AF 447 Thread No. 6
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It doesn't require the complex system to in fact break, or for you to forget your training, to introduce the possibility that a stressed human mind trying to start to appreciate an unanticipated possibility never achieves sufficient confident to diagnose and then act. The awareness of a complex intervening layer is in itself sufficient to frustrate intelligent problem solving, at least in a timely way.
A 'big red button' which forced direct law, with direct law behaviour a set of memory items, would seem a reasonable last resort to offer a bemused crew.
Not forgetting appropriate display of unusual trim conditions and cancellation of any warning cancellations, naturally.
Not forgetting appropriate display of unusual trim conditions and cancellation of any warning cancellations, naturally.
Dozy, is it your position that only the PNF was operating under the awareness that the aircraft was in Alternate Law? I do not think that what has been released from the CVR supports that position. As a number of others have noted, we have no access to various non-verbal communication that went on between them.
Further that point, given the difficulty PF had initially with roll control, one can be fairly certain that he was all too aware that he was in Alternate Law.
The more cogent point made is what BEA seems to have addressed in its findings of how and what preparation, training, and comfort with flying in Alternate Law at high altitude the crew had to fall back on. One could couple a "recency of training data point" to link to the choice to select TOGA ... which takes us back to Lyman.
If his mindset was overspeed, applying TOGA does not seem to fit the problem he was trying to solve.
Further that point, given the difficulty PF had initially with roll control, one can be fairly certain that he was all too aware that he was in Alternate Law.
The more cogent point made is what BEA seems to have addressed in its findings of how and what preparation, training, and comfort with flying in Alternate Law at high altitude the crew had to fall back on. One could couple a "recency of training data point" to link to the choice to select TOGA ... which takes us back to Lyman.
If his mindset was overspeed, applying TOGA does not seem to fit the problem he was trying to solve.
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@Lonewolf_50:
I'm not trying to reply for Dozy, but I wanted to add a comment:
IMHO the lack of an acknowledgement by the PF (according to the CVR transcript) to the PNF calling Alternate Law does leave open the possibility that the PF had not really "heard" that statement.
Agreed, but later he deployed the speedbrakes, which therefore does fit with an overspeed mentality. My view is that the PF's mental picture may have changed (perhaps multiple times) during the whole event sequence, which would therefore explain the seemingly contradictory actions - they were not contradictory at the time he did each one, as his mental picture of the situation had changed in the meantime.
In other words, if we consider that he may just have been trying several different actions because he didn't have any confidence of his diagnosis, then it is perhaps easier to understand why, during the whole event sequence, he did seemingly contradictory things like TOGA and later speedbrakes.
That's my current "model" to try to explain the PF's varied actions. Does this make sense as a possibility?
I'm not trying to reply for Dozy, but I wanted to add a comment:
In other words, if we consider that he may just have been trying several different actions because he didn't have any confidence of his diagnosis, then it is perhaps easier to understand why, during the whole event sequence, he did seemingly contradictory things like TOGA and later speedbrakes.
That's my current "model" to try to explain the PF's varied actions. Does this make sense as a possibility?
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Diagnostic
Yes. It is possible PNF was alerting PF to AL with loss of RAS, as a second, and more determined way of getting the PF in AL 'mode'. Most of PNF's comments were of this type: "Watch out..." "Less Lateral..." "Loss of speeds......Alternate Law". He was, if not the scold, the short fused "instructor", albeit seemingly with good motive.
Yes, again. PF's seeming variable mind set re: overspeed/STALL occurs in a domain where they are not radically different in value. At least initially. We must not forget that the aircraft at a later time warned him of impending STALL each time as he was about to recover. We do not know yet, but at many times post a/p loss the a/c and PF were at odds, as PNF was with PF. Finally, with the arrival of the Captain, who seemed of no use, was there any time after the loss of autoflight that any one was on the same page as the others?
With such a fundamental lack of basic airworthiness, it at times seems bizarre to focus on details...... To what effect?
He did deploy brakes. He was ready to a second time, in presence of Captain, when Captain said "No, do not use brakes". For all we know, it was the lack of a complete stow of a starboard side spoiler that caused the chronic Right Wing drag/drop.
Do we know exactly when Alternate Law 2 selected?
Yes. It is possible PNF was alerting PF to AL with loss of RAS, as a second, and more determined way of getting the PF in AL 'mode'. Most of PNF's comments were of this type: "Watch out..." "Less Lateral..." "Loss of speeds......Alternate Law". He was, if not the scold, the short fused "instructor", albeit seemingly with good motive.
Yes, again. PF's seeming variable mind set re: overspeed/STALL occurs in a domain where they are not radically different in value. At least initially. We must not forget that the aircraft at a later time warned him of impending STALL each time as he was about to recover. We do not know yet, but at many times post a/p loss the a/c and PF were at odds, as PNF was with PF. Finally, with the arrival of the Captain, who seemed of no use, was there any time after the loss of autoflight that any one was on the same page as the others?
With such a fundamental lack of basic airworthiness, it at times seems bizarre to focus on details...... To what effect?
He did deploy brakes. He was ready to a second time, in presence of Captain, when Captain said "No, do not use brakes". For all we know, it was the lack of a complete stow of a starboard side spoiler that caused the chronic Right Wing drag/drop.
Do we know exactly when Alternate Law 2 selected?
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Stimuli in order to be able to analyze a/c "behavior"
Hi,
A lot of sense considering he was always trying to "understand".
Diagnostic
My view is that the PF's mental picture may have changed (perhaps multiple times) during the whole event sequence, which would therefore explain the seemingly contradictory actions - they were not contradictory at the time he did each one, as his mental picture of the situation had changed in the meantime. In other words, if we consider that he may just have been trying several different actions because he didn't have any confidence of his diagnosis, then it is perhaps easier to understand why, during the whole event sequence, he did seemingly contradictory things like TOGA and later speedbrakes. That's my current "model" to try to explain the PF's varied actions. Does this make sense as a possibility?
My view is that the PF's mental picture may have changed (perhaps multiple times) during the whole event sequence, which would therefore explain the seemingly contradictory actions - they were not contradictory at the time he did each one, as his mental picture of the situation had changed in the meantime. In other words, if we consider that he may just have been trying several different actions because he didn't have any confidence of his diagnosis, then it is perhaps easier to understand why, during the whole event sequence, he did seemingly contradictory things like TOGA and later speedbrakes. That's my current "model" to try to explain the PF's varied actions. Does this make sense as a possibility?
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Hi,
You know .. PF's actions may well be the result of his ignorance of the phenomenon that came to him.
His state of mind can be that of someone who does undestand nothing of what happend
And therefore he will do actions that are actually testing and according to results .. do other activities .. hoping that one of them will be good to solve the problem he could not analyze
OT .. but ...
This reminds me a auto crash stop on a diesel generator
The group suddenly stopped and the engineer in charge has undertaken many tests dismantling and replacement parts
Having to resume investigations .. I immediately understood by examining the log data measures engine parameters. that something unusual had happened at the oil system (temperature and pressure)
An worn lubricating oil pump was the problem and not the fuel injection system and turbo blowers that had been dismantled ...
The other mechanic was therefore not understood and therefore tried anything
If he was lucky .. it would have started with the oil system ..
This was not the case ....
A loss of 8 hours of time and money .
You know .. PF's actions may well be the result of his ignorance of the phenomenon that came to him.
His state of mind can be that of someone who does undestand nothing of what happend
And therefore he will do actions that are actually testing and according to results .. do other activities .. hoping that one of them will be good to solve the problem he could not analyze
OT .. but ...
This reminds me a auto crash stop on a diesel generator
The group suddenly stopped and the engineer in charge has undertaken many tests dismantling and replacement parts
Having to resume investigations .. I immediately understood by examining the log data measures engine parameters. that something unusual had happened at the oil system (temperature and pressure)
An worn lubricating oil pump was the problem and not the fuel injection system and turbo blowers that had been dismantled ...
The other mechanic was therefore not understood and therefore tried anything
If he was lucky .. it would have started with the oil system ..
This was not the case ....
A loss of 8 hours of time and money .
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In an emergency, not knowing what to do comes from not knowing what you face. Not knowing what you face is caused by a lack of, or misleading, cueing.
It is not helped by not knowing what one should do if one knew to do it. That is not aided by having to read something to try to understand what it is one does not know. If three of you do not know, the airplane will do what it does, whether you know what that is or not.
If you do not know what the airplane is doing, you should be home playing rummy. If the airplane is coy, or misleading, that can be judged as lack of skill in understanding what it is supposed to do, unless something comes up that the aircraft cannot do, in which case the three who do not know will be blamed for not doing what they didn't know to do in the beginning.
The fact that the airplane and by proxy her designers, did not know, is not important, for they are not present, only the evidence of their work is.
The mistakes they made can be corrected with new work that can be added to the aircraft and utilised until the aircraft once again comes across something it cannot do, and the pilots will be required to understand immediately what it is they do not know, and most likely were not carefully taught.
Repeat........
It is not helped by not knowing what one should do if one knew to do it. That is not aided by having to read something to try to understand what it is one does not know. If three of you do not know, the airplane will do what it does, whether you know what that is or not.
If you do not know what the airplane is doing, you should be home playing rummy. If the airplane is coy, or misleading, that can be judged as lack of skill in understanding what it is supposed to do, unless something comes up that the aircraft cannot do, in which case the three who do not know will be blamed for not doing what they didn't know to do in the beginning.
The fact that the airplane and by proxy her designers, did not know, is not important, for they are not present, only the evidence of their work is.
The mistakes they made can be corrected with new work that can be added to the aircraft and utilised until the aircraft once again comes across something it cannot do, and the pilots will be required to understand immediately what it is they do not know, and most likely were not carefully taught.
Repeat........
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Contrary to Airbus SAS philosophy?
Hi,
Dificult to imagine a change in their minds to implement this (very reasonable) last resort.
"Collision" of K.I.S.S. x K.I.C.S.
Complex Systems can deliver, at certain situations, Stupid outputs. Again the old "Testability issue" of Complex Systems.
Mr Optimistic
A 'big red button' which forced direct law, with direct law behaviour a set of memory items, would seem a reasonable last resort to offer a bemused crew.Not forgetting appropriate display of unusual trim conditions and cancellation of any warning cancellations, naturally.
A 'big red button' which forced direct law, with direct law behaviour a set of memory items, would seem a reasonable last resort to offer a bemused crew.Not forgetting appropriate display of unusual trim conditions and cancellation of any warning cancellations, naturally.
Dificult to imagine a change in their minds to implement this (very reasonable) last resort.
"Collision" of K.I.S.S. x K.I.C.S.Complex Systems can deliver, at certain situations, Stupid outputs. Again the old "Testability issue" of Complex Systems.
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@ RR_NDB and jcjeant:
Agreed, yes - one interpretation is that the PF was basically "trying things", to see what happened, at least on some occasions (e.g. the speedbrakes). I had written something very similar in an earlier draft of my posting, but I deleted it, to try to be brief
So we're thinking along similar lines, I believe.
From that standpoint, the various actions from the PF make a little more "sense" IHMO. If he was indeed in that "let's try X and see if it helps" mode, then perhaps the intermittent stall warning helped to drive & reinforce exactly the wrong actions from him. As I think most people agree, on some occasions, it seems that he stopped doing the correct (ND) inputs, when the SW started to sound, as if he was "testing" his ND actions, to see if they helped, without the real "belief" that this was the right thing to do. (Before anyone says it, yes, I know this doesn't explain the lack of apparent recognition / acknowledgement of the 50+s of continuous stall warning initially.
)
@jcjeant - re your OT: I have seen many similar examples of that type of poor troubleshooting too
Yours is a good example of someone guessing at a (wrong) diagnosis, and not confirming that it explains the available data (e.g. oil temperature & pressure). Thanks for that story.
Agreed, yes - one interpretation is that the PF was basically "trying things", to see what happened, at least on some occasions (e.g. the speedbrakes). I had written something very similar in an earlier draft of my posting, but I deleted it, to try to be brief
So we're thinking along similar lines, I believe.From that standpoint, the various actions from the PF make a little more "sense" IHMO. If he was indeed in that "let's try X and see if it helps" mode, then perhaps the intermittent stall warning helped to drive & reinforce exactly the wrong actions from him. As I think most people agree, on some occasions, it seems that he stopped doing the correct (ND) inputs, when the SW started to sound, as if he was "testing" his ND actions, to see if they helped, without the real "belief" that this was the right thing to do. (Before anyone says it, yes, I know this doesn't explain the lack of apparent recognition / acknowledgement of the 50+s of continuous stall warning initially.
)@jcjeant - re your OT: I have seen many similar examples of that type of poor troubleshooting too
Yours is a good example of someone guessing at a (wrong) diagnosis, and not confirming that it explains the available data (e.g. oil temperature & pressure). Thanks for that story.
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Won't "They" merely repeat that Direct Law is available anyway? Why the Button?
Wouldn't "They" be correct?
As far as cancelling the cancellating logic and eliminating the current obligatory autotrim into STALL, and adding BUSS (they did), and a workable AoA cueing system, that will be done, assuredly. But it will be acknowledged as "probably not really necessary anyway". Won't it?
I suppose in the end, after all is said and done, arrogance is not that lethal, the statistics show us that. Don't they?
Wouldn't "They" be correct?
As far as cancelling the cancellating logic and eliminating the current obligatory autotrim into STALL, and adding BUSS (they did), and a workable AoA cueing system, that will be done, assuredly. But it will be acknowledged as "probably not really necessary anyway". Won't it?
I suppose in the end, after all is said and done, arrogance is not that lethal, the statistics show us that. Don't they?
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When the PFDs are changed (as per A380) to provide conclusive evidence of where the side-stick is, who has got control, along with rudder pedal position and AoA indication - then the "big red button" will be redundant.
If the AoA scale is colored "red" to the top, one would need to believe you are stalled. SS down while keeping wings level and get the nose down and keep it down until the AoA is back under 5 degrees.
On the otherhand, with PFDs as shown above, you'd be hard pressed to get the aircraft into a stall. "Human Factors" notwithstanding!
If the AoA scale is colored "red" to the top, one would need to believe you are stalled. SS down while keeping wings level and get the nose down and keep it down until the AoA is back under 5 degrees.
On the otherhand, with PFDs as shown above, you'd be hard pressed to get the aircraft into a stall. "Human Factors" notwithstanding!
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Crew decision (and not automatically decided by the System)
Hi,
mm43 @ #1005
I would prefer to decide when to use the last resort. My understanding of "big red button" is of a resource not offered automatically by the System. A resource to be used when i decide to "fire" the System. Then starting to use the System just to provide what i will need to "hand" fly the a/c.
The "reconfigs" after that could (should) be implemented gradually, eg THS, etc. and presented to the crew.
mm43 @ #1005
...then the "big red button" will be redundant.
I would prefer to decide when to use the last resort. My understanding of "big red button" is of a resource not offered automatically by the System. A resource to be used when i decide to "fire" the System. Then starting to use the System just to provide what i will need to "hand" fly the a/c.
The "reconfigs" after that could (should) be implemented gradually, eg THS, etc. and presented to the crew.
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When the PFDs are changed (as per A380) to provide conclusive evidence of where the side-stick is, who has got control, along with rudder pedal position and AoA indication - then the "big red button" will be redundant.
Correct me if I'm wrong, but I don't think it is how the 380 is equipped ?
To me it is more the kind of Animation you can obtain from FDR data.
What is seen as "big red button" is a simple way to force Direct Law and benefit from a more 'conventional' aircraft.
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The concept of leaving AB Flight Laws behind, and with the select of a button, at that, is an odious proposal.
It infers that the simple, "DIRECT" method of flight control is superior to that of laboriously designed degrading (cascading?) electronic systems that are inferior to manual control in certain situations: THEY ARE.
This is all about PRIDE, and TURF, and MARQUE.
Nothing to do with flight control, or safety.
It infers that the simple, "DIRECT" method of flight control is superior to that of laboriously designed degrading (cascading?) electronic systems that are inferior to manual control in certain situations: THEY ARE.
This is all about PRIDE, and TURF, and MARQUE.
Nothing to do with flight control, or safety.
Diagnostic.
Later, yes. Agreed.
Yes, that is a very good way to present the event from his perspective. He kept tyring to fit what was happening into a mental picture that he recognized. It seems he never succeeded.
Yes.
Makes a lot of sense to me. 
Agreed, but later he deployed the speedbrakes, which therefore does fit with an overspeed mentality.
My view is that the PF's mental picture may have changed (perhaps multiple times) during the whole event sequence, which would therefore explain the seemingly contradictory actions - they were not contradictory at the time he did each one, as his mental picture of the situation had changed in the meantime.
In other words, if we consider that he may just have been trying several different actions because he didn't have any confidence of his diagnosis, then it is perhaps easier to understand why, during the whole event sequence, he did seemingly contradictory things like TOGA and later speedbrakes.
That's my current "model" to try to explain the PF's varied actions. Does this make sense as a possibility?
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CONF iture,
Correct me if I'm wrong, but I don't think it is how the 380 is equipped ?
Correct me if I'm wrong, but I don't think it is how the 380 is equipped ?
Strangely, the image was part of an Airbus power-point presentation on their revised Stall Recovery Procedure.
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@Lonewolf_50:
Many thanks for your comments. I think it will also be very interesting what the human factors part of the final BEA report says. IMHO sometimes CRM in critical situations works well (e.g. Sioux City UA232), and sometimes it doesn't, like here
I'm lucky in my job that I'm often working with engineers who I have worked with before, which makes it easy to build-up knowledge of each other's strengths & weaknesses, and act accordingly to speed-up the process of reaching a common goal. I can only imagine how difficult it is to work on a flight deck, potentially with people you've never (or only rarely) worked with before, and where you could be put into a time-critical troubleshooting situation at any point.
Many thanks for your comments.
I think it will also be very interesting what the human factors part of the final BEA report says. IMHO sometimes CRM in critical situations works well (e.g. Sioux City UA232), and sometimes it doesn't, like here I'm lucky in my job that I'm often working with engineers who I have worked with before, which makes it easy to build-up knowledge of each other's strengths & weaknesses, and act accordingly to speed-up the process of reaching a common goal. I can only imagine how difficult it is to work on a flight deck, potentially with people you've never (or only rarely) worked with before, and where you could be put into a time-critical troubleshooting situation at any point.
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Originally Posted by mm43
Though I suspect that with the twin PFDs that a similar configuration is available when the correct page(s) is/are selected.
It would be, after all this time ... an implicit acknowledgement that sidestick input information is valuable after all, or even worse, could be necessary.
Thanks for the link.
I would rather think that the slide in question must be just an extract from a full video animation.
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To my recollection there has been precisely one non-fatal incident and one accident where it might (stress *might*) have been useful for the PNF to see what the PF was doing with the stick. That's not many bearing in mind we're talking 23 years of FBW Airbus service these days...
I don't see why the "big red button" is coming into the discussion again either - this was not a "what's it doing now?" accident. Indeed the aircraft effectively gave them the BRB effect - giving the pilots full authority plus autotrim in Alternate Law, which at least one of the pilots mishandled. I'm loath to go back to what I was saying several threads ago, because I don't want to induce a hamster wheel effect, but this kind of accident has happened in non-automated aircraft as well - I don't think the FBW had a hand in this case either. Some may disagree, but so far there has been no evidence to support that assertion.