Lonewolf_50

Gerard C, thank you for your response.
OK, difficult, challenging ... requires either different technique or more effort than hand flying in normal law. Right?
If that's the case, this mode of flying would need to be practiced in order for pilots to develop a feel for doing it when required.
Agree?
Do you say this under the assumption that most pilots do not get the opportunity to hand fly the A330 in Alt 2 law at cruise altitude?

I think OK456's points are worth accomodating.
Understood. Most pilots you know will also take the correction out as they approach the desired altitude. You make a correction for a deviation that you notice, then you make a counter correction to re-establish the performance you require (Airspeed, Alt, etc). While the trace shows a series of corrections and counter corrections in roll, the same cannot be said for pitch.

mm43
Thanks, will need to look at that again when I am on a PC that loads images. (Bear, reserve further comment for you until I have done so).
That got me chortling.

The answer does not necessarily lie in any cockpit. It may lie in any number of dark corners of "the system" as it currently operates.

Lyman

Lonewolf

"That would explain the initial NOSE UP"....

If so then, my friend, that is HUGE. Because post "INITIAL NOSE UP", is territory that is covered well by Yourself and F4. A combination of Pilot inputs and g sensitive commands may have nibbled 447's way up to 17PU.

On the graph, with the NOSE pitching down (and the altitude increasing), is evidence of the disconnect between PF, his instruments, the FCS, and the Weather. IMHO.

airtren

Clandestino,

Your unabated insistence on the instrument flying is appreciated.

That indirectly suggests the importance of adequate training, and in this case, the impact of the the lack of it, which is mentioned in the BEA Report.

Here it is again: the training has the role of getting the important elements into the pilots reflexes to the point that they can do what's needed without any hesitation, or doubt, regardless of the external disruptions, or conditions.

A reminder seem to be in order though, of the failure of some of the instrument indications, which compounded the lack of adequate training. So far there are the comments on the CVR transcript that speak, and hopefully the recovery and processing of data left on some of the recovered computers will allow restoring the indications on the PF (right side) Instruments which were not recorded by the FDR.

Not quite. (note: my conversion to italic in quote)

The THS position is an indication of how far a main longitudinal (NU/ND) control surface deflection is, which would be a confirmation on the action needed, if in doubt, which was plenty that night.

But even a well trained, well aware, good pilot taking the quick initiative of a full ND stick, I am quite sure would have taken a quick glance to the THS wheel, and its position indicator, just to confirm once more for himself, in a fraction of a second, where things are, before acting with the stick....

Furthermore: if I take the reference to THS at its full NU position, when the a/c was already in full Stall, we can only refer to Stall Recovery, not Stall Avoidance, as the procedure to be applied.

Stall Recovery points again to incomplete training, and practicing, as the ND is counter-intuitive and counter-reflex to the reflex of holding altitude - altitude is known that is being lost.

Developing reflexes similar to, or for Stall Recovery is done for military pilots, in addition to those for holding altitude, and it is not just by telling them what needs be done, but by hours and days of practicing.

Perhaps an analogy is called - "the skater/hokey player/ice figure skater" analogy:

"Skating" cannot be taught just by telling one how to do skate. It needs practicing, so that one develops reflexes that add to, or counter those of walking.

Furthermore, a good Hockey Player skating reflexes will not make him instantly an ice-figure skater. It again, requires more than the understanding of what need be done, it requires practicing, and building adequate reflexes.

We could in fairness narrow down such a number to those "at night, and turbulence"

I was moved by your Saint-Exupery previous reference, but your reference to Kant is not less, it's more.... Kierkegaard next?

That is important, but alone will not do it.... as there is a lot, lot more than that to it...

MurphyWasRight

.
That is depressingly similar to the statistics and response to the known O ring issue on the Space Shuttle solid boosters.

A back up safety system that has prevented disaster 30 times does not prove that the systme is safe.

Personally a 3% chance of buying the farm if a known fault occurrs is a disturbing thought.

Lyman

Who said this is not as important as what it means:

"The Pilot, if input ND would cause the THS to follow." (POST STALL).

That is categorically incorrect. No "sustained input" would budge that THS off NUFULL. Neither would it have moved UP if there was room left for it.

I think it was FUNCTIONALLY locked. takata told us so, and I believe him.
It was essentially unavailable, PARKED in NU. No excuses for STALLSTALL, but once STALLED, this a/c was done. IMHO.

It is shown in airtren's and mm43's graphs. Why the THS moves only that one time, and directly to FULLNU? And then STAYS PUT?

The g traces. And ALTERNATE LAW COMMANDMENTS.

If so, and I truly believe it to be the case, that might limit the Pilot's options?

I think the PF's insistence on NU had a (good) reason, and simply because we can't see it, does not make it laughable.

I also think his efforts at flying had zero to do with what he may have thought of a long litany of numpties may have in the way of judgment for him. (To include myself, with respect).

Lonewolf_50

Bear, I don't think your'e right about that. Alt 2 latched does not mean "flight control locked and no longer able to be moved." The THS movement lags behind Side stick commands, since the elevators are the flight control surfaces that first adjust to meet the change in condition called for by the Side Stick.

This order of operations aids and abets smooth flight. The elevators first change, and THS then adjusts (unless in Direct law) to the new demand to reduce the need for elevator deflection. This sequential set of flight surface changes creates a new equilibrium point, from which the next control deflection change is made.

With that in mind, unless we can conclude that, at a certain AoA, elevators lost the ability to change the airflow, and thus could not initiate that order of operations wherein the THS adjusts to the new position, then your statement that the THS could no longer be moved cannot be agreed.

Also, in the incipient, early stall time period, when the aircraft first stalled (within the first minute and while there was still some momentum carrying the aircraft up, see HN39's graph two threads ago for that relationship) there is ample reason to believe, and energy available, and the THS at a low enough angle, to recover from the stalling regime with sustained nose down.

Lyman

You misunderstand, and I was less than clear. The THS was FUNCTIONALLY unavailable. It was "LOCKED" by "DESIGN". Not a deliberate blunder, but a blunder, due blind spot created by belief in a less than "best" system.

a/p LOSS - STALL...............Phase ONE (my description)

STALL-STALL - THS migration........Phase TWO (again, mine)

Rest of Descent - Impact...... Phase THREE. (my label).

Look at how clearly the THS movements occupy the PHASE TWO, and are absent from ONE, and THREE?


The THS is inhibited above 1.25g and below .75 g.

Where are the 'Disinhibited' g regions? Climbing, she was gyrating, experiencing g excursions. At Apogee, she was 'docile'/g compliant, and the THS rumbles UP. Descending, she bucks, ROLLS, and nods, g non compliant (per THS LOgIC). THS UNAVAILABLE BY (lack of) DESIGN.

This is opinion, and to grow it wants an FBW (330) wonk, and that is NOT ME.

(You inject: "But she was recoverable, and Pilot.....". That is not germane to the THS FUNCTION as relates 'g'.....) Yes the PF commanded NU, and the THS complied; stipulated, and rejected as not relevant? Availability of THS is this topic, for me, relative to DESIGN.

Maybe a different thread, for my opinion goes beyond what we see, here, even in the traces. We could set up an exercise independent of this accident, because DESIGN is a concrete thing, and can disguise itself in "traces". OR PF inouts, etc. Mixing a theoretical with an actual may not be appropriate?

Lonewolf_50

Bear, you lost me. The "locked" descriptive seems not to mesh with the design feature that leaves open control of the THS, to move up or down, via the trim wheels regardless of elevator position or AoA. (If that isn't the case, it means my understanding is deficient).

No further comment.

rudderrudderrat

It must be a complete waste of time building simulators with full motion in your case then.

roulishollandais

All the posts show that we only look at the failures of the aeronautical skills, without interest at software reality.
To be sure of the way of flying of such an aircraft with software beside the Captain and the FOs, it is MANDATORY to use computer science rules.

The safety of any software is very complex to establish, but possible.

Find there an short but very important extract of the Inquiry Board report after the first flight of Ariane 5 launcher who ended in a failure (Chairman of the Board J.L. LIONS, Académie des Sciences, Médall Fields) :


"The view had been taken that software should be considered correct until it is shown to be at fault. [...]
The Board is in favour of the opposite view, that software should be assumed to be faulty until applying the currently accepted best practice methods can demonstrate that it is correct".

DozyWannabe

With all due respect, that's a straw man argument. Full-motion simulators are there to teach you a measure of how the aircraft responds and how it feels - and as such are as valuable in teaching sticking to the instruments *in spite* of what you feel as they are teaching when that feel is a positive reinforcement of technique.

VGCM66

Once upon a time there was an expression "flying by the seat of one's pants" that was accepted and even admired. We stopped believing in that nonsense long ago and there is no turning back.

Fly by the seat of one's pants

rudderrudderrat

Hi DozyWannabe,

With all due respect, experienced pilots miss the absent acceleration clues in full motion simulator.

Some complain of motion sickness during turns on the ground. (The real heading doesn't change despite what the visual is doing.)
Some find it more difficult to keep straight on the runway due to the missing side ways acceleration sensation.
Some find it more difficult to judge the flare rate due to the missing vertical acceleration.
Some are too enthusiastic with pitch change during TCAS RA events due no sensation of delta g.

Most of us modify our inputs by what we feel as well as what the flight instruments say. Even autopilot inputs are modified using accelerometers.

hetfield

What do you dream at night?

CONF iture

Next time, give it a try, include also your capacity to sense deceleration, you'll see how effective and simple it is really. Your pax will love it too you know.

DozyWannabe

I'm well aware, and I'm certainly not going to argue the toss with you on that count, having no full-motion simulator experience (although I have nearly lost my lunch when my AEF instructor demonstrated a barrel roll and half-loop (Immelmann Turn) in a Chipmunk, so I know something of the phenomenon... )

However, the point I was trying to make was this - based on my understanding, as trained pilots it is ultimately at your discretion as to how much emphasis you place on your physical sensations versus what the instruments are telling you. Based on what I was taught before I succumbed to long hair, rock music and pacifism (in no particular order) and washed out of the Air Cadets as a result (in fact, somewhere in the dustiest recesses of my Mum's loft is a box containing my Cranwell prospectus and completed application form - lest anyone think I was never serious), it is a rare occasion indeed where your instruments are more likely to give a false impression than your inner ear. Even if one of the instruments in the scan is giving you faulty information, there should be enough information provided by the others to keep you right-side-up and give you a sporting chance of getting back to terra firma in one piece.

There have been more than a few examples in the last couple of decades where pilots have mishandled airliners due in whole or in part to failing to trust their instruments, most or all of which were functioning normally (Flash Airlines and Birgenair to name a couple). Don't get me wrong, I understand the importance of feel in the tactile channel, but on the other hand I think that safe airliner operation is more than feasible without it. I also think that the arguments for retaining autotrim in Alternate Law outweigh the arguments against - with the proviso that the behaviour of the systems in Alternate Law are taught properly (which, according to PJ2 in the R&N thread, they are and always have been based on Airbus's own training materials):



@Bearfoil/Lyman/Will Fraser:

That is an out-and-out misrepresentation. What takata posted was this (emphasis mine):

Sustained nose-down input at the apogee and/or rolling the trim wheel forward manually would therefore have been perfectly successful in trimming *down* at high-g loading.

I'm now more than a little suspicious of your continued attempts to sow misinformation in this thread and the others.

Old Carthusian

I am afraid for all those arguing otherwise and suggesting that perceived acceleration is a valuable tool in evaluating your situation that Clandestino is right. If you ignore your instruments you run into a dangerous game where you can misperceive with great ease. This has been proved again and again and it can even vary within an individual depending on their physical and mental state. The only way to ensure safe flying is reference to your instruments.
With reference to those arguing that the displays were somehow confusing, this is rather a training/human problem. You work with your equipment as it is not as you would like it to be and if you enter a new cockpit environment you take time to lean the differences. These gentlemen were familiar with the cockpit environment though and as such should have responded appropriately. The reason they didn't is due to human psychology not machine failure.

glad rag

"pawned" I believe is the current youthful vernacular?

Once again, the original purpose of the discussion on these threads have been twisted for whatever purpose.
It is entirely possible to see a point where all knowledgeable contributors no longer post due to the possibility of their postings being taken, re submitted falsely and then distributed further.

HarryMann

So that's false

even though the majority of the descent was between those figures anyway.

Lyman

So look at the g accels again 2:10:51/2:11:46. As the THS is cranking in FULLNU, the g decreases "accordingly".

No further comment.