Organfreak

OK465,
WOW! That is damned interesting.

Here are the three pertinent pages of A330 FCOM, and sorry for the squashing of the images- (ah...the Mysteries of Photshop).

mm43

@ LymanThe BEA have made it quite clear that comments made that were not relevant to the conduct of the flight were eliminated from the CVR transcript. If the stall warning had been acknowledged verbally in any form, or some speech construct inferring the like, then the BEA would be less than honest not to include it. I have no reason to suspect that either was the case.

mm43

@ OK465

It would seem that the major differences in ALT Laws are:-

ALT1:
Pitch attitude (Θ) protection lost.
Hi Speed and Stall speed are alternate.

ALT1A:
As ALT1 but Stall protection is lost.

ALT2:
As ALT1 but lateral normal law is lost and replaced by
lateral alternate (Roll = DIRECT; Yaw = Alternate)

ALT2A:
As ALT2 (Stall protection is lost)

ALT2B:
Pitch attitude (Θ) protection lost.
Hi Speed and Stall protection lost.
Bank angle protection lost

Source - A33Zab in AF447 Thread No.6, and in

ALT2B no Hi and Lo speed stability (= VMO2/ Vc prot),

as explained earlier in this thread.

CONF iture

There is enough data to affirm FD were displayed at times. So there are more than obvious reasons to investigate what those FD were displaying for those periods. Everybody is questioning why the PF did what he did, the answer could be just there ...

bubbers44

Are there pilots that follow the flight director blindly? Didn't happen when I was flying.

CONF iture

1. pulling can lead to high-mach-low-threshold transient stall warning if aeroplane is jerked into climb, reasonably smooth pull from about 1.5 to 5° will avoid it
Easy stuff in turbulence

2. when settled at 5° pitch, AoA will be near cruise pitch and will gently increase towards 5° as speed is bled off. By the time it gets there, you won't be at high mach anymore.
Easy stuff in turbulence

3. If no valid mach, stall warning reverts to low threshold
I like that ''If''

4. stall warning is not stall itself - a fact cheerfully ignored by those unable to tell the difference between "approach to stall recovery" and "stall recovery".
It does not matter, both should trigger the very same procedure (the new one) NOSE PITCH DOWN + THRUST REDUCE

5. when arguing about Habsheim showoff, you repeatedly claimed that alpha prot prevented aeroplane from achieving higher lift at even higher AoA (backside of the power curve, anyone?) and now all of a sudden, stall warning is considered to be the edge? Are you having it both ways or are you about to make a breakthrough in aerodynamics - discovery of the area of fantastic aerodynamic performance between alpha max and stall warning?
Because Alpha Max is simply not Alpha Stall Warning and Airbus did that for a reason.
Alpha Max = protection = do whatever you like = still flying
Alpha Stall Warning = Do NOT stay there = still flying but for how much longer ?

Airbus chief pilot has got all of it now : No more 5 degrees pitch up - Finished : "When you lose the speed indications in cruise, that is the most simple procedure to apply : You have to do NOTHING"

Clandestino, it could be understandable you recommend to apply 5 deg of pitch up as a first measure the time to get some figures from the QRH, but it is absolutely non sense you pretend to be comfortable to apply it vitam eternam. It tells a lot how you see yourself as a pilot ... as it shows in your writing style too.

RetiredF4

Thanks for reposting this list.

When BEA and others like Clandestino state, that other UAS events had a positive outcome, can the difference to AF447 partially be found in this list? BEA does not state in which kind of Alternate Law the other events ended, i couldn´t find it at least. So all those events could be just in simple ALT 1, quite a difference to the ALT2B AF447 dropped to.

AlphaZuluRomeo

Hi Lyman

Re: your #1215

• I don't remember releasing "the entirety of the audio" is a standart practice (source: other accidents). More the contrary, in fact. In that light, presenting this release as "waited" as you do will only lead to disapointment/rise in conspiration theories when this release does not occur.
• I'm aware of -at present time- two versions of the transcript:
  - the official version (by the BEA, in IR3)
  - the version "leaked" by Mr Otelli in his book, build from an earlier transcript of the CVR than that used by the BEA in IR3, as far as I can tell.
  Even if both versions have been quoted numerous on times by various media, I'm not aware of any version/sub-version that contains the apparent recognition of the stall by any of the crew member. Would you be so kind as to provide a link to that version/sub-version/comment, in order for its credibility to be assessed?

Thanks

HazelNuts39

Right! So where have we got to:

Either do nothing or -
- 5° pitch up will not stall the airplane
- pull up gently to avoid stall warning
- if stall warning occurs: reduce pull up
- use small, brief stick inputs, watch the result before making further inputs
- get the QRH for correct pitch and thrust setting

thermalsniffer

AZR:

Doomed Flight AF 447: An Airbus Programming Error? - SPIEGEL ONLINE


"Exactly what orders he issued are not part of last Friday's report. But sources close to the investigation are saying that he said: "This is a stall. Reduce power and nose down!""

No comment on credibility of article, reporter, source, etc.

OK465

MM43:

Thanks for re-posting the list.

I respect A33Zab's obvious knowledge, but that list leaves a lot to be desired and has some flaws of logic and terminology in it if you were to use it for training, i.e.

...as if stall 'protection' (wrong term) is available in ALT2, but not lost until reconfig to ALT2A?? In any case both stall 'protection' & theta protection take a hike in all laws other than normal, so 1A, 2A are what exactly?? Just vanilla 1 & 2??

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

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?

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?

A33Zab is an excellent source of info, but there's probably a lot of A330 pilots who don't even know he exists.

OK465

B44:

I trained a whole lot of pilots in the 727, and yes there were some who could get caught by this, even back in 'your day'.

Lonewolf_50

COnf:
Conf, I will presume that your point is for stall at high altitude, or for an aircraft with underslung engines, since
At high alt/high mach, overspeed can be a risk
Reducing power on underslung engines removes some of the "pitch up" input from thrust vector being below, as opposed to coincident with, the longitudinal axis.

As I ponder the point you make, it seems a simpler response to lower the nose, as doing so you will decrease AoA without touching power.
However, if you reduce power => you reduce thrust => decrease airspeed / Mach ... so ... might your power reduction risk ofsetting a nose reduction and thus keep you near stall AoA if you are trying to avoid stall?

IS part of the nose down/power reduce response intended to cause an altitude reduction and thus change the performance environment of the aircraft?

In chewing over your point, I conclude that your recommendation is confined to approach to stall/stall in the high altitude / high mach environment.

Do I understand you correctly?

AlphaZuluRomeo

thermalsniffer

Thanks for the link.
I forgot about that... errr... is that a novel?

Well, a simple thing:

"At no point" on the cockpit voice recorder "is the word stall ever mentioned," Chief Investigator Alain Bouillard said in an interview.

So, as far as I'm concerned, source is dismissed. Thanks again.

A-FLOOR

I'm somewhat surprised at the comments that the crew never mentioned being in a stall at all, as this is exactly how I remember it from reading an early report about the CVR transcript (capt telling his crew they are in a stall shortly after he returned to the FD). This is exactly one of the things which really stuck with me from reading that, so I'm dumbfounded how it ended up not being mentioned at all in the interim report.

Surely there must be other people who remember reading it as well?

GarageYears

Nope

In fact that "stall" was never mentioned was what stuck in my mind.

Organfreak

@A-FLOOR:

Well....no, sorry. That's the very first time I've heard that one, after following these threads closely since 6/09. This Der Spiegel article is full of other mistakes, misrepresentations, and inaccuracies as well. Forget it.

We've spent three years here trying to figure out how they didn't know they were stalled. (Not to mention why they pulled up, so I won't mention it.)

roulishollandais

Has anybody some information about
1. A330 feedback equations including speed parameter V ? and information about A330 cross-over velocity Vco?
C* =? Knz.nz + Kq.q and is it standard C* ?
2. relative position of the accelerometer ? in normal flight and stalling deeply,
3. where does the "speed" input in the feedback come from in the UAS case?

Thank you

CONF iture

The answer was in the revised procedure that never showed up, following the known and discussed cases of Air Caraibe. Airbus acknowledged it was necessary to think about something to help a crew in such circumstances … We are still in the wait … Is it part of the recommendation chapter in the coming report … ?

Airbus initially wrote the reply to UAS in cruise is to adopt 5 deg of pitch up. The BEA confirmed such procedure in their press conference. Now, Airbus, through his chief pilot, says differently …

Big clarification up is necessary regarding UAS procedures, more specifically at high altitude. Pilots need clear procedures and relevant TRAINING !

The last time I did practice the exercise, it was just after take off and the first warning we got was : WINDSHEAR WINDSHEAR ... consistant with my airspeed going in the red.

roulishollandais

The decision of the Court of Cassation of France, that was expected June 15, finally arrives September 24, 2012.
It responds to the request of the Lawyer Me Soulez-Lariviere about the jurisdiction of the French criminal courts for a disaster in the non-territorial waters.
This was the case TOTAL, but also concern the flight AF447, since Mr. Soulez is one of the lawyers defending the leaders of major French civil aviation and has already expressed his opinion hostile to that jurisdiction to the crash of Mont Ste-Odile.