The way this thread is going we desperately need the final report to get back on the track. Why won't they give it to us?

What is the expected result from a gradual blockage of the drain hole alone?

PJ2, yes, if they had maintained level flight they wouldn't have gotten an overspeed, but if he climbed for whatever his reason with trapped pitot pressure and reducing static pressure he may have gotten an overspeed warning that caused him to pull up into a stall. Normally a pilot wouldn't do that but for some reason he did. Unfortunately the captain wasn't there at the time to prevent it, if that is what happened. I hope they don't drag their feet on releasing the FDR and CVR reports because this could happen again if they sit on it. The aircraft they were flying was already known to have faulty pitot tubes but hadn't been changed yet when this accident happened.

RR_NDB:
RT? Why not make the demand: PREDICTIVE!

I already mentioned before and is repeated by others:

They (FCPCs) know when the speed is missing, they don't know the probes iced up. That will be the task for CMC to correlate warning with failure.

How critical is a Pitot probe icing? not a red alert - immediate action required - in view of the A/C industry in general.

UAS caused by Pitot Icing = Transient.

"Whenever unreliable airspeed indication is suspected and aircraft attitudeand thrust are not consistent with the flight phase, initially disregard all speed indications and use pitch attitude and thrust setting as primary flight references." Like NW did and the other incidents.......

Note: the statement above is NOT from airbus.


Question to all.

Considering the ECAM messages, after clearing the A/P disconnect the first CREW action will be:
-THR LEVERS……..MOVE

@RR_NDB: presented In RT (repeat interval 5 sec., must be important)
Timestamped 02:10:06

They know from heart T/L need to be moved towards 'frozen' N1.

45 sec. passed.

BEA states: 02:10:51 ....The thrust levers were positioned in the TO/GA detent and.....
In what postion was it in between? What is the expected cruise N1 with data just before the event at 2::10:04?

bubbers44;
Yes I know. I make that observation in my post. I've had this occur in a B767 and that is precisely what happened...the airspeed increased beyond the VMO, (didn't get the Overspeed warning though) but in our case we ignored it because we had the standby AS to help us guess which one had the correct reading.

My point in this part of the argument is that the speed increase in a thousand foot increase at the beginning of the pitch-up isn't dramatic...it isn't in the order of "50kts", say...and it isn't much more in a 3000ft increase...it isn't large enough to warrant a pitch > 10deg to reduce speed.

3holelover;
It depends upon whether the tube downstream of the drain hole is also plugged due rain unable to drain fast enough from the pitot tube. If the tube is blocked, the effect is the same as if both the tube and the drain hole is blocked and the airspeed would drop. If the blockage was due to water (flight through heavy rain), the speed could fluctate between actual and lower indications and would do so in relation to the changing amount of blockage. If the drain hole itself is plugged but the tube itself is clear, then I think that there is no effect on the sensed total pressure and the airspeed would be accurate.

All this is largely from the A300-600 FCOM information on "Abnormal Procedures - PITOT PROBE DESIGN, (posted by Chris Scott or gums which I can no longer find on the previous threads) - Thank you Chris for finding Tubby Linton's post.

A33Zab;
Thrust Lock would keep the thrust at the cruise setting existing just prior to the UAS event. In response to the "THR LEVERS....MOVE" message, the thrust levers would be moved out of the CLB detent and set to the N1 existing just prior to the event. That would be just below the MCL detent (slightly less than 30deg TLA), probably around 84% N1.

Causality
 

A33ZabYes, Real Time! It´s technically possible today*!

PREDICTIVE, unfortunately it´s not possible, as we all know.

Please, see Causality, here.

May be in the future an special Radar (or Laser?) could anticipate probable conditions to (sub heated sensors) Pitot icing degradation.

They were cruising at M .80 at FL350 so how much static pressure change with a climb would it take to go above mach limit with a blocked pitot tube? I don't know but am trying to understand why they pulled up into a deep stall.
Something must have spooked them. I don't think just losing AS would. Maybe the stall warning going off again at the latter part of their descent and pulling back into a deep stall to silence it also caused them to pull up into a stall as the overspeed warning sounded. The guy flying was pretty new on the aircraft.

PJ2, quote:
All this is largely from the A300-600 FCOM information on "Abnormal Procedures - PITOT PROBE DESIGN, (posted by Chris Scott or gums which I can no longer find on the previous threads)

Not guilty, m'lud... Is this what you are looking for?

http://www.pprune.org/tech-log/44963...ml#post6442305

See also tubby's next post.

Re ASI 2, I hope the BEA will let us know about the QAR in their next report.
Good night!

Why the "pitch up"
 

Hi,

PJ2Indeed, so far, a mystery.

On the recording (video never) i will elaborate in next post. The idea is:

We probably should (for the investigation) to record some "internal parameters" of the System. AFAIK FDR is not for that. The current "recording" doesn´t take into account certain important "internal mechanisms" probably important for a better (impartial) analysis from the investigation branches. I don´t like the idea to be dependent on the plane manufacturer for some more complex details during the investigation analysis. The complexity of the "advanced planes" it seems correlated to "Moore´s law":):8

For 45 seconds, thrust could have been anywhere between idle and climb thrust. It all depends on what was trying to achieve the A/THR at the time of disconnect. Was it trying to reduce the speed, was it chasing the M 0.80, was it just set to the proper EPR to maintain the requested selected Mach ...
BEA knows ...

Additional thought : For close to 3 minutes, the Captain, a guy with experience, was in the flight deck ...
What were his comments ?
Any Directives ... !?
He didn't come back to just shut up ... did he ?

BEA ...

Hi,

PJ2 wrote (and many others)
It's no failure with the Pitot tubes
They worked as expected (it's not a failure of the Pitot tubes .. it's a use of the Pitot tubes outside the limits [domain] of their certification)

Sorry RR_NDB but I'm not understanding what your saying.What do you mean by "internal mechanisms"? I've never heard of the term in accident investigation or flight data analysis work.

Also, what makes you say that an investigation is, "dependent upon the plane manufacturer for some complex details during the investigation analysis." What does that mean? What are you trying to say? What, specifically, are these "complex details" to which you refer? What do you mean by "advanced planes"?

You claim a connection with "Moores Law", but you don't explain the connection and just leave your readers guessing. I looked it up using your link. There's no connection to AF 447 or flight data work whatsoever.

If you're advancing some kind of notion that this is all a conspiracy on the part of manufacturers to suppress or even hide information from the investigators then I don't think you know very much about aviation, flight safety work, accident investigation or flight data analysis and the way it all works together.

So....is it your thesis that, "manufacturer's making it difficult for investigators by controlling all the parameters on the FDR so we only get to see what they want us to see"?

Hello Chris, yes, thank you, that's what I was trying to find. Searching for an image isn't possible and the PPRuNe search engine doesn't work well for me in IE8, tho' it could be the operator - I should have recalled that it was tubby linton's. I thought it was good info - I have nothing like it in any of my (Airbus) FCOMs.

bubbers44;
We don't know yet who was flying the aircraft. There have been good arguments for either scenario. Hopefully that information will be in the next BEA report when it comes out.

- I would like to know more about the Relief Pilot position at AF.

- On initial training is the RP given a full endorsement on the airplane?

- Is the endorsement maintained or is it intentionally allowed to lapse because the RP can legally only occupy the front seats in cruise?

- Does the RP get to takeoff and land the aircraft or is the RP position strictly Cruise Altitude? If not, how does the RP gain handling experience, if at all? (One can have several thousand hours on an airplane and actually never even fly it let alone handle it in circumstances faced by the crew of AF 447.)

- Can the RP occupy the Left Seat to replace the captain or, due to licensing legalities, must the First Officer sit in the left seat? And if so, what kind of recurrent training does the F/O receive?

- If the F/O occupies the left seat, does this apply "in Cruise Only" or is s/he allowed to takeoff and land from the LS?

- If the F/O does indeed replace the captain, is there some concern regarding the switching of seat positions in terms of familiarity, comfort, and trained, automatic reactions. (I think most here who do this work and perhaps instruct would agree that although one gets used to it, there IS a distinct difference when flying from a seat that is not normally one's own - it isn't nearly as comfortable, in other words.)

There are a number of other questions, but all this will come out sooner or later. I am hoping that the next BEA report addresses some of these basic human factors questions as part of the research supporting the final report.

OK465
That was a nice discussion about rolling your swept wing bird with rudder. Every swept wing tactical aircraft I flew rolled nicely at high AOA with rudder. It was considered the nature of the beasties and was essential to obtaining max maneuvering performance. You could even hold the aircraft in a stall and pick up the low wing with rudder when one wanted to drop. The wing drops became progressively more abrupt, however, so there was a limit to how long you would want to do that.

I have inadvertently overstated wing leveling ability with regard to Alt 1 Law (and Normal Law). I was intending to infer ability of the system to keep the shiny side up.

Per FCOM FLIGHT CONTROLS
Of course the system is not a wing leveling system, it is an attitude holding system, until you get into Alt 2 law. Then the wing attitude in roll becomes the sum of pilot inputs, environmental inputs, and lateral imbalance/rudder mistrim inputs. In Alt 2 law, the pilot must control the wings. No hands off is possible unless the aircraft is in perfect trim and the air is smooth.

Sorry RR_NDB but I'm not understanding what your saying.
 

My objective now is to clarify to allow a perfect understanding of what i said (briefly in a short text). As i told you i will elaborate later.

I will start from your last phrase, a question:

Not! absolutely NOT!

Not! absolutely NOT!

I suspect a Safety Board could not be able to analyze some details (e.g. glitches) that may occur (and perhaps occurred) in this case. Svarin raised and elaborated on that. We may never be able to understand what happened because the required information could vanished (like the AS not measured). The complexity (State of the Art machines) of the Airbus SAS "advanced planes" may suggest a future rethink of the FDR concept. Why? Because when Airbus SAS advanced planes introduced FBW plus a new "control" philosophy (Laws, protections, etc.) put another "crew member" in the cockpit" and it´s behavior has to be fully analyzed (and understood) in an accident. This "complex crew member" was "flying" the a/c before AP/AT disengagement. And was also flying after (THS moved). And this "crew member" is "made" of Hardware, Software, internal links (subject to WRG failures, etc.) and is naturally subject to do unpredictable things. Despite it´s State of the Art characteristics. (Redundant, etc.) We can remember the (extreme) Reagan´s SDI Testability issue.:} And IIRC was you that posted an excellent text on "possible" and "probable" things.

The growing complexity of the "on board Systems" makes me remember the "Moore´ s Law" (named after Intel co-founder Gordon E. Moore, who described the trend in his 1965 paper.) I just made an analogy to the "prophecy", Intel Guru´s made that i observed closely all these years since i designed my first computer in 1975 using the first microprocessor, the Intel 4004 using it´s chipset. You may observe i put in the end of my phrase: :):8 to say you i was commenting with a "nerd´s humour". And the growing complexity concerns me. Why? Because i worked in complex Electronic Systems Design (in Test and Measurement area) dealing with Testability, Diagnosability and System Testing, Module Testing and Components Testing. In AF447 analysis we never will know the actual AS during certain moments, simply because this info. was not measured. And this occurred not by Pitot failure.:} As jcjeant told you. Other(s) System failure(s) (with the PF inside the loop) may never be possible to understand. Why? Because the mentioned "internal mechanisms" were not recorded. Complexity brings fantastic features, at a price. Observe i´m not saying what (if) occurred. We actually know very little. My objective now, as you well said, is to understand the "persistent pitch up". And i´m just remembering the complexity of the required analysis to allow a full understanding of a complex System like the ones being gradually put in the entire Aviation Industry with the leadership of Airbus SAS (paying the toll on the pioneers)

The current FDR concept deals with this "crew member" considering it as an Engineering black box. This point, as i told before, i will elaborate later.

:zzz: (must awake early for a monday with some CB´s ahead:) I tried here to do my best to clarify, preparing what i will present later on the issue.

Finally i must mention the title of my post: Why the "pitch up"

The motivation to write "briefly in a short text" was only related to the most important (before July end) as you emphasized perfectly.

I am entirely open to further clarify to you or (anyone) any point before going deeper into the "probable need for more data" to fully "understand" the behavior of the "complex crew member" :) in an investigation of accidents involving "advanced planes"

RR_NDB;

Ah, thank you, now I do understand much better what you meant. Will respond more fully shortly.

Quite simply, there is no "Relief Pilot" slot in AF crews : the two F/Os should be fully qualified for all phases. F/Os were flying from Right seat at the time of AF447... but after that point it changed and Left seat training was also implemeted for F/Os.

More likely above 95% N1 depending on ISA.
I'll post later the tables for cruise at Mach 0.80 & 0.82 @ ISA +10, +15, +20.

Cruise Tables for GE engines:
http://takata1940.free.fr/cruise_02.jpg
http://takata1940.free.fr/cruise_03.jpg
http://takata1940.free.fr/cruise_04.jpg
http://takata1940.free.fr/cruise_06.jpg
http://takata1940.free.fr/cruise_07.jpg
http://takata1940.free.fr/cruise_08.jpg

Forgive me if this is wide of the mark but I haven't seen it discussed here..

Is it possible the pilots seat position contributed to the incident? For example if he left it in the position the captin had set it to, and that was a bit far back for him, could that have caused him to in advertantly apply back stick?

At least one problem with this theory is that I don't think the PF was the one that took over from the captain.

Hi,

So .. it's possible Air France will have some problems

Says jcjeant.
But the investigation is obviously pointing at the contrary on this specific point.

Crew composition
 

For the reason PJ2 has stated – pilot development – it makes absolute sense to ensure that all copilots remain fully qualified in the R/H Seat. I now infer from takata that Air France may not have had a formal system for training copilots to act as PF in the L/H seat. There is no doubt that using the sidestick with the hand you don't normally use results in a very different "feel". This left/right discrepancy also applies to all switch selections.

This may not be relevant to AF447, because the pilot in the R/H seat appears to have been the PF almost to the end. However, in the event that the more experienced pilot was occupying the L/H seat as relief pilot, he MIGHT have been discouraged from taking control because he had not been trained to fly with the L/H sidestick. I suggest this merely as a tentative possibility, because – in any two-pilot operation (which this was, in a sense) – one has to cover the incapacitation case.

I remain curious why, in the present absence of CVR evidence in the public domain, takata is emphatic that the more-experienced copilot was in the R/H seat. I appreciate that ground staff at GIG would be aware who was occupying which seats just before departure.

It needs to be said that, AFAIK, there is no evidence that Air France procedures were inferior to those of other airlines.

While you all debate FDRs etc, is there any merit in prioritising PF' s data rather than LHS?

Why the pitch up?
 

It might have been a mix of several factors causing the pitch up.
As i´m unable to think in bits and bytes i´ll do the traditional approach (aerodynamics and human behaviour).

My first thing to do after takeover from autopilot or student (i have the aircraft) was o get a feel for the flightcontrols. Grip the stick and do some small inputs to see if it acts correctly and autopilot is deactivated or the other guy has his hands of the stick. That was an automated habit.

Flightcontrol response is different depending on speed, altitude, CG, and in case of FBW on LAW. As somebody stated before the flightcontrol response of the A330 is more sensitive in ALt2 than in normal, and CG in cruise is more aft then during TO and LDG, where stick time is more present.

AF447 was not flying in undisturbed air, also there is no proved evidence yet that it was turbulence in a significant severity. However, the possibility that there was turbulence affecting smooth flight can be taken as assured.

Hand flying in FL350 seems to be a seldom live expierience by an FO, if it gets necessary in an event the CPT probably will do the flying and then the problem will be quickly solved or the flightlevel will be reduced to get better lifties. So it can be assumed, that whoever was flying at 02:10 could not rely on a lot of handflying expierience in Alt LAW in FL350, and not at all in less than smooth air.

Let me get to my point.
2:10:05 - 2:10:20
AP and AThr disconnect and Alt Law, and a PF / FO with minimal handflying expierience gets the AC in his lap with a roll to the right, takes the stick and tries to get a feel for it like in lower altitude, intends to counter the roll and to set the pitch 5° NU for the UAS procedure, simultaneously trying to counteract some mild or not so mild turbulence. He gets it wrong, his input is to big aggrevated by some outside lifties, and the pitch gets higher then intended. AOA being 4° at the beginning, raised quickly to above 10, triggering the stall warning (yes, i think that was a valid stall warning). Same time he is distracted by the cacophonie of the warning systems while trying to figure out what´s happening.
Only 15 sec passed, we are now at FL375 and Pitch is 10°, AOA not known but somewhere around 10°.

Imho it does not need any technical glitch to get in this high pitch there, not enough expierience for such a situation, some turbulence and a bad day will be sufficient.

02:10:20 - 02:10:45
Now the nose is up and PF tries to get it down again, but PF is over cautious from unintentional NU expierience and his ND input is not big enough to get the nose down quickly, but sufficient to keep the aircraft in an somewhat less then 1G slight upward trajectory. There is again speed indication at 215 Kts, but is it valid? The aircraft looks stable, time to sort out the warnings, ecam.....
Only 20 sec have passed, speed is down to 200 and the climb stopped around FL 375, balistic trajectory basically ended and AOA increased and trigggerd the stall warning in the end. AOA at the beginning before unloading somewhere around 10, then down to 4 after unloading, increasing above 6 again due to decaying airspeed and stopping of climbrate (change of relative wind).

Everything is gone haywire within 45 seconds from routine to nightmare (actually we dont see it that way from our armchair, but the PF might have seen it that way). AF447 is now off track off heading turning to the bad zone of the WX area, 2.500 feet above cleared altitude without contact to ATC, at low speed and all good helpers for cruise flight are on leave when mostly needed. Aditionally the most expierienced help, the captain unfortunately is not on the flightdeck.

02:10:51 - 02:11:40
Stall warning sounds again and the indicateing valid speeds are decreasing through 200kts, and (BEA does not state it, but it looks logical to me, therefore i take that guess) the altitude starts to decrease despite the fact, that pitch is still 10° NU. Natural instinct says power (TOGA) and keep the ship from falling into the bad WX area below (SS up), also we know, that this was the big mistake. The aditional thrust kept the altitude from decreasing initally and brought the ship even to FL380 (again overcommanding of SS and THS trimming), but now gravity strikes again, even the pitch increased from 10 to 16°, the aircraft starts its fall in this attitude (stall) out of FL380 down through FL350 at 02:11:45, at what time the captain entered the cockpit.

I stopp there, because the question was why pitchup. If there are computer glitches aiding this pitchup, we will know later. I for myself stated my oppinion how the events happened above, using A33Zab´s very helpfull chronology of events.

Hi Chris,
Simply because it was supposed to be the procedure when the Captain is taking his rest: the new PF, acting as Captain, should be the most senior F/O from the RHS following what AF believed to be the best use of its crews when two F/Os are left alone in the flight deck. Note that, in this case, the PNF (junior F/O) is also acting from the seat he is not used to (hence, more F/O training for LHS after AF447).
At take-off time, those slots could have been filled differently as the junior F/O could have been PF with the Captain PNF (as he was, see report). The next cruise leg was nonetheless flown by the same PF (senior F/O) as during the second cruise leg (when acccident happened). The junior F/O was certainly resting after the climb and came back for the second cruise leg, sitting in Captain's seat. The Captain seems to have been PNF all the time until his rest.
There is no hard evidence of that: it is based on AF routine and clues from the meteo briefing. If the first cruise leg has been flown by the junior F/O, the Captain would have made the briefing to his replacement (senior F/O). The pilot talking (PF) is obviously the same one that is in charge once the Captain is resting: hence he is also the one flying (senior F/O) and this is fully consistent with known AF routine.

Folks - why waste time on speculation? It is not rocket science to find out who was in the RHS. I guess that IF we need to know BEA will tell us. In any case, does it really matter?

Hi,

First BEA report:

1.5 Renseignements sur le personnel
Compte tenu de la durée de vol prévue et conformément au manuel d’exploitation d’Air France et à la réglementation en vigueur, l’équipage de conduite était renforcé.
La réglementation définit l’équipage renforcé comme suit :
« Un équipage de conduite dont le nombre de membres est supérieur au nombre minimal requis pour l’exploitation de l’avion et au sein duquel chaque membre de l’équipage de conduite peut quitter son poste et être remplacé par un autre
membre de l’équipage de conduite ayant la qualification appropriée »(4).
Les procédures de la compagnie aérienne(5) précisent que pour renforcer la fonction de pilotage, un membre d’équipage doit posséder la même qualification que le membre d’équipage qu’il vient renforcer et, qu’en outre, durant la période de repos du commandant de bord, un pilote possédant la même licence que lui doit être aux commandes. En l’état actuel des données rassemblées, il n’est pas possible de déterminer quelle était la composition de l’équipage de conduite en fonction au moment de l’événement.

And I read nothing more in the second preliminary report ... and nothing in the last note about who is who ...
Maybe they will know for the end of this month ?
Very important to know ... remind the number of people life hanging in the hands of the PF

Well...
Usual stuff from you aimed at the very same goal. Please, just read the last findings in the last BEA note and you'll see it written black on white:
Which mean that they obviously perfectly know who was where.... they just didn't tell it to you for some very reasonable reasons at this stage of the investigation. Remember those previous press headlines (Times, etc.) about "Baby AF pilot killed 228!".

Nonetheless, the only relevant part of your quote is this one:
Which mean that during the Captain resting time, the Pilot Flying (PF) must be the one having the same licence as the Captain (ATPL), hence the PF must have been the senior F/O and it seems also that he really was, despite those news headlines, because that is what the BEA is already saying about it (read it again and again): The composition of the crew was in accordance with the operator’s procedures.

Clear enough, isn't it?

Hi BOAC,
Basic common sense would call for all the cockpit displayed informations to be recorded. I don't know if it is possible but they should try it, especially whith today machines that are using all the sources for their flight systems.
But I guess they would have collected more than DFDR data in AF447 case.

- can we have a link please or is it a typo?

Takata- we understand PF's ASI readings were not recorded.

cwatters, quote:
"Is it possible the pilots seat position contributed to the incident?
"For example if [...] that was a bit far back for him, could that have caused him to inadvertantly apply back stick?"

It's possible but, as you note, the PF was apparently in the R/H seat, and had been for some time. Some pilots move their seats back during meals, but not normally when the PF. Seat position is adjusted fore/aft and up/down either electrically or mechanically (the latter being inadvisable in turbulence). The seat is manoeuvred so that the pilot's eyes line up two balls suspended on the frame between the two windshields. The elevation and rake of the sidestick armrest is also very important. Accurate sidestick control is difficult without it.

takata,
Thanks. Can you clarify what you mean by first cruise leg and second cruise leg, just in case I am misunderstanding your terminology?

BOAC, Sir,
Perhaps you would be so kind as to provide us with a list of subjects that we can discuss in advance of the next BEA report, without occasioning your displeasure? Or perhaps we should merely suspend our conversations altogether? Pray forgive us simple Airbus folk.

Hi,

FLIGHT AF 447
English version:
http://www.bea.aero/docspa/2009/f-cp...90601e1.en.pdf
French version:
http://www.bea.aero/docspa/2009/f-cp...cp090601e1.pdf

Indeed .. and so BEA for the "reasonable reasons" .. don't negate it ... and let the rumour run .....
I wonder if it's reasonable
BEA communicate .. yes .. but don't inform .. at least not in better way than the tabloids ..

Flight details:
a) from take-off to top of climb -> all 3 pilots are in the flight deck
b) the cruise flight time is then divided in three parts ("legs") for resting.
. 1st: one pilot is resting (junior F/O)
. 2nd: one pilot is resting (Captain) => event start at the begining of it.
. 3rd: one pilot is resting (senior F/O)
c) from top of descent to landing -> all three pilots are in the flight deck.
Does it make sense?

My thanks, Takata - I should know better than to estimate! I flew the RR on an A333.

Thanks for the information on AF cruise procedures. It is important to understand that there are no "Relief Pilots" but all F/Os are fully-licensed on the airplane and can take off and land.

Canada has seen fit to create the CRP - Cruise Relief Pilot License, a non-flying position where the RP sits in the front seat during cruise only and never handles the aircraft. I don't think that's appropriate but we lost that battle years ago. They have ATPLs and get the full airplane course but competency on the aircraft is not renewed and instead, recurrent training covers the basics and the Emergency Descent, which the RP must be able to do from the LS when replacing the captain. The RPs I flew with were superb crew members but to me the creation of the "CRP" license comes from the same thinking that permitted the creation of the MCPL: It just doesn't cut it when the going gets tough. It's part of the same kind of thinking that states that demonstrating and training the approach to the stall is not required for FBW aircraft. It's all about the illusion that automation solves all the problems of flight. And....it's all about money.

It's not the aircraft that is the problem. It is the hubris engendered by "automation" that fools those who don't fly but who think they understand aviation.

- entirely up to you 'Airbus folk', but I would prefer anything RELEVANT and based on known facts for a start?.

I think you're wrong there.

As an ancient (Concorde...) I'm not too familiar with the data the current AB 'FBW' systems passes on to the FDR, or the exact way this is done.

On Concorde, with an AFCS easily as complex as those of the various ABs we're talking about - even if it was analogue rather than digital - we 'had our fingers' on a lot of signals (both analogue and logic) inside each of those 'black boxes'. All of those went to the flight test recorders (been there, done that, haven't got the T-shirt, but I still have the G-BSST tie), and AFAIK all the essential ones went to the FDRs on the production aircraft.

BTW, Concorde was 'advanced', even if implemented with 1960s technology. And yes, the data we recorded allowed us to fully understand the behavior of the "complex crew member". Like why she 'twitched the rudder' whenever somebody talked on HF... (ancient anecdote).

A discussion about FDRs and FDR data might be interesting, but I think it's totally outside the scope of an internet forum, even one like PPRuNe.
I 'did' FDRs late in my engineering career, so at least I'm familiar with the concepts.

Quote from BOAC:
"...I would prefer anything RELEVANT and based on known facts for a start?."

Known facts are still in fairly short supply, and some may never be known. As you evidently think you are an important arbiter in these matters – despite your lack of any Airbus experience – please provide a list of what topics YOU THINK are relevant. And we'll give it our usual polite consideration.

Otherwise, put a sock in it?

'The stall warning sounded twice in a row. The recorded parameters show a sharp fall from about 275 kt to 60 kt in the speed displayed on the left primary flight display (PFD)'

What does 'twice in a row' mean - why not continuously ? Doesn't the warning continue until the a/c is unstalled (or switched off at <60kts, though why it isn't latched if V is initially valid eludes me).