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AF 447 Thread No. 11

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AF 447 Thread No. 11

Old 14th Apr 2013, 14:47
  #21 (permalink)  
 
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Originally Posted by HazelNuts39 View Post
From BEA's Final Report, para. 2.2.5:

Thanks!
Using max speed (for the actual config) for setting FCS parameters for the longitudinal Flight Control would explain the visible high level of dampening of the Elevator Control.
That makes a lot of sense when looking at the Traces for Elevator movement vs SS input.
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Old 14th Apr 2013, 16:52
  #22 (permalink)  
 
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Alpha prot is a function of Mach. No valid airspeed - no alpha prot. Latched.
Not entirely though. Because there is a maximal alpha prot for the low machs, and they could take this one into account even with lost airspeeds, i.e. they could have limited the trim up say up to 14 degrees AOA as is the case for low speeds. Granted you are still stalling, but not as badly.

It's like, say, assume that you don't have the slats and flaps position sensor. Yet, would you remove the load factor protection because the limits are a function of the position of slats and flaps? You can still take the worst case values, that shouldn't impact maneuverability.
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Old 14th Apr 2013, 19:10
  #23 (permalink)  
 
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Granted you are still stalling, but not as badly.
Agreed, the THS would have stopped at about - 5.9 degrees. According to Owain Glyndwr's analysis the AoA would have reached 36 degrees.
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Old 11th Jun 2013, 23:01
  #24 (permalink)  
 
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In ref to http://www.pprune.org/7886998-post1329.html

Originally Posted by PJ2
There is salesmanship mixed with marketing from airplane makers and everyone else, and then there is the reality of an airplane's design which must be trained, learnt, and understood well.
First sim practice was about manual flying to get a taste of the sidestick, even direct law to confirm how the new design was 'conventional'.
Later on emphasis was on the protections and how to apply full back stick to get the most of it or how to abandon to the electronics ...
Last on the priority list was the stall ...

Buying an airliner has to do with expected profits not much with stall protection and Ziegler was not exactly a salesman either.
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Old 12th Jun 2013, 08:43
  #25 (permalink)  
 
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Devil Written eight months before AF447

ZIEGLER BERNARD's book :
"Les Cow-boys d' Airbus"
Editions Privat
Toulouse november 2008
ISBN 978-2-7089-9217-7
Forword Jean Pierson

Picture of the cover :
Cowboys_NEW_couv1-1_zps41048f5b.jpg Photo by femmes_pilotes | Photobucket

Originally Posted by Bernard ZIEGLER
Page 65 :
'Donc, j'ai fait bien des mauvais coups par le monde avec quelques "bandits" de la mafia commerciale.'

Page 79 v
'Il devint impossible de faire un tonneau, d'excéder les vitesses limites,de décrocher l'avion et surtout de risquer de briser la voilure en tirant trop fort'
Translation :
'So I did many bad things in the world with some "bandits" in the trade mafia.'

Page 79 'Since it was impossible to make a barrel to exceed speed limits, to stall the plane and especially risk breaking the wing by pulling too hard'

Last edited by Jetdriver; 12th Jun 2013 at 23:34.
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Old 12th Jun 2013, 09:46
  #26 (permalink)  
 
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Excuse me guys... You quote passages where the author/speaker describes the behavior in normal law (i.e. the most common case), and under the pretext that it was not explicitly mentioned in each occurrence it was normal law, you cry foul?
Are you not able to tell the difference between a "commercial" speech and technical instructions?

We understood long ago you don't like what Airbus or Ziegler once said. Now what is the use of repetition? Do you intend to change your mind? Because so far, it is not a convincing speech.

Last edited by AlphaZuluRomeo; 12th Jun 2013 at 09:46.
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Old 12th Jun 2013, 14:01
  #27 (permalink)  
 
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Hi AlphaZuluRomeo,

- Repetition ? I apologize if that book has already been quoted
- Commercial Speach ? I don't think that book can be considered as ad.
- Unsaid "normal law" ? Bernard Ziegler, EPNER Test Pilot, X Engineer knows that has to be mentioned.
- What is said and missed in that book are deliberate provocations, he chosed to associate that to AIRBUS' name, AIRBUS' workers who are allowed to see another message.
- What I found sad, is that this book has been written by Bernard ZIEGLER after the end of the trial of Ste-Odile after many years of justice problems, where he showed he was able to give very acurate precisions.
I was very shocked by the tittle of his book. Really not commercial at all for AIRBUS and for AVIATION.
- Should Bernard ZIEGLER tried to explain a little more that had been misunderstood he could do it freely. He did not chosed that way.
That book is the last image HE wanted to give from himself and his conception of FBW. Once again he decided to say the plane will not stall.
AF447 8 months later showed he was wrong.

Precision : I chosed no sentences out of context

SAD !
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Old 12th Jun 2013, 14:51
  #28 (permalink)  
 
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Gentlemen, I suggest paying heed to PJ2.

When the F-18 first came out, it had a variety of wonderful new features and capabilities, and a few buckets of its own PR hype. Some criticized the 'hype' for what it was, because "no aircraft is magical."
All of the hype didn't stop Blue Angel #5 from crashing (low level, pilot ejected) in El Centro back in 1987, due IIRC to engine fuel starvation (inverted, IIRC, but memory is fuzzy). Note: I later heard that there was an issue in early Hornets with fuel pumps that seems to have caught the pilot at a bad time, an issued later fixed ...

Tell me: was that crash due to the overselling of a high performance jet by MD? Methinks not.

PJ's point on knowing your aircraft and how it flies, and training for how it actually works versus PR noise is true for any aircraft. If the AB and or AF training programs, or industry training programs, need improvement, then of course that improvement is worth clamoring for. Kvetching about PR noise seems pointless.
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Old 12th Jun 2013, 15:25
  #29 (permalink)  
 
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Obviously, toffeez

roulishollandais, I have no inclination to nitpick, let me just agree to disagree with most of your opinions expressed above, as a whole

If you have a personal problem with Mr Ziegler regarding how he expressed his views as a book author:
This opinion is fine by me, I have no intent to comment it; instead I respectfully suggest to contact Mr. Ziegler directly (or via the publisher).
This would avoid giving the impression that professional pilots may have taken for an absolute truth what is written in a popular book, even if the official technical manuals of the concerned aircraft clearly show them otherwise.
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Old 12th Jun 2013, 21:10
  #30 (permalink)  
 
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Snoop

Originally Posted by AlphaZuluRomeo
theimpression that professional pilots may have taken for an absolute truth
AlphaZuluRomeo you pointed it well. The problem is not with a popular book or my relations with Zieglers but with the fact that effectively the pilots are human like others, receiptive to false, short, pleasant message which suddenly comes in contradiction with S/W in a bad moment.
But feel free to disagree with my opinions. Am I allowed to suggest to read Ziegler's book to make one's own idea?
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Old 12th Jun 2013, 21:39
  #31 (permalink)  
 
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In terms of the algorithms/logic and human interface, are any changes on the cards as a result of this accident.

I am still a bit puzzled as to why the system, which had plenty of data to deduce the thing was falling and likely stalled, couldn't be a little more helpful to the crew.
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Old 12th Jun 2013, 23:32
  #32 (permalink)  
 
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Originally Posted by roulishollandais View Post
Am I allowed to suggest to read Ziegler's book to make one's own idea?
Please, be my guest! I for one did this long ago
People who will follow your suggestion will soon discover the sentence just before the one you quoted from p.79, which explicitely describes that the FBW technology made it possible to implement "protections" against flight envelope departure before giving some examples (= your quote); this allows any pilot who have read his manual, or even only the ECAM to understand that protections lost means that he now can execute a barrel roll, exceed the speeds limits or stall the aircraft.

Last edited by AlphaZuluRomeo; 12th Jun 2013 at 23:33.
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Old 13th Jun 2013, 00:17
  #33 (permalink)  
 
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Good grief, am I actually reading here that there are (or were, until recently) pilots out there who actually thought their machines were so magic that they could never stall?

Maybe some basic physics knowledge should be a prerequisite for pilot training?
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Old 13th Jun 2013, 08:13
  #34 (permalink)  
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Originally Posted by 3hole
there who actually thought their machines were so magic that they could never stall?
- sorry to spoil your day, but there still are - all Airbus pilots who (correctly, as I understand it) believe that if all is working properly in Normal Law it cannot happen, and full back stick can be the way out of trouble. The problem, of course, as we have seen, is breaking that mind set when..............................
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Old 15th Jun 2013, 05:35
  #35 (permalink)  
 
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In a scarebus, if in doubt of airspeed, call up the FPV. 2.5-4 deg is cruise, 7-8 is green dot, S, or F speed. Above 8 your AOA is too high. Unfortunately use of the FPV as an AOA is not taught by airbus.

It is used everyday by fighter guys with HUDs.

AF447 would never have happened with better trained pilots. Period.

AF447 crew flew into a thunderstorm, which iced up the Pitot static system, then inputed controls that stalled the aircraft. They failed to recognize the stall and crashed 4 minutes later.

There are some bright engineer types on here. The brightest engineer in the world cannot make up for a poorly trained pilot. The poorly trained pilot will eventually figure out how to screw it up. AKA AF447.
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Old 15th Jun 2013, 07:39
  #36 (permalink)  
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AF447 crew flew into a thunderstorm,
- oh Lord! Here we go yet again - round and round. NO THEY DIDN'T - read the report.

Incidentally, a thing called an attitude indicator would have done the job rather than FPV.
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Old 15th Jun 2013, 08:02
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I have a question regarding all these laws: was it put somewhere on the ECAM that the plane was now in Alternate 2B law? The ECAM just says "Alternate", which is pretty vague. Does it matter to know if you are in alternate 1 or 2 (and the subcategory)?
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Old 15th Jun 2013, 08:31
  #38 (permalink)  
 
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was it put somewhere on the ECAM that the plane was now in Alternate 2B law?
No, just alternate, as you have correctly observed.

The ECAM just says "Alternate", which is pretty vague.
It is not, because...

Does it matter to know if you are in alternate 1 or 2 (and the subcategory)?
...it does not if you are trying to fly the airplane. The situation might be somewhat different (and differing from reality) if one tries to promote conspiracy theories on anonymous web board. The most important information; that protections are no longer available can be perceived just by glancing the PFD, where attitude limits markings, the green "=" are replaced by yellow "x" signs.

AF447 would never have happened with better trained pilots. Period.
How do you measure quality of the training? How do you know that the fellow you are training actually understands and believes what you are telling him and is not just trying to make it through the exams and get a piece of paper unequivocally stating he is competent? How do you know that when the chips are down he won't just jettison everything he was taught and revert to some deeply rooted notion of his which might be flawed, even fatally?

Anyone finding plausible answers to these can found a consultancy business and retire a millionaire.
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Old 15th Jun 2013, 10:04
  #39 (permalink)  
 
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Originally Posted by Clandestino View Post
How do you know that when the chips are down he won't just jettison everything he was taught and revert to some deeply rooted notion of his which might be flawed, even fatally?
As a Non-Front Office resident (aka SLF) I was always hoping the Sim Checks would help to find this out. Looking at this truly unfortunate accident and the findings as to how it unfolded however, I' afraid you might be right, though...

Although I'm not really convinced that more automatisms will do any good to correct this from a more enigneering perspective I am positive that the aircraft could have known its actual flight attitude at least roughly. A combination of Integral over G loads in all 3 axis versus GPS data would have given a flight path and attitude over Ground. That leaves out wind speed but even that could have been factored in as a trend based on history data of the previous 5 minutes or so when it was still reliable. In case of unreliable air speed an average over the last (couple of) minutes with 'good' data should be a suitable and sufficient working hypothesis.
Based on that information there should be a possibility to give Pilots more indication of the actual attitude and situation even if all Air data is lost or considered unreliable.
We will see if a Manufacturer will go into that direction even though we should hope that the lesson of AF447 has been learned world wide.

Last edited by henra; 15th Jun 2013 at 10:05.
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Old 15th Jun 2013, 10:33
  #40 (permalink)  
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Originally Posted by henra
to give Pilots more indication of the actual attitude
- what more 'indication' do you consider they could possibly have wanted? Two large and one small instruments not enough?
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