So let's get to the point.
Is it your opinion the pilots were trying to do the right thing but the flight control computers, "HAL" if you insist, grabbed their arm and didn't let them?
If so, please point out where, as it would be a serious factor in AF477 and definitely should be discussed here.
Otherwise, maybe a separate general FBW thread would be a more fruitful place for a discussion of these matters?

Why not answer my question, which you yourself raised with your answer? We are not talking about instrument flying and its carrying water to the sea to try to teach me how it is done. All of my 3.336 instrument approaches where handflown from start to end and successful terminated. Most of them in german wx conditions, not under the sun of california.

The discussion is about recognizing actions (not outcome) of handling flight control inputs in a non normal situation like AF447 was in.

I did lots of instructing in the backseat of the F-4. Our sticks had been interconnected and i could feel through critical maneuvers. Let us look at stall approaches, where a wrong flight control input lead to departure. On the stick the wrong input could be felt and corrective action could be taken immidiately and thus departure prevented, whereas on the instruments the faulty input would show later, when the faulty input had already lead to departure and uncontrolled flight. Better to be one step ahead than one step behind.

In the case of AF447 at 02:12:45 the PNF and the captain had been both aware of the right bankangle and gave instructions to the PF to correct that bank as they could not observe any action of the PF to correct this bank on the instruments. In reality the PF was aware of the same fact and told them, that he already had full left SS without success. That information was vital as it showed, that correction with aileron alone did not work and helped the captain to refocus on solving the bank problem with rudder input. It took considerable time to unmask this information and it was not visible on any kind of instruments.

It can be assumed, that had the PNF took control of the aircraft prior receiving this information at 02:12:45, that he as well would have used aileron firsthand and would have lost valuable time as well.

I never said, that the SS should be replaced by a yoke, but i do not turn a blind eye to the fact, that in this stressfull situation the awareness of the crew concerning the behaviour of the aircraft in relation to the flightcontrol inputs of the PF was totally lost, that the captain was not able to grasp the situation when he came back to the cockpit and that the mentioned timeframe starting at 02:12:45 is a master example for the lack of direct feedback. Not that this is the only situation in these horrible 4 minutes, there are others as well. It is only a question of perspective.

Right SS - full back, left SS - neutral. Do you understand why the aeroplane pitched down even with full back sidestick, full NU elevator and THS in heavy nose up position, increasing towards stop?

Do you understand why the crew had what you call "bank problem"?

I do.
But please tell me your oppinion and how it would influence the discussed matter concerning recognition of correct or incorrect SS input as discussed.

Retired F4

I would hesitate to compare an F4 with an A330.

Could you please provide your explanation behind "I do"? Methinks that therein lies the problem but I wouldn't like to waste bandwidth by going tangentially.

http://www.pprune.org/tech-log/46839...ml#post6799108

And feel free to PM me, that way we may waste time, but no bandwith.

I would too, therefore i was not tempted to do it.

Thanks for the link, Retired F4.

Great. So you recognize that aeroplane was stalled yet keep on drumming on roll behaviour. For Finnegan's sake, can you picture A330 flying at 40° AoA with about 100 KTAS? Ugly, eh? Spoilers are blanketed by wing, rudder is blanketed by fuselage and ailerons don't have much say - going up they're in wings wake, going down makes a bit of difference but very low forward speed makes them not particularly efficient.

What the heck does sidestick have to do with behaviour of aeroplane that is at extreme AoA, beats me. Oh yes - there's a theory that with yoke somehow CM1 would recognize that CM2's control inputs do not have much effect on aeroplane so he would recognize that the aeroplane is stalled and that first and foremost is AoA reduction.

Well, I'm not buying it. He was listening stall warning for 54 seconds and made not a comment about it, let alone done something.

So far, I have found two fuel sources that keep this Hamsterwheel turning

1. People having no grasp of aerodynamics, instrument flying or aeroplane system making elaborate analysis of some technical detail. Not able to take subtle hints their theories are spectacularly flawed, they resort to personal attacks when told so in no uncertain terms.

2. People that have some idea how flying works, take out a detail out of whole picture then trying to reconstruct the whole scene just on that little detail. That their picture bears not much resemblance to original seems not to bother them much.

Salute!

@ Zorin

Sorry if I did not my point clear.

- My main point is that even in "direct" law the elevator does not follow the stick inputs as most think. And I am also not sure that "gains" and rates for the ailerons are eliminated.

- I do not feel that the reversion sequence is clearly understood until one goes thru it many times and notes what's protected, what isn't and actually sees/feels the results of control inputs. My personal preference would be to have only one "alternate" law, then "direct" law, and the THS would require manual settings in both.

- The auto-trimming of the THS did not "help". The pilot would have had a harder time holding the AoA and pitch attitude if the THS had stayed where it was when air data went awry. So in that regard I DO THINK the computers got in the way.

Simply stated, I lay most of the fault with the crew but can not rule out contributions by some of the 'bus FBW and display/warning implementations.

@CONF:

By attempting to force me into the debate on your terms, I think you'll find that it is you who is arguing like a politician. I've already stated numerous times that I don't want to go there again because we've already been there before - you *know* we've been there before, and because I've stated my position that I don't think it's relevant to this case I think it's only fair that is accepted.

Probably going to take a break for a while after this, as it appears the thread is being sucked into the old "interconnected" debate for something like the fifth time, but just to summarise:

Based on historical data, we have incidents where inappropriate backpressure following UAS has occurred on aircraft equipped with interconnected yokes and independent sidesticks, most of which have led to an airframe loss. We also have historical data that proves lack of interconnection is no barrier to recovery (specifically the other 30-or-so A330/340 incidents which did not lead to a crash). That suggests to me that any round-robin discussion of interconnection vs. independence is not relevant to the case at hand, which is why I'm not going to get involved any further there.

Yes, the Airbus sidestick design drops the tactile feedback channel, but whether that is a big deal or not largely depends on your opinion. Some pilots who have grown up flying on feel distrust the design, and they wouldn't be human if they didn't. From an engineering standpoint most of the reason for having interconnection (i.e. the ability to apply extra leverage from the second pilot in the old cable days) was gone by the time controls became fully-hydraulic over 40 years ago. The yokes are cumbersome, and inadvertent bumping or moving of the columns have led to several incidents over the years, some of them fatal. The Airbus engineers ran the sidestick design past the pilots (at least one of whom was the most respected safety pilot in the world at the time) and got approval. Muddying the issue was the rise in automation during the '70s and '80s and a lot of people got their wires crossed - not helped by the press, who always like a "let's you and him fight" situation.

To my mind, this is irrelevant in this discussion for the reasons I laid out in my third paragraph, and what makes it more so is that while arguing over whether having a badly-positioned yoke in front of him might have made the PNF react more decisively, the thread is missing the point that neither of the F/Os at any point seemed to acknowledge that they were in a stall, and without that it's arguable that even if the PNF had taken control he might not have been able to recover in time.

The reason I say this comes from my sim session, which taught me some things I didn't know - namely that when stalled, the tendency is for the aircraft to respond to aileron input with a roll in the *opposite* direction, and as such it is advisable to use the sidestick for pitch only and to control roll with gentle rudder, which took less than 30 seconds to explain (albeit several attempts for my lead feet to get right :) ) - but if we are to believe what the BEA is saying then this little bit of life-saving knowledge was something that these professional line pilots had never been told, or at least not recently.

So (sorry for the lengthiness of this rant), Air France was routinely sending up 3-man crews, two of whom had no manual handling instruction at high altitude, in a type that they were aware had a known problem with the pitot tubes that in a worst-case scenario would force the handling crew into handling the aircraft manually at altitude. That's almost priming the system for an accident eventually, and no amount of debate over automation or interconnection will alter that fact. Whether Air France were alone in this practice (I suspect they weren't), they were the ones who ended up with the bad cards and had the accident and in my opinion it is they who should shoulder the lion's share of responsibility for allowing it to happen. I think "blame" is a non-helpful concept in aviation accident investigation and I'm not a fan of the continental practice of making it a judicial matter because it makes getting at the truth problematic (although, truth be told, the Anglo system is much the same but handled by the civil courts).

@gums - I can assure you that once the aircraft stops responding in the manner you expect, the last thought on your mind should be what is protected and what isn't - it's safest to assume that nothing is protected and the utmost caution be taken to get your response right.

Safe journeys folks.

Dozy. You're last paragraph re: pilots/Air France. Excellent. It pulls together a major portion of the impetus for disaster we see in this tragedy. I completely agree. Allow me a small addition? With the stage set for LOC in manual under these conditions, (and they were stinko), Airbus shows a remarkable blind spot in monitoring their product whilst in service. This is not a third world fifth owner operator, it is a legacy Flag Carrier.

Wildly expensive and complicated machine systems need nurture. In seeing to it that her operators were allowed singly to abuse her care and operation was a major player in her demise. Her makers lost the marque.

If one truly believes that as automatics increase in capability, Pilotage can degrade, the coffin business will bloom, leastwise whilst airborne.

And some people have very little grasp of the varied ways in which people gather and process information. :rolleyes:

There have to be a whole lot of jet pilots who have never flown a swept wing jet at very high & at stalled AOA. They have been spending their lives avoiding just that situation.(Non-tactical flying)

A swept wing jet does not behave like a straight wing trainer at high AOA. The dihedral/roll effect from the swept wings is very powerful, particularly at high AOA.

Hi,

I don't buy any A330 simulation of stall like you don't buy a cat in a bag
The real thing (full stalling) was never tested on the A330
This was not made cause certainly was taken in account the risk and money
So the choice was to not put in danger the life of a test crew and the risk to loss a frame .. but this imply to put the life at risk of the line crews and the passengers in case of a stall .. as the pilots don't know how the plane will really act at the eventual recovery manoeuvres
Very bad choice
It's really a big issue in the aircraft industry to not perform all the needed tests .. and this not only apply to the planes but also for the parts used
The life boats of the Ocean Ranger (drill rig) where tested many time by nice weather and all was good
When the tragedy was there .. the life boats were pushed by the wind against the columns of the rig .. were crushed even before touch water .. killing all people in
The design of survival gear was not good (location) for bad weather .. but this kind of situation was never tested
Heuristic ?

First, this paragraph creates a wrong equivalence, by generalizing and taking historical/statistical data out of the very specifics of the context of each case.

Then, the paragraph is diffusing, or blurring the main point from the "visual contact", and/or "virtual secrecy" of the placement of the A330 SS, which is the problem pointed out by several posters, to "interconnection" and "independence", which no-one mentioned other than you.

Addressing the "visual contact"/"virtual secrecy" would be a lot more helpful in converging on this discussion....

It's "the placing of the SS" that makes visual contact with it impossible, not the "SS". The paragraph is another example, mentioned before, of extrapolating or extending one problem of a mechanism, to the entire mechanism, or system, which creates the road blocks of being able to converge in this discussion.

...while the more decisive reaction is emphasized correctly, the paragraph is missing the point that an earlier and more effective correct action of the PNF could have prevented the Stall, during approach.... or could have made the recovery from Stall possible....

Of course they weren't, ....

What Air France, or others did, while being "a cause", is in fact, also "an effect".

Why did they do that? what is the cause? what put them at ease, that it is possible to do that without significant risk?....

I just settled all the arguments!
 

Two points to keep in mind:
-There is no record of what was displayed to the PF, and thus, no proof that he had all the info he needed on his displays. There is no reason to "know" either way if he had working displays. (As we all know, pilots have vigorously resisted the suggestion to install video cameras on the flight deck, just as they resisted the addition of CVR at one time.)
-It hasn't been determined, and probably cannot be, what the poor PF meant when he said, "We have no more indications." Correct me if I'm wrong, but I believe that many here have interpreted that to mean "no speed indications." There's no reason to assume that as gospel.
-Oh, here's a bonus third point! If PF had had a working AoA display, and he had looked at it, ya never know that 228 people might still be walking the earth today.

I'm weighing-in in support of what airtren, Machinbird, and F4 have been trying to say. As a dispassionate observer, their views make the most sense to me, and I have no AB, FBW, or Boeing axe to grind. Suggestions that such contributors are prejudiced or "anti-AB" are simply paranoid, in my view. (See airtren's comment above.) Anyone unwilling to weigh ALL possible factors is not being intellectually honest, yeah you, DW! :p

Clandestino
 

Let me use some more bandwith then.

Read my post. I did not do that.

I´m fully aware how a basic aircraft works or better not works in a stalled condition, they are all similar. ANd i needed no sim time in a A320 like DW to know what ailerons do in a stalled condition.

Nothing at all. Could you quote me where i made such an mistake?

Is that your theory? Amazing. I only used it as an example to answer OC´s statement, quote below.

Not more and not less. By the way, i still wait on the answer to my question, how the PF or the captain could have seen on the instruments, that despite the continuous right bank PF had full left SS.

Or is this answer no longer relevant as it does not fit in the "everything is right, nothing needs to be changed" scheme?


The simple answer is he should have failed his medical previously due to a hearing problem, or he wanted to kill himself, or....
what is your answer?

Now where do i fit in?

I like the term KISS, but not in the cause of accidents. I like to turn every stone and look under it, and most of the people you acuse to turn the hamster wheel do the same. Its collecting bit for bit, some turn out to be one way streets, some need further consideration.

I take out a detail and discuss it, but the reconstruction will need lots of those details to get the picture complete. To cry out loud when one of those details is discussed that this is against A or that the whole accident is hung on one single nail is tiring.

I for myself leave it anyway to BEA and Airbus and whatever agency is responsible to make the final saying. But that does not keep me from telling my oppinion on certain aspects of this accident.

But if you do not like this "hamster wheel" then it would be very simple to just stop reading it.

Interesting reading but the strong inference must remain that the 3 crew at no time seriously considered that they were stalled and at no time applied appropriate inputs to attempt to address a stall. Can't see how yoke/aoa gauges are relevant. Perhaps they would have made a difference, we can never know, but they should not have been needed in any case. Dialogue articulating the pull-up inputs is clear enough on the transcripts so can't think anyone was seriously misunderstood for any appreciable period.

Had the situation finally been appreciated and the subsequent recovery hindered through lost time or absence of some instrument, OK. But it never got to that point.

Problem one: those "most" include the ones who designed Airbus, the ones who certified and the ones who fly it. Direct law in pitch is proportional stick-to-elevator displacement.

Problem two: AF447 went into ALT2 so it wasn't in direct pitch. To oversimplify: ALT2 in pitch is basically G demand. That the aeroplane remained in ALT2 is indication inertial reference was working.

Problem three, which really is mostly limited to fora: Airbus control laws are difficult to understand for someone with just a passing interest in aviation. Those with dedication and capability can master them without giving too much thought to them. Bad news is that not everyone can be an airline pilot. Good news is: those who really can have extremely good chances of getting to grips with Airbus.

Opinion of certifying authorities is that it matters not.

Correct for almost any aeroplane. Caveat is that it works as long as there is enough rhoveesquared and controls are not blanketed. No transport aeroplane has ever been put intentionally far beyond stall AoA therefore while sim behaviour is extremely realistic just above stall AoA, it turns into guesswork as AoA is increased, which is not a problem at all. Sims, just like aeoplanes, re not meant to be operated outside the envelope.

Say what?!? Professional line pilots are trained to avoid stall, roll control via rudder while stalled is domain of flight testers and those bent on serious aerobatics! Life saver would be push forward!
So? There are thirty-seven cases of unreliable airspeeds on 330/340 aeroplanes listed in interim2. Companies are de-identified, however, given registration and date, it is easy to find out who was the operator at the time of the incident. On a few occasions it was AF crews, that despite having no training at manual handling, actually lived through the experience. This might lead the AF into believing that all of their crews would cope with the problem under any circumstances.

Of course, it would be mistake to interpret this as "It was deceased pilot's fault". There definitively were organizational precursors but pilots were not lambs lead to slaughter by tricky aeroplane and inadequate training.

There are strict demands how one who wants to fly and avoid getting killed flying has to "gather and process information". As I said: not everyone...

He couldn't. No one flying FBW Airbus can know what exactly is his significant cockpit other doing with the stick. If it's such a big deal, why would it get overlooked by those allowing thousands of Airbi flying passengers commercially?

Relevant or not is not my question.
I don't force you to anything - If you have nothing to argument you don't have to write that long either.

At least I'm not the only one to perceive what I would qualify also as intellectual dishonesty.
I also think you need one.

Rebuttal
 

Mr Optimistic said:
First, ND input was tried (for not long enough) but it brought the stall warning back on. That may not be a good excuse but it is perhaps a REASON.

"We can never know" if an AoA indicator would have helped. And there, you've made my case, thank you. Likewise, we "can never know" whether-or-not seeing a yoke buried in his lap might have helped PFN come to a realization. In other words, you who insist that some of these things made no difference really have no solid evidence for those claims. Pure opinion.

Of course, there is no such thing as foolproof, but should we not err on the side of making the Airbus as "foolproof" as possible? Of course we should. Why shouldn't pilots have every possible tool in their box, given the many opportunities here for profound confusion?

To which Clandestino offered:
Well sir, now that we have AF447, maybe they will reconsider, eh? Are certifying authorities always right the first time?
Where is the icon for 'pppfffttt!'?

Thank You. In all of the techno babble, "sim-geek", bovine scat, the fact remains that the crew saw something that convinced them to ignore a stall warning. Either they were incrediblly stupid, or incrediblly confused by what they saw, felt and heard. No amount of FBW, SS, automation, defense changes the fact that three qualified aviators flew the bird into the ocean. What I find disturbing is that the airplane (AB) was designed to prevent such an event, but failed.

The lead up to the stall almost certainly had to result from mental processing overload on the PF, and a hesitancy to act on the part of the PNF.

I agree that none of the 3 in the AF447 front office seem to have acknowledged or verbalized a stall (According to the released transcript). I have to assume that once stalled, the experience was too far from their training to recognize and would therefore have had to be puzzled out on an intellectual basis for a successful outcome.

Mixing the discussion of yoke vs stick and presence of AOA is like mixing oil and water.
If you had ever flown with an AOA gauge, had observed one in various flight regimes and in the Sim, and had became comfortable with the veracity of the indication, then when the stall warning began to squawk, your eyes would be programmed to look at the AOA indication for confirmation, particularly when the airspeed is no longer available in front of you. As long as AOA is moving in response to control motions, the operational assumption should be that it is valid (operational assumption = bet your posterior on it).
If the AF447 crew had an AOA indication and had been trained to use it, the only valid explanation for allowing the stall would be a death wish or both pilots sleeping.
There is a world of difference between stall warning and AOA.

Let's be careful about the semantics lest somebody starts believing these words.

The aircraft is designed with the means to have prevented this event.

It is not designed with the pilot out of the loop.

Machinbird uttered:Sorry, Mr. Bird, I had no intention of conflating the two things. What I intended to say is that they both share the attribute of "might have helped, who knows?"

The rest of your comments about AoA indicator are spot on and exactly what I meant but didn't have the skills to say so.

Quote:
Originally Posted by Machinbird
And some people have very little grasp of the varied ways in which people gather and process information.

Clandestino
So, are you suggesting that the crew for AF447 were not properly selected....?

Hi,

Clandestino
So .. are the AF447 airline pilots or not ?

Clandestino
Heuristic ... the good choice for evaluate a problem ?

Clandestino
Heuristic .. again
Heuristic is a invite to disaster

Certainly not.
If it was true AF447 would have landed at CDG.

The shoal continues to multiply. Gentlemen this accident is about perception and psychological factors. It is nothing to do with the machine. I have consistently mentioned 'Know your machine'. In my view, the flight crew didn't and here I have to break cover. In my view they were incompetent and unsuitable to be flying an aircraft - their lack of professionalism and disregard for the procedures caused an accident in a recoverable situation. In my view they were part of a culture that had developed in Air France based on arrogance and casualness. I referred some threads ago to the Clipper Skipper syndrome - pilots who could do no wrong and didn't have the skills needed. Some of you should go and read up on the Pan Am accidents in the 1970s. In my view Air France their airline cut training and ignored important aspects of flying - they also are culpable.
As for the arguments that the instruments are unreliable I have never seen so many straws being grasped in one go. Read the reports again - the instruments were functioning effectively. It was the flight crew who didn't know what to do. NO CRM, No SOPs, No UAS procedure just frozen incomprehension. A yoke wouldn't have helped here at all. NO training, No chain of command. This is a human disaster not a machine failure. We must be realisitic here this is a pilot failure brought on by poor procedures. This was not an extreme case - this was an unusual situation which could have been recovered and has been in other situations. AirTren talks about information when perception is the key. Why did the crew ignore the stall warning? Why did they ignore their reliable instruments? They were not up to the job - that is the real cause of the accident.

I doing ok Clandestino, thanks, Old Carthusian may now realize that instruments don’t necessarily tell what the flight control inputs are …

Now for you Clandestino :
You are the Captain on AF447, as you enter the flight deck the stall warning stops, the pitch is going down.

1. The equipment is a A-330, you don’t know for sure which pilot has control and don’t know which inputs are applied.
2. The equipment is a A-310, you see the right seater with 2 hands on the control wheel to maintain it to his stomach for half a minute.

Which scenario do you consider the most informative for you ?

Instruments are more reliable than human perceptions Conf iture and I haven't changed my opinion one bit. Certainly not on the spurious irrelevancies that have been presented so far.

Who said otherwise ?

AirTren, retired F4 to name a couple. Those who argue that a yoke would have helped. By implication you yourself (and I do apologise if I have misread your posts) also seem to think that

"Old Carthusian may now realize that instruments don’t necessarily tell what the flight control inputs are"

Instruments do precisely that because that is what they are designed to do.

To my knowledge those guys have never pretended that "Instruments are more reliable than human perceptions" but I will let them reply.

"Those who argue that a yoke would have helped"
I am positively one of them.
Note : I do not pretend it would have avoided the crash but I do pretend it could have helped to avoid the crash.

But it is interesting to read you, and I think we are here in a situation where you read what you think you read and not necessarily what is actually written :

My comment IS :

• you may now realize that instruments don’t necessarily tell what the flight control inputs are.

My comment is NOT :

• you may now realize that instruments don’t necessarily tell what the aircraft is doing.

Of course they did - go back and read their posts. You will find numerous statements on how the yoke was more reliable than instruments. AirTren goes as far as to construct a whole castle in the air about it. Retired F4 talks about the yoke being more reliable than instruments. I would submit his memory is at fault here.
Given the way the PF reacted a yoke would have made no difference - simple as that. The cause of the accident lies in the human factors and we may never know exactly what caused the PF to act as he did. However, your preference for a yoke is an irrelevance to the cause of the accident. It would not have helped because of the circumstances of the crew on that flight.
As for your final point my comment still holds. Instruments do tell you what the flight control inputs are. That is their purpose - to give a pilot a measurable and reliable indicator of his flight control inputs.

Old Carthusian - leaving aside SS/yoke arguments, I see a matter of some concern in your understanding of instrument flying. You have no 'career' information in your profile, so I have to conclude you are inexperienced in Instrument flying.

There are two glaring inaccuracies in your recent posts that I do not wish other pilots to absorb:

1) Post #69 "Yes by looking at the instruments. An input produces a certain pattern on your instruments and you can understand what your aircraft is doing" It might not and you cannot always.The instrument reflects what the aircraft is doing after the input and that may well NOT be what you intended. See AF447?

2) Post #76 "Your artificial horizon will tell you if the plane isclimbing or banking" It will not. It will, of course, certainly tell you if your nose is high or low. Perhaps you do need to re-read the AF447 report? Then tell us what PNF's EADI showed in terms of 'climb'?

Lastly, I would point out that no-one knows what PF's instruments were displaying anyway? We are (naturally) assuming they were functioning correctly - and they probably were, but we do not know.

That is a hard accusation of you, and a personal one. If you make such peronal accusations, you should at least quote where i did so. Lets find out whose memory is at fault.

As we exchange personal genialness, i would assume that your personal knowledge concerning flying itself seems limited, and the knowledge concerning aerodynamics and other vital aircraft dynammics is not existent.

Your analysis concerning the human factor stands well and was not doubted neither by myself nor by a lot of other posters, but it does not stand alone. There are contributing factors to any accident i´ve known so far.

To close his eyes and cry down other voices like you do here with my oppinion by disqualifying my memory places you as the first ever poster on any forum on my ignore list.

Old Carthusian,
But on Airbus, the F/CTL ECAM page is not normally displayed in the cruise. A pilot would have to deliberately select that page.

BOAC
Of course artificial horizon will tell you if you are climbing - what do you think the gap between the horizon line and whatever symbol is used for the aircraft means? Yes it means your nose is raised but it also can be used to ascertain that the aircraft is climbing. OK here I am guilty of simplfying a bit (which is a problem for me, I value brevity and expect others to understand this.) but then so are you - it serves both purposes very adequately. What it will not tell you is your rate of climb, you need the altimeter for that and if you quoted in full you would have included my mention of the the altimeter.
The instruments are there to provide an indication of the results of your inputs. Without them you are very much guessing every flight and they are certainly more reliable than your personal impressions. As for AF447 I suspect that BEA knows pretty much what the PFs instruments were reading - they may not have chosen to release the information but they do have it. Everything released though points to a psychological reaction by the PF which was not dealt with adequately by the captain or PNF. It does not point to any problem with the aircraft. Your final point is a straw man argument - if there is no reported problem with the PFs instruments then there is no reason to impute a problem.
Retired F4
Memory - a very unreliable thing especially were flying is concerned. It's nice to be so assured about every flight you've participated in but me I cannot. I have to check and then maybe I can summon up a reliable memory. If I disqualify my memory then I also have to mistrust your memory.

Old Carthusian,
Isn't that exactly the same error that PF also made?