Air France 447 - On topic only!

[Fear_of_Flying]

I don't think human nature is our ally in this conversation because it seems to me that, at the end of the day, people want to have a satisfactory explanation for things. If the gap between certainty and available information is too great, people are quite willing to fill that gap in with suppositions in order to arrive at an explanation that is plausible and not contradicted by what is known.

Yet consider if the AF accident were more typical, occurring over land, with much more evidence at our disposal. Would we have been satisfied with a preliminary report based on the error messages, a report that could have essentially been made the next day after the crash? Of course not. Since when was the totality of a final report, "See Preliminary Report"?

Don't crash investigators constantly have to guard against arriving at a conclusion too soon, before all possibilities have been examined and ruled out? How many accidents have appeared to be caused by one thing, only to have turned out to be caused by something completely different?

While I agree that we have a "most likely candidate" for the AF crash, I also think that by nature we are willing to accept whatever we can get our hands on given the limiting circumstances, and then we become comfortable with our satisfactory explanation, filling in the unknown spaces with suppositions.

We were told repeatedly by authorities during the early investigation that there was indeed a missing piece still to this accident, but conveniently that piece seems to have fallen into the distant background over time, to have become incidental, as we become more inured to the notion that of course it would have been extremely difficult - nearly impossible in fact - to save the aircraft once the speed data was lost in those conditions.

Yet is it not reasonable to speculate that subsequent to the initial crisis, a secondary event occurred that ultimately led to the aircraft's demise? Perhaps it would turn out that the plane could have and should have been saved, except that some other terrible mistake was made.

What explanation would we have come up with had the Colgan aircraft simply vanished after the fact, and we had no way of analysing the data and the wreckage? Would we not most likely have settled on the explanation that the primary cause was a stall at low altitude brought on by icing conditions?

As it turned out, of course, the initial (pre)stall event could have and should have been dealt with properly, but was not. In fact, the real disaster was caused by pilot actions following the initial crisis.

[TeeVee]

The chain of EICAS message was compatible with a speed disagree problem.
It was also similar to other speed disagree problems.
The airplane was flying in a weather coductive of heavy icing.

Certainty?
Absolutely not.
Likehood?
Yes, quite a bit.

Ball lighting?
Give me a break...

When Tee-Vee said that, by the weight of the preliminary report, it could habe been iced pitots as well as a ball lighting with the same chance, he was way off.

And it doesn't take an expert in anything to say what I'm saying.

By the way, "certainty" is never the result.
All NTSB report end with "The board finds that the PROBABLE cause was...."

Gabriel, to the best of my recollection, you and I have never argued. please re-read my post that set evan off and tell me where i said there were equal chances. here is the post(with emphasis added):

"how so? the interim reports are filled with a lot of nothing. a few acars messages, the results of the examination of a paltry number of jet parts, the post-mortem on a few bodies...not to mention that it was drafted by potentially biased folks (haven't the french quite clearly showed the world how biased they are with their deplorable actions and rulings re the concorde crash??? yeah, i thought so!)

this tells the world what exactly? that the "authorities" have ZERO clue as to what really happened.

now mind you, i'm not defending vanghell's theory, but from what i recall from reading the "interim report" (which will most likely be the final report) i'm not sure that you can say the "evidence" contradicts his theory."

[Fear_of_Flying]

By the way, "certainty" is never the result.
All NTSB report end with "The board finds that the PROBABLE cause was...."

Yes, but in life, "probable cause" is usually the best we can hope for, and is, I think, exactly what our modern psychology insists upon, no more and no less.

Back in the Middle Ages, when people knew so little, they wanted an absolute explanation for everything, they wanted certainty, and so they turned to religious authorities to get that. Today's modern mind is skeptical and somewhat scientific, and so we know we can seldom get beyond what is probable, what is supported by evidence.

But "probable cause" fulfils the same need that certainty did in eons past. People want that explanation, and if all we have are a series of error messages, a food cart, several bodies and a tail fin to provide us with a probable scenario, we will ultimately be satisfied that we can do no better in reaching an understanding, and we will accept the conclusion that the iced pitot tubes, in those circumstances, led inevitably to disaster.

Yet looking at the broader context, and what we usually demand in order to accept an explanation for an airline crash, we might discover that our need to have a plausible hypothesis overshadows the deficiencies contained therein.

[VANGHELL]

few clarifications...

First, I have to apologize, for sparking a debate which, probably, not many of you have signed up for, when this thread started! I have been away for a few weeks and haven’t been looking over the thread for quite a long time, but I have managed to read through all the posts since my last intervention.fficeffice" />>>
>>
Although important to aviation, a discussion about the human character, and about human bias when purely discussing possibilities, and making a brain storm about what could have happened, is a little bit too far, for the subject at hand. Need I remind you Gabriel: “discussion is being taken mainly on-topic, with respect, constructively, with technically sound discussion, where everybody is learning”!!!!!!! This was your first post on this thread, and you are way off the topic. As far as I know this is a public forum, and everybody has the right to post his/her own opinion! Further more: even though you have started this thread (a very laudable initiative, given the fact that the previous thread had somehow disappeared, or whatever…), you are not entitled to ownership of this discussion, and opinions which don’t fall in your understanding of what might have happened to AF447, aren’t necessarily wrong.>>
>>
It seems to me that you have taken the interim report for granted, and are convinced it is the truth about what happened, that is stated in it. The use of such clichés as: “conductive thunderstorm”, “severe icing conditions”, “area of extreme turbulence”, “EICAS messages confirming a speed disagree problem”, and so forth are nothing but biased attitude on your part! It fits snuggly into what you consider as being the cause/causes of this accident, and are one in a line, which is getting longer by the day, who has been convinced of what other, potentially biased folks have argued that happened.>>
>>
Let us consider what is already known as hard facts: >>

• ACARS messages transmitted to AF HQ about speed inconsistency! This only tells you about the effect of whatever happened; leaving everybody to speculate about what is the cause of such a conflict.>>
• The weather at the time was fierce, and could have harbored icing conditions! But this doesn’t mean that a thunderstorm or “severe convective thunderstorm system typical of ITCZ conditions in that time of year” (to be more precise), couldn’t also harbor the following conditions: severe updrafts and downdrafts, hail, intense electrical activity (in the form of lightning), super cooled water, intense turbulence, zero visibility, and the list can go on… of which every single one can be a “killer”.
• “The aircraft hit the water at a significant rate of vertical speed, relatively flat”.
• Few parts of the wreckage, and human remains were found, which includes the captain, as I recall! This could mean a lot of things, but most probably that he was not in the cockpit at the time.
• AF knew about several speed inconsistency incidents, which is shown in an Internal AF memo NT 34-029 issued 20 August 2008, page 4/5, but the “OPERATIONAL IMPACT:” was deemed “NIL”.

>>
Other than that, very few elements are known, and can only be guessed at. This leaves us with a myriad of possibilities, of which I could (or anybody else for that matter) deduce that AF447 collided with a UFO, in the middle of a thunderstorm from which it was taking power because of the intense electrical activity going on at the time… or maybe not! Maybe it was a missile from a Brazilian battle ship, mistaking AF447 for a jet fighter! Or maybe……….
>>
I’m not picking a fight… but this is already too much! Let’s just talk about possibilities, not about what the human condition is, about the human character, or about bias, or whatnot! I’m sure those directly involved in the flight’s history, be it those who lost their lives, or the families involved, or the industry as a whole, would appreciate a technically sound discussion, from which those involved can draw conclusions, or come up with solutions, so everybody can benefit from them, and to make sure nothing like this ever happens again. I’m sure that’s what we all want!
>>
Thank you all very much! >>

[Fear_of_Flying]

First, I have to apologize, for sparking a debate which, probably, not many of you have signed up for, when this thread started! I have been away for a few weeks and haven’t been looking over the thread for quite a long time, but I have managed to read through all the posts since my last intervention.fficeffice" />>>
>>
Although important to aviation, a discussion about the human character, and about human bias when purely discussing possibilities, and making a brain storm about what could have happened, is a little bit too far, for the subject at hand. Need I remind you Gabriel: “discussion is being taken mainly on-topic, with respect, constructively, with technically sound discussion, where everybody is learning”!!!!!!! This was your first post on this thread, and you are way off the topic. As far as I know this is a public forum, and everybody has the right to post his/her own opinion! Further more: even though you have started this thread (a very laudable initiative, given the fact that the previous thread had somehow disappeared, or whatever…), you are not entitled to ownership of this discussion, and opinions which don’t fall in your understanding of what might have happened to AF447, aren’t necessarily wrong.>>
>>
It seems to me that you have taken the interim report for granted, and are convinced it is the truth about what happened, that is stated in it. The use of such clichés as: “conductive thunderstorm”, “severe icing conditions”, “area of extreme turbulence”, “EICAS messages confirming a speed disagree problem”, and so forth are nothing but biased attitude on your part! It fits snuggly into what you consider as being the cause/causes of this accident, and are one in a line, which is getting longer by the day, who has been convinced of what other, potentially biased folks have argued that happened.>>
>>

Let us consider what is already known as hard facts: >>

• ACARS messages transmitted to AF HQ about speed inconsistency! This only tells you about the effect of whatever happened; leaving everybody to speculate about what is the cause of such a conflict.>>
• The weather at the time was fierce, and could have harbored icing conditions! But this doesn’t mean that a thunderstorm or “severe convective thunderstorm system typical of ITCZ conditions in that time of year” (to be more precise), couldn’t also harbor the following conditions: severe updrafts and downdrafts, hail, intense electrical activity (in the form of lightning), super cooled water, intense turbulence, zero visibility, and the list can go on… of which every single one can be a “killer”.
• “The aircraft hit the water at a significant rate of vertical speed, relatively flat”.
• Few parts of the wreckage, and human remains were found, which includes the captain, as I recall! This could mean a lot of things, but most probably that he was not in the cockpit at the time.
• AF knew about several speed inconsistency incidents, which is shown in an Internal AF memo NT 34-029 issued 20 August 2008, page 4/5, but the “OPERATIONAL IMPACT:” was deemed “NIL”.

>>
Other than that, very few elements are known, and can only be guessed at. This leaves us with a myriad of possibilities, of which I could (or anybody else for that matter) deduce that AF447 collided with a UFO, in the middle of a thunderstorm from which it was taking power because of the intense electrical activity going on at the time… or maybe not! Maybe it was a missile from a Brazilian battle ship, mistaking AF447 for a jet fighter! Or maybe……….
>>
I’m not picking a fight… but this is already too much! Let’s just talk about possibilities, not about what the human condition is, about the human character, or about bias, or whatnot! I’m sure those directly involved in the flight’s history, be it those who lost their lives, or the families involved, or the industry as a whole, would appreciate a technically sound discussion, from which those involved can draw conclusions, or come up with solutions, so everybody can benefit from them, and to make sure nothing like this ever happens again. I’m sure that’s what we all want!
>>
Thank you all very much! >>

Your post implores us not to discuss "bias, or whatnot!", yet that is mainly what your post is about.

Your post suggests that evidence is limited, many possible causes are still on the table, yet you would like a technically sound discussion from which we can draw conclusions and learn. How is that?

You acknowledge that this is a place where people may express their opinions, yet you want us to avoid certain elements of that discussion simply because you find them to be too far off base, even though we have, according to you, not much of a base to start with.

[Evan]

It seems to me that you have taken the interim report for granted, and are convinced it is the truth about what happened, that is stated in it.

Interim report(s). There are two of them. What is stated within them are truths about what happened. These truths alone do not explain the resulting crash, thus the mystery remains unsolved. Your post reveals that you have a very poor understanding of the revelations of the reports, a very poor understanding of the technologies and science involved, a very poor level of historical knowledge regarding similar unreliable airspeed events, and a very poor level of research relative to the members of this thread with whom you are disagreeing.

This is not to say that you don't have a right to post here. It is saying that you have an obligation to read this thread and (more importantly) the previous one before taking up the discussion. Once you have done this, you will see the event in a clearer light and understand the value and quality of the findings of the interim reports.

Particularly on this thread, opinion without a certain in-depth technical understanding is a useless nuisance to the rest of us.

[Fear_of_Flying]

Particularly on this thread, opinion without a certain in-depth technical understanding is a useless nuisance to the rest of us.

The arrogance reaches new heights. On whose behalf are you speaking, exactly, and what level of technical understanding do you, Evan, deem sufficient for someone to rise above the level of mere nuisance with their petty ideas?

[Gabriel]

Gabriel, to the best of my recollection, you and I have never argued. please re-read my post that set evan off and tell me where i said there were equal chances. here is the post(with emphasis added):

"how so? the interim reports are filled with a lot of nothing. a few acars messages, the results of the examination of a paltry number of jet parts, the post-mortem on a few bodies...not to mention that it was drafted by potentially biased folks (haven't the french quite clearly showed the world how biased they are with their deplorable actions and rulings re the concorde crash??? yeah, i thought so!)

this tells the world what exactly? that the "authorities" have ZERO clue as to what really happened.

now mind you, i'm not defending vanghell's theory, but from what i recall from reading the "interim report" (which will most likely be the final report) i'm not sure that you can say the "evidence" contradicts his theory."

TeeVee,
I've already replied to you in my post #214.

You are right, the interim report doesn't absolutely contradicts the possibility of a light ball as much as it doesn't absolutely confirms that an unreliable speed event was a necessary link in the chain of events that led to the accident.

In the interim report, there is no evidence at all that gives the slightest hint about a ball lighting (which is not the same than absolutely contradicting), and there is strong evidence that leads to an unreliable-speed-related event (which is not the same than absolutely confirming).

[Deadstick]

Particularly on this thread, opinion without a certain in-depth technical understanding is a useless nuisance to the rest of us.

Um, scuse me Evan, but as I recall you don't hold any type of airman certificate.

[Gabriel]

While I agree that we have a "most likely candidate" for the AF crash,

I don't agree. IMHO opinion, what we have is:

- A strongly likely candidate (beyond any reasonable doubt, if you wish) that one necessary link was an unreliable speed event.

- A very likely candidate that ice was the cause of the above.

- A lot of suspicious candidates of why the plane was lost after that, since the unreliable speed alone shouldn't bring a plane down. One or more of these candidates may be guilty, and there may be other guilty links that are not even candidates yet.

- Ball lighting doesn't fin in any of these categories.

We were told repeatedly by authorities during the early investigation that there was indeed a missing piece still to this accident, but conveniently that piece seems to have fallen into the distant background over time, to have become incidental, as we become more inured to the notion that of course it would have been extremely difficult - nearly impossible in fact - to save the aircraft once the speed data was lost in those conditions.

What on Earth leads you to that? I think that even Evan has shown to be very aware that the unreliable speed is just a necessary, but not sufficient, link.

Yet is it not reasonable to speculate that subsequent to the initial crisis, a secondary event occurred that ultimately led to the aircraft's demise? Perhaps it would turn out that the plane could have and should have been saved, except that some other terrible mistake was made.

Reasonable to speculate? Perhaps it would turn out?
What are you talking about?

That's one of the most certain things here. Other A-360 have suffered an unreliable speed event and were not lost. That proves beyond any reasonable doubt that something else, in addition to the unreliable speed alone, was necessary to bring the plane down. Whether we will ever learn what it was is another story. And chances are that we will not. If the information from the black boxes is not retrieved, the best we'll ever have will be several speculative scenarios of how things could have been to end as they did.

But, when one doest know something, it's not only Ok but necessary to say simply "I don't know". "I can't explain it hence it's an alien starship (or a ball lighting for the matter)" is not acceptable.

[Gabriel]

Yes, but in life, "probable cause" is usually the best we can hope for

Exactly. That's why saying "the report doesn't abslotuely confirm (or excludes) something" simply makes no sense.

[Evan]

The arrogance reaches new heights. On whose behalf are you speaking, exactly, and what level of technical understanding do you, Evan, deem sufficient for someone to rise above the level of mere nuisance with their petty ideas?

"a certain level of technical understanding"

Not an airmanship certificate. Not a technical degree.

Where does one get this understanding?

By carefully reading the reports and both threads in their entirety.

Beyond that, by taking initiative to find and research other technical publications and reports related to the incident.

Is that arrogance, or just a reasonable request for anyone interested in contributing anything valuable to this forum?

[Evan]

But "probable cause" fulfils the same need that certainty did in eons past. People want that explanation, and if all we have are a series of error messages, a food cart, several bodies and a tail fin to provide us with a probable scenario, we will ultimately be satisfied that we can do no better in reaching an understanding, and we will accept the conclusion that the iced pitot tubes, in those circumstances, led inevitably to disaster.

One of the most immediate things a crash investigation must focus on after an accident like this is isolating contributing factors which might cause a recurrence before the final report can be completed. ACARS told us right away that pitot failure was highly likely, and this, combined with a known pitot issue, prompted the fleetwide replacement of pitot tubes with more robust probes of a different manufacturer. Another thing which became immediately clear was the presence of intense CB activity. Questions were raised about the possibility of supercooled water in these systems, and precautions were raised.

THESE TWO ACTIONS will probably prevent a reoccurrence, even while we don't yet know why these factors resulted in a crash. That is the value of what is currently known.

While we need to understand how, and in what sequence, these factors can lead to a catastrophic loss of control, we have reduced or removed two of the initiating factors in the sequence. So on the one hand we have learned a great deal, and on the other we have an enduring mystery that needs to be solved.

[Gabriel]

Although important to aviation, a discussion about the human character, and about human bias when purely discussing possibilities, and making a brain storm about what could have happened, is a little bit too far, for the subject at hand. Need I remind you Gabriel: “discussion is being taken mainly on-topic, with respect, constructively, with technically sound discussion, where everybody is learning”!!!!!!!

Mind you, I consider myself one of the most respectful, constructive, and technically sound members of this forum.

This was your first post on this thread, and you are way off the topic.

Mind you. I STARTED this thread!!!
And this threads follows another closed thread on the same subject where I posted dozens of "constructive, respectful and technically sound" posts.

As far as I know this is a public forum, and everybody has the right to post his/her own opinion!

Everybody, including you, is welcomed, and your opinion is accepted and respected, which doesn't mean agreed upon.

Of course that "everybody" includes me too. If I don't agree with you, I feel entitled to tell you that and, because I'm constructive, to tell you why too.

Further more: even though you have started this thread (a very laudable initiative, given the fact that the previous thread had somehow disappeared, or whatever…), you are not entitled to ownership of this discussion

We agree on that.

and opinions which don’t fall in your understanding of what might have happened to AF447, aren’t necessarily wrong.

Give me one evidence that a ball lighting might have been involved and will start talking.

It seems to me that you have taken the interim report for granted, and are convinced it is the truth about what happened, that is stated in it.

No, but the interim report is about all we have. Leave at a side, and we don't have much beyond that a plane went down.

The use of such clichés as: “conductive thunderstorm”, “severe icing conditions”, “area of extreme turbulence”, “EICAS messages confirming a speed disagree problem”, and so forth are nothing but biased attitude on your part! It fits snuggly into what you consider as being the cause/causes of this accident,

It's not me. It's the official professional investigation team. And they and I don't know what are the cause/causes of this accident, beyond that an unreliable speed event was one necessary but no sufficient link.

Let us consider what is already known as hard facts:

Now we are talking.

ACARS messages transmitted to AF HQ about speed inconsistency! This only tells you about the effect of whatever happened; leaving everybody to speculate about what is the cause of such a conflict.

The ACARS messages were not only about speed inconsistency. There were many others (I don't recall exactly, but more or less AP off, AT off, error messages in the pilot's PDF, reversion to alternate law, freezing of the rudder limiter, and others) that are what one expects AFTER an unreliable speed event. That doesn't says a thing about the cause of the unreliable speed event, but it's as much proven as it will ever be that there was an unreliable speed event with it's cascade of related failures at the beginning of the sequence.

• The weather at the time was fierce, and could have harbored icing conditions! But this doesn’t mean that a thunderstorm or “severe convective thunderstorm system typical of ITCZ conditions in that time of year” (to be more precise), couldn’t also harbor the following conditions: severe updrafts and downdrafts, hail, intense electrical activity (in the form of lightning), super cooled water, intense turbulence, zero visibility, and the list can go on… of which every single one can be a “killer”.
• “The aircraft hit the water at a significant rate of vertical speed, relatively flat”.
• Few parts of the wreckage, and human remains were found, which includes the captain, as I recall! This could mean a lot of things, but most probably that he was not in the cockpit at the time.
• AF knew about several speed inconsistency incidents, which is shown in an Internal AF memo NT 34-029 issued 20 August 2008, page 4/5, but the “OPERATIONAL IMPACT:” was deemed “NIL”

Well, it looks you are taking the french reports as "hard facts" after all.

Other than that, very few elements are known, and can only be guessed at. This leaves us with a myriad of possibilities, of which I could (or anybody else for that matter) deduce that AF447 collided with a UFO, in the middle of a thunderstorm from which it was taking power because of the intense electrical activity going on at the time… or maybe not! Maybe it was a missile from a Brazilian battle ship, mistaking AF447 for a jet fighter!

And how is any of that compatible with an unreliable speed event with no sudden loss of pressure, electrical power, hydraulics or other system failures, and with the plane hitting the water essentially intact? (oh, you forgot to include that part of hard fact, or are you choosing what parts of the report are reliable for you and which aren't?)

I’m not picking a fight… but this is already too much! Let’s just talk about possibilities, not about what the human condition is, about the human character, or about bias, or whatnot!

I’m sure those directly involved in the flight’s history, be it those who lost their lives, or the families involved, or the industry as a whole, would appreciate a technically sound discussion, from which those involved can draw conclusions, or come up with solutions, so everybody can benefit from them, and to make sure nothing like this ever happens again. I’m sure that’s what we all want!
>>
Thank you all very much! >>

Fair enough. Let's start with this:

YOU've said that a ball lighting was the most likely cause.
Now YOU support that. I'll be here for the constructive discussion.

[Fear_of_Flying]

What on Earth leads you to that? I think that even Evan has shown to be very aware that the unreliable speed is just a necessary, but not sufficient, link.

Reasonable to speculate? Perhaps it would turn out?
What are you talking about?

That's one of the most certain things here. Other A-360 have suffered an unreliable speed event and were not lost. That proves beyond any reasonable doubt that something else, in addition to the unreliable speed alone, was necessary to bring the plane down. Whether we will ever learn what it was is another story. And chances are that we will not. If the information from the black boxes is not retrieved, the best we'll ever have will be several speculative scenarios of how things could have been to end as they did.

In post 218, Evan says the following:

While pilot error could one day be determined to be a factor, I doubt this will be reconciled to a primary cause. More paramount is the issue of previously undocumented weather phenomena and the inability for certain air data probes to reliably operate within it. Another large factor is the cascade of vital system failures following an unreliable airspeed event, and the barrage of ECAM messages that ensue. Add darkness and turbulence to this confusion, loss of autoflight, alternate law, loss of instrumentation in IMC, and you have a recipe for disaster. What happened here is most certainly a recipe for pilot error rather than pilot error itself.

It seems to me the implication of this post is that the pilots found themselves without flight data in overwhelming circumstances, so it is unlikely that the primary responsibility would fall on them: they were simply unable to accomplish what might have been an extraordinarily challenging task.

My suggestion was more along the lines that it's possible an altogether redeemable situation was completely botched - a different nuance given the same set of information - that puts the focus of the cause back on pilot error.

So to your point that it is "proven beyond a reasonable doubt" (really? I thought we just got over our lack of certainty) that something else happened beyond the loss of speed data, the question is, was it simply that the pilots were helplessly falling in a dark turbulent abyss without much legitimate chance of success given the circumstances, or did they take inappropriate actions that contributed significantly to the aircraft's fate?