounter, the airplane was approximately wings level. Before the second encounter, the airplane was already in a 23º left bank, and, according to the Board’s simulations, the rolling moment generated by the second wake would have acted to roll the airplane (in the absence of countering control inputs) about 10º farther to the left and would have resulted in no significant yaw. However, if the first officer sensed a roll acceleration to the left while already in a left bank, he may have been prompted to react with a more aggressive control response.

The Safety Board emphasizes that the second wake encounter did not place flight 587 in an upset condition, and the airplane’s response to the wake did not indicate that an upset was imminent.197 Therefore, the Safety Board concludes that the first officer’s initial control wheel input in response to the second wake turbulence encounter was too aggressive, and his initial rudder pedal input response was unnecessary to control the airplane.
From what I recall and, I think, is again verified by reviewing the NTSB-sponsored creation of the animation (and a big thanks to SMOC for finding and posting it) is that the 23° left bank that existed at the initiation of the 2nd wake encounter seems (to me at least) to remain essentially constant until the very rapid right control wheel and right rudder applications. I fully recognize that this is simply an animation of the FDR traces – and that the FDR information was (as I recall) produced after being “filtered” from the digital recording to be able to print it as an analog trace – and I would feel a lot more comfortable with a “discussion” of what could have happened to generate the observed control application, rather than have someone simply say that “the F/O sensed a roll acceleration to the left.”

Of course, I certainly entertain the logic of a momentary on-set acceleration being immediately noticed PRIOR to the airplane actually beginning to move (and thereby NOT recorded on the FDR) and have that on-set acceleration recognition prompt the pilot to apply substantial right control wheel deflection simultaneously with substantial right rudder input – BEFORE that acceleration actually produced an FDR-recorded rolling movement. In fact, I think that such razor-thin timing is very likely what actually happened … but I also think that would result from one of only two sets of circumstances:

First – this pilot was always reacting almost before anyone else recognized the need for any reaction – and in my experience that almost never occurs; and

Second – the F/O was bordering on or had reached a panicked mental state.

Unfortunately, THAT I have seen … and believe me, if you’ve ever seen it, you will always remember it! In fact, I think it is entirely possible that the Captain had either noticed or suspicioned something being inconsistent with what he had previously seen from that F/O and that was why he asked “Are you all right?” pretty much AS the F/O applied those extreme control inputs and said “Let’s go for power please.” I think it’s also important to note that the F/O comment on power was annotated as being spoken in “a strained voice” – also a reaction to panic.

Apparently, the F/O continued to apply these substantial control inputs – very likely after the first such input, were made thinking they were necessary to counter what the airplane was doing … and the airplane was merely doing what it was commanded to do by the F/O control inputs.

Again, I take no particular joy in making these comments – but I think it’s a logical way to make all the pieces of the facts make some kind of sense.

OK – I’m ready for the critiques.

bubbers44 4th October 2013 23:41

Owain, thanks for the pedal vs rudder deflection chart. I have never seen it. I am sure there is no reverse input from the rudders to the pedals so if the graph is correct the inputs were made from the cockpit. I just don't understand why. I don't feel AA pilots can not make mistakes because of the numerous ones in our history. I just feel we need to defend our pilots when there is a question about what input they had in a crash. I feel the same way about other airlines having a crash and blaming the crew. I always try to defend my crew until it is obvious they screwed up. I hope we all do.

Teldorserious 4th October 2013 23:50

NTSB Press Release
National Transportation Safety Board
Office of Public Affairs
________________________________________
NTSB SAYS PILOT'S EXCESSIVE RUDDER PEDAL INPUTS LED TO CRASH OF AMERICAN FLIGHT 587; AIRBUS RUDDER SYSTEM DESIGN & ELEMENTS OF AIRLINE'S PILOT TRAINING PROGRAM CONTRIBUTED

OCTOBER 26, 2004

Washington, D.C. - American Airlines flight 587 crashed into a Queens neighborhood because the plane's vertical stabilizer separated in flight as a result of aerodynamic loads that were created by the first officer's unnecessary and excessive rudder pedal inputs after the aircraft encountered wake turbulence, according to a final report adopted by the National Transportation Safety Board today. The Board said that contributing to the crash were characteristics of the airplane's rudder system design and elements of the airline's pilot training program.

At about 9:16 a.m. on November 12, 2001, flight 587, an Airbus A300-605R (N14053), crashed in Belle Harbor, New York shortly after taking off from John F. Kennedy International Airport on a flight to Santo Domingo. All 260 people aboard the plane died, as did five persons on the ground. This is the second deadliest aviation accident in American history.

The aircraft's vertical stabilizer and rudder were found in Jamaica Bay, about a mile from the main wreckage site. The engines, which also separated from the aircraft seconds before ground impact, were found several blocks from the wreckage site. The Safety Board found that the first officer, who was the flying pilot, inappropriately manipulated the rudder back and forth several times after the airplane encountered the wake vortex of a preceding Boeing 747 for the second time. due to The aerodynamic loads placed on the vertical stabilizer he sideslip that resulted from the rudder movements were beyond the ultimate design strength of the vertical stabilizer. (Simply stated, sideslip is a measure of the "sideways" motion of the airplane through the air.)

The Board found that the composite material used in constructing the vertical stabilizer was not a factor in the accident because the tail failed well beyond its certificated and design limits.

The Safety Board said that, although other pilots provided generally positive comments about the first officer's abilities, two pilots noted incidents that showed that he had a tendency to overreact to wake turbulence encounters. His use of the rudder was not an appropriate response to the turbulence, which in itself provided no danger to the stability of the aircraft, the Board found.

The Board said that American Airlines' Advanced Aircraft Maneuvering Program contributed to the accident by providing an unrealistic and exaggerated view of the effects of wake turbulence on heavy transport-category aircraft. In addition, the Board found that because of its high sensitivity, the A300-600 rudder control system is susceptible to potentially hazardous rudder pedal inputs at higher speeds. In particular, the Board concluded that, before the crash of flight 587, pilots were not being adequately trained on what effect rudder pedal inputs have on the A300- 600 at high airspeeds, and how the airplane's rudder travel limiter system operates.

The Safety Board's airplane performance study showed that the high loads that eventually overstressed the vertical stabilizer were solely the result of the pilot's rudder pedal inputs and were not associated with the wake turbulence. In fact, had the first officer stopped making inputs at any time before the vertical stabilizer failed, the natural stability of the aircraft would have returned the sideslip angle to near 0 degrees, and the accident would not have happened. (The Board estimated that the sideslip angle at the time the vertical stabilizer separated was between 10 and 12.5 degrees.)

The NTSB issued eight recommendations in today's report. Among the seven sent to the Federal Aviation Administration were those calling for adopting certification standards for rudder pedal sensitivity, modifying the A300- 600 and A310 rudder control systems to increase protection from potentially hazardous rudder pedal inputs at high speeds (a similar recommendation was issued to the French equivalent of the FAA, the DGAC), and publishing guidance for airline pilot training programs to avoid the kind of negative training found in American Airlines' upset recovery training.

Because this crash occurred two months after the September 11 terrorist attacks, there was initial concern that it might have been the result of an intentional criminal act. The Board found no such evidence, nor did any law enforcement agencies provide evidence that the accident may have stemmed from criminal conduct. The Board said that witnesses who reported observing the airplane on fire were most likely observing misting fuel released from broken fuel lines, a fire from the initial release of fuel or the effects of engine compressor surges.

A summary of the Board's report may be found under "Publications" on the agency's website at NTSB - National Transportation Safety Board. The full report will appear on the website in about four weeks.

DozyWannabe 4th October 2013 23:56

Yup, I remember that discussion. As I recall it related to the "variable stop" rudder pedal limiting system as used on the A300-600. For the record, the same system is used on the DC-8 and DC-9/MD-80-90 series.

misd-agin 5th October 2013 00:13


Anyone remember the 60 minute Hoot Gibson interview? I do..he said straight to the camera..."every CFI out there thinks I did it, well I didn't...it was the rudder".
32 yrs later and you remember the exact quote? 60 Minutes? Or CBS Reports special?

misd-agin 5th October 2013 00:16


you omit the link to training exercises presented as a wake encounter, where the simulator was manipulated so that it did not respond to pilot inputs while the simulated airplane banked to 90 degrees.
It wasn't a secret. They'd tell us beforehand - "I'll have control of the simulator to put you in an unusual attitude. At that point I'll let go off the control and you'll be flying."

bubbers44 5th October 2013 00:34

Sounds like good training to me. I did similar things teaching basic students. JFK JR could have used another session before his crash. I think we have all had vertigo. Training lets us overcome it. It saved my butt once.

DozyWannabe 5th October 2013 00:56


Originally Posted by OK465 (Post 8082617)
Nope.

A300-600 is variable stop....high breakout....and with nearly linear variation in pedal force versus deflection.

MadDog is indeed variable stop but....moderate breakout....and most significant, load feel curve is highly non-linear.

Doesn't matter if it behaves differently, it's still the same system.

JammedStab 5th October 2013 01:23


Originally Posted by flarepilot (Post 8082378)
Do consider one thing ...on the preceding page one of the posters says the FO did the correct thing on the first wake encounter...and did something different during the second...why would he?

Always difficult to know what one is thinking but you go through on 747 wake and it may be a surprise even if you discussed it before takeoff. Now you perhaps think quickly if there is a way to try to smooth out the next encounter for the pax in the back. Why not try rudder to reduce the effect. Turns out that Airbus designed a plane with overly sensitive rudders that you didn't realize can easily go full deflection.

Oops, the first rudder input did a huge amount of yaw, better bring it back. Oops went too far the other way with these small pedal inputs that have a large effect. Damn, I am overcontrolling it, good thing we are relatively slow. CRACK.

Meanwhile, the captain assumed that it was bad wake turbulence from that heavily loaded 747.

Only a guess of course.

misd-agin 5th October 2013 03:04


A300-600 is variable stop....high breakout....and with nearly linear variation in pedal force versus deflection.

A300-600R has a light breakout force.

APA submission to the NTSB, page 8 -

http://alliedpilots.org/Public/Topic...submission.pdf


The change in maximum force and degrees of rudder per pound between the A300B2/B4

and the A300-600 is highly significant. The A300 family (should say A300-600R. Look at chart on page 8) has the distinction of having the

lightest breakout force and the highest number of degrees of rudder travel per pound of

force of any other transport category aircraft. Once a pilot initiates rudder movement, he

or she will be challenged with the most sensitive rudder handling qualities of any

transport category airplane. This sensitivity is a precursor to a characteristic known as

Aircraft Pilot Coupling (APC), a condition typically “…not feasible for a pilot to realize

and react to in real time,” and considered unacceptable in U.S. certified designs


(National Research Council 15). Simply, a very light application of force coupled with a

very small movement of the rudder pedal will yield full deflection of the rudder.

HazelNuts39 5th October 2013 06:57

Is the rudder pedal force sensitivity that much of an issue when a pilot pushes the pedal to the stop with a force of 140 lbs?

BARKINGMAD 5th October 2013 15:10

"BE GENTLE WITH ME, HENRY!!!!"
 
Have I missed something during the long transition from mil to civil aviation?

Or possibly neurons dissolved by too much sleeping lotion has erased the memory?

As far back as I can recall, rudder use in swept-wing aircraft was a delicate subject, as was the teaching of its use on the same 'frames.

On the Gnat Advanced training course in the RAF, we were given ONE demo of its use and effects at high altitude (to allow for the subsequent recovery if needed!) and that was it. Yes, squeeze it to remove drift before X-wind touchdown, but no more. The skin of the fin was cutaway on those 'frames with cracks in the attachment brackets, so we could compare them during walkaround, having "memorised" the crack shape and extent as we signed out the tech log in the line hut. Any noticeable discrepancy and it was back to the hut for another, please?!

This was as a result of fatalities due to fin separation in previous accidents as the phenominal rate of roll of that aircraft was the perceived cause of the early fatigueing.

Now it appears from the A300 accident that coarse and assertive rudder use was at one time being trained as an upset recovery technique. Where did the disconnect intrude into the mind of those who thought this was an acceptable and beneficial method of regaining control of a swept-wing public transport medium to heavy aircraft?

Forward the tape to the 90s and the recommendation from Mr Boeing that the full&free rudder check on the 747 should take 2 seconds from neutral to full deflection, both ways, and avoid crashing the rudders against the stops with coarse inputs.

This was apparently introduced as the routine inspections luckily discovered the PFCU attachment brackets were cracking as the barn doors on the 747 VS assembly were being crashed from side to side against the stops by the inadequately trained gorillas then operating them.

Fast forward the tape (yes I know, VHS-speak!) to today, and observe the massive rudder on the 73NG being slammed against the stops by the current crop of Captains, and if you don't see it from outside, then try sitting in the seats in the aft row and FEEL and HEAR the clunk as they hit the stops.

It gives me the chills when I feel it, and I am forced to ask what are the type-rating trainers and the line trainers up to by allowing this crass, clumsy and careless handling?

It all goes to show that there are some lessons in this game which we have forgotten, at our peril, when it comes to having respect for the flying controls and their effectiveness.

Are there any NG engineers out there who can reassure me the NG rudder assembly is NOT suffering from this abuse so that I'll sleep easier?

roulishollandais 5th October 2013 18:17


Originally Posted by [URL=http://alliedpilots.org/Public/Topic...submission.pdf
[...] certification “loophole” [...]

That "certification is "Europe" certification ! Terrifying !
Thank you misd-agin

Did the other aeronautical agencies try to copy ?


Originally Posted by BARKINGMAD
Fast forward the tape (yes I know, VHS-speak!) to today, and observe the massive rudder on the 73NG being slammed against the stops by the current crop of Captains, and if you don't see it from outside, then try sitting in the seats in the aft row and FEEL and HEAR the clunk as they hit the stops.

It gives me the chills when I feel it, and I am forced to ask what are the type-rating trainers and the line trainers up to by allowing this crass, clumsy and careless handling?

It all goes to show that there are some lessons in this game which we have forgotten, at our peril, when it comes to having respect for the flying controls and their effectiveness.

Are there any NG engineers out there who can reassure me the NG rudder assembly is NOT suffering from this abuse so that I'll sleep easier?

Have nice dreams BM !

VinRouge 5th October 2013 18:53

there were a number of issues with this accident.

design. The -600 had different aileron control sensitivity to that of previous models. in turn, this led to the engineers tweaking the control loading required for max deflection, making the rudder more sensitive. this meant pio in yaw was increasingly likely.

this was a minor point; the big one was the negative training recieved in the simulator, in particular, the use of rudder to control roll during an upset. i believe, but am not certain, that the sim profile actually had the instructor turn down the control authority of aileron in the sim, and thus reinforcing the inappropriate use of rudder to control yaw.

a few on here need to do a bit of research. go off and read up on dynamic vs static loading requirements, then have a look at part 25 design requirements. understand the effects of moment of inertia, angular acceleration and aerodynamic damping and you will realise that no re-definition of Va has occurred.

do multiple, max amplitude in phase doublets on the rudder on any aircraft enough and you will snap the fin off.

Teldorserious 5th October 2013 20:24

I am going to have to get into an Airbus sim...

Slow flight, departure stalls, stall spin recoveries, wake turbulance, microbursts...

Probably all I will hear from the back of the sim...

'yeah, um, gee, try not to use the rudder to much...yeah I know the wings were 90 degrees and the plane was going to roll on it's back, but you know, um, well, gee, you see the tail hydros are really sensitive, and the tail, well, um, gosh, you see, well, the NTSB says the plane will right itself..oh, yeah, I know you were going to hit the ground, but you know, um, well, gosh, that's the recomendation, um, well, yeah, uh huh...'.

This probably has to be the most stupid conversaton on an aviation forum I have ever been part of.

Una Due Tfc 5th October 2013 20:36

Sorry to intrude lads, but back when this happened I was training in an MRO and our instructors ran the (approximate) maths to show the loading this fin was under. They came to the conclusion that any large jet transport aicraft would have lost the fin under that loading, composite or aluminium. The increase in load with each reversal was enormous. The fin on that A306 actually failed far above it's max load certification, our engineers were impressed at how long it held on for.

If you recreated the circumstances on a Boeing, Embraer or any medium or heavier aircraft, that many reversals at that speed that low will rip your tail off was their conclusion

Teldorserious 5th October 2013 21:53

UNA - There is no way your instructors were aeronautical engineers with the Airbus structural data, then punch in an accurate description of the wake turbulance event, then assuming they actually had the actual correct FDR inputs instead of some 'gamed' numbers, then of course found the only Arnold Swarzeneger pilot in the fleet that could bang 140 lb inputs back and forth in the sim to come up with 'sideloads' that imposed 'vertical loads' to take the tail off.

I mean I have been in the sim where I asked them to do a dual bucket deployment. ha. Trust me, these guys can't simulate the tail coming off. At best they can sit around a table with the numbers Airbus gave them, trying to convince the FAA that some perfect storm of rudder input and wake turbulance, conbined with a super special snowflake sensitive rudder system, that some how got through flight test cerfication, but you know, now needs to be recertified, because, you know..NOW they know it's quirky.

Come on.

AirRabbit 6th October 2013 01:56

I know that no one has asked, but … after reading the recent posts and looking again at the NTSB animation, I’d like to offer my thoughts … but before I do there are 2 things I need to explain:

1. Proprioception is awareness of the position of one’s body in time and a defined space; and the proprioceptors are located in subcutaneous tissues of muscles, tendons, joints that respond to stimuli applied to the body. There is conscious and subconscious proprioception – in a simplified description, one is recognized, processed by the brain, and recognizes a solution or response … and the other is not processed by the brain, the body simply responds … much like quickly jerking your hand away from a hot stove, or blinking your eye if it is threatened.
2. Anyone who flew the B727 very likely received a substantial amount of training on how to recover from a “dutch-roll.” And you probably recall that the primary control response was the aileron (control wheel) and the process was to recognize the direction of bank and apply a large amount of aileron opposite the roll, and immediately return the control to the neutral position. When the airplane began to roll in direction of your last aileron correction, and as soon as the airplane passed wings-level, again apply a large amount of aileron (control wheel) against the rising wing – or opposite the roll – and immediately return the controls to neutral. It’s the “return to neutral” part that is every bit as important as the control insertion to stop the “dutch-roll.” This is what all maximum control applications during certification require … return the control to the neutral position.

OK – now for my thoughts on the AA587 circumstance.

We know about the rudder sensitivity (if we call it that – but even then, the rudder shouldn’t have been all that much of an “unknown” to someone who’s flown the airplane as long as this crew had flown it) and we know that the F/O had quite successfully transitioned the first wingtip vortex (in fact, looking at the animation again – one could call it quite professionally – in that he allowed the inherent stability of the airplane to do it’s “thing”), but I think that encounter really heightened that F/O’s “fear factor” to the point that he was operating on “the panic bubble” – where he was not yet quite panicked, but he was right at the edge. Remember the F/O questioning the Captain about the ATC clearance, asking if the Captain was “comfortable” with the takeoff following distance? I believe the F/O was showing preliminary signs of nervousness, even before they pushed the throttles forward for takeoff. And I don’t think he had rid himself of that nervousness – I think it was peppering the back of his mind throughout the climb-out.

Pilots typically set up a mental regimen by which they fly (which might be described as …“scan – mentally process – feel – mentally process – scan – mentally choose a response – physically respond – scan – mentally process – feel the motion – visually confirm the motion cue – mentally process – etc.”). I think the F/O was riveted on flying the departure and controlling the airplane – and doing so more intently than he normally would. I think he was spending a lot of subconscious effort being concerned about where the JAL747 was ahead of them WHILE concentrating on his departure – still nervous but still performing. Then – bang, they encountered the 1st vortex. It jostled the airplane a bit – and I think the F/O did just what he was trained to do – keep the controls essentially neutral – correcting minor deviations as necessary – most notably, applying a very minor roll correction. And the vortex was successfully transitioned … but … and here’s the real BUT… I think that first event escalated the fear the F/O had been forcing down and brought it right up to scream in his face! I call it “the panic bubble.” He wasn’t panicked – yet. But he was nowhere near the calm F/O that questioned the Captain before the takeoff roll.

Had they not encountered that 2nd vortex, the F/O very likely would have taken a couple of deep breaths and, within the following 5 to 10 minutes, calmed down to the point that everything would have seemed to have been, and likely would have been, “back to normal.” I think he was beginning to mentally process what had just happened (what he saw, felt, heard … what controls he used, how much input, held for how long, any repetition required, etc.) as he began a turn to stay on the departure course … and he knew he had to continue the departure. I think the Captain noticed a change in his F/O – probably not overt … but a change nonetheless – and I think that was the reason he attempted to calm the F/O, and probably himself, by nonchalantly asking “a little turbulence there, eh?” just after the encounter subsided. But I believe that attempt at “down playing” what had just happened didn’t penetrate the F/O’s “panic bubble.”

He knew he had to maintain pitch, bank, heading, altitude, climb rate, airspeed, etc., follow the published departure AND follow ATC instructions – but I think he was more concerned about the JAL747 that he was following. I think those things grew and grew in significance and the panic bubble was growing, not reducing. Now he was trying to recall just how bad that turbulence had been and how bad it could have been. How close was that other airplane? In short, he was mentally pushed to the limits – but he was still trying to perform his duties of flying the airplane. However, before he could get things back into the regular process with which he was familiar … yep … BANG … 2nd vortex encounter. But here, the F/O was spooled up – quite a bit – and now, the panic bubble burst, and his response was one of panic – his proprioception receptors (recognition not requiring processing by the brain) fired, and knowing his airplane was being forced into more of a left bank – and having already established a 23° left bank – just like snapping your hand away from a hot stove, this F/O slammed a right control wheel and a corresponding right rudder control input – almost to the stops. Whether the following and all subsequent control applications (both wheel and rudder) were a result of his proprioception or his realization that what he just did was likely too much – I can’t say … but when you’re responding out of panic, there isn’t much room for recognizing magnitude and incorporating finesse.

bubbers44 6th October 2013 02:17

Any pilot that takes 5 to 10 minutes to regain compsure isn't a safe pilot. By then it is all over. Maybe 5 seconds if he is slow. One second if he is normal. We don't have the luxury of time in the cockpit. Some things require immediate reflex actions, some don't.

Deciding to divert to an alternate, take your time. Wake turbulence or windshear a second is too long.

tdracer 6th October 2013 04:11


UNA - There is no way your instructors were aeronautical engineers with the Airbus structural data, then punch in an accurate description of the wake turbulance event, then assuming they actually had the actual correct FDR inputs instead of some 'gamed' numbers, then of course found the only Arnold Swarzeneger pilot in the fleet that could bang 140 lb inputs back and forth in the sim to come up with 'sideloads' that imposed 'vertical loads' to take the tail off.
So, Teldorserious, how do you explain that in the aftermath of the crash, Boeing structural engineers did the same analysis and came up with the same answer - that the same rudder inputs would have failed the tail on a Boeing aircraft?

You never directly answered my earlier question - do you honestly believe the NTSB is corrupt and falsified the data?

And if you're willing to answer yes to that, I have another question: Why would they do that? Why would a US Government Agency falsify data to protect a foreign company - a company that competes directly with one of the USA's largest companies? And why would Boeing go along with it?

Oh, and while you're at it, why would American Airlines go along with it - exposing themselves to untold millions in lawsuits - when they could have piled all the blame on Airbus for a defective aircraft?

A Squared 6th October 2013 04:26


Originally Posted by tdracer (Post 8084127)
So, Teldorserious, how do you explain that in the aftermath of the crash, Boeing structural engineers did the same analysis and came up with the same answer - that the same rudder inputs would have failed the tail on a Boeing aircraft?

Or along the same lines, how do you explain that even before the AA crash, Boein issued an amendment to the Operating Manual of the KC-135 stating that reversals of rudder application can cause the vertical stabilizer to fail. (previously posted in this thread)

Interesting, isn't it, how Teldorserious just seems to ignore these things that don't fit her fantasy.

Brian Abraham 6th October 2013 06:14

God, I hate having to repeat myself, but Teldorserious ain't an aviator in any form or fashion, so I fail to understand why any take his posts with any measure of credibility, or even engage him in conversation.

PJ2 6th October 2013 07:10

Brian;

It's interesting. Teldorserious started the thread and frankly, I like where the thread itself has gone; I have learned a great deal from others and am putting some of it to use in my flight data work.

But each poster sooner or later proves his or her capabilities as well as his or her disposition towards civility-above-all-else-including-ego, and serious discussion when engaging other like-minded serious professionals, many of whom come here for the joy at the level of such discussion as well as great information.

It's ironic that after beginning, his subsequent posts are puzzling, but there it is, not the first, nor the last occasion we'll see. He's been on my ignore list for some time.

roulishollandais 6th October 2013 10:22


Originally Posted by AirRabbit
1. Proprioception is awareness of the position of one’s body in time and a defined space; and the proprioceptors are located in subcutaneous tissues of muscles, tendons, joints that respond to stimuli applied to the body. There is conscious and subconscious proprioception – in a simplified description,oneisrecognized, processed by the brain, and recognizes a solution or response … and the other is not processed by the brain, the body simply responds … much likequicklyjerking your hand away from a hot stove, or blinking your eye if it is threatened


Originally Posted by Bubbers44
. I think we have all had vertigo. Training lets us overcome it. It saved my butt once.

As a freefaller we used unconscious proprioception and developed subcutaneous muscles and sensors like the dancers but we use too sight and other senses to control body attitude ref horizon or to join relative freefallers . During the freefall each time we leave the aircraft we fall first in low gravity and have to find the good dynamic balance with very little movements. As pilot, and specialy IFR pilot we do not trust proprioception. Itwould be a dangerous fault denying IFR flight possibility, but ONLY instrument informations -exception is position of the body in the armchair, neck position, and control of fingers, legs and fixing the inside of the body. As Bubbers44 says training overcomes vertigo created by contradictory proprioceptions. Performance in spinning armchair with blinded eyes used for astronauts training shows that difference : freefallers are much better than fighter pilots. Pilots trust instruments not body feelings.

Brian Abraham 6th October 2013 13:24

Totally agree with the thrust of your post PJ2, only some have not learnt to ignore his exceedingly strange and ignorant posts. Renewing his instructors rating, give me a break.

SMOC 6th October 2013 14:25


I am going to have to get into an Airbus sim...

Slow flight, departure stalls, stall spin recoveries, wake turbulance, microbursts...
Teldo... this comes to mind! :}

http://virtualmystic.files.wordpress...6/simcrash.jpg

Brian Abraham 6th October 2013 15:27

SMOC, The statement "Personally, I would'nt let Buba pull my kids wagon" certainly applies to our friend.

misd-agin 6th October 2013 15:27

OK465 - thanks for the correction/clarification.

I've seen a chart listing breakout forces, force needed for full travel, pedal travel, etc. I thought it was in the submission but apparently it isn't.

Teldorserious 6th October 2013 18:02

Brain are you still mad that I outted you as a fraud? Why the mods put up with your incessant trolling is beyond me. Maybe they don't care?

AirRabbit 6th October 2013 19:13


Originally Posted by bubbers44
Any pilot that takes 5 to 10 minutes to regain compsure isn't a safe pilot. By then it is all over. Maybe 5 seconds if he is slow. One second if he is normal. We don't have the luxury of time in the cockpit. Some things require immediate reflex actions, some don't.

Deciding to divert to an alternate, take your time. Wake turbulence or windshear a second is too long.

I’m not describing the necessity to compose one’s self … I’m describing the ability to not react out of panic, but rather function as you have been trained, choosing what your reaction will be – and I’ve described this in pilots as being somethink like …“scan – mentally process – feel – mentally process – scan – mentally choose a response – physically respond – scan – mentally process – feel the motion – visually confirm the motion cue – mentally process – etc.” this pilot was doing that up until the 2nd vortex … but I think he was on the verge of panic, keeping it under control, and likely, working his way out of it. Unfortunately, the 2nd vortex hit and burst that panic bubble – and from there everything he did (in my opinion) was the execution of what he knew but motivated out of panic. As I also said previously, most people think they know how to recognize someone who has panicked … perhaps some may … but I do know that when you’ve seen someone really panic, it’s something you won’t easily forget. And unless you know the person, or are really familiar with the circumstances, you might not recognize that the actions you see are very likely executed out of knowledge but that person is not calmly exercising that knowledge – he is being motivated out of panic – and that is something that is beyond the control of the person. In fact, the dictionary definition of panic is “… a sudden sensation of fear which is so strong as to dominate or prevent reason and logical thinking, replacing it with overwhelming feelings of anxiety and frantic agitation consistent with an animalistic fight-or-flight reaction.” To me, this is what I think that F/O was doing ... reacting with a skill set and doing so out of panic ... attempting to function without thinking logically or reasoning to any degree and was, instead, functioning out of an overwhelming feeling of anxiety and frantic agitation.


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