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AF447 wreckage found

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AF447 wreckage found

Old 24th Jul 2011, 05:25
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RWA
 
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Quoting Hyperveloce:-

the maintained NU inputs are the PF inputs


Not your fault, Hyperveloce, because the BEA Note leaves so much out. But the only mention of a 'left noseup input' at any stage before the upset is this:-

From 2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the controls". The airplane began to roll to the right and the PF made a left nose-up input.


The next relevant entry, referring to at least 11 seconds later, says:-
At 2 h 10 min 16, the PNF said "so, we’ve lost the speeds" then "alternate law […]".

Had the PF maintained a 'left noseup input' throughout those eleven seconds the aeroplane would probably have been 'standing on a wing.' But the PNF appears to have been (relatively calmly) going on doing his job and reading and passing on the messages appearing on his screen. That suggests to me that the PF had in fact merely corrected a tendency to roll after the autopilot signed off, and then levelled off and followed the prescribed procedure of 'flying pitch and power.'

The next entry in the BEA note (with no time stated) says:-
The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started to climb. The PF made nose-down control inputs and alternately left and right roll inputs. The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left.

No mention of any 'nose-up inputs' - indeed, that entry strongly supports the view that the climb was 'uncommanded' and that the PF took appropriate action to counter it?

The PF is reported, much later on, as maintaining 'noseup inputs,' but that was after the stall had occurred. And, as I said earlier, I think that the most likely reason for those is that the pilots thought for quite a while that they were in a dive rather than a stall.

So IMO, as BOAC said, "The climb is still unexplained."
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Old 24th Jul 2011, 05:50
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RWA,

Would you not agree that the nose-up request was from the pilot flying (the left part is irrelevant after had correct the roll right and not necessary for the report). Also, you are quite incorrect about 'next mention' of nose up inputs being 'quiet some time later'...do your research mate:

- 2h 10m 51s PF maintained nose up inputs;
- Around 15 second later the PF continued to make nose up inputs;

I can keep quoting, but the most important one is in the 'New Findings' section:

- The inputs made by the pilot flying were MAINLY NOSE UP.

Hyperveloce was quite justified in what he said. In this case, it is 'your fault' mate, do your research.
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Old 24th Jul 2011, 18:59
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Control Systems

Greetings to you all,
Reading the last stream of posts (were I keep seeing a redundant quoting of BEA´s interim report), it came to me that it would be a nice idea to refresh some basics about reconfigurable Control Systems and a good reading while waiting for BEA´s next report.
The paper covers CS in a general way, but FCS and AFCS are also addressed.

http://users.encs.concordia.ca/~ymzhang/publications/ARC32-2-98Zhang_pp.229-252.pdf

Last edited by Jetdriver; 25th Jul 2011 at 11:45.
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Old 25th Jul 2011, 11:33
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New interim report to be published on 29 July.
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Old 25th Jul 2011, 13:38
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Cool

Hi,

Indeed (press)
Vol Rio-Paris : rapport vendredi sur "les circonstances exactes" du crash - LeMonde.fr

Le Bureau d'enquêtes et d'analyses (BEA) français a annoncé, lundi, qu'il publierait vendredi un nouveau rapport présentant "les circonstances exactes de l'accident" du vol d'Air France AF447 Rio-Paris qui s'était abîmé en juin 2009 au large du Brésil, faisant deux cent vingt-huit morts.
The Bureau of Investigation and Analysis (BEA) French announced on Monday it would issue a new report Friday with "the exact circumstances of the accident" of Air France flight AF447 from Rio to Paris, which had damaged in June 2009 off the coast of Brazil, making two hundred and twenty to eight dead.
And .....
Le Figaro - France : AF 447 : le rapport d'étape de l'accident publié vendredi

Last edited by jcjeant; 25th Jul 2011 at 15:56. Reason: Add Le Figaro link
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Old 25th Jul 2011, 14:34
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Originally Posted by Techman
I have tried really hard to make sense of Bearfoil's posts as I figured someone so prolific a poster must have something important to say. All I see are lots of words used to say nothing. It is like listening to a politician answering a question.

Do I need a decoder ring and is it worth the price of a cereal box to get one?
You can always do what I have done and put him on your Ignore List
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Old 25th Jul 2011, 14:54
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Tio Pablo, thanks for that link. A bit rough going, but worth the read nonetheless.
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Old 26th Jul 2011, 08:37
  #2168 (permalink)  
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Sorry we seem to be disagreeing so much, Poit.

Quoting Poit:-

Would you not agree that the nose-up request was from the pilot flying (the left part is irrelevant after had correct the roll right and not necessary for the report).
You’ve flown light stuff, same as me. You’ll know that one almost never uses the stick in one dimension, ‘coordinate the controls’ is the rule. A bank usually entails a loss of lift and also produces a turn. My best guess is that, in order to get back on course and also maintain height, the pilot put on opposite bank and also used a touch of up elevator – and then levelled out. All perfectly normal. And, as I also said the PNF then read out and cancelled a couple of messages, in a pretty calm manner; if the PF was busy standing the aeroplane on its tail the PNF would surely have been saying different things (to say the least )?

(In this connection, I dislike the tendency of some (particularly that newspaper article) to suggest that the PF was ‘inexperienced.’ If you look him up, you’ll find that he had the best part of 3,000 hours in his logbook, including about 850 on the A330).

"Also, you are quite incorrect about 'next mention' of nose up inputs being 'quiet some time later'...do your research mate:"
Don’t recall saying that? I thought I wrote, ‘much later on’? The BEA’s (very thin) report times the ‘left noseup’ command at ‘2 h 10 min 05.’

The next ‘event’ the BEA describes is the ‘zoom climb.’ No mention of any noseup inputs before or during that; indeed it describes nosedown inputs. All the evidence is that the PF countered the climb and pretty well got the aeroplane back to level flight. The next event is timed as follows:-

“At 2 h 10 min 51 , the stall warning was triggered again. The thrust levers were positioned in the TO/GA detent and the PF maintained nose-up inputs.”
I make that 46 seconds between noseup inputs? Surely that’s ‘much later on’ in the context of an accident that only took about four minutes from start to finish?

May help if I explain that I tend mentally to break this (and any other) accidents down into phases. Lacking proper information form the BEA, I currently see these as follows:-

1. ‘Signoff’:- AP/ATH disconnect, pilot takes manual control, corrects an uncommanded bank, and begins flying ‘pitch and power.’

2. ‘The climb’:- No stick input either way at first. Then nosedown to arrest the steep climb.

3. ‘The stall’ – stall warning sounds, pilot applies standard ‘stall avoidance’ procedure at that time (apply TO/GA power and seek to minimise altitude loss). Stall warning stops.

(One thing that can’t be ‘fitted in’ to the various phases, in that we don’t know when it occurred, is that at some time during one of these phases, the THS wound itself up to ‘full up.’ Typically, the BEA note refers to it taking ‘about 1 minute’ but it doesn’t say which minute. I’d appreciate other people’s opinions at to when they think it happened?).

4. ‘The free-fall’ – aeroplane begins losing height at 10,000 feet per minute. I’m on record that my own view, on present evidence, is that the pilot(s) thought that the stall avoidance had worked and that they were in a dive, not a deep stall.

5. ‘The attempted recovery’ – somewhere above 10,000 feet, power was reduced (again, the BEA doesn’t say when) and the PF applies ‘pitchdown inputs.’ Angle of attack improves and the speed indications return. BUT – the stall warning sounds again…….

6. ‘The crash’ – the aeroplane belly-flops into the Atlantic.

To the best of my knowledge, that’s all we know so far. Comments, additional points, corrections, further information from anyone all welcome.

Last edited by RWA; 26th Jul 2011 at 10:10.
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Old 26th Jul 2011, 08:45
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5. 'nose up inputs' ?
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Old 26th Jul 2011, 09:28
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Troisième rapport.

Hello, just read in the Var Matin that Friday 29th the BEA is coming out with a third report and a analysis. Let's hope we get some more facts. Of course I am thinking about the beloved ones of the deceased but also about the pilots who are flying these aircraft daily.
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Old 26th Jul 2011, 09:42
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Ok here is the official announcement.

Le troisième rapport d'étape du BEA sera publié le vendredi 29 juillet 2011. Ce rapport présente les circonstances exactes de l'accident avec des premiers points d'analyse et de nouveaux faits établis à partir de l'exploitation des données des enregistreurs de vol.

A cette occasion, un point presse sera organisé au BEA à 14 h 30 le même jour.
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Old 26th Jul 2011, 09:56
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Quoting Mr Optimistic_

5. 'nose up inputs' ?
Many thanks, Mr O, edited!
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Old 26th Jul 2011, 10:09
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RWA

For the umpteenth time
pilot applies standard ‘stall avoidance’ procedure at that time (apply TO/GA power and seek to minimise altitude loss).
that is !

Give it a break your theory and misinterpretations are wrong, you are like a broken record and never reply to the posts that contradict you. You wait a few days / posts and post the same rubbish again. If you have nothing NEW to say don't say anything.

You need to read and digest how the airbus flight controls work not how you think they work.
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Old 26th Jul 2011, 10:33
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Quoting iceman50:-

that is !

Give it a break your theory and misinterpretations are wrong, you are like a broken record and never reply to the posts that contradict you.
On the contrary, I answered your last (also somewhat abusive) post, with a source, in my Post 2086 above.

"Investigators have been left attempting to explain why the crew of Air France flight AF447 failed to recover the Airbus A330 from a high-altitude stall, a predicament which has been the subject of a recent revision of safety procedures.

"The revision concentrates on placing greater emphasis on reducing excessive angle of attack - the critical characteristic of a stall - rather than the classical approach of training pilots to power their way out of a near-stall with minimum loss of altitude.

A formal document detailing the rationale for the revision points out:
"There have been numerous situations where flight crews did not prioritise [nose-down pitch control] and instead prioritised power and maintaining altitude."

Operational experience has shown that fixating on altitude, rather than the crucial angle of attack, can result in an aircraft stalling.
Revised stall procedures centre on angle-of-attack not power

If Flightglobal (and I) are wrong, please inform us what the recommended procedure actually was back in 2009, and what changes were made recently?

Last edited by RWA; 26th Jul 2011 at 10:57.
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Old 26th Jul 2011, 10:44
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Originally Posted by iceman
For the umpteenth time Quote:
pilot applies standard ‘stall avoidance’ procedure at that time (apply TO/GA power and seek to minimise altitude loss).
that is !
- maybe have a glance at http://www.pprune.org/tech-log/41537...procedure.html ? It may be of interest to you.
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Old 26th Jul 2011, 11:10
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BOAC

It is NOT new, it has just been re-emphasised by Airbus Boeing regulators etc as some pilots / checkers were thinking like RWA as in maintain ALTITUDE. The procedure being continually mentioned by RWA was recovery from low speed NOT a stall and even that did NOT mention MAINTAIN altitude. There again perhaps I have been teaching and checking it incorrectly for the last 10 years on the A330 / 340 and been taught stall recovery incorrectly for the 30 years before that.
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Old 26th Jul 2011, 11:12
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(In this connection, I dislike the tendency of some (particularly that newspaper article) to suggest that the PF was ‘inexperienced.’ If you look him up, you’ll find that he had the best part of 3,000 hours in his logbook, including about 850 on the A330).
For a Cessna 172 pilot, this is "experienced." For an air-transport pilot, not.
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Old 26th Jul 2011, 11:54
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Making stuff up

RWA:

1. ‘Signoff’:- AP/ATH disconnect, pilot takes manual control, corrects an uncommanded bank, and begins flying ‘pitch and power.’
So where is the evidence there was any attempt at pitch and power at this point??? You have simply made this up. We are simply told there was a roll correction and nose up input. Followed by a 3000 foot climb...

There is no mention of any attempt to control power until some point later when the misguided TO/GA selection was made. At least that's the only mention of any power adjustment I can find in any segment of the BEA note until much later when power was reduced.
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Old 26th Jul 2011, 12:04
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Hi,
Originally Posted by RWA
3. ‘The stall’ – stall warning sounds, pilot applies standard ‘stall avoidance’ procedure at that time (apply TO/GA power and seek to minimise altitude loss).
Where did you get that?
There is NO such a "Standard stall avoidance procedure" for A330 due to NORMAL LAW flight envelope protections. If you want to refer to what is really relevant, you'll need to check into the "Abnormal Operations" related to ALTERNATE LAW, where stall avoidance procedures are described.

Here, you'll learn what the correct procedure is 3.04.27 page 6 (Rev 18, 2003). There is two cases: low speed and high altitude.
a) low speed: Apply TOGA and (at the same time) reduce pitch angle (angle-of-attack).
b) high altitude: Relax back pressure on sidestick (reduce angle-of-attack).

Where is then this "standard [imaginatory] procedure" you were talking about for high altitude stall warnings:
=> Apply TOGA and maintain back pressure on sidestick !?!
Both actions recorded are wrong for the situation: TOGA is not needed, neither is this pulling up.

This was the second stall warning, the first was ignored or responded by a pitch up if volontary applied. There is no trace of your:
1. ‘Signoff’:- AP/ATH disconnect, pilot takes manual control, corrects an uncommanded bank, and begins flying ‘pitch and power.’
Pitch was wrong and power was not unlocked (no trace of this in BEA narrative). You are retaining bank correction without pitch correction. Why are you making up this stuff?

Same about this:
Originally Posted by BEA
At 2 h 10 min 51, the stall warning was triggered again. The thrust levers were positioned in the TO/GA detent and the PF maintained nose-up inputs. The recorded angle of attack, of around 6 degrees at the triggering of the stall warning, continued to increase. The trimmable horizontal stabilizer (THS) passed from 3 to 13 degrees nose-up in about 1 minute and remained in the latter position until the end of the flight.
Around fifteen seconds later, [~0211:06]
How can you say that you don't know when THS moved to 13°?
This is obviously timmed starting at or closely after 0210:51 and then ended also close to 0211:51.

Originally Posted by RWA
If Flightglobal (and I) are wrong, please inform us what the recommended procedure actually was back in 2009, and what changes were made recently?
Of course you are completely wrong.
What changed was the emphasis on Pitch rather than Thrust, as large thrust increase may have an adverse effect on pitch reduction at low speed. At high altitude, it doesn't change a glitch as stall warnings would be triggered at the onset of buffet, likely at an already high Mach, without many excess thrust available, hence only a question of AOA at the limits of the safe flight envelope.
Check by yourself the relevant part of A330 FCOM in use before 2009:


Last edited by takata; 26th Jul 2011 at 12:45.
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Old 26th Jul 2011, 13:09
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I suspect that like me, none of the contributors here of late actually know what Air France taught for recovery from the approach to a stall in the A330 in those days, nor how much 'reliance' was instilled in crews in the infallibility of the AB in not 'letting you stall'. It is worth noting that unlike the impeccable Iceman, some trainers were NOT teaching things correctly - in the UK at least.. This is the first para from post#14 in my link (with my emphasis) from April 2010

A very good document from British CAA that has a lot in common with the new procedure:

Applicability: RETRE, TRIE, TRE, SFE, TRI, SFI
Effective: Immediate
STALL RECOVERY TECHNIQUE
1 Recent observations by CAA Training Inspectors have raised concerns that some instructors (both SFIs and TRIs) have been teaching inappropriate stall recovery techniques. It would appear that these instructors have been encouraging their trainees to maintain altitude during recovery from an approach to a stall. The technique that has been advised is to apply maximum power and allow the aircraft to accelerate out of this high alpha stall-warning regime. There is no mention of any requirement to reduce the angle of attack – indeed one trainee was briefed that “he may need to increase back pressure in order to maintain altitude”.



Wait until 29 July?
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