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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.
The function is normally there to either transfer control, or in the case of PF incapacitation. No need to change seats. |
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? |
Out of interest, what happens in this 'computer game' if the one who has 'lost' control then presses the button for the requisite time?
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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 ? 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. 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. Dozy: I'd say the extreme AoA was probably fouling the static data from 02:11:47 onwards.
Originally Posted by houlett
When a french pilot said GAUCHISSEMENT he speak 's about ROLL
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 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". ...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. 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. GerardC In all, 4 stall warning activations. Would not YOU be confused : nose down -> stall ; nose up -> NO stall. 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. 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.
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? |
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? |
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:
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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. |
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. 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? |
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.
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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. |
Hi,
Any lawsuits already been filed? 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. |
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. Perhaps google translate is to blame for this? :E:oh: |
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. |
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......
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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: 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 |
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? 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. |
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.
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. 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. |
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@DozyWannebe
Hello DozyWannebe,
What do you mean by:
Thank you, |
@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. |
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