AF 447 Thread No. 7
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We can't say
Hi,
Organfreak
Too many variables to take into account (uncertainties)
For them (and for us)
Organfreak
I am of the impression that many/most pilots here would have sussed this stall
and flown out of it
Too many variables to take into account (uncertainties)
For them (and for us)
Last edited by RR_NDB; 17th Mar 2012 at 17:46. Reason: Link add
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Hi,
Lyman
Organfreak
In this video ... at time 46 minutes 18 seconds
Pouvait t-on sauver l'avion ? ask the interviewer? ... on ne sais pas répond le chef instructeur pilote d'Airbus ....
Interviewer question:
It was possible to recover the plane?
We don't know answer the chief instructor pilot of Airbus !
Lyman
Once in the climb, and probably very quickly, the odds go sour for recovery
Code:
Please cite an authorative source or support your contention with known facts
Interviewer question:
It was possible to recover the plane?
We don't know answer the chief instructor pilot of Airbus !
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We will be able to understand what occured?
Hi,
Bear,
Perfectly K.I.S.S.
Even BEA may not have all required info
Bear,
Perfectly K.I.S.S.
Even BEA may not have all required info
Last edited by RR_NDB; 17th Mar 2012 at 17:57. Reason: "'s
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Finite State Machines could present "surprises"
Hi,
Bear:
Even the designers cannot explain all anomalies occurred since the introduction of these advanced planes.
Important information is simply lost. And FDR is not designed for that.
Bear:
but no one could ever say why she behaved that way
Even the designers cannot explain all anomalies occurred since the introduction of these advanced planes.
Important information is simply lost. And FDR is not designed for that.
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Originally Posted by RR_NDB
And FDR is not designed for that.
Personal opinion only, since the AP and A/THR dropped at the beginning of the AF447 event, it is extremely unlikely that any control inputs came via that route. Any surprise control inputs would then have to be through the basic ALT2 control structure which appears to have been debugged quite well.
(Although the aircraft must have 10000 times more experience in Normal law than in ALT2 law.)
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The aircraft's behavior in pitch was consistent with stick input.
In really does take the cake to accuse BEA of manipulating data while doing so repeatedly oneself. While the aircraft entered alternate law, it seems some here entered alternate reality.
In really does take the cake to accuse BEA of manipulating data while doing so repeatedly oneself. While the aircraft entered alternate law, it seems some here entered alternate reality.
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HN39 Post #807
If I may ask as a non-pilot: If you're struggling with roll control and your scan has narrowed to the ADI, is it plausible that you miss pitch altogether? Is it possible that he was aware of increasing pitch attitude, but didn't care because 15° was his target all along? Perhaps he only reluctantly and half-heartedly gave in to the PNF's urging "You're climbing, go down" until at 02:10:49 he changed his mind and went for 15°
HN39 Post #815
The second stall warning came at 02:10:51, 2 seconds after he began pulling up again.
If I may ask as a non-pilot: If you're struggling with roll control and your scan has narrowed to the ADI, is it plausible that you miss pitch altogether? Is it possible that he was aware of increasing pitch attitude, but didn't care because 15° was his target all along? Perhaps he only reluctantly and half-heartedly gave in to the PNF's urging "You're climbing, go down" until at 02:10:49 he changed his mind and went for 15°
HN39 Post #815
The second stall warning came at 02:10:51, 2 seconds after he began pulling up again.
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Originally Posted by Hamburt Spinkleman
In really does take the cake to accuse BEA of manipulating data while doing so repeatedly oneself. While the aircraft entered alternate law, it seems some here entered alternate reality.
It is now a free speech world, however, and we are all free to step on our lolly as many times as one can stand.
Credibility? What's that?
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scans and safety
Hi Maching Bird,
Thank you for your scan instruction. What I have written in my post is the most academic manner to do which is learned for IR in France, on slower and less powered aircrafts that yours !
In all cases scan has to be rapid, effective, used,
and AF447's CVR shows a very different scenario !
What do you think about learning effective stall with aerobatics to all airline pilots (and not airline too) ?
Computer systems cannot help us to land when we have fire on board, no more electricity, no more system. A pilot must be able to try to do that, and bring the aircraft and the passenger on the ground.
That is only pleasure !
Originally Posted by Machinbird
We had to hawk the pitch attitude very carefully and note any trends on the altimeter, then apply a correction to pitch to hold altitude. There was too much lag in the VSI to use it for altitude maintenance. All I used the VSI for was to verify I had set pitch and power about right for a descent rate or climb rate.
It is interesting to learn that there has been a change in scan patterns as a result of new technology.
It is interesting to learn that there has been a change in scan patterns as a result of new technology.
In all cases scan has to be rapid, effective, used,
and AF447's CVR shows a very different scenario !What do you think about learning effective stall with aerobatics to all airline pilots (and not airline too) ?
Computer systems cannot help us to land when we have fire on board, no more electricity, no more system. A pilot must be able to try to do that, and bring the aircraft and the passenger on the ground.
That is only pleasure !
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Prime factors are what was in the loop after Law change
Hi,
Machinbird:
I agree!
We have to concentrate (first) on "elements" working in the "great loop". This includes PF (receiving "inputs" we don't have) and A/C "mechanisms" (all that had to work).
Other factors, IMO are to be neglected. Including:
Machinbird:
...it is extremely unlikely that any control inputs came via that route.
I agree!
We have to concentrate (first) on "elements" working in the "great loop". This includes PF (receiving "inputs" we don't have) and A/C "mechanisms" (all that had to work).
Other factors, IMO are to be neglected. Including:
basic ALT2 control structure
Last edited by RR_NDB; 18th Mar 2012 at 00:25. Reason: Text impvmt including Title
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Scientific (and serious) approach requires patience and "Stability"
Hi,
Hamburt Spinkleman:
We can assume this, i agree.
With some months (years) delay.
This happens in high profile cases.
As MB said:
Hamburt Spinkleman:
We can assume this, i agree.
While the aircraft entered alternate law, it seems some here entered alternate reality.
This happens in high profile cases.
As MB said:
It is now a free speech world
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Prime factors (to be considered first)
, i agree.
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Redundancy and reliable inputs
Hi,
With current design this is "almost" impossible.
Smoke can be much worse:
See Dubai flight 6
PF had no chances even to change comm to other ATC. The "element" suddenly inserted in the loop had no vision ahead. We may say: smoke from a cargo fire "broke the loop".
You need fresh air to be able to see ahead. This can be done with a hood.
PS
The same (similar) effect that could explain AF447 PF actions. No valid and reliable inputs to him? Almost zero confidence in the inputs (them) received? This may explain what we learned so far.
no more electricity, no more system.
fire on board
Smoke can be much worse:
See Dubai flight 6
PF had no chances even to change comm to other ATC. The "element" suddenly inserted in the loop had no vision ahead. We may say: smoke from a cargo fire "broke the loop".
You need fresh air to be able to see ahead. This can be done with a hood.
PS
The same (similar) effect that could explain AF447 PF actions. No valid and reliable inputs to him? Almost zero confidence in the inputs (them) received? This may explain what we learned so far.
Last edited by RR_NDB; 17th Mar 2012 at 19:52. Reason: Text impvmt
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Originally posted by Machinbird ...
It would appear from NeoFit's chart that FD data became available just in time to be suspect as a cause for the second pull up leading to the stall.
It would appear from NeoFit's chart that FD data became available just in time to be suspect as a cause for the second pull up leading to the stall.
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Organfreak
Lyman claimed:
Quote:
Once in the climb, and probably very quickly, the odds go sour for recovery
Quote:
Once in the climb, and probably very quickly, the odds go sour for recovery
Please cite an authorative source or support your contention with known facts. There have been hundreds of comments in these forums stating that the stall may have been recoverable. Is it just that you enjoy being a maverick?
Last edited by Organfreak; 17th Mar 2012 at 17:30. Reason: HTML typo
Last edited by Organfreak; 17th Mar 2012 at 17:30. Reason: HTML typo
http://www.pprune.org/7066105-post66.html
As for the AF447 accident: I am an instructor on the A320 and we are now doing high altitude stall demonstrations during recurrent training. When given similar circumstances as the AF447 guys, less than half of the pilots can successfully recover even when they know it is coming. It is not because the pilots do not know how to recover from a stall, it is because pilots at all levels have not been trained in the dynamics of high altitude stalls. High altitude stalls are very different animals. Recovery at high altitudes require significant nose low pitch, to be held for a very uncomfortably long time, and you have to accept a VERY high rate of descent (15,000fpm or higher). AFTER that you have to have a very slow pitch up because a secondary is very easy to occur. Historically when training stalls pilots are taught to lower the nose to the horizon and add full power and to minimize altitude loss. You cannot recover from a high altitude stall using that procedure. If you read what happened, and know how to correctly recover from a high altitude stall, it becomes clear that the AF447 guys were caught off guard because the aircraft did not recover in a way they were accustomed to when training lower altitude stalls.
I have a lot more sympathy for the actions of the AF447 guys having trained and demonstrated high altitude stalls in Airbus FBW aircraft.
I have a lot more sympathy for the actions of the AF447 guys having trained and demonstrated high altitude stalls in Airbus FBW aircraft.
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Originally Posted by Machinbird
FD data became available just in time to be suspect as a cause for the second pull up
MACH:
IF (big IF), in fact, the FD 'bit' him at any point, I 'spect it's the return at 2:10:47 when the CAS is 216k and aircraft vertical speed is +1500 FPM which is what the FD vertical command would have defaulted to because the FD buttons were still engaged. With the nose already having come down from 10-12 degrees to 5.6 degrees (1500 FPM) this would be a 'relatively' subtle nose up command initially that, if flown, could rapidly go full scale taking him back to the documented 13 degrees after 2:10:51 as airspeed continues to decay.
V/S 1500 would also have been annunciated on the FMA at this time.
The FD would indeed only default to ALT CRZ* if within FMGEC CRZ ALT altitude capture parameters (i.e. 34,976), and the FD would, at the earlier time of 2:10:17, have been in the process of providing a vertical command consistent with leveling off at FMGEC/FCU CRZ ALT. It was only available in this mode for 4 seconds before it dropped out again. By 2:10:47 they were well above FL 350 (default mode is V/S).
IF (big IF), in fact, the FD 'bit' him at any point, I 'spect it's the return at 2:10:47 when the CAS is 216k and aircraft vertical speed is +1500 FPM which is what the FD vertical command would have defaulted to because the FD buttons were still engaged. With the nose already having come down from 10-12 degrees to 5.6 degrees (1500 FPM) this would be a 'relatively' subtle nose up command initially that, if flown, could rapidly go full scale taking him back to the documented 13 degrees after 2:10:51 as airspeed continues to decay.
V/S 1500 would also have been annunciated on the FMA at this time.
The FD would indeed only default to ALT CRZ* if within FMGEC CRZ ALT altitude capture parameters (i.e. 34,976), and the FD would, at the earlier time of 2:10:17, have been in the process of providing a vertical command consistent with leveling off at FMGEC/FCU CRZ ALT. It was only available in this mode for 4 seconds before it dropped out again. By 2:10:47 they were well above FL 350 (default mode is V/S).
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Why Persistent NU?
Hi,
After saying "i have the controls" PF became (with the tacit concordance of PM and later the CPT, most of time) the "processor" and the "controller". He was put in the loop substituting in a difficult environment important elements, A/P and A/THR.
PF "output" (SS handling) was evidently based on uncertainties (as per NeoFit graph). His "inputs" are unknown to us and he expressed "high speed" suspicion. His "outputs" were not random, and soon showed a definite "bias to climb" the plane. A bias so strong, to put the plane in a steep climb going above REC MAX.
Probably this is not just explained by "lack of training", surprise, etc. Something very important, together the lack of "reliable" inputs may be was feeding his "processor" during important moments, leading (or misleading him to do that).
His "output" was not random. There was a pattern. This pattern was about the same during most of critical moments before stalling the plane.
After stalling, the reason could be partly explained by what was put in post #66
RetiredF4::
IMO, in this case is very important is to understand why the plane was put in the stall. Looking to all reasons that lead to this: Crew error(s), System anomalies (it's outputs, processing of UAS data), man-machine interface issues, etc. In order to learn from this crash this is absolutely necessary.
PS
The wreckage orientation in seabed proved later to be the coherent with A/C heading when hitting surface. When you have a "pattern" this normally "carries" important information.
After saying "i have the controls" PF became (with the tacit concordance of PM and later the CPT, most of time) the "processor" and the "controller". He was put in the loop substituting in a difficult environment important elements, A/P and A/THR.
PF "output" (SS handling) was evidently based on uncertainties (as per NeoFit graph). His "inputs" are unknown to us and he expressed "high speed" suspicion. His "outputs" were not random, and soon showed a definite "bias to climb" the plane. A bias so strong, to put the plane in a steep climb going above REC MAX.
Probably this is not just explained by "lack of training", surprise, etc. Something very important, together the lack of "reliable" inputs may be was feeding his "processor" during important moments, leading (or misleading
him to do that).His "output" was not random. There was a pattern. This pattern was about the same during most of critical moments before stalling the plane.
After stalling, the reason could be partly explained by what was put in post #66
RetiredF4::
It is not enough to look at the ability of the aircraft to be flown out of the stall, but to judge the success of recovery atempts in view of the knowledge of the crew (and not only of this AF crew) and the ability of the aircraft.
IMO, in this case is very important is to understand why the plane was put in the stall. Looking to all reasons that lead to this: Crew error(s), System anomalies (it's outputs, processing of UAS data), man-machine interface issues, etc. In order to learn from this crash this is absolutely necessary.
PS
The wreckage orientation in seabed proved later to be the coherent with A/C heading when hitting surface. When you have a "pattern" this normally "carries" important information.
Last edited by RR_NDB; 17th Mar 2012 at 22:29. Reason: txt impvmt
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His "inputs" are unknown to us and he expressed "high speed" suspicion.
No pilot actually commented on the "noise", and perhaps this created a common acceptance of "over speed". The don't use the spoilers pronouncement could fall into this "thinking".
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Accelerated degradation of the "effective aircraft"?
Hi,
After worsening conditions: WX then ice crystals, obsolete AS sensors failing simultaneously, "law change", non trained (to this situation) PF applying large SS inputs at high FL, etc. one may ask:
The lack of reliable info during so many time together with non reliable SW and other factors (noise, alarms, etc.) are to promote, GRACEFUL DEGRADATION of the "effective aircraft" (System+PF) or are a recipe for ACCELERATED DEGRADATION? Stressing HF, etc. Actually their fate was sealed VERY FAST.
It seems like exactly when they needed most reliable resources,( e.g. good man-machine interface to allow them to do just the very basic: aviate.) their inputs (mainly the input to PF) were sub standard (lacking, intermittent and perhaps, misleading). This probably will be understood by summer.
PS
mm43:
We have to check carefully the timing.
The attitudes of PM and later CPT are coherent with "lack of enough info.". Like being unable to do any better, despite some moments briefly raising some "not so strong questioning". Seeming (with available info. we have) more doubts than what would be required to act with confidence.
After worsening conditions: WX then ice crystals, obsolete AS sensors failing simultaneously, "law change", non trained (to this situation) PF applying large SS inputs at high FL, etc. one may ask:
The lack of reliable info during so many time together with non reliable SW and other factors (noise, alarms, etc.) are to promote, GRACEFUL DEGRADATION of the "effective aircraft" (System+PF) or are a recipe for ACCELERATED DEGRADATION? Stressing HF, etc. Actually their fate was sealed VERY FAST.
It seems like exactly when they needed most reliable resources,( e.g. good man-machine interface to allow them to do just the very basic: aviate.) their inputs (mainly the input to PF) were sub standard (lacking, intermittent and perhaps, misleading). This probably will be understood by summer.
PS
mm43:
his "inputs" rejected the visual evidence in favour of the cockpit vibration and unusual noise actually being what he "expected" in a high speed situation.
We have to check carefully the timing.
The attitudes of PM and later CPT are coherent with "lack of enough info.". Like being unable to do any better, despite some moments briefly raising some "not so strong questioning". Seeming (with available info. we have) more doubts than what would be required to act with confidence.
Last edited by RR_NDB; 18th Mar 2012 at 00:15. Reason: Post #880 inclusion
