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AF 447 Thread No. 8

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AF 447 Thread No. 8

Old 12th Apr 2012, 16:47
  #21 (permalink)  
 
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Originally Posted by christn
when a stressed pilot forms the wrong conclusion, he/she tends to stay with it regardless of ineffective attempts to correct the wrong problem. I have seen this in my field (gliding safety and accident analysis) only test pilots, or rare individuals, can keep a clear head and systematically fault find.
Originally Posted by Old Carthusian
The cause of the accident is unfortunately the flight crew who did not respond in an appropriate manner to the situation.
 

If the pilot corrects the wrong problem, or if response is not appropriate, it means that the effective aircraft is NOT OBSERVABLE to him : not enough or not the good sensors and data to analyse the situation, or wrong connection in HMI (human machine interface partS, first of all SOPs, CRM, training, selection, health, etc.).

I say it never enough : To work a dynamic system has FIRST to be observable and controllable. Stability, sensitivenes, robustess, optimisation, price, etc. come long after.
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Old 12th Apr 2012, 16:59
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Originally Posted by Old Carthusian
I also wonder about all this mistrust of BEA - surely this is misplaced especially as the courts are involved? Having read several BEA reports they have always struck me as models of professionalism
We have to accept the difficulty of the BEA's work, living day and night with the crash.

At the trials, reference to the Annexe 13 and the good use of the recommandations has to be said by pilot's unions. It would be the best way to help the BEA to do the safety problems OPEN.

In the forum we don't do another trial, nor another BEA report : we are together to get better, communicating in a larger point of view that the BEA is allowed to do.
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Old 12th Apr 2012, 17:13
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@roulishollandais

I say it never enough : To work a dynamic system has FIRST to be observable and controllable. Stability, sensitivenes, robustess, optimisation, price, etc. come long after.

Observable and controllable. Yes, but respectfully, this is a bare minimum.

This is (must be) the state at DEGRADED. Whilst in cruise, the system, no, the interface, must be INTUITIVE, No? Unremarkable and fluid "get" without Stopping to think.

Thinking takes time, sometimes too much. Here is the fulcrum of the issue, as the system is challenged, reversion in mechanical and Human actions must be synonymous, and synchronized. No time for independent reversion, the machine into less control, whilst pilot reverts to "abstract". The partnership should not degrade whilst facing rarities, it must grow closer. Confidence and continuity come first, always. How Stone Age to stop the flow, retrieve a handbook, and start to study......
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Old 12th Apr 2012, 18:37
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Originally Posted by Lyman View Post
Perhaps he is saying...... "The airstream sounds wrong"

Not bad airspeed, but wrong "speed of air". The airstream sounds quiet, or too fast?


If so, the two separated phrases still belong together.

"...announce de Vitesse...". Is it his first declaration "crazy speed?"
No Lyman... that's twisting it to non-sense....

"annonce" is like in the typical "voice announcement" of a train arriving, or leaving a railroad station, or an airport terminal station..
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Old 12th Apr 2012, 18:42
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As a Frenchman, pilot of AB, how would you say: "Sounds Fast" ?? How could he be commenting on Sound, and speed, unless CONFiture is dead on?

IOW, how to say: Noise inconsistent with IAS?
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Old 12th Apr 2012, 21:43
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@Lyman

I have the distinct feeling that everyone is trying to read too much into the 'reported transcript' of the CVR.

Why? Because even with the short phrases that are being debated, the intonation has been lost in the transcription, and the BEA had the advantage in hearing the intonation and being able to help by adding 'linkage words' that weren't necessarily there. Let's face it, the ambient cockpit sound in which the words were spoken will have impacted on how the transcript was presented in the French language.

One can only but hope that the translation from French into English was peer reviewed using the same background knowledge - but probably not; and the reason for this debate.
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Old 13th Apr 2012, 01:04
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mm43,

I have the distinct feeling that everyone is trying to read too much into the 'reported transcript' of the CVR.

Why? Because even with the short phrases that are being debated, the intonation has been lost in the transcription, and the BEA had the advantage in hearing the intonation and being able to help by adding 'linkage words' that weren't necessarily there
I agree with you. When the adrenaline is flowing big time as it must have been in this event in these moments, words may not flow smoothly as one is multi-tasking at the time.

In the AA DC-10 event in Chicago, there was one word on the CVR, Damn! That was it. Wonder how that translates into French...
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Old 13th Apr 2012, 02:11
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mm43 TurbineD

Fellas. I know you both too well to think your comments are intentionally patronizing. I know what I sound like, and readily concede I am looking under every stone. As my flight instructor said (ref: checklists), "leave no turd unstoned".

Four seconds after STALLWARN, and PNF "What's that?" PF says, "We have a bad announcement..." That means sound, and that also means STALLWARN, given the indexed chronology supplied by BEA. So a bad announcement may mean "Decrochage Faux...." Maybe not. By now, the adrenaline is still in the coolie hats atop their respective kidneys, they are cool.... I will keep that bit of information aside, but will not reject it. Notwithstanding the apologetic tone of you two guys, trying your best to put a happy face on......what?



two much.....
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Old 13th Apr 2012, 02:54
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Lyman,

Your version of "leaving no stone unturned" is commendable, and I'm not in the business of being patronizing.

However, this debate around what was said and what was seen by the pilots, is the very reason that the BEA wants mandatory recording of RHS parameters along with a "look" at what these guys should have been seeing. No doubt the BEA are confused by the actions taken and the words spoken when the recorded FDR LHS data shows something else.

Trying to recreate what was actually on the RHS PFD is fraught with danger.
  • It can be assumed the same was available on the LHS PFD, but
  • Was the PNF on the same page?
  • Neither of the pilots referred to any discrepancies between PFDs, and
  • The PNF was aware (at times) of what the PF was doing and commented when required.
Should data have subsequently been recovered from the QAR, I believe we would have heard through some 'leaky pipe' by now.

I am also unable to understand why the PF was able to look at an overly blue PFD and not accept that he was in fact "attempting a climb to the stars".

So, there you are. Was the RHS PFD overly blue??
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Old 13th Apr 2012, 03:15
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@mm43

"So, there you are. Was the RHS PFD overly blue??"

I have to say no, and guess that it showed some horizon, and a nose between 3 and 9 degrees UP. They were satisfied, reasonably, with the sitch til Stall. No screaming, no yelling, no snatching the SS. "We have the engines... So...".

What neither of them saw, anywhere, was AoA. Up to and through the actual STALL, there was no mention of doom. "Let's hope we're climbing, we are at four thousand."

Hyperfocused on loss of altitude, they had not noticed the Stall, would you? Nor had they any reason to mention anything, evidently. I frankly do not believe the data, as released, can lead to rational conviction of PE. Failing the release of all data, and I am a hard sell, to be sure, I think "Cause unknown" is as good as any. We don't know why, only what, and that is insufficient. Absence of evidence is not evidence of absence of care, or competence, it just is not.

My pea brain says even though they had nose up, and knew it, they could not get to "Stall..." only to: "push the Nose DOWN? Are you nuts? Look at the VSI!"

Ciao
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Old 13th Apr 2012, 08:07
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How much blue? At 02:10:18 when the PF says "On a pas une bonne annonce de ... vitesse" (how many seconds to pronounce that sentence?) the Pitch Attitude is 11 degrees NU. The PFD then looks like this:


From the video posted here.
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Old 13th Apr 2012, 08:43
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My point is this though - we can trust the information released by BEA and that their investigation will be fair and correct. I also understand the call for more transparency but they do have more important things to consider than keeping people informed about every little phase of the investigation. All that will happen is that the organisation will be delayed by queries and nonsensical comments from outsiders. Given the amount of comment that has already gone on on this topic without any conclusion one way or the other is it surprising that BEA are taking a long time. There is a lot to consider in this accident even if the basic causes are already known.
roulisholandais
I like the point about not observable but this is just one possible aspect of the problem which may in fact not be significant. It may be that the pilot himself is making the aircraft not observable and the available evidence actually points to this being the case. Given how many A330s, 320s, 340s are flying around without similar problems one has to think that indeed the flight crew were the main issue not the machine. I would expect many more accidents if the machine was a problem.
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Old 13th Apr 2012, 09:52
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HazelNuts39,
How much blue?
Exactly! At FL370+ why?

We will never know.
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Old 13th Apr 2012, 11:44
  #34 (permalink)  
 
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mm43

The altitude was barely above select cruise, @ 35.3k. @ 2:10:18. So my question might be: only 35,300? Why is this a/c climbing so sluggish? I don't dispute the Pitch picture, but it didn't match with Alt, necessarily, after ten seconds of climbing. The video catch does not represent the dynamic nature of the trends?

HazelNuts39

It was ".....annonce..................." " ........de vitesse......." Not ".....annonce de................". "...........vitesse....". Four seconds between annonce and de. Annonce and de are separated, not together.

PF was inputting ND three times at 2:10:18, and airspeed shows 70 knots, and we don't know if the displays were consonant with DFDR. A/S is duff, else he Stalls here...... He is comfortable with this Pitch, yes? What does that say? If it is what he sees, after all.....


I will ask my French expert re: " annonce". Besides, STALLWARN is a result of speed plus AoA, could he not mean "Stall 'vitesse' ? Not a reference to AirSpeed, but a ref to StallSpeed. Did he have the StallWarn bug present on his tape? Why is speed tape missing from video snatch? I believe his comment refers to a bogus StallWarn.

Your comments are most appreciated, it is quiet on my "side".

Last edited by Lyman; 13th Apr 2012 at 11:57.
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Old 13th Apr 2012, 13:47
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Originally Posted by A33Zab
The 'zipper' means it is - not active - (AP was in ALT HLD mode not in V/S mode)
As you mention, the selected MACH trace shows also a similar 'zipper'.
But my question has been here all along :
WHERE is the AP/FD vertical engagement mode trace ???
That trace would tell if the 'zipper' is irrelevant.
In the meantime that trace is central to figure what were commanding the FDs when displayed.

Why such trace is missing ?
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Old 13th Apr 2012, 14:13
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Originally Posted by mm43
The PNF was aware (at times) of what the PF was doing and commented when required.
It is inexact to state so ... The 3 pilots were reading attitudes, vertical speeds, altitudes ... but at no time did we hear - PULL - PUSH - DONT PULL - STOP PULLING - YOU PULL TOO MUCH ...

Only in final despair, under GPWS warning, came up a - TIRE TIRE TIRE -

Sidesticks at their best ...
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Old 13th Apr 2012, 14:47
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I thought thought the zipper was doing nothing more than a resolution issue with the data ie the lsb switching on and off and nothing 'real'.
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Old 13th Apr 2012, 15:41
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Devil "Old Carthusian"

I really hate to say something so personal in public, but it needs to be said:

OC's posts all seem to be written entirely from the point-of-view of Airbus. No room for any possible factors other than pilot error. Seems preposterous to me that anyone would insist that it was just that simple. Unless I learn otherwise, I'm assuming that these posts are generated by someone at AB. (OC's profile is entirely empty. Who was that masked man?)

If I'm wrong, I am sure I'll burn in hell.
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Old 13th Apr 2012, 16:46
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Organfreak;

Does it matter? I'd welcome Airbus participation in the discussion on this thread.
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Old 13th Apr 2012, 17:06
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Better to remain silent and be thought a...
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