DozyWannabe

The CVR trace includes the phrase "We've lost [the] speeds" from the PNF and "We haven't got a good display ... of speed" from the PF between 2:10:14 and 2:10:18, so I'd say they were aware that they had a UAS situation, or something akin to it.

CONF iture

Does not fit too well IMO : After the initial and rapid drop, the bird would have had to show some positive path to go from 34600 to 37500 feet.

Why should they ?

Lyman

Dozy. Of course, I just posted that. I am referring to the assumption here that UAS was instantly annunciated or "got" by the PF, and he perforce needed to....bla...bla...bla...

Where is the fact that shows he knew the problem (a/p loss) was IAS related? Not simply MET related overwhelm in a/p?

2:10:14 is nine seconds after drop, an eternity if manual flight was necessary to control the ship post a/p. Even in NORMAL LAW, nine seconds can be too long to maintain control and formulate a Flight path. Our pilot had ten minutes since rest? Here be HUMANS, Sir.

Doze look at your quote from BEA: The PF notices "We haven't got a good speed?"....2:10:14.

Doesn't that show you PF was not grokking UAS (If it even existed at drop?)

DozyWannabe

Agreed.

I think Dani summed it up pretty well:

One of the things that bothers me about some of what I'm hearing with regard to inhibiting controls during a Stall Warning - especially during an unreliable instrument incident - is that it violates a central tenet of the Airbus design philosophy, and something I think you would be on board with, CONF - namely that in the case of a failure, the pilots must have full authority over their controls based on the assumption that the pilots will be able to troubleshoot more effectively than a machine which may or may not be suffering from bad inputs.

I'm inclined to think that if a hypothetical pilot tried to trim, required that trim for an escape maneouvre and the control logic stopped them from recovering, that Airbus would be coming in for all kinds of abuse.

You can't have it both ways...

Lyman

One is extremely impressed with the stability of the ship from STALL.

She "stays where one puts her".

Like that's a good thing?

Dozy: The aircraft itself disables trim when in Overspeed prot. In a climb, what trim is necessary to maintain PITCH? TRIM is where one wants to "reside"; manuevering with trim when sudden changes in controls may be needed, is a burden, not a help. Especially with powered controls and FBW.

Whose muscles need relief? Authority is not in need of enhancement, and feedback is nonexistent. Que?

CONF iture

To the contrary I'm afraid Dani is making some stuff up :

"It is strongly recommended that you never use the bird in case of unreliable instruments."
belongs to him, not to the FCOM.

As quoted, the FCOM is far less restrictive :

"If remaining altitude indication is unreliable:
Do not use FPV and/or V/S, which are affected."

Something of interest, Airfrance FCTM even recommends its use :

Sorry Dozy, As I'm not sure to well understand that one, would you rephrase it for me, please ?

Dani

How can you know that it's reliable if you haven't even started to compare? The doomed crew wasn't able to start a serious trouble shooting let alone to perform the first few memory items. How could they know which information is reliable and which not? They basically were trying to figure out something, and never came to a conclusion until impact.

Clandestino

Electronic Instrument System number 2. It consists of PFD2 and MFD2. It is in front of CM2. CM2 is the pilot sitting in the RH seat. Determination of RH / LH seat is made relative to the direction of the flight, tailslides excepted.

No. Single HDG V/S / TRK FPA button on FCU affects both sides.

CONF iture (or anyone else, for that matter), can you tell the difference between following two statements:

If remaining altitude indication is unreliable: Do not use FPV and/or V/S which are affected.

and

If remaining altitude indication is unreliable: Do not use FPV and/or V/S, which are affected.

Positive answer to this is crucial towards understanding what Dani has written and what is written in FCOM. Critical reasoning tests during airline selection process are not there to amuse psychologists or create work for them.

mm43

These statements appear to create an English grammatical juxtaposition, and the intention (IMO) is to state,

"If remaining altitude indication is unreliable: Both FPV and V/S are affected, and must not be used."

Dani

I can positively state that there is a coma.

Anyway, for any pilot there is no discussion of the meaning: If something is not trustworthy, do not use it! Which leads you to the crystal clear conclusion, that you first have to find out what is working before you believe it.

Pilots do not read checklists like layers or laymen. Anyway one can safely argue that the AF447 crew did not read the QRH during their last 3 minutes nor did they understand its content.

Lyman

As long as we're into vocabulary, the difference in two words helps understand the poor performance.

Chronic, versus Acute. Too little anxiety, Too much Confusion, and little understanding of the destination. At 4000 the Captain decides they will crash? How long does it take a French Pilot to spot a Trend?

PuraVida is on the money. This deal had its beginnings well ahead of its beginnings.

AlphaZuluRomeo

OK, thanks, let's say the hypothesis was null & void, because the bird wasn't present (selected) at the "beginning" (02:10:05).

I'm still unconfortable with what I see as a contradiction (regarding this famous bird) :
1) as CONF iture quoted, no bird selection on the FDR traces:
Then, if we believe the FCTM, that means "no bird":
2) on the other hand, in the same #3 interim report, one can read:
So: What of the ACARS message? What of the analysis of “take that”?? Is it possible to have a bird on a PFD, and in the same time the HDG/VS - TRK/FPA knob on the HDG/VS position in certain/degraded circumstances? If yes, what about the previously discuted hypothesis?

Dani

In a fully functional EIS (which is PFD, ND and MCDU, not MFD) it is not possible that you can have FPV and FD displayed at the same time.

The ACARS message FLAG PFD is there as a proof that bird had been selected. But it does not say for how long. My guess is that they selected it, saw the flag, switched it off again. The time of the selection would be too short to show on the graph.

OK465

I love the semi-quarterly FPV discussions.

The FPV has its own FD in the TRK/FPA mode with the FD button selected.

The FD pitch commands for the FPV are 'selected flight path angle' and this value is displayed in the same window where selected V/S is displayed in the HDG/VS mode.

There is one button to cycle between TRK/FPA & HDG/VS and there are two FD buttons, one on each side (next to the LS buttons) which when selected will provide a flight director for pitch and bank steering (dual cue) with HDG/VS selected OR a flight director (single cue) for flight path angle and track steering with TRK/FPA selected.

Triple ADR bad: No FPV, BIG FPV flag

Double ADR bad: FPV available, reliable

CONF iture

Who said urgency there is to select it ... Neither the FCOM neither FTCM.
Your statement, "It is strongly recommended that you never use the bird in case of unreliable instruments" is not backed by anything.

Apparently EIS includes PFDs NDs and ECAM (not MCDU)
But thanks to both of you for the replies.




Clandestino, what is the purpose of your question as Dani and FCOM wrote the very same thing, coma included :
"If remaining altitude indication is unreliable:
Do not use FPV and/or V/S, which are affected."

Not supposed to and not aware of any such reconfiguration.
But if it did happen, it would be a bug ...


More interesting than a guy writing a book, why the Judge refuses to include the full FDR data to the procedure ... ?
The families should mobilize now or accept to be served a part only of the story, the part with the 'deficient' crew ...
My thoughts to the families of those pilots. I know what will be told if I crash my AB.

Dani

I do not dispute that this is my opinion only. But you could ask any Airbus pilot, instructor and most of all any Airbus instructor and he would tell you the same, in the sense of:

In case of unreliable instruments, switch off everything and fly pure raw data only. First memory items are: autopilot, flight director and autothrottle off. This means that you DON'T switch on the bird (as you do normally in an Airbus when you switch off your FD, e.g. during a visual approach).

Then you start your damage assessment: Where I am, what I am flying, where am I going, what is working, what are we doing.

When you are stable, you have found some reliable instruments, did your switchings aso, you are allowed to try out the bird. Only then. But not before.

One has to realize that the FPV is an even more "artificial design" and further away from raw data than the flight director. That's why it may be even more corrupted than the later. That's why you should never use it with unreliable speed.

OK465, the "flight director" of the bird is called FPD, not FD. Of course it has it's own "flight director" but please don't confuse people with wrong names. FD is generated by FMG(E)S, FPD by IRS.

Clandestino

Correct. I've mixed-up EFIS and EIS. AFAIK there's single EIS and two EFIS sets are part of it, so EIS 2 could be a) change of EIS architecture since I've last checked with two EIS being installed since 2009 b) EIS output to EFIS 2 c) typo, with F in EFIS ommited.

To show that......is correct, however, the understanding part is somewhat lacking and the interpretation that only some TRK/FPA information are affected and some might be used when there is no valid altitude info is solely based on disregarding the coma and is wrong.

Seems that TRK FPA vas selected for 6 seconds without apparent effect on RH instruments. However, even if FPA was displayed it would be of no use; spikes in computed FPA began just as FPA vas apparently selected. Even if spikes are matter of graph rendering, as DozyWannabe suggested, it is pretty certain that FPV was no longer reliable so no useful data could be obtained from it. Seems that Dani's interpretation of FCOM is correct and FCOM warning is there for a good reason. As for the army of ignorants that will now again start their old howling on how the instruments should actually work far outside the flight envelope, I can't think of anything else except probably ineffective suggestion to learn some basic stuff about flying before moving into discussion about its advanced part.


Correct... partially. With two ADRs detected failed, remaining GNADIRS will continue to supply FPV, however, with one failed and remaining two telling different stories, crew has to make intelligent decision on which one is right and shut down the wrong one to get to "two failed, one OK" configuration - that's decision that just can't be offloaded to the computer at the current technological level.

AlphaZuluRomeo

Thanks, Dani, could be that. Anyone knows the frequency of that parameter on the DFDR? If 2 seconds or more, Dani could have the answer. If less... the lesser, the more improbable. (see below, this parameter might be registered every 6 seconds)

Hi Clandestino,
I assume you find those 6 seconds in the §1.16.6.3 of the 3rd report? If so, take care, perhaps a translation issue.
The original french text is:
L’étude des paramètres pertinents enregistrés permet de conclure que la sélection du FPV n’a pu intervenir qu’entre 2 h 11 min 48 et 2 h 11 min 54.
In this text, we speak about the "action to select FPV", and the time frame it may have token place. It means not the "FPV selected state" and the duration of the latter. Now the english version (BEA's):
Based on a study of the other relevant parameters it may be concluded that the FPV was selected between 2 h 11 min 48 and 2 h 11 min 54.
This means, to me, the "FPV selected state"... which is wrong IMO.

Perhaps this is better: (my try, sorry in advance, not english-speaking native)
Based on a study of the other relevant parameters it may be concluded that the crew selected the FPV somewhere between 2 h 11 min 48 and 2 h 11 min 54.

I agree on the second part of your post, i.e. even if displayed, FPA = no use in AF447's case.
I don't understand what are "the other relevant parameters" quoted by BEA. I would like to know if this has something to do with the frequency by which the parameter quoted by CONF iture is registered on the DFDR (and shown on the traces).

PuraVidaTransport

Dozy
Agree, for a full recovery, the pilots needed to put in some nose-down inputs, gain enough speed and then pull back into level flight. My point was that to say the aircraft was 'held' in the stall by the nose-up inputs (and resulting THS position) is false. If they would have reduced thrust the entire decent, we would have seen the nose going up and down continuously as airspeed rose and fell. With reduced thrust, the pitch angle never got over 0. In addition, the stall alarm may have functioned better as the airspeed in that case would have probably been over 60kts most of the time.
I have a feeling, if the nose would have been going up and down continuously, the stall alarm was going most of the time etc. that the pilots may have figured out they were stalled. Looks to me like they were convinced that with nose up, full thrust etc. that they couldn't possibly have been stalled especially with the way the stall alarm responded. Also, the decent rate with reduced thrust would not have been 10,000 ft. per minute giving the crew more time to resolve the problem.
Sorry to offend by posting my reply in the other thread but the constant misinformation especially about a 'deep' stall has gotten tiresome.

OK465

Dani, the flight director for the FPV is indeed correctly termed the Flight Path Director (FPD) as opposed to FD, as you say.

My bad. I certainly don't want to confuse anyone.

However, the steering cue called the FPD is selected by the FD button, and provides the equivalent single cue steering commands for the FPV that the dual cue pitch and bank steering bars provide for the aircraft attitude symbol in all FMA annunciated lateral and vertical modes other than selected TRK & FPA.

It provides, for the FPV, managed nav steering, climb/descent/alt hold steering, approach steering, both ILS & RNAV, all from the same FMGEC inputs that are used by the other 'FD' steering bars. FPD is only purely inertially referenced when TRK & FPA are annunciated in the FMA, precisely because these are inertial parameters.

In addition, with failure of any inputs required to display proper FPD steering, an 'FD' flag will be displayed, same as if the dual cue FD had been in use.

It's a 'flight director' in the same sense that a HUD steering command symbol is, no different.

(As a side note, I still think the jury is out on the pitch moment issue regardless of how 'tiresome' it may be. Lot of assumptions being made...)