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AF 447 Thread No. 5

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AF 447 Thread No. 5

Old 31st Jul 2011, 15:12
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the stick move of first 10 sec. after AP disconect 2:10:07 --- 2:10:18
the moves are more or less horizontal so I think he did not realise that he pulled, just fight with the rolling ship....left right left right left right.... realising that he had no longer correct speed at this time
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Old 31st Jul 2011, 15:13
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Originally Posted by BOAC
- ah - thanks for that. I am waiting for Wednesday to download that.
Re 'p114', be careful...
From personal experience, with a typical French-to-English translation, the wordcount and pagecount of the English text tend to be in the order of 20% less than those of the French text.
So p'114' in the French report is unlikely to be the same page as in the English translation......
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Old 31st Jul 2011, 15:17
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If he didn't know he pulled, and the a/c had been in Normal Law at that point, would the FCS know that he didn't know? Otherwise occupied with his Roll problems, what was his PITCH 'up to' ?
Old 31st Jul 2011, 15:22
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No lightning. No lightning strikes.

Dark night, in the clouds, flying through ice crystals, moderate+ turbulence, on the periphery of a Cb cell, that's the environment outside.
An A-320 flying between Paris and Geneva at FL 270 in and out of the clouds in daylight when the crew suddenly spotted a Cb ahead (unanticipated), couldn't quite get around it. The turbulence knocked a generator off-line, and the captain's panels went dark. Stuff happens. But there is no indication of something similar happening to AF 447.

Interesting that, in the Geneva flight, the turbulence was sufficient to send loose material in the cockpit flying about, one item cracking the co-pilot's headset.

The BEA 'lessons learned' report didn't identify the airline or give the incident date, but that crew also was inattentive to its radar.
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Old 31st Jul 2011, 15:52
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At the risk of making myself appear more foolish than I already have, I feel compelled to offer an observation;

Some time back, in one of these threads, someone posted a link to some utubes of some Airbus simulator training in progress. At the time, probably because I've had very little experience in the pointy end during flight, I was struck by the "automaton" nature of the behaviours I saw. I thought it truly looked as though pilots had become mere accessories to the computers, with little room for thought and/or any sense of actually "piloting" their machines.

It looked to me, as I watched the gents twiddling knobs and going through checklists and pecking away at keys, that these sorts of pilots had been programmed to deal with their jobs as a computer tech might with his network administration tasks.

It struck me that these were not at all like the pilots of old who could fly any big old bird with several broken bits and malfunctioning whatnots, because they knew the basics of keeping their machine in it's element.

"Two kinds of pilot" I thought. "Old" and "New". "Old" could fly almost anything with wings, but not a newer, glass and computer machine. "New" could fly the computer generation "smart" birds, but probably not an old DC3.

I'm still mulling over those distinctions, but it has occurred to me more recently that this particular airplane needed both kinds of pilot, and the two "New" types that were in the seats just had none of the abilities of that "Old" type. I simply cannot fathom any of the type "Old" failing to recognize a stall. ... at any point during a 35000ft descent.

These poor blighters were more computer programmers than pilots. They needed an old geezer.... and when their best shot at that re-entered the cockpit, he'd missed the beginning of it all, and in any case his AF training had probably left a whole quilt of cobwebs on any "Old" pilot within him.
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Old 31st Jul 2011, 16:06
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Amen, 3holelover

You have it right 3holelover. As Old Carthusian pointed out a couple of pages back, the overall AirBus safety record is splendid, but clearly when things go wrong, the Bus needs someone who can fly an airplane.
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Old 31st Jul 2011, 16:09
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I am going to do my best to answer, as I can't fully parse your post, and am guessing that my post have have been unclear, and thus difficult to understood.

My post was only referring to the fact that the PF's action on the SS could have had a good reason to have a NU component, due to the context of the pitch/roll/power state of the plane left to him immediately after the AP disconnect.

That as opposed to those that are the opinion that there was no reason for a NU action..

As far as the AF 447 accident, I mentioned several times that IMO, there are multiple confluent causes, which the "pitot tubes" are only a part of, in one category, and part of multiple classes in that category. The category is "a/c components failure".

Originally Posted by bearfoil

Would you consider other than Pitot issues as cause? That would involve other than a "time interval" approach? The A/P is 'dynamic' (constant) in its inputs, No? So the disconnect is "instant", not sequential? The important vector is the 'logic' of its loss? Not the "cause"?

So also the discussion involves a possible "remnant" of NORMAL LAW? Unfortunately, this introduces "mode Confusion".

Last edited by airtren; 31st Jul 2011 at 16:22.
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Old 31st Jul 2011, 16:13
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It may be out of character for me to say, but AirBus had 32 episodes of some hairy UAS that ended "well".

Neither Black, nor White, the upshot of 447 is that the Pilots may not have been ready, the a/c was, and neither could save the flight from destruction. Isolating any one 'format' is not helpful, there is a SYSTEMIC problem.

That said, 3hl and Ed are also exactly correct.

airtren. I get your post perfectly. Isolation of events is proper, as is a "global View". Neither is helpful, if all things as a whole are not considered together.

"Somewhere between "Do Nothing" and ACM".... is the 'moving' target?
(relative to a/p loss/handover)........
Old 31st Jul 2011, 16:17
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Thanks for posting Grity,

I think there is a possibility that with no training/practical experience in using the SS in Alternate 2, with no pitch/roll protections, he not only didn't realize that his amplitude of commands is excessive.

Based on the graphs, I also think that he didn't realize that his perceived Neutral Position of the SS, was in fact "off-neutral", on the NU side, and thus what he thought that it's a return of the SS to Neutral, was in fact a SS NU command.

Originally Posted by grity
the stick move of first 10 sec. after AP disconect 2:10:07 --- 2:10:18
the moves are more or less horizontal so I think he did not realise that he pulled, just fight with the rolling ship....left right left right left right.... realising that he had no longer correct speed at this time
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Old 31st Jul 2011, 16:28
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Originally Posted by 3holelover
These poor blighters were more computer programmers than pilots. They needed an old geezer.... and when their best shot at that re-entered the cockpit, he'd missed the beginning of it all, and in any case his AF training had probably left a whole quilt of cobwebs on any "Old" pilot within him.
Don't agree on that single point.

The PF said he didn't have control of the plane. In fact he had full control of the plane, he was just a muppet.

Captain turns up, PF says aircraft out of control, what's the captain supposed to think? He has to believe the PF, that the aircraft is out of control, and he (and PNF who should have caught this sooner) simply ran out of time to work out it wasn't.

Reading that CVR transcript, words fail me.

The PF fooled them both and a couple of hundred people died.
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Old 31st Jul 2011, 16:30
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Not a bad write-up... thanks.
Somebody in a much earlier post referred to the 'video game generation'.
That may be a bit excessive, but there is some underlying truth in it.

There were autopilots in the 'olden' days (even the pre-WWII 'very olden days'), but they only did the simple jobs, like ATT HOLD, ALT HOLD, HDG HOLD, and suchlike, relieving the human pilots from the mind-numbing (on long flights) task of simply maintaining altitude or heading, without letting them lose 'situational awareness'.

'George' was a much-appreciated crew-member in those days. Nowadays, 'HAL' is no longer looked at in the same way.....
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Old 31st Jul 2011, 16:33
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Something like a wing leveler was in there at the start?
Old 31st Jul 2011, 16:46
  #1133 (permalink)  
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Good post. You have to embrace new technology, but build on the basics of the past. Buying a satnav for your car doesn't justify no longer being able to read a road atlas, just in case, if we are talking analogies. Old drivers should learn to use their satnav, and new drivers should still learn how to read a road atlas. It's not old ways v new ways. There were enough clues for most old school flyers to have recognised an aerodynamic stall, and there are enough references from the BEA to the effect that there was insufficient high altitude crew manual flight training (AF and generally). Something has gone awry in training and the human/aircraft interface, probably due to commercial pressures that have sadly prevailed, so it needs to be remedied. There is no IAS event without the substandard pitots, but pilots are there to deal with such problems.

Last edited by Welsh Wingman; 31st Jul 2011 at 18:21. Reason: Typos
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Old 31st Jul 2011, 16:46
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referring to your post,

I'm happy that at least two people read my message ...
Unfortunately those two people don't understand why I posted this message (certainly Lemurian)
I wanted to put the light on a discripancy between the two reports.
This is about the licences of the PF (and this is a important point)
Read again ... if you had not seen the PF licenses discripancy as reported by........ BEA
I always read your posts (), but I still fail to see your fine point in this particular
one, notwithstanding your appeal to participate in a boy-scout like scavenger hunt (I think that's about what the French "jeu de piste" means, or, since your German is probably fine: "Schnitzeljagd").
Surely you do not want to infer in a definite manner that the terms used (remember also, we speak of the years 2000/1) in the 1st report mean a JAR licence (e.g. the word JAR does not appear) whereas the present one rather would hint a national professional pilot (but with out using the abreviation PP actually!)?
So what exactely do you think is of any significance here for the genesis of the accident?
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Old 31st Jul 2011, 17:58
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Originally Posted by HN39
More analysis to be done by BEA (and perhaps me). Why did AP and A/THR disconnect 2 seconds before the speeds dropped?
The trace on page 110 shows a Mach drop at the time of the AP disconnect.
Q. Is there only one Mach source to be registered ?

AoA 1 seems to be almost locked to 2.1 deg for the initial climb, up to the time 2 10 51.
Q. What's the consequence on the Flight Control System ?

THS never moved during the initial climb ... Why is that ?
Is it G related ?
Is it Protection related ?
THS trace is absent from page 31 and 32 graphics ... Why is that ?
ELEVATORS traces are also absent from those graphics ... Why is that ?

Originally Posted by P44
Ainsi, il apparaît à ce stade des travaux que l’essentiel des mouvements de l’avion dans l’axe longitudinal (assiette, vitesse verticale, altitude) est le résultat des actions du PF, à l’exception de faibles variations vraisemblablement dues à l’aérologie.
... not too impressed by that one.

Originally Posted by P26
L’exploitation des 5 fichiers audio déchargés a permis de mettre en évidence que l’événement ne se trouvait pas à la fin de l’enregistrement des 5 pistes et que leur durée était inférieure de plusieurs dizaines de secondes aux valeurs attendues.
La synchronisation des différentes voies a montré qu’une partie des données était manquante. Par ailleurs, l’exploitation du contenu binaire de la mémoire EEPROM confirme l’incohérence des pointeurs utilisés par le moyen de lecture du constructeur pour débuter et terminer le déchargement des données.
And of course so not impressed by those comments on the CVR ...

No reason for the victim's families (especially pilot's families) to not obtain the numeric data.

Has anyone seen further comment on the WRG ACARS message ?
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Old 31st Jul 2011, 18:32
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On the initial roll

My apologies if this has been pointed before, I've read all the posts but for the ones from a couple posters that I skip over some of the time.

Just to settle a minor point that has sometimes in the past been discussed, this report clearly identifies the reason for the uncommanded initial roll to right:

La présence de turbulences, mise en évidence par l’activité du PA pour contrôler le roulis dans les secondes qui ont précédé, a provoqué à sa déconnexion un départ de l’avion en roulis à droite jusqu’à environ 8°.
My translation (caveat: I'm not French nor English native speaker):
The presence of turbulence, evidenced by AP activity in order to control roll in the preceding seconds, caused upon its disconnection a departure of the plane in roll to the right, to around 8º.
It was presumed by most posters that this was the case but I like to see any loose ends closed, so this is my 0,02€ contribution until the official translation is given.
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Old 31st Jul 2011, 18:39
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Originally Posted by CJ
Re 'p114', be careful..
- thanks for the warning, but now I know where it is I'll find it.

Re: This 'neutral' position for the SS (#1128)- is it not spring centred?

If that strange pic by 'grity' represents the Right SS, is 'below the line' nose up?
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Old 31st Jul 2011, 18:39
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Would an entry into a robust updraft cause the reduction in IAS? Would it cause the a/p to lower the nose to hold altitude? Was the a/p handling Roll excursions that were rapid enough to challenge its remaining performance?

Loss of THS response with repeated ND inputs is apparent on the traces. It remains full UP. the elevators show PF commanding ND.

Is anyone interested in looking closely at the 30 seconds prior/post a/p loss?

airtren: Would those lateral excursions of the ss possibily be related to the Human body's reaction to changes in posture due ROLL? Might they have been reactions to, rather than attempts to control, ROLL? PF: Loose restraints?

CONFiture: Are you aware of "missing traces" on other investigations by BEA re: Airbus? Because, at some point, after repetition, malicious becomes insulting.......

Last edited by bearfoil; 31st Jul 2011 at 18:50.
Old 31st Jul 2011, 19:02
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Human Factors Nightmare

Ian, please don't hate me for what follows:

First note: if the two pilots were both aware of them being in condition UAS, what is the likelihood that they were skeptical of stall warning, knowing that airspeed is a component of stall AoA calculations? That might explain in part the apparent "ignore" of the stall warning.
But I think that you are correct.
The first reaction to everything falling apart is disbelief that it is happening. So being sceptical of the stall warning is a 'normal' reaction. Like many other things when flying you have to believe the instruments - and - in this case when that was tried the normal instruments in the scan were either obviously invalid or flagged as in error. So it can't be true.

Then the PF appears to have followed 'normal law' control procedures when the aircraft was in alternate - and he had accepted that. But under pressure one reverts to ingrained behaviors. So his 'learned' response was inappropriate for the aircraft state. The only way to prevent this happening is continual training in reversions to manual control and upsets at cruise level. How many line pilots here have that? How many can say that they have more than a few minutes actual manual piloting in alternate law at cruise level?
So when everything goes pear shaped - the crew are dropped into a situation that they have NO consistent experience of even in straight and level flight - but here they are in an upset that possibly gave one chance at recovery.

Second note:

From the latest release, the aircraft went into a condition of unreliable airspeed. What leaped out at BEA was that (if I read this rightly) the crew didn't progress to the unreliable airspeed checklist/procedure as was standard practice at the time. (If I misunderstand that, my apologies).

The information released shows me a PNF who had to focus on flying problems rather abruptly. His requirement to assist (rather than take over from??) the PF, to include the switch to (F/O 3 on the ATT select?? takata's illustration informs this) indicates to me that he felt that the PF was having difficulty with his PFD. Given the number of things going wrong on displays, and the PF being unclear on what he was seeing (from PNF perspective) giving the PF a better inertial unit to run his would be a helpful copilot (role) assisting PF. (If this guess is off, apologies).

In the meantime, hand flying at altitude with UAS in Alt 2: is this trained for?

If not, the PF was playing catch up.
This raises another issue that I have not seem mentioned much here. A 'constituted crew' where the Captain and FOs have flown together for some time and know each other and how they work will almost ALWAYS be better in an emergency than a random selection by roster. It may suit the bean-counters to have freedom to vary crew composition but it fails to engender team spirit. More importantly, when you have flown with someone for sometime you can both react and work-together almost intuitively. Someone should really quantify this teamwork effect in monetary terms as the accountants do not understand anything else.

A human factors question arises that may be answered by AF SOPs or habits, or it may not have an answer.

With what appears to be the senior pilot between the two recognizing a pilot who was fighting the aircraft a bit, or chasing it, his initial "talk him back into the scan/situation" is what most of us would do as good copilots ( in terms of our role at the time.)

At what point should/would it have been "I have the controls" when the PF kept chasing the attitude and the PNF kept having to prompt him to go in a different direction? (Aside: Isn't that the question every Captain must have a clear answer to before takeoff, or an instinct for, in terms of his threshold of "that's enough, I have controls" when his copilot is flying?) If the PNF made a number of inputs on the SS but didn't take controls, I know a few CRM people who'd be aghast, as the preference is that one pilot is on controls, the other isn't. (We could probably spend all day debating the intricacies of what's behind that.) WIth a SS, his inputs won't be felt by the PF, so the "summing" function may have less than the desired effect, as opposed to conventional controls where the PF would have felt what PNF was doing. <== Is this a shortcoming of SS, or an advantage? I can see it both ways. (Anyone whose instructor "rode the controls" while you were learning probably sees the issue here).
This dual attempt at controlling the aircraft is probably again a symptom of not having a constituted crew who all know each other well, rather than an administrative 'pecking order' or 'authority gradient' in the cockpit.

The problem of sidesticks and the visibility of what a pilot is doing both for the PNF and perhaps for the pilot himself. is a subject of debate among cockpit designers and pilots. Personally, I would think that for single seat aircraft and for 'flying the computer' a sidestick is probably good. For instances where a dual crew have to fly an aircraft manually (even if through some computer assistance) then the larger central yoke or joystick rapidly shows others what the PF is doing without the need for verbal or instrument clues that may not be easily available due to noise or vibration.

There are a HUGE number of human factors issues that will need to be investigated
  • Multiple Alarms on multiple failures causing cognitive overload
  • (In)Consistency of alarms (the stall warning) poor alarms reinforcing disbelief in instruments
  • Belief in alarms - the crews MUST know which alarms to ALWAYS believe and the system needs to ensure that there are NO false alarms
  • Display of reliable data/information during failures - it is sometimes better to have NO data than BAD data
  • Manual flying of a squirelly aircraft at cruise in bad weather in alternate law (is it possible at all without constant practice?) with limited instrument information. The crew did not have this training. (Does ANY crew?)
  • CRM and crew performance in upsets with constituted crews compared to random selections of front crews.

I am sure that there are more but this crew had EVERY one of those issues and probably 30 seconds at the beginning of the incident to get everything right or it would be too late. It proved too difficult for this crew to manage.

Is everyone sure that the crew they are next flying with would do any better in similar circumstance?
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Old 31st Jul 2011, 19:08
  #1140 (permalink)  
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Ian W?

SS v Yoke? (at the very end)


PF: "But I have been pulling for quite awhile"........

something like that?

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