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-   -   AF447 wreckage found (https://www.pprune.org/tech-log/447730-af447-wreckage-found.html)

ChristiaanJ 3rd August 2011 16:24


Originally Posted by xcitation (Post 6616930)
I think Takata and others suggested that PF was PIC so the left seat FO could not take over in such a manner. It has been suggested that he might have liked to based on wording and dual input.

I think it's been described here before.... There is a button on the sidestick that - when held down for a given time - transfers control to that side stick.
The function is normally there to either transfer control, or in the case of PF incapacitation.
No need to change seats.

xcitation 3rd August 2011 16:48

Christiaan

I know about overide button on SS.
However I also read that the FO in left seat lacked the authority, unless he declares FO in right seat incapable. Difficult in this situation as there was no obvious medical problem with PF. Il voudrait un coup d'état, non?

BOAC 3rd August 2011 16:58

Out of interest, what happens in this 'computer game' if the one who has 'lost' control then presses the button for the requisite time?

Lonewolf_50 3rd August 2011 17:57

JJFFC

2/ Don't forget that neither the PNF nor the Capt. ever knew that the PF made an initial huge nose up => how many of us could have imagine that ?
From CVR release, early in the event PNF was nagging PF to get his nose down, or to stop climbing.

Am I right in saying that on this type if inputs are made on both sidesticks the system will take the algebraic sum of those inputs?
In which case if one pilot was maintaining full and up and the other full down this would equal neutral - not what you need for stall recovery.
Back to "take the controls" if you have to come on to the controls ... CRM issue.
MountainBear:

I have held that
(1) the logic of the stall warning system is flawed
(2) that this accident illustrates the nature of those flaws
(3) that these flaws are one possible explanation for the pilots behavior doing one specific phase of the accident
(4) that the professionals who designed the system should be held accountable for those flaws to the extent they played any role in this accident.
Rational position to take. I'm on board with most of it.
Dozy:

I'd say the extreme AoA was probably fouling the static data from 02:11:47 onwards.
More likely fouling pitot data. Static doesn't tend to be in the airstream, unless they've changed that recently. You don't want to contaminate static air with dynamic pressure, do you? :confused:

Originally Posted by houlett
When a french pilot said GAUCHISSEMENT he speak 's about ROLL

Merci, monsieur. :ok:
Three miles

If they felt they were fast and descending perhaps they thought this was a high speed stall warning? In which case relaxing the back stick but still mantaining some might make sense.
IMHO the ignorance {me - Ignoring?} of the audible stall warning could only be caused by the pilots assuming, that the stall warning would be triggered by too low speed (instead of AoA).
Speed incorrect -> Stall warning -> ignore it
When the speed came back they had stalled the plane and the speed stayed low => assumption: still incorrect.
Why should they believe now, that the speed was more correct than before?
Why should they believe with all this confusing stuff around them, that any other indication was more correct?
The speed even became lower and lower and the stall warning disappeared at some point. -> continue to ignore all this
Well said.
Kalium:
I wonder what he {captain} would have done if he'd heard nearly a minute's worth of stall warning.
Might have changed his SA, that.

Mimpe:

When the birds hit the 737 over Manhattan, pretty much the first action fronm Sullenberger was.." My Aircraft".
Good point, but Sully was the Captain. :) There was no role ambiguity for him. PNF had that to deal with.

...my concern is that PF may well have been more than just worried about overpeed. Its clear he had lost his initial crucial scan, was overcontrolling, and I feel as the aircraft slowed with zoom climb, may well have crossed the rubicon of lapsing into a sensory interpretation of what the aircraft was doing.
Possible. How often do AF train hand flying on instruments at high altitude? How comfortable was he in that scan and that task?

I feel the decleration he was experiencing in the late stages of the climb, heightened by marked anxiety, probably ended in a somatogravic illusion of acceleration, and persistent nose up inputs unto death ... situation required immediate transfer of control to PNF, whose spatial orientation and understanding of the situation appears clearly superior throughout. No time for egalitarian social norms.
Yes, early on. By the time the Captain got there, he confessed that he wasn't sure what was wrong. His SA hadn't quite deciphered the SW when it was correct. :(
GerardC

In all, 4 stall warning activations. Would not YOU be confused : nose down -> stall ; nose up -> NO stall.
Was this sort of thing ever practiced in the sim among A330 pilots? Among AF pilots?

This whole scenario reminds me how dependent we are on airspeed as a crosscheck for performance.
ross M:

About auto switching back to normal law protections. (That puts the robot into a struggle with the pilot for control deflection).

As I understand law changes, latching Alt 2 requires substantial effort to revert to normal law. Auto switch is probably not a good idea, from a design perspective, and for any pilot flying.

If you keep getting spurious inputs, auto re-engage would kick you back to Norm Law from Alt Law even if the problem didn't go away.

You could get stuck into the following cycle: Alt Law kick Norm kick Alt kick Norm kick Flicker -- talk about a pain to fly.

Imagine flying with the electric trim kicking on and off, intermittently. Eventually, you secure the trim so it stops doing that to you. (Yes, I've had trim weirdness like that in the dim and distant past. Ended up being a touch of hydraulic contamination. )

RWA: nicely said, thanks. So many good minds at work today! :)

carlosgustavo:

LONEWOLF_50. I dont know if you are right about the sound of stall inside a stall. All Airbus says on the O. Manual is: WHEN STALL WARNING STOPS PILOT MAY INCREASE BACK PRESS AGAIN IN ORTHER TO RECOVER TRAJECTORY.
I dont for you, but seems To me that if it works as you say Anywhere in the Operations Manual should be a Caution warning that at high AOA stall warning stops. BUT IT DOESNT.
Thanks for tour answer. Is good To learn from others and To share thoughts. Good flights.
The stall warning alpha looks (from my tech info) to trigger stall warning at a value of alpha less than stall alpha. That tells me you get the warning before you actually hit that critical alpha and stall.
Does that make sense to you? (I may be missing something). It makes sense to me.

For your kind words: Muchas gracias, carlos, y vaya con Dios. :)

Originally Posted by somebody
To that point the PNF did not brief CAP that the stall warning had been ringing for a minute.

Aye, he seems to have filtered that noise out.

BOAC:

Out of interest, what happens in this 'computer game' if the one who has 'lost' control then presses the button for the requisite time?
He gets to keep "flying," eh? :eek:

carlosgustavo 3rd August 2011 18:05

Excellent link To the matrix of the accidente. Looks real To me.
They were more focus on bank than in pich.
Anybody else think of a SPIN induced by stall plus turbucence that they didnt recognice because of the IMC condicions?

DozyWannabe 3rd August 2011 18:15


Originally Posted by Lonewolf_50 (Post 6617184)
More likely fouling pitot data. Static doesn't tend to be in the airstream, unless they've changed that recently. You don't want to contaminate static air with dynamic pressure, do you? :confused:

I'm trying to make sense of the VSI trace after 2:11:45. Do those look like viable readings or is something messing with them? AFAIK VSI does not use pitot data as an input...

Lonewolf_50 3rd August 2011 18:17

Dozy, your comment on AoA fouling VSI implies to me that you think AoA had an impact on what was being read/sensed in the static ports. (But if that isn't what you were thinking, sorry about that). We have had considerable discussion on high AoA causing some problems with pitot tubes and the pressure they are sensing.

I'd need to look at the trace on a screen that doesn't have issues with images. Not all of the ones posted here come through on this machine/system.

carlos:
Don't think there was a spin. I wandered off the reservation on that score some months ago, before the data had been analyzed and some of it released.

The BEA reconstruction of the descent indicates a single "turn" (over three or four minutes) that changed heading of AF447 about 270 degrees to the right.

That doesn't look like a spin, but more of a stall with some waffling and rolling going on, mostly to the right.

xcitation 3rd August 2011 18:36


Originally Posted by Lonewolf_50
carlos: the reconstruction of the descent indicates a single "turn" (over three or four minutes) that changed heading of AF447 about 270 degrees to the right.

So, no, not a spin, but a stall with some waffling and rolling going on, mostly to the right.

+1
When I have rec flown in stormy weather in a light a/c I was forced down on a grass airfield. On landing I have been spun around 180 deg to wind once speed slows and wet. Very unsettling as a/c was still on runway. The a/c has lost force on its flying/control surfaces and then becomes a weather vane. With less force on AF447's flying and control surfaces the influence of wind/gusts is greater. Did AF447 right turn into the wind direction?

ross_M 3rd August 2011 19:12

Any lawsuits already been filed? I smell lots ahead. Plenty of blame to pass around and all defendants have deep pockets. Air France, Thales and Airbus must already be scampering for their lawyer teams.

carlosgustavo 3rd August 2011 19:20

You are probably right Wolf, 270 degrees turn is not much, but between
2.11.35z 2.12.15z they are stalling and turning right between 16 and 40 bank and the VSI gets its higher values, even unreliable. At that monent IDLE thrust is selected producing a pich down moment that stops the stall of the right wing stoping the rotation but mantaining the Stall.

Worse of all Wolf is that no investigation will solve this.

jcjeant 3rd August 2011 19:40

Hi,


Any lawsuits already been filed?
If you had return early from your travel to the Moon (the dark side of) ... or read the press you can know that two lawsuits are already filed in France
One against Airbus and one against Air France ....

Le Figaro - Flash Actu : Af447:familles veulent accs aux donnes


L'association Entraide et Solidarité AF447, qui représente les familles des victimes du crash du vol Air France Rio-Paris en juin 2009, tente d'obtenir des magistrats instructeurs l'accès à l'ensemble des données des enregistreurs de vol, a indiqué mercredi son avocat.

La juge Sylvie Zimmermann a cependant refusé en juillet cette requête, au motif que l'enquête technique du Bureau d'enquêtes et d'analyses (BEA) n'était pas terminée et l'association a fait appel de cette décision, a déclaré Me Alain Jakubowicz.
En tant que partie civile, Entraide et Solidarité AF447 peut consulter les pièces du dossier de l'instruction menée par les juges Sylvie Zimmermann et Yann Daurelle, une enquête dans laquelle Air France et Airbus sont mis en examen pour homicides involontaires.

"Le problème est que les données ne figurent pas au dossier. Tout le monde en parle, notamment au travers du BEA, mais nous n'y avons pas accès car la juge dit qu'elle ne les a pas", a déclaré Me Jakubowicz.
"Il y a cependant un déséquilibre puisque Air France y a accès au travers de l'enquête du BEA", a-t-il ajouté.


L'association, qui a plusieurs fois dénoncé la partialité des informations du BEA et leur orientation vers la faute de pilotage, a fait le 13 juillet une demande formelle pour avoir accès à l'ensemble des données. Mais Sylvie Zimmermann a rejeté cette requête dans une ordonnance rendue le 18, selon Me Jakubowicz.
Entraide et Solidarité AF447 a fait appel, mais aucune date n'a pour l'heure été fixée pour ce débat qui se déroulera devant la chambre de l'instruction.

Réagissant au fait que le BEA a retiré de son dernier rapport une recommandation concernant les alarmes de décrochage, Robert Soulas, président de l'association, a jugé mercredi dans un communiqué que "ce triste épisode jette définitivement le discrédit sur l'investigation technique" et "génère une crise de confiance sans précédent envers les autorités d'enquêtes".
La catastrophe avait fait 228 victimes. Dans son dernier rapport d'étape, le BEA a notamment mis en cause la formation et les réactions de l'équipage après le décrochage de l'avion.

Mutual Aid and Solidarity Association 447, which represents the families of the victims of the crash of Air France flight from Rio to Paris in June 2009, trying to get magistrates access to all the data flight recorder, said Wednesday's lawyer.

Judge Sylvie Zimmermann, however, refused this request in July on the grounds that the technical investigation of the Bureau of Investigation and Analysis (BEA) was not completed and the association has appealed the decision, said Mr. Alain Jakubowicz.
As a civil party, Solidarity and Mutual 447 may consult the documents of the investigation carried out by the judges Sylvie and Yann Zimmermann Daurelle, a survey in which Air France and Airbus are under investigation for manslaughter.

"The problem is that data are not included in the file. Everyone talks about it, particularly through the BEA, but we do not have access because the judge said she did not," said Mr. Jakubowicz .
"But there is an imbalance, since Air France has access through the investigation of BEA," he added.

The association, which has repeatedly denounced the BEA bias information and orientation error in piloting, July 13 made a formal request for access to all data. But Sylvie Zimmermann rejected that request in an order made on 18, according to Mr. Jakubowicz.
Mutual aid and solidarity called 447, but no date has so far been set for this debate to be held before the Board of Education.

Reacting to the fact that BEA has withdrawn its last report a recommendation on the stall warning, Robert Soulas, president of the association, said Wednesday in a statement that "this sad episode definitely throw discredit on the technical investigation" and "generates an unprecedented crisis of confidence towards the authorities investigated."
The disaster had caused 228 victims. In its latest progress report, including the BEA has challenged the training and the reactions of the crew after dropping out of the plane.

Lonewolf_50 3rd August 2011 20:50


The disaster had caused 228 victims. In its latest progress report, including the BEA has challenged the training and the reactions of the crew after dropping out of the plane.
Gotta love Le Figaro :rolleyes: ... they start a rumor about pilots dropping out of the plane --, wait, what's this, skydiving at night in a thunderstorm over the open ocean? I know pilots are adrenaline junkies, but this is something else again! :E How the heck did they get back into the plane before it hit the water? :confused::p

Perhaps google translate is to blame for this? :E:oh:

SeenItAll 3rd August 2011 21:19

To me the issue seems to be whether we want pilots to fly an aircraft by playing a computer game, or whether we want them to fly an aircraft according to the laws of physics.

It seems pretty clear that the AF pilots were doing the former rather than the latter. The basic difference between the two is that with the computer game, it is the computer's instructions and feedback that are your "law." The stall warning starts to sound, this means that the aircraft is approaching stall. Placate the computer by pulling nose up and the stall warning stops -- the computer responds by telling you that you are playing the game "correctly." Note that although these pilots were likely trained to understand that the computer game has other "rules," such as keep an appropriate speed and attitude, the computer states that the stall warning has priority over all these other rules -- so you don't address them until you've dealt with job #1, silencing the stall warning.

In contrast, flying the aircraft according to the laws of physics tells you that if you are in a severe nose-up attitude with less than 60 knots of airspeed at FL 370 (or even any two of these three conditions), you are in stall. These laws also tell you that in an A330 weighing over 400,000 lbs. with a maximum of 140,000 lbs. of thrust, you cannot climb out of a stall as you might with an F-22. While AB software engineers have done wonderous things with FBW, they have not repealed Sir Isaac Newton.

Now I don't know enough about A330 maneuverabilty to know whether once the stall was entered, it was recoverable, but shouldn't these guys have known that nose-up had no dynamic hope? Or were they just expecting that the FBW computer would find some deus ex machina way of extracting them from this dire situation?

In fairness, AB should certainly change its stall warning protocol to make more clear when it is inhibited because of unreliable airspeed. And I guess it may also be possible that the accelerations in the cockpit made it impossible for the pilots to gain any situational awareness. But the tapes seem to suggest a relatively nonviolent descent into the ocean. In the end, it all comes down to what you can rely on. These pilots relied totally on the computer, and were willing to suspend any belief in physical law.

grity 3rd August 2011 21:34

hi jcj risc a look at side 44 of the 3. report there are the values around 2:10:10 with much more details shown the purple line not the blue......

jcjeant 3rd August 2011 21:35

Hi,


Gotta love Le Figaro :rolleyes: ... they start a rumor about pilots dropping out of the plane --, wait, what's this, skydiving at night in a thunderstorm over the open ocean? I know pilots are adrenaline junkies, but this is something else again! http://images.ibsrv.net/ibsrv/res/sr...ilies/evil.gif How the heck did they get back into the plane before it hit the water? http://images.ibsrv.net/ibsrv/res/sr...s/confused.gifhttp://images.ibsrv.net/ibsrv/res/sr...ies/tongue.gif

Perhaps google translate is to blame for this? http://images.ibsrv.net/ibsrv/res/sr...ilies/evil.gif:oh:
Drop out is to be understand as STALL .. I'm sure you known that :ok:
Must be certainly better jokes in the BEA offices ..
Don't forget that NTSB and a Brazilian party are also members (maybe as observers ?? but ..) of the investigation team .....
I wonder how all those people different by culture and language are communicating ... :8

exeng 3rd August 2011 22:16

BOAC
 

Out of interest, what happens in this 'computer game' if the one who has 'lost' control then presses the button for the requisite time?
Well BOAC the one who had 'lost control' now regains control - simples really - I have control -no I have control - no really I have control etc etc.

About as sensible as if no overide is pressed an input by the same amount in the same direction doubles the input, or if in the opposite direction negates the original input. Remember Hamburg.

I flew with one of our colleagues back in LGW days on the 737 who twice in two trips on a xwind landing put aileron in the wrong way. Frightening yes - but at least I could see what was happening and correct it before the inevitable - don't think that would have been possible on any Airbii.

Still the bus does have some good points like terrain escape which in my opinion is better than any Boeing, 777 included.

DozyWannabe 3rd August 2011 23:36


Originally Posted by exeng (Post 6617656)
About as sensible as if no overide is pressed an input by the same amount in the same direction doubles the input, or if in the opposite direction negates the original input. Remember Hamburg.

Aye, but if used and co-ordinated correctly you can get double the roll rate, which could be useful in an escape maneouvre, or if you see your opposite number doing something that doesn't look right you can negate their input before taking control.


I flew with one of our colleagues back in LGW days on the 737 who twice in two trips on a xwind landing put aileron in the wrong way. Frightening yes - but at least I could see what was happening and correct it before the inevitable - don't think that would have been possible on any Airbii.
Well, you could *see* it happening on a FBW Airbus (you have an ADI in front of you after all), that's never been the problem - the complaint has always been about *tactile* feedback. The thing is that tactile feedback used to serve multiple purposes when controls were directly connected to flight surfaces - you could feel how the surfaces were responding, you could feel what the other pilot was doing and assist if necessary (indeed you could also put more welly behind the maneouvre). But in todays modern world of hydraulically-controlled surfaces with no manual reversion you're down to being able to feel the other guys inputs, plus whatever the q-feel system is telling you. In a lot of cases this is nothing to be sneezed at, but in some cases it can give a false impression of having an effect on the flightpath when in fact you are not. UA232 was an exemplary display of CRM and aircraft control, but one of the interesting factors was the captain and co-pilot forcing their yokes forward and to the left, long after it was obvious that it was having absolutely no effect.

Airbus's philosophy was based on the idea that when going by the book, only one pilot should be manipulating the flight controls at any one time *except for extraneous circumstances* in which they designed the sidesticks to act in the same manner as the yoke, but by summing the inputs algebraically rather than by respective force. Backdrive was considered and ruled out because it added extra weight and complexity (complexity being the main issue), as well as causing extra problems in the event of systems failure or maintenance errors (e.g a cross-wired sidestick on one side).


Still the bus does have some good points like terrain escape which in my opinion is better than any Boeing, 777 included.
As always, there are usually positives and negatives to any differences in design philosophy, and to say that one is objectively better than another in all aspects is not only foolish, but tiresome after a while. ;)

mm43 3rd August 2011 23:45

BEA Interim Report No.3 (English) Released.

English Version

JJFFC 3rd August 2011 23:58

@DozyWannebe
 
Hello DozyWannebe,




What do you mean by:
  1. "this is the only correlation" at 02:12:35 ?
  2. "correct behavior" at 02:12:40 and 02:12:48 ?
I understand that the stall alarm stoped after "stick forward" ?

Thank you,

DozyWannabe 4th August 2011 00:25

@JJFFC

Simple. AF's argument is that the stall warning sounded at the same time as the pilots fed in nose-down inputs (i.e the correct way to recover from a stall) on every occasion. They are using this to argue that the stall warning gave a false impression to the pilots that they were doing the wrong thing by putting the nose down.

By matching up the trace graphics to the best of my ability it appears that this is not the case. On one occasion, the stall warning comes on at around the same time PF puts in a nose down input, but after then there appears to be no match whatsoever, and in my opinion appears to be in response to the pitch angle of the aircraft (which is stalling and out of control) as opposed to any sidestick input. In fact, if I've lined things up correctly, it appears in a couple of cases that the stall warning stops as nose-down is input, which would reinforce the correct behaviour by the terms that AF are putting forward.

TioPablo 4th August 2011 00:43


A protection to me means a limit, something is prevented that could conceivably cause a serious problem
Dear Bear, sorry for my late answer... Was busy with other things...
What I meant to say all the time with the faulty switch of state (imo), is that the "reminder" given by Direct Law to use manual trim could have given a hint to the pilots about their attitude... And therfor: act as a protection...
If you don´t have any indication about your speed... What is the best action?
TO/GA?
Well, I don´t think so...
For me would be IDLE and trim-out to best gliding speed (AoA). Then pay attention to the blaring show...
If that switch of state (Direct Law thus), would have helped the pilots or not is at this stage irrelevant (or not). I think everybody were very busy during this years trying to solve this event and I´m almost certain we all will do their best to improve whatever went wrong. And as I said before.. I hope pilot unions will be there to see that safety recommendations (as issued by BEA), are implemented in a very near future.

JJFFC 4th August 2011 00:43

@ JcJeant
 
I believe that the stall warning has nothing to do with the mental problem of the PF : whatever the stall warning, the PF wanted to nose up and didn't understood why the PNF and the Capt asked him not to.

Abstract :

2 h 13 min 40
PF : But I’ve been at maxi nose-up for a while
Capt : No no no don’t climb
PNF : So go down


2 h 13 min 45
PNF : So give me the controls the controls to me
PF : Go ahead you have the controls we are still in TOGA eh

2 h 14 min 05 4,024 The pitch attitude is 14°.
Capt : Watch out you’re pitching up there
PNF : I’m pitching up?
PF : Well we need to we are at four thousand feet :ugh:

(My) Conclusion:

The Capt. didn't knew how much the PF was nosing up but knew he shouldh't have.

The PNF knew he had to nose down but his fear prevented him from a strong forward stick;

The PF has alway wanted to nose up except when asked by the PNF or the Captain not to do.

The actions of the PF have been unbelievable / misunderstood by PNF and the Captain.

Not only the PF has created the stall by a stupid nose up but he has commited "a crime" when at 02:11:39 he took the controll back from the PNF without annoucement and continued to nose up against PNF and Capt.

JJFFC 4th August 2011 00:46

@DozyWannebe
 
Thank you :

Your observation is of such an importance regarding the debate with JcJeant and in France that I prefered to have you repeted it.

CONF iture 4th August 2011 01:40


Originally Posted by DozyWannabe
Well, you could *see* it happening on a FBW Airbus (you have an ADI in front of you after all), that's never been the problem - the complaint has always been about *tactile* feedback.

No Dozy, the PROBLEM has always been to know IF and HOW your partner makes flight control inputs.

But what do you know about flying a multi crew aircraft after all ... ?
Do you only know about flying ?

Sorry, but just getting tired of hearing you talking as even a 30000 hours retired Captain with 25 years on FBW Airbus would not dare to.

Please, let others talk if you don't know, or at least, let room for healthy reserve or doubt in your talking.

grimmrad 4th August 2011 01:42

Not a pilot or even from the industry but I think the issue is that the stall warning activates if the plane gets close to a stall and STOPS once it is in the stall. So, imagine middle of the night, bad weather, some weird faults, suddenly stall warning. As someone pointed out (by whatever reason if I hit quote I do not get the quoted text) nose down gave stall warning, in nose up it stopped - not because the stall situation is gone but quite the opposite. If that is not confusing under normal circumstances how would it be in their particular situation...?

DozyWannabe 4th August 2011 01:51

@JJFFC : I'm not saying I'm right, but I'm saying that there is certainly room for debate. This wouldn't be the first time that interested parties have used the press to push their case while only providing the details that supprt their side of the story...


Originally Posted by CONF iture (Post 6617931)
No Dozy, the PROBLEM has always been to know IF and HOW your partner makes flight control inputs.

But what do you know about flying a multi crew aircraft after all ... ?
Do you only know about flying ?

Sorry, but just getting tired of hearing you talking as even a 30000 hours retired Captain with 25 years on FBW Airbus would not dare to.

Please, let others talk if you don't know, or at least, let room for healthy reserve or doubt in your talking.

CONF, we've been *well* aware of your position on non-backdriven sidesticks versus interconnected and/or backdriven yokes for over half a decade. I'm not saying your opinion is without merit - it has plenty, in a theoretical sense. But there are thousands of Airbus FBW pilots around the word that do not consider it a problem - this is not about *my* opinion, this is about *theirs*.

Given that we've had at least one similar incident where having an interconnected yoke made no difference whatsoever to the outcome (Birgenair), surely you must therefore consider that the theory which supports your personal preference may not necessarily be the solution in all cases?

jcjeant 4th August 2011 02:03

Hi,


But there are thousands of Airbus FBW pilots around the word that do not consider it a problem - this is not about *my* opinion, this is about *theirs*.
And those who maybe had a problem with are no more there for give theirs opinion ... sad ...
Only people alive can give theirs opinions

Graybeard 4th August 2011 02:41

DW

Given that we've had at least one similar incident where having an interconnected yoke made no difference whatsoever to the outcome (Birgenair), surely you must therefore consider that the theory which supports your personal preference may not necessarily be the solution in all cases?
Birgenair was different, because the lower ranked FO knew what was happening, and was emotionally powerless to correct the Capt. . The FO could have overpowered Capt. by pushing harder on the yoke. Could he have done that with a joystick?

As for your argument that the 777 backdrive can fail: it's built to the same safety standards as the Cat IIIc autoland, i.e., 10 -(7?) probability of undetected failure.

DozyWannabe 4th August 2011 02:44


Originally Posted by DozyWannabe (Post 6617846)
...the stall warning comes on...and in my opinion appears to be in response to the pitch angle of the aircraft (which is stalling and out of control) as opposed to any sidestick input.

http://i1088.photobucket.com/albums/...fdr-att-sw.png

2:10:12 - *bang*

2:11:55 - *bang*

2:12:08-10 - *bang*

2:12:28 - *bang*

2:12:33 - *bang*

2:12:40 - *bang

2:12:48 - *bang*

2:13:52 - *bang*

2:14:20 - *bang*

I rest my case.

Fox3WheresMyBanana 4th August 2011 03:29

OK, after reading the English version:

1 None of the pilots are even looking at the attitude indications OR

2 The PF is ignoring the stall warner because of the unreliable speeds, and

3 The PF is flying the stall warning / unreliable airspeed procedures for the Take-Off/Go-Around phase of flight, i.e. aiming for 15 degrees Nose-Up attitude, not the high altitude procedure.

Look at the stick input and pitch attitude after 2:11:00. The PF is trying to maintain 15 degrees pitch attitude. He states "I'm in TOGA".

At only one point, before 2:11:00 when the PNF insists, does the PF consistently apply Nose-Down controls. After that I think it's clear he's convinced they have a high speed situation because of the buffet, and thus completely fails to spot the stall.

I think it's possible that the PNF does think they are stalled when the Stall warner sounds at 2:10:51. The power comes up and he warns the PF about lateral stick. But the PNF either doesn't realize or doesn't see a problem with the PF trying to maintain 15 degrees NU.

No emergency procedures are verbally identified. No drills are done. No cross-checks of Attitude, or anything else, are called.

I'm not flying Air France again.

Thoughts on this theory anyone?

xcitation 4th August 2011 03:34

Microphone strikes wall
 

Originally Posted by BEA #3, Page 43
there is a noise on track 1 of the CVR, at about 2 h 10 min 55, which might be the impact of the microphone striking a wall, heard at a stable frequency.

If PF was not belted (as found in the recovery) then could his mic and therefore head have hit a wall! I know this is purely speculative but a surprise to read it.

xcitation 4th August 2011 04:02

The PNF insisted 3 times for the PF to descend. Finally PF responds with confusion and finally appears to recognize he has climbed.


Watch your speed (PNF)
Watch your speed
Okay, okay okay I’m going back down (PF)
Stabilise
Yeah
Go back down
(no response recorded)
According to the three you’re going up so go back down
Okay
You’re at go back down
It’s going we’re going (back) down
I’ll put you in in A T T (*)…
We are in yeah we are in climb


IMHO the PF appears to not be aware of his own actions, was he in physiological shock/mentally impared?
I have to say that the informality of the response to the requests is startling. Perhaps something is lost in translation or culture? It's almost like the PF is getting irritated by the request to descend. It is incongruous with the gravity of the situation. It reminds me exactly of the response of a teenager when they are asked to clean their room!
No doubts, he is at the wrong flight level, stall warnings blaring so I would be looking for an immediate roger, descending back to FL350. Due to the gravity of the situation and after 3 failures to descend would it be reasonable to think PF is mentally impared/SS fail and take control?

jcjeant 4th August 2011 04:08

Hi,


I have to say that the informality of the response to the requests is startling. Perhaps something is lost in translation
No .. you have a good feeling
This conversation between pilots seem's a extract of a bad Hollywood catastrophe movie .... with Laurel and Hardy

xcitation 4th August 2011 04:12

DW
are you saying that the nose ups did not cause the stall warning.
Are you trying to correlate stick inputs to warnings. Remember there is inertia to such a heavy close to max weight. This creates lags in response. The thin air at high altitude makes responses woolly compared with dense air close to the ground.

xcitation 4th August 2011 05:04


Originally Posted by Fox3WheresMyBanana
OK, after reading the English version


Originally Posted by Fox3WheresMyBanana
1 None of the pilots are even looking at the attitude indications OR

IMHO PF was not reading the att ind due to physiological shock. I think the other 2 did see att ind.
The wings to flat horizon the standby horizon (CAP)

The horizon (second) (PNF)


2 The PF is ignoring the stall warner because of the unreliable speeds, and
Ok.


3 The PF is flying the stall warning / unreliable airspeed procedures for the Take-Off/Go-Around phase of flight, i.e. aiming for 15 degrees Nose-Up attitude, not the high altitude procedure.

Good call.


Look at the stick input and pitch attitude after 2:11:00. The PF is trying to maintain 15 degrees pitch attitude. He states "I'm in TOGA".

At only one point, before 2:11:00 when the PNF insists, does the PF consistently apply Nose-Down controls. After that I think it's clear he's convinced they have a high speed situation because of the buffet, and thus completely fails to spot the stall.
For me more curious is at the start AP disconnects and PF does aggressive stick back. Zoom climb begins. After 4 seconds the first brief stall warning occurs. It is largely ignored and they continue the climb to FL375. IMHO he PF was in shock and mentally impared by epinepherine surge.


I think it's possible that the PNF does think they are stalled when the Stall warner sounds at 2:10:51. The power comes up and he warns the PF about lateral stick. But the PNF either doesn't realize or doesn't see a problem with the PF trying to maintain 15 degrees NU

Agree.


No emergency procedures are verbally identified. No drills are done. No cross-checks of Attitude, or anything else, are called.
Agree.

L-38 4th August 2011 05:11

A very strong and convincing scenario, Fox 3! I have often had similar thoughts about Colgan Air 3407 (the Buffalo NY crash). Both pilots unexplainably maintained their aircraft in a stalled condition during nighttime adverse wx, with unfamiliar a/s indications.

Flying the stall warning / unreliable airspeed procedures for the Take-Off/Go-Around phase of flight in a simulator, was probably their most practiced of the unreliable airspeed procedures. . .something to revert to when one’s head is locked and “tunneled” in a similar, but very different situation.

This incident certainly dramatizes that verbally identifying emergency procedures, drills, and cross-checks of attitude, ect, is of the utmost importance of such cockpit discipline.

ankh 4th August 2011 06:28

stall, or high speed stall?
 
This aircraft was in a 'normal' not a high speed stall condition? (I'm wondering if the pilots could tell the difference, in the situation as they were experiencing it). http://www.pprune.org/flight-testing...eed-stall.html

A340Fan 4th August 2011 06:40

Pilots pulling out of the BEA workgroup on AF447
 
Just heard on the french radio Europe 1 that the pilot representatives announced that they quit the BEA workgroup due to profound disagreement with the (quote) biased inquiry (end quote). This comes, of course, after it became public that the recommendation for Airbus to revise the stall warning logic was removed from the 3rd interim report right before publication.

Mimpe 4th August 2011 07:33

For all the various reasons above, an aggregated international body should do this investigation based on the raw data. I feel there is no confidence in the French investigation , especially amogst pilots and the travelling public. This is one of the most important crash investigations in history, and it requires clearly independant and fearless conclusions...no consideration AT ALL should be given to extraneous commercial factors .

Artificial horizon, altitude and derived groundspeed were all clearly available.The stall clearly warned and occured at the top of a zoom climb of at least 5000 fpm, leaving a persisting unacceptable nose up attitude clearly visible on the AH and a persistent initial stall warning. Airbus has to reprogram the stall parameters to any value that might reliably assist in extreme attitudes. I suppose a clearly visible AoA indication might have helped.

Fox, I pretty much agree with you...PF was impaired, but there is a toxic soup of design (stall programming parameters, non visible control inputs, digital verses analogue style readouts, etc ), Emergency response to aicraft upset and spatial disorientation, major CRM flaws, weather, possible unkown effects of other parties in the cockpit (unclear), the deleterious effects of automation technology on clear thinking problem solving at first principles level......even possible cultural traits affecting handover proceedures and flight discipline.

My favourite training adage was, " when things get really bad, take your own pulse first"

MountainBear 4th August 2011 07:39


But there are thousands of Airbus FBW pilots around the word that do not consider it a problem - this is not about *my* opinion, this is about *theirs*
On the Brittleness of Software « Dark Matter

The point, DW, is that the knife cuts both ways. I won't denigrate either your efforts or your opinions. I will say that there are plenty of experts (both pilots and in academia) that disagree with your assessment of the stall warning system and the way it behaved in this particular situation. If you are going to insist that your battery of experts deserves respect then you must also give respect to the battery of experts that disagree with you.


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