|
jcjeant: I believe if you refer to the original French version, you will get a bit different nuance to these interactions.
While the English document says, "the Captain attended the briefing between the two co-pilots" the original French is "le commandant de bord assiste au briefing entre les deux copilotes." The verb "assiste" in French translates better into "participates." Thus, a better interpretation is not just that the Captain was present, but that he interacted as well. So although he may not have been the leader of the briefing, he was more than just a listener. For the second phrase, the English document says, 'the PNF said "you can maybe go a little to the left […]".' But the original French says, 'le PNF propose "tu peux eventuellement prendre un peu a guache [...]".' I would translate this as 'the PNF suggests "you could go a little to the left"' which is a little more directive than "maybe." While these alternative translations don't reverse the interpretation of what was going on, I think they suggest there was a bit less diffidence in the cockpit than is suggested by the English document. |
However, if the PF (or the 'system') stalls the aircraft at altitude and can't recover because the controls won't respond or the instruments don't indicate a stall or the PF's training is lacking; then IMHO that is NOT pilot error. Of course it's not. An opinion: Is that that there are basic software design misconceptions, with regard to the interface between humans (pilots) and the aircraft automation, built into certain commercial passenger aircraft. These misconceptions have been compounded and endorsed (perhaps in misguided good faith) by certain airline operators who believe that they can reduce their 'pilot training' costs by using aircraft that can 'fly themselves'. These airline operators would have a philosophy something like this: Why waste money on over-training pilots if the aircraft automation can handle the aircraft in flight? We can just train our pilots to fully believe in the aircraft automated systems can't we? The systems cannot go wrong can they? But maybe they can... This aircraft went down 3.5 minutes after the AP disengaged and handed control to the PF, without apparently giving any indication to the PF as to why the AP disengaged. A supposedly highly sophisticated aircraft automation system just gives up in a flight situation which it cannot handle and gives control to the humans on the flight deck without any indication as to why it did this? WTF! Is there an SOP for the pilots to deal with this situation? If so, can the SOP be effectively executed in less than 3.5 minutes (or before the aircraft falls out of the sky) and if not, why not? These questions really bother me. I cannot imagine how those guys on the flight deck felt or what they thought when confronted with this situation, not to mention what the passengers/CC went through, if they were (God forbid) ever really aware of their situation... So how about we take all the software writers who conceived this system, the beancounters who drove it's implimentation and the managers who approved it, put them all on the same type aircraft in a identical situation (with the managers in the drivers seats) and just say 'OK, you have control guys'... |
Hi,
The english translations of the original French BEA reports must be treated with caution. The BEA clearly states that the authoritative version is the original French copy. Entre 1 h 59 min 32 et 2 h 01 min 46 , le commandant de bord assiste au briefing entre les deux copilotes, au cours duquel le PF dit notamment que « le petit peu de turbulence que tu viens de voir […] on devrait trouver le même devant […] on est dans la couche malheureusement on ne peut pas trop monter pour l’instant parce que la température diminue moins vite que prévu » et que « le logon a échoué avec Dakar ». Le commandant de bord quitte le poste de pilotage. A 2 h 08 min 07 , le PNF propose « tu peux éventuellement prendre un peu à gauche […] ». L’avion entame un léger virage à gauche ; la déviation par rapport à la route initialement suivie est d’environ 12 degrés. Le niveau de turbulences augmente légèrement et l’équipage décide de réduire le Mach vers 0,8. The captain attended (assiste) the briefing (the captain is there observing the discussion between the two pilots .. he don't take the lead of the discussion) Or J'assiste a un match de football I attend a football match Le verbe assiste n'a pas le sens d'assister en tant qu'aider The verb has no meaning attends to attend as helping :) EG: Je t'assiste a lever ce meuble I help thee to lift this furniture Or Je te porte assistance I bring you support If the captain is there for help it will be ... Le capitaine apporte son assistance pendant le briefing Captain assists during the briefing Can you possibly or maybe (éventuellement) take a little to the left (it's a proposition .. a polite suggestion .. he offer a choice to the PF .. it's not a order) The sens of the sentences from french to english is exactly the same ....... The french language is full of words meaning the same thing ... c'est la finesse de la langue française :) |
Re: Icing or Specifically Ice Crystals
|
French & English
jcjeant,
with all due respect, but to my taste SeenItAll's perception of the appropriate french-to-english translation is better than yours. secondly, the way the weather avoidance is phased is a GOOD example of CRM, polite phrasing is an important part of the game. |
Hi,
with all due respect, but to my taste SeenItAll's perception of the appropriate french-to-english translation is better than yours. Je ne suis peut-être pas un champion de l'orthographe ni sociétaire de l'académie française mais j'ai quand même quelques connaissances de la syntaxe ... :) While the English document says, "the Captain attended the briefing between the two co-pilots" the original French is "le commandant de bord assiste au briefing entre les deux copilotes." The verb "assiste" in French translates better into "participates." Thus, a better interpretation is not just that the Captain was Si vous assistez a un briefing ou si vous assistez a un tournois de tennis .. vous ne prenez pas part au briefing ou au jeu ... vous êtes juste un spectateur Le BEA (en français dans le texte) emploie le verbe "assiste" Si le BEA voulais que l'on comprenne que le Cdt était part active de ce briefing .. il aurais du employer le verbe "participe" Si c'était vraiment cela l'intention du BEA ... le rédacteur de cette note doit revoir sa syntaxe .. car il induit les lecteurs en erreur La bonne formulation: Le Cdt participe au briefing avec les deux pilotes Salutations. PS: Translation in english on request :8 |
Engine Anti Ice
Answer to # 1473
On the subject of Engine Anti Ice below -40, or not: you will get your answer if you read the Boeing Bulletin. Engine Anti Ice heats the cowl inlet lip and the spinner bullet nose. In that way, it prevents the build up of large chunks of ice, that may break off and damage compressor blades further down the engine. To be used in regions of supercooled droplets. Ice crystal icing takes place inside the compressor section of the engine, there where Engine Anti Ice does not heat anything. So, turning on TAI below -40 serves no purpose. Ice buildup on cowl lip or spinner does not occur, because the ice crystals bounce off them. In general. On the subject of pitot icing: yes, it can happen, on Airbus as well as Boeing. TAT probe icing happens as well, probably more often than pitot icing. It can be observed from the TAT anomaly phenomenon (again, read the Boeing Bulletin). For crystal icing to occur, you do not have to fly through any solid wall of red, just the light green outskirts will suffice. On the subject of stall recovery - even when not stalled, when ever is 15 degrees nose up an appropriate attitude at FL 350 in a big lumbering airliner? |
After flying quite a few pure glass cockpits there is something very comforting about getting a purely analogue aircraft......
|
EMIT,
A very nice summary of engine anti-ice usage. The only thing I would add is the warm air used for the nacelle and spinner cone anti-icing comes from bleed air off the compressor. So if you use it when it is not needed, it hurts the overall engine efficiency. |
@GY
"From 2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the controls". The airplane began to roll to the right and the PF made a left nose-up input."
So... What would be the correct input (in your eyes), given an undesired roll-right (nose-down), event? You prolly are aware of the term "Heuristics" and its relationship to "intelligent" software design... |
A very nice summary of engine anti-ice usage. The only thing I would add is the warm air used for the nacelle and spinner cone anti-icing comes from bleed air off the compressor. So if you use it when it is not needed, it hurts the overall engine efficiency. |
French/English translation
Entirely in agreement with jcjeant.
Le verbe "assister" ne signifie aucunement que le Cdb prend part à la discussion. Il est présent et entend l'échange entre les deux co-pilotes mais ne "participe" pas à cet échange. Il n'y a aucun doute la-dessus. Il n'est nulle part fait mention que le Cdb ait dit quoi que ce soit à ce moment là sinon il aurait pris part et donc aurait participé. As for the second phrase "tu peux éventuellement prendre un peu à gauche" cannot be translated as "you could go a little to the left". The french translation of "you could go a little to the left" is " tu pourrais aller un peu vers la gauche". And that does not meet the original french wording. The meaning of the "eventuality" is left out. Cela fait partie des nuances de la langue française. Amicalement |
Interesting article which calls attention to the Trimmable Horizontal Stabiliser having remained virtually at full nose-up from very early on; calling attention to the fact that the same thing had happened before, to an A320 near Perpignan in November 2008:-
One question lies with the trimmable horizontal stabilizer (THS). The critical phase of the flight, from autopilot disengagement to the crash, lasted 4 minutes 23 seconds. During the last 3 minutes 30 seconds, the position of the THS went from 3 degrees to 13 degrees nose-up and then remained unchanged. Yet, from about 2 minutes before the crash, the pilot flying switched to pitch-down inputs. So, as French website aerobuzz.fr pointed out, why did the THS stay in such a nose-up setting? This may hint at the flight control law being no longer “normal” but in a mode (“alternate” or “abnormal”) where the autotrim function is deactivated. In that instance, the crew has to trim the stabilizer manually. In an A320 accident that took place near Perpignan, France, in 2008, the crew’s failure to recognize this situation contributed to the catastrophic chain of events. In the case of AF447, the crew did mention “alternate law” in the recorded conversation. Also found an article on the Perpignan accident. This confirms that the investigators determined that "a progressive pitch-up deflection of the horizontal stabiliser as the A320 decelerated" had contributed to the accident. The investigators concluded that water in the AoA sensors (which they thought had probably been introduced by sloppy maintenance on the ground) had frozen at altitude and caused the malfunction:- "With the workload mounting in the cockpit, because the aircraft was on approach to Perpignan, the low-speed test commenced. But the blockage of the angle-of-attack sensors resulted in an underestimation of the limit speeds for the A320's angle-of-attack protection. "The crew waited for the triggering of these protections while allowing the speed to fall to that of a stall," says the BEA. It says this "passive" wait for the protective systems, a lack of awareness of the risks, and confidence in the operation of the aircraft's systems "tend to show" that the captain and the ANZ pilot started the manoeuvre as a "demonstration of the functioning" of the angle-of-attack protection "rather than as a check"." Although the stall warning sounded, and the captain increased thrust and pitched the aircraft nose-down, the configuration of the aircraft - notably a progressive pitch-up deflection of the horizontal stabiliser as the A320 decelerated - and the failure to understand the jet's behaviour, resulted in the situation deteriorating and the crew's losing control of the stall recovery. All seven occupants were killed when the A320 struck the water, just 62s after the stall alarm. |
Forgive me for being an occasional 'dipper' into this thread (no time to read it and the others to completion) but has anyone overlaid the ACARS messages onto the BEA transcript yet to possibly point out what the aircraft thought it was doing whilst those in the cockpit were clueless?
|
I'm not a jet pilot or engineer but..
Has the possibility of a fault with the PF stick been ruled out? Suppose that fault added a constant nose up. Presumably that would cause the THS trim to exagerate the problem? A stuck bit fault in a digital system can appear to add a constant to an otherwise correct value (eg it adds 1,2,4,8,16 etc) but you would hope error detection catches such faults. Anyway Google finds.. Chapter 5. Flight controls Airbus A320 Family Non-Normal Notes 5.19. Sidestick unannunciated transducer faults It is possible for a failed sidestick transducer to cause uncommanded control inputs. If no fault is detected, the result is that the aircraft behaves as if that input had actually been made. Generally, the autopilot will disconnect and any attempt to control the aircraft with the failed sidestick will fail. The aircraft should be recovered with the other sidestick using the takeover button. Keeping this button pressed for 40 seconds will lock out the failed sidestick, and the autopilot can then be re-engaged. The autopilot should not be disconnected in the normal manner as pressing the takeover button will re-introduce the failed sidestick and the uncommanded input; use the FCU instead. |
Mike-B
whilst those in the cockpit were clueless? |
This aircraft went down 3.5 minutes after the AP disengaged and handed control to the PF, without apparently giving any indication to the PF as to why the AP disengaged. A supposedly highly sophisticated aircraft automation system just gives up in a flight situation which it cannot handle and gives control to the humans on the flight deck without any indication as to why it did this? WTF! Is there an SOP for the pilots to deal with this situation? If so, can the SOP be effectively executed in less than 3.5 minutes (or before the aircraft falls out of the sky) and if not, why not? These questions really bother me. PF flies aircraft and states I have Control. It can, and should, be 'effectively executed' in <5 seconds. Priority #1 is flying (and Airbus philosophy) and far above discussion, let alone diagnosis, of "why" the AP disconnected. The reasons it can do so are numerous - and largely irrelevant at the time. A supposedly highly sophisticated aircraft automation system just gives up in a flight situation which it cannot handle and gives control to the humans on the flight deck without any indication as to why it did this? WTF! |
Pointed out to me by a private aviation group, interesting comment here.
Credit AVweb. AVmail: June 6, 2011 Letter of the Week: Airbuses Fly "Like a Video Game" I would like to offer my comments and perspective with regard to the Air France Flight 447 accident. I have been a A-330 captain since 2003 and have over 4500 hours in the aircraft. While many A-320 pilots undoubtedly have more series time, I believe this probably makes me one of the most experienced A330 pilots in the world. When asked how I like the aircraft, I tell people that there is likely no easier airplane to take over an ocean, and that the systems design and presentation is superb. That said, the automation is more complex and less intuitive than necessary, and the pilot-aircraft interface is unlike that of a conventional aircraft. Most important with regard to this accident is the fly-by-wire sidestick control. The sidestick itself has a very limited range of motion, making inadvertent over-control very easy. Of even greater significance, the stick itself provides no "feel" feedback to the pilot. That is, unlike a conventional aircraft, the pilot does not get a sense through pressure of how much input is being sent to the control surfaces. The most important advice I give to pilots new to the Airbus is to treat the aircraft not as an airplane, but as a video game. If you wait for the sidestick to tell you what you are doing, you will never get an answer. Taking into consideration that Air France 447 was at FL 350 (where the safe speed envelope is relatively narrow), that they were in the weather at night with no visible horizon, and that they were likely experiencing at least moderate turbulence, it does not surprise me in the least that the pilots lost control of the aircraft shortly after the autopilot and autothrust disconnected. Let's keep in mind that these are not ideal conditions for maintaining controlled flight manually, especially when faced with a sudden onslaught of warning messages, loss of autofllght, confusing airspeed indications, and reversion to "alternate law" flight control, in which certain flight envelope protections are lost. A very bad Airbus design feature is thrust levers that do not move while in autothrust. They are instead set in a detent which would equal climb trust in manual mode. If the pilots did not reset the thrust levers to equal the last cruise power setting, they likely eventually ended up in climb power, making it difficult to reset the proper cruise power setting and adding to what was likely already a great deal of confusion. But the real problem probably occurred immediately after the pilot flying grabbed the sidestick and took over manually. Unfortunately, airline pilots rarely practice hand-flying at high altitude, and almost never do so without autothrust engaged. As a result, we forget that the aircraft is very sensitive to control inputs at high altitude, and overcontrol is the usual result. Because the Airbus sidestick provides no feedback "feel" to the pilot, this problem is dramatically compounded in this aircraft. I believe the Air France pilot grabbed the sidestick, made an immediate input (because as pilots, that's what we tend to do), and quickly became quite confused as to what the aircraft was truly doing. This confusion likely was exacerbated by fixating on airspeed indications that made no sense while trying to find a power setting with no airspeed guidance. When transitioning from autopilot to manual control at altitude in the Airbus, the most important thing to do at first is nothing. Don't move a thing, and then when you do, gently take hold of the sidestick and make very small inputs, concentrating on the flight director (which, in altitude hold, should still have been providing good guidance). Of course, this is much easier said than done with bells and whistles going off all over the place, moderate turbulence and a bunch of thunderstorms in the area. As I said before, treat it like a video game. So why did the Air France pilot find himself at the limits of sidestick travel, and then just stay there, maintaining a control input that simply could not logically be correct? When things go really bad and we are under intense pressure, it is human nature to revert to what we know from previous experience. Remember, the Airbus flies like no other aircraft in that the sidestick provides no feedback to the pilot. It is a video game, not an airplane. I believe the Air France pilot unintentionally fell back on all of his previous flying experience, in which aircraft controls "talkedF" to him when he moved them. Distracted by many confusing inputs, he instinctively expected to be able to control the aircraft by "feel" while dividing his attention to address other matters. I've seen it happen in the simulator, and in an Airbus this is a sure way to lose control of the aircraft and is possibly the most dangerous aspect of Airbus design philosophy. One last note: Airbus pilots often claim that the aircraft "can not be stalled." When the flight controls are in "normal law" this is a reasonably true statement. However, in "alternate law," as was the case here, stall protection can be lost. If we ever practiced this in the simulator, I don't remember it. Lest anyone think I am blaming the Air France pilots for this accident, let me be clear. Despite all of my experience in the aircraft, I am not the least bit certain that I would have been able to maintain control under the same circumstances. I do feel certain that were you to spring this scenario on pilots in a simulator without warning less than half of them would have a successful outcome. Safely flying the 320, 330 and 340-series Airbus requires something of a non-pilot mindset. Name Withheld Editor's Note: We have spoken with the writer of this letter to confirm his identity and honored his request for anonymity. |
Originally Posted by Carjocky
A supposedly highly sophisticated aircraft automation system just gives up in a flight situation which it cannot handle and gives control to the humans on the flight deck without any indication as to why it did this? WTF!
Any autopilot/autothrust system needs inputs to work. If one of more of the required inputs are lost, it will stop working. When the autopilot dropped out here it was clear to the pilots why it had dropped out, and it told them what control law they were now in. The PF verbalised the control law, and the reason for the autopilot dropout. Flying without an autopilot is not a problem. Flying with unreliable airspeed is not a problem, and there is a QRH procedure to help you climb or descend, fly level and fly an approach. It doesn't take any time to "do" this procedure, since the first action for UAS in level flight is to do nothing - ie maintain the cruise pitch and thrust using manual controls. Unfortunately here the pilots for some reason (much debated and not yet understood) increased the pitch and stalled the aircraft. The exact details of the effect and strength of the turbulence is not yet known. They then had to unstall the aircraft, with UAS. This, again, they failed to do as they did not reduce the pitch. From the scanty information from the BEA, the only "surprise" from the aircraft was the lack of stall warning at very low speed. It might have been better if it was not suppressed, but to any pilot with more that 10 hours experience it should have been obvious that they were stalled. Quite why they did not see and correct the stall has yet to be explained - but there may well be more clues in the full report. |
Chers
Flamant Rose et jcjeant, I still am in disagreement with you: Entirely in agreement with jcjeant. Le verbe "assister" ne signifie aucunement que le Cdb prend part à la discussion. Il est présent et entend l'échange entre les deux co-pilotes mais ne "participe" pas à cet échange. Il n'y a aucun doute la-dessus. Il n'est nulle part fait mention que le Cdb ait dit quoi que ce soit à ce moment là sinon il aurait pris part et donc aurait participé Really, "assister" is not always employed in the restricted use you advocate. While I can agree with you for the assistance to a tennis-match, I do not definetely would agree for the assistance to a briefing. That at least others have the same feeling like me (note my careful, polite and non-authoritive wordings in my initial post), I might be allowed to substantiate by showing an exerpt from the very first google answer to the meaning of "assister" and its translation :): assister, verbe transitif Sens 1 Secourir, aider quelqu'un. Synonyme secourir Anglais to assist Sens 2 Seconder. Synonyme seconder Anglais to assist Sens 3 Être présent. Ex Assister à un match de tennis. Synonyme être Anglais to attend Note that the meaning that you state as exclusive (il n'y a aucun doute) even ranks only 3rd place. Now, I also have looked in some old dictionaries (50 y), and, curiously enough, the order is the other way around. Given these facts we possibly could agree on the following 1) assister is a word for which the extent of its meanings has some leeway 2) this leeway apparently seems to change in time 3) most likeky the BEA-writer was not conscious about all this semantic issues this when he used the expression 4) and anyhow we do not know his own perceiption of our subject of discussion. Bien Amicalement |
Hi,
Given these facts we possibly could agree on the following 1) assister is a word for which the extent of its meanings has some leeway 2) this leeway apparently seems to change in time 3) most likeky the BEA-writer was not conscious about all this semantic issues this when he used the expression 4) and anyhow we do not know his own perceiption of our subject of discussion. Bien Amicalement The verb "assister" can indeed be understand .. have the meaning of help someone or the meaning of rescue someone .. etc ... But as used in the stance of the BEA .. the meaning is the same than "assister a un tournois de tennis" You can't help a "thing" Briefing is a "thing" Vous assistez a une chose .. a un spectacle .. a un évènement Vous ne pouvez pas aider une chose .. un spectacle .. un évènement Mais vous pouvez aider .. assister .. secourir une personne .. un animal C'est juste une question de syntaxe .. le contexte dans lequel le verbe est employé It's no in the BEA stance two ways meaning ... it's only one .. and it's "attend" The BEA don't use the verb "assist" 3) most likeky the BEA-writer was not conscious about all this semantic issues this when he used the expression |
Basil:
At last a reasoned comment. I have reviewed most of the posts and have concluded that we should all wait for BEA to review the data and, at least, provide a complete time-line and FDR traces. |
To re-enter the translation discussion ...
Language is often quite flexible, and requires context and inflection to discern its particularly-intended meaning. The BEA transcripts give us neither. We don't know the precise context in which these phrases were uttered -- because the preceeding and trailing conversations are not provided; and because we only have the BEA text and not the actual CVR recording, we don't have the tone and inflection. Once (or if) the full CVR is made available, then we may better know exactly what these pilots really meant or were doing when they said these things. Of course it is also possible that the BEA selected its particular English translation because it thought that its selected words conveyed better the complete nuance of the conversation (for which they know the context and inflection) than the would be conveyed by a literal translation of the French. But I will note that it would be hard, on the basis of the BEA listening to a CVR, for it to conclude that the captain "attended" the briefing if he said absolutely nothing. :) |
two important views !
Please compare post 1219 and post 1491. We are dealing here with two very experienced men . The Shadow's possible analysis complies a lot with the experience of a many hours 330 skipper. In 1491 once more is brought forward the design of stationary throttles. From the beginning of the 320 design this was a mistake according to line pilots from various companies, Airbus interviewed.
To my best knowledge in the very beginning of the 320 ,Indian Airlines had a accident at Madras during push back and engine start . There the tow pin broke and the tow bar sheared the ground/air wiring on the nose strut. The acft. thought it was in the air with 0 IAS and the computer gave GA thrust without the pilots noticing it. It ended up with it's nose in the terminal. Imhu if we continue flying these planes and we will, training and pilot's system knowledge should get more attention. Yes it will cost a little more money. |
I have reviewed most of the posts and have concluded that we should all wait for BEA to review the data and, at least, provide a complete time-line and FDR traces. If you've noted my post 1486 above, the BEA analysed a remarkably-similar accident that befell an Air New Zealand A320 in November 2008. But, at first, they issued only a pretty 'non-committal' report that very closely paralleled the recent 'note' on AF447. It wasn't until September 2010 - many months after the AF447 accident - that they issued their 'final report' on the 2008 ANZ accident. OK - I'll stick my neck out. I think that the evidence provided by the Air New Zealand accident, plus AF447, already provides enough evidence to point to an urgent need to review both aircraft systems (particularly the operation of stall warnings, and such things as the THS 'default mode') and pilot training (particularly the difference between 'stall avoidance' and 'stall recovery'). And that such measures should be embarked upon next week at the latest. NOT in a year's time or more, when the BEA eventually issues its final report. On the face of it, as things stand, the same sort of accident could happen again tomorrow? |
Yes on the face of it. Likewise another airburst of a Rolls, a rollback of a TRENT, a runaway THS, etc. Not that that will happen. What's missing is an open disclosure of the mods, the research, and transparency to the flying public.
Oh.....and the ODDS. Informed decisions are the only kind that mean a thing. |
[quote+EMIT]
In general. On the subject of pitot icing: yes, it can happen, on Airbus as well as Boeing. TAT probe icing happens as well, probably more often than pitot icing. It can be observed from the TAT anomaly phenomenon (again, read the Boeing Bulletin). For crystal icing to occur, you do not have to fly through any solid wall of red, just the light green outskirts will suffice. [/quote] 1. If TAT probe ices up, how much impact would that have had on the pilot's observation during the crew brief (all three pilots) in re temperature not changing as forecast? How much impact would that have on the T value used by the ADC for various computations, and thus both displays and inputs to the Flight Control Computers? 2. If AoA vane/probe ices up, is there a warning associated with that which crops up on ECAM? I'd not expect an iced AoA probe to be noted in ACARS for maintenance, since AoA would most likely un ice as the aircraft descends. (Put another way, flying in and around ice isn't a maintenance fixable issue in re AoA performance in flight. ) If AoA is suffering from ice degradation, is that of any use in discussing this mishap? It appears that the AoA probe kept feeding FDR data all the way down. Is there any reason not to assume the AoA dat reliable? |
On the subject of pitot icing: yes, it can happen, on Airbus as well as Boeing. |
Originally Posted by Lonewolf_50
(Post 6501359)
2. If AoA vane/probe ices up, is there a warning associated with that which crops up on ECAM? .....
If AoA is suffering from ice degradation, is that of any use in discussing this mishap? It appears that the AoA probe kept feeding FDR data all the way down. Is there any reason not to assume the AoA data reliable? Please, let's not confuse AF447 with Perpignan, where it seems, during washing on the ground, water got into the AoA sensor part, which then froze at altitude, stopping the vane from rotating freely. Is there any reason not to assume the AoA data reliable? They can be corrected for AoA + IAS + Mach, etc. only within the flight envelope explored during test flights.... I would suggest the "AoA data on the FDR" are likely to be good enough to be accepted as a first ballpark figure, until we get the full records. |
We should review the incident to an A-340 (with the same control logic) which experienced a zoom during cruise over the North Atlantic. While this was reported as an near-miss incident, the circumstances have unmistakable similarity.
The A-340 was in turbulence and entered alpha-protection which, with no stick input commands alpha-prot (about 4.2 deg at M=0.6). Achieving this resulted in a zoom of about 2300 ft (as I remember). The angle of attack reported in the latest BEA summary is about the same. I'm traveling, so I can't refer to the report, but the incident was to A-340, TC-JDN on 2 October 2000. The report was AAIB Bulletin 6/2001. |
RWA, I went back a few pages to try and figure out the context of that which you isolated, and could not find the post. I think what was in my mind was that we have had a number of different mishaps and incidents discussed here, and pitot anomalies have been featured in either family of aircraft. (As contributing causes to incidents or mishaps/crashes).
I am not sure if I sensed an AB bash and was responding to that, or why I phrased it just so. So I can't answer your question, as I am not sure what post (in total) you were referring to. :bored: |
@ Goldfish85
|
1491-Excellent analysis regardless of accident findings
As much as the author of 1491 has spent in the Airbus , I have spent in Boeing and Douglas aircraft and although I finished my career( 26,000 hrs) in glass cockpits I consider myself a "steam gauge" pilot. In the days when we have the glass all over the place the problem in recreating this scenario will be determining "what the pilots saw"....what information was given to them and what screens were just blank?
Not too long after the Delta L-1011 crashed at DFW the airlines came up with an AAMP (Advanced Aircraft Maneuvering Program) that was meant to show the pilots of transports how to get max performance out of their aircraft...one thing we at our airline found out that when the sim was put out of the normal flight envelope and then handed over to blindfolded flight crew they were able to recover the aircraft by reference to the attitude indicators and airspeed alone....EXCEPT for our Airbus sims...all the screens went black with a big RED X across them...apparently since they were outside their flight envelope ...I say apparently because we could never get a response from Airbus on why this occurred except the same caveat I read in response to the professor from University of Berlin ...face it , if any fault is laid at the Airbus door for bad design/ cause of accident, that will be the end of Airbus....and the EU will not stand by for that....blame the pilots , they can't talk back. There's been enough doubt cast over the whole Airbus laws of control to warrant a serious review....One thing I do know....if I wanted to split -s a 747 from FL 410 , it would roll over and do what I asked it to . Nobody here has shown that the Airbus would or could. I am not trying to say that they don't have some great features but for 3 and one half minutes three very qualified pilots tried to avoid dying and were unable to do so because either they didn't know what was REALLY happening or because they couldn't do anything about it. Either way AIRBUS owes them and us a better answer than WE need more training...maybe they do in how to design Pilot's airplanes... |
Was this significant in terms of priorities and delays,
the commander took manual control of the aircraft because neither autopilot would engage. |
As much as the author of 1491 has spent in the Airbus , I have spent in Boeing and Douglas aircraft and although I finished my career( 26,000 hrs)... I have zero hours in a simulator, but I am pretty positive that simulators can only accurately reproduce the real life data they have been fed. Meaning that unless Airbus or Boeing deliberately fly an aircraft outside its envelope, and record the data, the simulator will not be able to reproduce accurately the aircraft reactions. |
Guys,
The mid-atlantic A340 zoom climb has little bearing on the AF447 accident. Try reading the reports. :ugh: The high speed protection was triggered by turbulence and the aircraft did what it was designed to do. The AF climb was pilot induced, it's there in the report quite explicitly. Why the pilot made nose up inputs is the real mystery here and it may possibly have something to do with his airspeed reading. The high speed protection was disabled when the aircraft went into alternate 2 law and was never available. |
"...The AF climb was pilot induced, it's there in the report quite explicitly..."
No it in't. BEA made NO conclusions, they only reported data. YOU say it was PF induced, conclusively. There is a mild difference. |
Good post 1491 (Basil) interesting in that the upper air handling is a challenge. BEA say trim was 29% usually that would be 38% I.e more aft.. That may be because of the AF configuration.. (note the cofg moves aft in flight due fuel transfer to tail) which makes the a/c even more sensitive in pitch.
I agree IMHO a very very difficult situation when one takes surprise/shock into account. |
Sim programming
WilyB,
The sims have a sets of equations describing everything from Engine Performance to turbulent weather to day/night to ACARS ...the data points to create that would take decades if they were collected and then programmed. The whole idea of the sim is it will do exactly what the plane would in the real world....if they had to program captured data points that means that the below glide slope approach some guy flew in the sim wouldn't be possible unless they'd captured the data points beforehand....the whole reason they can train pilots to fly the 787 or 380 before the plane ever flies is because they have detailed equations to describe all phases of flight....what happened to our Airbus sims is that the equations only described what the programmers in Toulouse expected pilots to see in normal flight regimes. |
Man Flex,
I agree with you. From the AF447 report: From 2h 10min 05sec, the autopilot then auto-thrust disengaged and the PF said, "I have the controls". The airplane began to roll to the right and the PF made a left nose up input. The stall warning sounded twice in a row. At 2h 10min 16sec, the PNF said, "So, we've lost the speeds" then "alternate law". The airplane's pitch attitude increased progressively beyond 10 degrees and the plane started to climb." It certainly sounds "quite explicitly" to me. It is reported data, no conclusion necessary. Relative to the mid-Atlantic A-340 zoom incident, I agree that was different in many respects. To begin with, erroneous speed was not the reason for the AP/AT disconnect, as was the AF447 AP/AT disconnect. For AF447, one of the first fault messages with cockpit effect was "PROBE-PITOT 1X2 /2X3 / 1X3 (9DA)", and IMO, this is what caused the AP/AT disconnect and lead to the cascade of subsequent events. |
| All times are GMT. The time now is 23:00. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.