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How safe is (airbus) fly by wire? Airbus A330/340 and A320 family emergency AD

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How safe is (airbus) fly by wire? Airbus A330/340 and A320 family emergency AD

Old 28th Dec 2012, 08:49
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PDF Interesting Report Pages 31-34

Le SPECIAL COMETEC N°5 est disponible pour tous les pilotes | Syndicat National des Pilotes de Ligne (SNPL)

French pilots union demand that Airbus change the following:
* Get rid of ALT 2.
* Get rid of AutoTrim in all modes bar Normal.
* For UAS, jump to Direct.
* AutoTrim when values are extreme, aural warning à la MD-11 "Stabiliser Motion".
* Rethink A/THR and non-moving levers.
* Link SSs.
* Replace Vector Stability with Speed Stability.
* Abnormal Attitude needs to be re-tested as it didn't function properly in Perpignan.

Last edited by Kimon; 28th Dec 2012 at 08:49.
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Old 28th Dec 2012, 09:16
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Hoorah!! Apart from number 7 which I do not comprehend (and NB do not need to!!!), commonsense at last. What took so long? Was it the horrendous loss of life that triggered this?
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Old 28th Dec 2012, 09:25
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with such demands....
they better taxi (ground mode = direct) to destination.
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Old 28th Dec 2012, 10:13
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French pilots union demand that Airbus change the following:
* Get rid of ALT 2.
* Get rid of AutoTrim in all modes bar Normal.
* For UAS, jump to Direct.
* AutoTrim when values are extreme, aural warning à la MD-11 "Stabiliser Motion".
* Rethink A/THR and non-moving levers.
* Link SSs.
* Replace Vector Stability with Speed Stability.
* Abnormal Attitude needs to be re-tested as it didn't function properly in Perpignan.
As a former Airbus pilot, I intended and managed to leave this technology, being convinced that it is not safe enough.
I had always asked for some of the above, plus the "instant direct law button", enabling to get away from wrong protection.
I am happy and comforted today, after being constantly belittled by the AB-lobby, that an union of pilots that fly such aircraft finally ask for some common sense.
We should have done that long ago, unite and ask for implementation of an apparent safer solution.

It did certainly not need the cynical QED written with blood. All the responsible that withheld improvement of the system, and still refuse to see its flaws, should go to look at themselves in the mirror and try to convince what they face, that such a union of professionals must be wrong.

Thanks dear colleagues, it's in Airbus' and the regulators hands now.

Last edited by Gretchenfrage; 28th Dec 2012 at 10:15.
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Old 28th Dec 2012, 15:34
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Reason Prevails?

Well, it seems that maybe, just maybe, reason has prevailed with at least one group of pilots. It's about time.
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Old 28th Dec 2012, 16:25
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I have always read Dozy's posts on Airbus and found his views interesting and informative. He has always, when the topic of 'pilot involvement' was raised, maintained that 'pilots' WERE involved in the development of the AB FBW/systems. Now it appears that perhaps some 'pilots'/users have other views on it. I wonder what Dozy will make of that?
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Old 28th Dec 2012, 16:40
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BOAC

I never bought Dozy's knee jerk defense of AB. The pilots to whom he referred were company pilots, paid by the airframer, and owned, proprietarily by the airframer.

Much admiration and great respect to the pilots of AirFrance, they forced the line to replace the pitot tubes immediately, and now have forced the hand of the manufacturer to correct glaring and dangerous shortcomings in the controls systems.

bonne chance mesdames et messieurs........
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Old 28th Dec 2012, 17:10
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What is the opinion of the rest of the world's pilots' unions on this list, or is that not something of interest any more?
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Old 28th Dec 2012, 18:45
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Direct Law & Unions

Had AF447 dropped directly into Direct, would it have made a difference?
I think on B777s if one of Pitots go loopy, it goes into direct as per the 2005 incident.
Regarding Unions, AF so far are the most vociferous than the rest - ipso facto - because AF is appears to be in a forced marriage with Airbus and that their relationship between flag carrier and home-turf framer got off in such an inauspicious manner that they both still live under Habsheim's shadow.
The relationship between Airbus and AF is like no other.
The endless blame game will never end so the solution is simple:let the Unions decide if they want to be all-Boeing or all-Airbus.

Last edited by Kimon; 29th Dec 2012 at 07:04.
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Old 29th Dec 2012, 00:15
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Cool

Hi,

Airbus, un avion fou ?
PNC Contact, hôtesse de l'air et steward, formation et information. – Airbus, un avion fou ?
Airbus, a crazy plane ?
Google Traduction
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Old 29th Dec 2012, 08:07
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jc -
Originally Posted by the Google translation
Airbus could not regain control of their aircraft when they reproduced stall Rio .
- do we have any information on this 'test'? Have I missed it on the forum?
Originally Posted by Lyman
BOAC
I never bought Dozy's knee jerk defense of AB. The pilots to whom he referred were company pilots, paid by the airframer, and owned, proprietarily by the airframer.
- I did not intend this to be a discussion on how we individually view Dozy's inputs but to see what they are. If you don't like them ignore them. Dozy has long argued that because certain 'pilots' were involved in the whole concept it was 'ok'. Now we have other 'pilots' involved.

Last edited by BOAC; 29th Dec 2012 at 08:15.
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Old 29th Dec 2012, 09:00
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Originally Posted by CONF iture
This would be a Question for HazelNuts39, at which angle the AoA probes should freeze for Alpha Floor to activate before M.53 is reached
Sorry, I don't know the values of alpha-prot and alpha-floor.
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Old 29th Dec 2012, 09:13
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Whether we like it or not automation is here to stay, as it's essentially a profit driven concern.

Most complex automation systems only work well within a narrow set of parameters. Inside this known zone of expectation the operator (pilot) and the computer can produce efficiency gains that are substantial. When the system falls outside it's comfort zone, which is possible due to many reasons like an input not catered for, or a malfunction, or an operator encountering an unfamiliar situation, the role of the operator, although unchanged in goal (fly the plane), changes in implementation (from being 30 seconds ahead of the plane to asking "what's it doing now") - the operator is reduced to fighting a complex computer in a complex battle to perform the simplest of tasks with the likely consequence of producing another unexpected outcome that makes the situation worse than before.

The solution is to have a voting button (please don't call it a panic button) that demotes the computer to observer status. But this still doesn't get the operator into the clear as the information presented by the computer may not be correct. However the operator, if experienced enough, is free to make a sound judgement on the quality of the data presented and discount it as he/she see's fit, unlike the computer. And there is the rub.
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Old 29th Dec 2012, 20:27
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Originally Posted by HN39
Sorry, I don't know the values of alpha-prot and alpha-floor.
I would think the values of alpha-prot and alpha-max are a percentage of alpha-stall. I have seen some figures already but cannot remember where exactly at the present time ... Don't think it was official documentation either.
I believe the value for alpha-floor can be variable somewhere between alpha-prot and alpha-max.
I'll try to remember where I have seen those data ... ?
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Old 29th Dec 2012, 21:47
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@CONF iture:

Alpha floor is activated:

if filtered AoA(3s) > threshold; which depends on CONFIG, GS variation and difference between GS and Vc.
or
SS NU >14° and theta > 25°
or
SS NU >14° and AoAprot.

Alpha floor is inhibited > M 0.53 or by FMGEC @ certain engine failures.
---

but that's what the book says, in your opinion it could be anywhere...
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Old 29th Dec 2012, 22:06
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Some members of the SNPL* have been involved in a long-standing political dispute with Airbus which is obviously going to have an effect on those demands. I personally (for all that may be worth) think it's wrong-headed, and it's certainly not based on a thorough understanding of the systems design. Others will feel differently, and that's their prerogative.

I doubt much will come of it because the existing system is demonstrably as safe as any of the alternatives on offer - the narrative history of the types and the stats bear this out.

Airbus hired engineering pilots like the late Capt. Corps and others of his calibre because they *wanted* that kind of input on the design - you don't hire a former ARB chief test pilot simply to make him toe the company line. It's almost slanderous to imply that may have been the case, or that his focus was on anything other than professionalism and safety above all else. Remember that he died in the Himalayas - he didn't need to be there but nevertheless he personally demanded to head up the technical investigation team on that accident. Understand that he not only dedicated his life to making your lives up front - as well as ours in the back - as safe as possible, he ended up *giving* his life in pursuit of that cause.

You can deride my input as "knee-jerk" (it isn't), you can throw as much mud at me as you please and I won't give a flying glob of monkey-spunk - but to refer to a pilot of Corps' character by putting his life's calling in sarcastic quotation marks, or to claim that he and his team would ultimately be little more than rubber-stamps for company policy is, in my opinion, utterly beyond the pale. Shame on you.

* - Aided and abetted by fringe agitators like Henri Marnet-Cornus and Norbert Jacquet...

Last edited by DozyWannabe; 29th Dec 2012 at 23:02.
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Old 29th Dec 2012, 23:26
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I have no idea who Monsieur Corps is. Other than having an unfortunate surname, I understand he worked for Airbus in the development of the Ziegler system. I found this from one of your posts on another thread, in reference to this unfortunately now deceased pilot.

"but also because he had a knack of explaining and proving the systems in public in a way that pilots could get behind (and as DP Davies' successor at the ARB before he joined Airbus, Corps had the "old-school" clout to make people listen)."

Sorry, that makes the gentleman a salesman. That he believed in it is not the question. He was paid.

The standard in business is to avoid "the appearance of impropriety". Objectivity is hampered by money. Assumptions mean nothing.

On the list the Pilots are demanding are certainly items that were approved by your paragon. Being fallible is human, and no reason for lack of respect. However, there is no shame in calling to question said fallibility.

Shame on me? You sure you're not a Lawyer?
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Old 29th Dec 2012, 23:42
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You're a piece of work, Lyman. Aside from a heartfelt suggestion to do your homework - and you can start here:

Gordon Corps - overview

Guardian article reporting his passing, with mini-bio (quoted in an email from my late professor)

Old Flight article on the A320 and Captain Corps' involvement

Another old Flight article

...a refutation - specifically that there is not and never was any such thing as "the Ziegler system" (he was effectively merely a figurehead on the A320 project) and the explanation that "Corps" is a noun that refers to a group of people, usually military in nature - at this point I have nothing more to say to you. So many posts of yours seem to be deliberately phrased to elicit an extreme response and ignore information that I know you've been privy to in the past that I can no longer trust anything you say.

To the rest of you - I sincerely request you reflect a little harder and longer before repeating things that are demonstrably untrue about the Airbus system - no matter what you personally may think of it - if only out of respect for one of your own, who has tragically been largely forgotten in the maelstrom of bitterness and politics regarding Airbus, and did the best job he could with the tools and team he had to make our lives as trouble-free and safe as possible.

[EDIT : Note also that the SNPL "Special COMETEC" dates from September and as yet we have heard no further word on the matter.]

Last edited by DozyWannabe; 30th Dec 2012 at 00:27.
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Old 30th Dec 2012, 00:27
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BOAC,

Dozy Wanabee has a tendency to regard Airbus FBW through rose-tinted spectacles, but he provides a comparatively mild, rational counterbalance to the ill-informed bigotry of many armchair critics who, like himself, have little or no flight time on them. Seems a pity that, despite all the time you have devoted to the AF447 threads and others on the subject, your own knowledge of the Airbus cockpit remains unashamedly negligible.

As for the SNPL, their opinion has to be seen in the light of their consistent opposition to Airbus technology since the introduction of the first two-pilot glass cockpit on the A310 in 1983, and the Habsheim affair in 1988. As usual, some of their demands are rhetorical; others may be arguable.

In case anyone infers otherwise, I've argued in principle against non-driven throttle levers and non-interconnected sidesticks since 1986, despite flying them full-time from 1988 - 2001. I doubt that even the highly-respected Gordon Corps (Lyman, please note) could have overruled Mr. Ziegler on those fundamental engineering issues. But the overall package is a good one. The fact that airlines discouraged, or even banned their pilots from timely removal of certain automatics (such as A/THR, AP and FD) is ultimately their fault, and contributed to AF447.


Last edited by Chris Scott; 30th Dec 2012 at 00:28.
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Old 30th Dec 2012, 00:39
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@Chris Scott - in general, thanks for the support, but I want to be clear here - no offence:

Originally Posted by Chris Scott
Dozy Wanabee has a tendency to regard Airbus FBW through rose-tinted spectacles
I most certainly do not. I am as well aware of its potential drawbacks as I am of its positive aspects and I completely understand why a departure from the de facto control setup that had been engineered to resemble the post-war state-of-the-art would cause consternation, particularly among the piloting community. Despite being a software man, my late Prof. was actually a dyed-in-the-wool sceptic and he taught us all to always question, test and evaluate in the way that all engineers should.

As an engineer, it is central to my credo that there is no such thing as a perfect system. The Airbus FBW control setup is an imperfect evolution of an imperfect system - that is not in question. The debate is therefore a subjective assessment of whether the benefits of the newer system outweigh the drawbacks, as opposed to the very real benefits and drawbacks inherent in the old system and as such it is not going to be resolved any time soon, if ever.

I doubt that even the highly-respected Gordon Corps (Lyman, please note) could have overruled Mr. Ziegler on those fundamental engineering issues.
Capt. Ziegler, despite having a degree in engineering, never really exercised that qualification. He may have been the project lead and arbitrator, but he had absolutely no authority to overrule Capt. Corps and his team on engineering matters. In fact all the teams had ultimate power of veto - if any aspect of the design could not be accepted by all, they all went back to the drawing board and started again.

That aside, I acknowledge and respect your opinion on interconnected PFCs and moving throttles. However I hope you will agree that the much-feared negative impact on safety held over these factors in the late '80s has not been borne out by the record of the Airbus FBW types. In fact we've had plenty of accidents in the interim where these elements were present and yet made no material difference to the outcome. Loath as I am to give much weight to anecdotal evidence, it does at least raise the question of how necessary such things are, does it not?

Last edited by DozyWannabe; 30th Dec 2012 at 01:36.
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