CONF iture

Not only.
Airbus has 2 published procedures now. Both are memory items.

1. STALL RECOVERY
2. STALL WARNING AT LIFT-OFF

So the first one must be applied at any altitude, except lift-off :
Historically, the answer to a stall warning was to apply full thrust and reducing the AoA, minimum altitude loss was a factor. Now not anymore: Above all it is making sure to reduce the AoA first and reducing thrust may be necessary. Smoothly increasing thrust comes only after stall indications are no longer present.

PJ2

CONF iture;
The "answer" showed up in 2006, in an Airbus presentation entitled, "Unreliable Speed; Latest Improvements". References to the correct procedure for UAS were in a number of FCTMs by 2007, all before the Air Caraibes event.
Yes, that's correct, they wrote that in November, 2002 under the heading, "Immediate Pitch Attitude and Thrust Guidance" followed by an admonition to "Respect the Stall Warning" and, "When the Flight Path is Stabilized" -Attitude/Thrust - Adjust".

This drill/checklist has gone through several revisions since its first appearance - the earliest I have is November, 2002.

The qualification to level off and troubleshoot when above circuit altitude or MSA clarifies the original checklist item, "When the Flight Path is Stabilized". Every drill, and guidance in the A330 FCTM emphasizes that leveling off and stabilizing the aircraft should be done as quickly as possible to avoid an overspeed. Stalling is not mentioned as a risk but every drill/checklist since 2002 also emphasizes the need to respect the stall warning. Later checklists provide guidance on the "flying technique to stabilize flight" with regard to pitch and power.

jcjeant

PJ2
CONF iture had already posted:
This reference come from a video (docu about AF447 in french language) posted earlier in another thread ....
EDIT:
Thank you HazelNuts39 .. I was searching for the video

HazelNuts39

PJ2;
The video is (goto 21:40)

PJ2

Ah yes, I do recall now, thank you all.

Link to two Airbus stall recovery documents - posted before, but to refresh:

http://fucampagne2008.unblog.fr/file...lprocedure.pdf

http://orleans.neting.com.es/esa/ESA...20recovery.ppt

Mr Optimistic

There was a statement long ago from an official source who had heard the cvr that one striking feature was that the word stall was not uttered once. No reason to think otherwise now especially as to think otherwise would require an answer as to why the appropriate commands were not forthcoming.

Lonewolf_50

Confiture: thank you!
The clarification
"In case of lack of pitch down authority, reducing thrust may be necessary"

makes sense, and clears up my misunderstanding.

Clandestino

It was basically the same procedure for both Rosemount and Thales replacement: no emergency AD, no immediate grounding until the mater is resolved, just the timeframe in which all probes are to be replaced while aeroplanes could keep on flying. What is the point you are trying to argue?

Are you trying to make a principle out of illustration? Namely: inexperienced=unsafe? So, what do you think was the experience in manual flight, at cruise altitude, in ALTN law of thirtysomething 330/340 crews that all of a sudden had to perform the feat? How come they survived?

Doing nothing would have saved them. So would executing the memory items. There are many combinations of power and attitude that will keep you flying. 17.9° pitch above MAX REC alt will not, even with TOGA.

How can one conclude that the exasperated (and a bit cut-off in post-production ) answer of mr Rosay to mediapersons working on dramatization of AF447 represents the one and only right thing to do, rendering all the prescribed procedures wrong, escapes me.

Note on page 43 and graph on the page 42 of interim 3 clearly show that turbulence was of short duration, light to moderate intensity and has completely stopped by the time the second, fatal, pull was initiated. Notwithstanding whether "Easy stuff in turbulence" argument is true or not, it is utterly inapplicable in AF447 case.

Your like or dislike does not alter the fact a bit. Page 20 of interim 3 refers.

It's attempt at dumbing down the procedure to unachieavable level, no matter if it proposed by Airbus or some PPRuNer. Applying such a procedure for low level approach to stall can easily result in unnecessary deaths and damage to property.

Straw man argument. It is supposed to be applied until QRH is brought out and correct values for weight found and set. If it takes five minutes of fumbling, it won't kill you in this five minutes. Or until the fuel runs out but that doesn't mean it should be applied indefinitely.

It's not me and BEA, it's just BEA. I only repeated its findings for the benefit of those too lazy to look it up themselves or are too preoccupied with their pet theories/agendas to notice them.

Maybe. What is the difference if low speed stability is available or not? It can be overridden by a pull on the stick and that certainly wasn't lacking.

Anyway, here's the important difference


Good question. Most important is to recognize that all the technical jargon about laws signifies that the safety nets are no longer there. Pilot able to understand the state of the aeroplane and to control it will perform well no matter the law. Pilot that gets disoriented and/or confused will not be saved by the computers in degraded FC laws.

HazelNuts39

I'm afraid I can't follow your argument here. The issue whether or not the memory items apply was not addressed in the Air Caraibe Memo. Airbus said they would think about a modification of the checklists to address ACA's problem which was that their pilots were 'intimately' convinced that the two stall warnings were 'inapproprié', and had decided to disregard the phrase "RESPECT STALL WARNING AND DISREGARD 'RISK OF UNDUE STALL WARNING' STATUS MESSAGE IF DISPLAYED ON ECAM":

jcjeant

clandestino
I just wanted to point out that to illustrate your experienced pilots was about you had cited a bad example (Yuri Gagarin)
Yuri Gagarin was not an experienced pilot .. he was a celeb pilot .. not because his flying experience
Here is the gist of my comment .. no more no less

mm43

@ OK465

I tend to agree that the various colors of ALT Law are not well documented, but can only assume that Airbus Industrie have determined in their wisdom that full divulgence will conflict with their KISS policy.

Best I can judge is that the switch to ALT2B was due to diverging CAS data which set up the ADR monitoring sequence with ADR2 being voted the "median". At the end of the monitoring period the new CAS "median" was not within 50KTS of the initial "median" value. Now that certainly matches the UAS criteria, but whether that should have been displayed or annunciated is debatable. The PNF announced, "We've lost the speeds", but then failed to check the QRH for guidance and the game was lost before reaching first base.

The following discussion between HazelNuts39 and Takata in AF447 - Thread No.5 should give you an insight into why the law change was ALT2B, and the implications for the remainder of the flight.

I do think that Clandestino summed up ALL the ALT Law states quite succinctly:- and this could be quantified by the "bucket is half full" approach which is eminently preferable to the "bucket is half empty" scenario when DIRECT Law is applicable.

wozzo

For the record, SPIEGEL reporting concerning AF 447 usually reflects the thinking of Gerhard Hüttig, a professor from Technical University Berlin and advisor to the lawyers of the families of German victims (E.g., he thinks Airbus A330/340 are dangerous & should be grounded because he "proved" in the sim that they can't be recovered from stall). I'm pretty sure he or the lawyers are also the source for most of the "insider" information.

Lyman

"Now that certainly matches the UAS criteria, but whether that should have been displayed or annunciated is debatable. The PNF announced, "We've lost the speeds", but then failed to check the QRH for guidance and the game was lost before reaching first base."......from mm43, above.

How is it debatable? Are you comfortable hand flying without speeds in these conditions? For thirteen seconds, now the ship is climbing? Now you will wait for UAS determination causing serious control changes in mode until 2:10:22?

What am I missing here?

The game was lost before crew had a chance to troubleshoot.

A33Zab

Flavours:
'Vanilla' 1 = Normal Lateral law
'Vanilla' 2 = Roll DIRECT law & Alternate Yaw law


For ALT1/2A 'alternate stall protection':


The ALTERNATE stall protection is based upon Vc.
When Vc < Vc prot a SS pitch order is a DIRECT! elevator deflection order, a stability order with limited authority is added to the SS order.

Quote:

My question regards the difference in failure modes that would create one or the other level of reconfig. I would have thought that 2A & 2B are a function of how many ADR's get flaky, i.e.

1 flaky ADR = continued Normal Law
2 flaky ADR = ALT2A
3 flaky ADR = ALT2B

Ok, but not exclusive to ADRs only. (e.g. loss of weight information)

Quote:

I guess I'd like to know how do I then get into each of these conditions and then how do I recognize which one I have, which ones 'latch', which can be recovered to a different level of reconfig, or do I even need to know any of this?

I can list them for you (from fragmented data) but don't know the latched state or possibility to recovery to a higher level.

Quote:

Simulators generally only provide a limited range of constrained failures to achieve one or the other reconfiguration level for training, so does the available documentation need to be enhanced?

Don't know, I am not a pilot, but from the side I would say you need to experience the difference between NORMAL & DIRECT SS manipulation and consider everything what is available to you as a bonus.

OK465

Thanks A33Zab & MM43.

This quote is from Takata, and if I understand it correctly, raises an interesting point about the 'latched' state of ALT2B and addresses some of the recent discussion about VLS availability and other displays.

It indicates to me that when speeds returned to normal at the apex at 5.6 degrees of pitch, that not only was VLS not available, but there was no red & black zipper (VSW) displayed either. Just a valid speed value (~215k) and speed tape and a SPD LIM flag.

So when the FD's returned, there was no visual indication of VSW, i.e. no real good visual indication of stall proximity or the inadvisability of pulling up again at this point. And without the classic aircraft response, a source of confusion in correlating the audio SW to the actual flight conditions.

I think this is why, at least I think, knowing what actually gets 'latched' may be of some use to the drivers.

Lyman

"It indicates to me that when speeds returned to normal at the apex at 5.6 degrees of pitch, that not only was VLS not available, but there was no red & black zipper (VSW) displayed either. Just a valid speed value (~215k) and speed tape and a SPD LIM flag."....OK.

Whether the stall bug returns with speeds or not is unclear, the BEA say that with ADRs out, the bug is not available, HazelNuts39 pointed that out, it is in #3.

OK465

Apologies if I'm going over old territory. Just trying to relate it to available documentation.

CONF iture

You are correct to underline one aspect of the memo on which, by the way, answers are still to be developed, as mentioned here earlier.

But point in debate is more general, it is not only about the memory items but the overall applicability of the UNRELIABLE SPEED INDICATION PROCEDURE :
Have we seen that modification yet ?

CONF iture

Admonition to respect Stall Warning but then part of the ACA Memo, everybody, Airbus included, thinks the Stall Warnings were inappropriate and the crew did well to ignore them.

A similar language is part of the AF info OSV :
here and here

So, a lot has still to be clarified and we are certainly not at the last revision for the UAS drill/checklist.

Note:
I post here a few slides of a "NEW" UAS procedure but I cannot certified the date of that revision ?
To note the clear request for 5 deg pitch attitude in cruise phase.

Clandestino

The point.

Aeroplane did not pitch up out of her own accord but because CM2 commanded her to. It stalled because CM2 kept on pulling when she was alredy above her practical ceiling. Aeroplane performed as expected. Pilots not at all.

If the name of the game is "situational awareness", then you are right.

Errrr... not quite. The apex of first pull-up was 12°, zoom climb made vertical speed go up to 7000 fpm (at FL362!), both recorded airspeeds (ADR 1 & ISIS) were false. Nose pitched down slowly, following the order form the right sidestick, IAS 1 returned to normal while pitch was 11°. ISIS speed started showing the correct value just about the time the aeroplane exited envelope following the second pull-up. Pitch was about 16° and alpha about ten.

For the time being, this seems to be the correct assessment. However, altitude display was available so why would anyone consider a good idea to pull, especially as MAX REC was discussed just a couple of minutes before and the aeroplane was very near it, or to pull while something is shouting "STALL STALL STALL" in the cockpit is something I find inexplicable in rational terms.

Response was completely according to the tired old cliche: To go up, pull back on the stick, to go down, pull back further.