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AF 447 Thread No. 8

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AF 447 Thread No. 8

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Old 30th Jun 2012, 09:18
  #1461 (permalink)  
 
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Hi Owain G,

Thank you for your explanation, I'll go along with that.

Didn't read that in Turbine D's post though.

BTW, speaking about the C* law, if anyone is still interested, I did another exercise. The graph below shows the calculated side stick angle to maintain a constant pitch rate of 1°/second from 2.4° to 12° pitch attitude, with nz feedback, and compares it to the AF447 DFDR side stick angles averaged over 2-second intervals.


Last edited by HazelNuts39; 30th Jun 2012 at 11:17.
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Old 30th Jun 2012, 14:18
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@HN39:

No sign of 'leading' elevator here:

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Old 30th Jun 2012, 15:58
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A33Zab,

Yes, I agree with you, Thank you.

The curve of integrated elevator angle gives a misleading impression because:

(a) At 02:10:18 the elevator changes from nose-up to nose-down while the side stick is still nose-up,
(b) At 02:10:40 the elevator changes from nose-down to nose-up while the side stick is approximately neutral,
(c) The elevator is slightly nose-up between 02:10:00 and 02:10:06,5, i.e. prior to any side stick action, and
(d) The graphical scales presenting the two parameters.

I've accepted Owain Glyndwr's explanation for (a) and (b) and am hoping to get an explanation for (c). I've edited post #1439 to rectify (d).

Apologies for causing "a storm in a glass of water" (as we say in dutch).

Last edited by HazelNuts39; 1st Jul 2012 at 10:20. Reason: (d) added
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Old 30th Jun 2012, 16:35
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(c) The elevator is slightly nose-up between 02:10:00 and 02:10:06,5, i.e. prior to any side stick action.
AP2 was engaged till 02:10:05
elevator was up-down-up in this time
???
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Old 30th Jun 2012, 17:00
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grity,

the elevator positions controlled by the autopilot are the purple dots. They do not seem to be part of the simulation which assumes zero turbulence. Perhaps I should have included the variations in AoA and normal acceleration in my item (c).

Last edited by HazelNuts39; 30th Jun 2012 at 17:51. Reason: clarification
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Old 30th Jun 2012, 18:57
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IMO the intention for the simulation was just to control if the flightpath of the climb and stall was controled (consistent) from the action of PF and system, or from outside like broken wing or elevator, extrem turbulences, hand of the lord, rocket or metorit...

not more
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Old 30th Jun 2012, 21:33
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@HN39:

"Don't sit down by the packages" (another dutch saying)

From the C* schematic below (Don't know the airliner it belongs to, but in principle it is valid for any FBW airliner) the SAS control has a inner f/b loop based on qmeas (thru wash out filter and Kq gain).



Last edited by A33Zab; 1st Jul 2012 at 03:03.
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Old 1st Jul 2012, 02:17
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A Small Peek at The BEA Report

The majority of you must have missed this since there was a distraction about pitch control. You would be talking about it otherwise.

In post 1453, A33Zab posted the content of a Flight Global article relating to the AF447 human factors. This was based on an April presentation by Former BEA deputy chief Jean Pariès who heads human factors consultancy Dédale.

In post 1458, NeoFit posted a link to the actual presentation by Pariès but it was not particularly obvious.

Here it is again:http://www.flyoperativtforum.no/Foredrag/FOF12/AF447%20accident%20-%20some%20deep%20lessons%20-%20Jean%20Paries.pdf
The presentation is entitled AF 447 ACCIDENT: SOME DEEP LESSONS.

Somehow I believe this will largely represent the BEA human factors thinking on this accident.

Last edited by Machinbird; 1st Jul 2012 at 02:18.
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Old 1st Jul 2012, 04:08
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Machinbird;

From the Jean Pariès paper -
Underlying assumption of the current safety model
  • Pilots, while focused on their current preoccupations, will...
    • recognize any abnormal situation
    • Implement "memory items" or "basic airmanship" response if relevant
    • (then) identify the situation, and implement the relevant procedure
  • ...through their monitoring of instruments, their perception of warnings, their awareness of the situation, and their "airmanship":
So, dealing with AF447, it has been established without too much doubt that other than "recognizing they were in an abnormal situation" the crew failed on all other counts. Does this mean that the HF response will be a complete re-write and a re-jig of the aviation industry's approach to safety?

I somehow doubt that will happen overnight, but adaption of current technology will most likely be used to lessen the "startle factor" and lead/prompt for the correct response. If that doesn't work, then the "technology" might just have to vote the "HF" out of the loop.
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Old 1st Jul 2012, 05:21
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the SAS control has a inner f/b loop based on qmeas (thru wash out filter and Kq gain).
That inner SAS loop is just an old fashioned pitch damper.
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Old 1st Jul 2012, 16:56
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Sim Shocks
Reading a number of PPRuNe threads it would appear that Simulators are used by a number of different airlines in different ways.
One pilot commented that he had done the same series of routine checks on TWENTY different occasions.
China Airlines use them to keep their F/Os in flying practice, because with their 747SPs flying their very long sectors ( which require four pilots) it must mean that each pilot would only have a limited number of opportunities of T/O or Landings available per month.

There were some interesting contributions by FRYBURG on 8th June on the Humbling Sim Experience thread.

I have never used/ seen a Simulator - they were not around, then !

I read of one where to keep the pilots alert, having found that the airfield was not getting closer at something like the right G/S, one found that the
B737 was on short finals for an aircraft carrier.

I might have been better with a " F/O Dead Drill", a one hour hold at Nantucket before landing at JFK. ( The F/O had been flooded with R/T from the replacement ATControllers, due to their industrial action. I took him to a briefing place before departure. He was all right.)

A Simulator Check of "Engine failure on Overshoot" before it happened to me would have helped on a heavy twin. My Chief Pilot said that "It had never happened before..." Two months later it happened again... To a different crew, who were killed. After that, that system was switched OFF, except for heavy T/Os.

Last edited by Linktrained; 1st Jul 2012 at 18:11.
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Old 1st Jul 2012, 19:11
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Snoop Pariès

I have been very very estonished to read Mr.Pariès, heading the human factors consultancy "Dédale SAS France", and also the "Former BEA deputy chief"! in AF 447 ACCIDENT: SOME DEEP LESSONS !

Reading the text (april 2012), clearly concerning AF447 as Machinbird , mm43, A33Zab, Neofit, iself, have seen it, it was even worse.

Originally Posted by French criminal code Article 432-12
The fact of a person holding public authority or discharging a public service by a person or a public elective office, take, receive or retain, directly or indirectly, any interest in a company or in a transaction for which it has, at the time of the act, in whole or in part, responsible for providing supervision, administration, liquidation or payment, is punishable by five years imprisonment and 75,000 euros fine.
Where is the independance of the BEA ???!!!
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Old 1st Jul 2012, 21:04
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Hi roulishollandais,

Relative to your post #1471, I don't see how the French criminal code cited would have any bearing relative to Jean Paries. If he were still an official of the BEA and also CEO of Dedale, it certainly would. It seems to me that Mr. Paries is an expert in what he does (and has done) and besides the AF447 presentation he gave, he has given dozens of others to various audiences around the world pertaining to aircraft safety.

If I were examining the human response aspects of the AF447 accident, I would want to hear him out on his thoughts, observations, recommendations and any other pertinent information that would be helpful in the analysis and/or recommendations offered going forward. There may not be many credible sources of this type of information to draw from, but I sure would like to hear from as many as possible leading to the final report out.

Also, didn't most or the entire upper echelon of the BEA turn over prior to the AF447 accident? Isn't this a new BEA organization team doing the AF447 investigation?

Just my opinion...
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Old 1st Jul 2012, 23:12
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Why i am waiting nothing coming from HFG

roulishollandais

I agree, absolutly

Nowadays, it's very fashionable to appeal to external consultants

I am so sorry coming back with Tarom event:
If the conclusions of the 447 HFG are of the same order as that of the Tarom thesis (sponsored by the bea), then, obviously, I wait for nothing of 447 HFG

Tarom report (Engl.) or try also here

Tarom HFG thesis (french)
('Fiche Nr 3 : incident A310 - Declenchement de la protection de vitesse en approche')

Last edited by NeoFit; 1st Jul 2012 at 23:27. Reason: Tarom report link
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Old 1st Jul 2012, 23:49
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Cool

Hi,

Turbine D
Also, didn't most or the entire upper echelon of the BEA turn over prior to the AF447 accident? Isn't this a new BEA organization team doing the AF447 investigation?
The investigation chief of BEA for AF447 case ( Alain Bouillard ) is the same as for the investigation of the Concorde ....
The only significant change after the AF447 event was the replacement of the BEA chairman (Paul-Louis Arslanian replaced by Troadec) and the depart of Arslanian was already scheduled prior the AF447 event


Bouillard (left) and Arslanian



Troadec

Last edited by jcjeant; 2nd Jul 2012 at 00:14.
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Old 2nd Jul 2012, 14:37
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Originally Posted by NeoFit
If the conclusions of the 447 HFG are of the same order as that of the Tarom thesis (sponsored by the bea), then, obviously, I wait for nothing of 447 HFG
Why?

An objective view of the evidence - even going back to 1988 - proves conclusively that BEA did *nothing* to protect or shield Airbus, and all accusations of such behaviour were lies concocted by the defence team of M. Asseline and those who followed him.
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Old 2nd Jul 2012, 15:30
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? Investigator Bias ... misconduct ... fraud??

Another topic -- a new thread --

Above, in slots #1471 & #1473, there seems a skepticism about the _investigation_:

So -- for that discussion of investigator-err, bias, misconduct, and fraud, see:
http://www.pprune.org/safety-crm-qa-...ml#post7273383
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Old 2nd Jul 2012, 17:55
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Really, IGh - "Hoot" Gibson again? Didn't he retire sometime around the last Ice Age? (not to take anything away from him...)
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Old 2nd Jul 2012, 21:51
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From the briefing, I noted that there had been one or two stall warnings roughly a minute before the upset.

I hadn't grasped that before.

It fits the vague idea I had that the pilots were initially, and in the end fatally, inclined to believe that the stall warnings were spurious, or perhaps as unreliable as the airspeed.
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Old 2nd Jul 2012, 23:12
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DozyWannabe
Why?
An objective view of the evidence - even going back to 1988 - proves conclusively that BEA did *nothing* to ...
I am not belonging M. Asseline team and those who followed him, but, AFAR, it seems to me that pilots must be informed about the specificities of the vessel they are handling.

Did you never heard something about "The reasons of State" ?

It has been discussed of Concorde on this (or a previous) AF447 thread.
After one of the Concorde Washington tire event, you probably remember that NTSB sent a letter to BEA (links or scans available within some deadline).
It others one terms, NTSB needed to open the umbrella and protect his back.

Which was the answer of BEA?
I summarize: everything is under control.

Okay, no problem .... till Gonesse Concorde Crash.

Now, what's new about pitot probes ?
No problem (and don't take care with near of 50 previous UAS events?)


IGh
Investigator Bias ...
Another topic -- a new thread --
Thank you very much for this new subject.
At the time I read it : only two posts ... but two Scuds !


Why Tarom report ? It and only an example to show the slowness.
At last but not at least: Tarom from french BEA report:
4.2 Recommandation intermeiaire
A la suite de plusieurs accidents pour lesquels le Bureau Enquetes-Accidents avait participe, la recommandation suivante a ete emise le 24 janvier 1995 :
...
4) Consequences:
* la reaction des systemes automatiques de vol entraine des configurations potentiellement dangereuses : hors trim, poussee moteur(s) incompatible avec la trajectoire souhaitee par le pilote, ...
* L euipage, soit ne se rend pas compte de la situation, et donc ne peut pas prendre les mesures correctrices, soit constate la configuration de l avion sans en comprendre les causes. Cette incomprehension (egalement liee a une connaissance limitee des systemes) entraine une perte de temps dans l analyse de la situation, voire une analyse erronee, generalement associees a un deficit de communication entre les membres d equipage

3 Un rapport preliminaire a ete publie le 3 novembre 1994.
Ceci a entraine des attitudes tres dangereuses: assiettes ou roulis tres importants, perte de vitesse (jusqu au decrochage) ou vitesse excessive, etc.

En consequence, le Bureau Enquetes-Accidents recommande:
- qu une etude soit lancee pour que la priorite du pilote sur les systemes automatiques de vol soit maintenue en toutes circonstances.


Ceci pourrait se traduire:
a) par la deconnexion des systemes automatiques de vol (pilote automatique et auto-manette ou auto poussee) en cas d antagonisme entre les actions du pilote et celles du systeme automatique de vol ou du directeur de vol.
b) et/ou par une information claire en cockpit (eventuellement une alarme) alertant l equipage d un tel antagonisme.
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