AF 447 report out
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What did they do?
But ... the DGAC take the recorders (with no judicial seals) and keep them 1 week
and this was outlawAfter that .. they were requested by a judge ...
That's a good point for launch any "conspiracy theory"
You do know that the "switching /altering flight recorders" accusation was a lie, don't you?
Last edited by jcjeant; 19th Jul 2012 at 11:59.
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@jcj:
It seems to be a truism that when regulators get themselves involved in accident investigation and resolution, things go wrong (e.g. UK CAA with the BA 747 approach incident, US FAA several times - but notably with the DC-10 'Gentlemen's Agreement' post-Windsor).
The point is that because journalists frequently can't be bothered to learn the difference between the investigatory body and the regulator, on that occasion the BEA were unfairly tarnished.
Re: that incident, the apparent "time discrepancy" that the retired AAIB investigator noted turned out ot be a misreading of the data. The photo sent to the Swiss for analysis proved nothing, as the only person to suggest that the boxes in the photo and the ones from the crashed aircraft should have been one and the same was a journalist. Generally when you've got non-technical people searching for something, you have another example around to show them what it looks like.
It seems to be a truism that when regulators get themselves involved in accident investigation and resolution, things go wrong (e.g. UK CAA with the BA 747 approach incident, US FAA several times - but notably with the DC-10 'Gentlemen's Agreement' post-Windsor).
The point is that because journalists frequently can't be bothered to learn the difference between the investigatory body and the regulator, on that occasion the BEA were unfairly tarnished.
Re: that incident, the apparent "time discrepancy" that the retired AAIB investigator noted turned out ot be a misreading of the data. The photo sent to the Swiss for analysis proved nothing, as the only person to suggest that the boxes in the photo and the ones from the crashed aircraft should have been one and the same was a journalist. Generally when you've got non-technical people searching for something, you have another example around to show them what it looks like.
Last edited by DozyWannabe; 19th Jul 2012 at 12:08.
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It seems to be a truism that when regulators get themselves involved in accident investigation and resolution, things go wrong
And things can go wrong when those regulators are not punished in any way for those actions ....
Last edited by jcjeant; 19th Jul 2012 at 12:10.
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Please take your stupid conspiracy theories to an appropriate forum.
Just talking about the fact (not theory) that DGAC detained (illegally) the recorders (and under no supervision of any) during one week (no judicial seal on ... as required by the law)
Normally the recorders had to be detained by the BEA (the lone official body in France, allowed to make investigations) .. and had to be sealed by judicial supervisor (like in the AF447 case)
Last edited by jcjeant; 19th Jul 2012 at 13:57.
Fundamental question- Why not a requirement to stall commercial ac?
Hello all-
Long time lurker, GA type who has learned so much from this thread and everything else on PPRune- Thanks so much for an excellent forum.
Of course full stalls are never trained in the real world, but I can't imagine why there isn't a requirement for commercial pilots to have regular sim experience? I understand that current sims can't model stalls because no one ever spins and stalls commercial AC in testing, but whey don't they?
In a FBW environment, wouldn't it be easy to wire up a prototype and remotely pilot it beyond the envelope? This should generate data for design and efficiency that didn't exist before and give sims accurate data for stalls and spins?
Test pilots increase the odds of total failure incrementally, so I would imagine that a lot of data could be collected before the airframe is lost and planning on loosing the airframe would be the same as wing bending and pressure testing- You just factor the loss into the total cost of the program.
Perhaps the AC will provide great data in approach to stall and recovery after a spin or two. Maybe great data can be obtained falling off the high and low ends of the coffin corner- It might have the opportunity to be recovered after a high altitude stall, and if it makes it this far, the holy grail would be attempted recovery from a deep stall (assuming the AC can be deep stalled)-
If you get good data from that, maybe a high speed dive until the wings come off, but if I understand modeling correctly, everyone of these data points should allow better sim modeling for unusual attitudes.
Am I missing something? Is the cost of an aircraft the only thing stopping an approach that seems like common sense from the outside?
Much appreciated, and sorry if this was an insane question.
Long time lurker, GA type who has learned so much from this thread and everything else on PPRune- Thanks so much for an excellent forum.
Of course full stalls are never trained in the real world, but I can't imagine why there isn't a requirement for commercial pilots to have regular sim experience? I understand that current sims can't model stalls because no one ever spins and stalls commercial AC in testing, but whey don't they?
In a FBW environment, wouldn't it be easy to wire up a prototype and remotely pilot it beyond the envelope? This should generate data for design and efficiency that didn't exist before and give sims accurate data for stalls and spins?
Test pilots increase the odds of total failure incrementally, so I would imagine that a lot of data could be collected before the airframe is lost and planning on loosing the airframe would be the same as wing bending and pressure testing- You just factor the loss into the total cost of the program.
Perhaps the AC will provide great data in approach to stall and recovery after a spin or two. Maybe great data can be obtained falling off the high and low ends of the coffin corner- It might have the opportunity to be recovered after a high altitude stall, and if it makes it this far, the holy grail would be attempted recovery from a deep stall (assuming the AC can be deep stalled)-
If you get good data from that, maybe a high speed dive until the wings come off, but if I understand modeling correctly, everyone of these data points should allow better sim modeling for unusual attitudes.
Am I missing something? Is the cost of an aircraft the only thing stopping an approach that seems like common sense from the outside?
Much appreciated, and sorry if this was an insane question.
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The perseverance of the French authorities in the location and examination of the wreckage is to be applauded though I expected nothing less.
In fact ... by analyzing ACARS report and preliminary reports before discovery ... Airbus certainly had the certainty that (exept pitot tubes) .. his plane was not implicated technically
This required that the wreck (and recorders) was discovered at any price that leaves no room for doubt or speculation about the quality of their product
Last edited by jcjeant; 20th Jul 2012 at 19:22.
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Airbus FBW in AF447
To quote a paragraph on Page 187:
However, positive longitudinal static stability on an aeroplane can be useful since it allows the pilot to have a sensory return (via the position of the stick) on the situation of his aeroplane in terms of speed in relation to it's point of equilibrium (trim) at constant thrust. Specifically, the approach to stall on a classic aeroplane is always associated with a more or less pronounced nose-up input. This is not the case on the A330 in alternate law. The specific consequence is that in this control law the aeroplane, placed in a configuration where the thrust is not sufficient to maintain speed on the flight path, would end up by stalling without any inputs on the side stick. It appears that this absence of positive static stability could have contributed to the PF not identifying the approach to stall.
If I were a lawyer looking to blame Airbus I believe this would be my "smoking gun" so to speak. However also in the report the paragraph prior states:
When there are no protections left, the aeroplanee no longer possesses positive longitudinal static stability on approach to stall. This absence specifically results in the fact that it is not necessary to make or increase a nose up input to compensate for a loss of speed while maintaining aeroplane attitude. This behaviour, even if it may appear contrary to some provisions in the basic regulations, was judged to be acceptable by the certification authorities by taking into account special conditions and interpretation material. Indeed, the presence of flight envelope protections makes neutral longitudinal stability acceptable.
So the certification authorities have allowed a "relaxation" of certification standards. Airbus themselves designed a flight control system that contributed to this accident.
Again if I were a lawyer, I would love to examine the "special conditions and interpretation material".
The certifying authorities and Airbus still have many questions to answer. This final report has no doubt marked the beginning of some serious legal process
However, positive longitudinal static stability on an aeroplane can be useful since it allows the pilot to have a sensory return (via the position of the stick) on the situation of his aeroplane in terms of speed in relation to it's point of equilibrium (trim) at constant thrust. Specifically, the approach to stall on a classic aeroplane is always associated with a more or less pronounced nose-up input. This is not the case on the A330 in alternate law. The specific consequence is that in this control law the aeroplane, placed in a configuration where the thrust is not sufficient to maintain speed on the flight path, would end up by stalling without any inputs on the side stick. It appears that this absence of positive static stability could have contributed to the PF not identifying the approach to stall.
If I were a lawyer looking to blame Airbus I believe this would be my "smoking gun" so to speak. However also in the report the paragraph prior states:
When there are no protections left, the aeroplanee no longer possesses positive longitudinal static stability on approach to stall. This absence specifically results in the fact that it is not necessary to make or increase a nose up input to compensate for a loss of speed while maintaining aeroplane attitude. This behaviour, even if it may appear contrary to some provisions in the basic regulations, was judged to be acceptable by the certification authorities by taking into account special conditions and interpretation material. Indeed, the presence of flight envelope protections makes neutral longitudinal stability acceptable.
So the certification authorities have allowed a "relaxation" of certification standards. Airbus themselves designed a flight control system that contributed to this accident.
Again if I were a lawyer, I would love to examine the "special conditions and interpretation material".
The certifying authorities and Airbus still have many questions to answer. This final report has no doubt marked the beginning of some serious legal process
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@bonernow
The stability question is being bounced around quite a lot in the most recent Tech Log thread on the subject. I'd suggest having a peek in there to get a better idea of what those paragraphs state.
The idea that standards were "relax[ed]" is a contentious one - they were simply changed to accommodate changes in technology, as they have been for every iteration of airliner design from the beginning.
While the design removes the traditional signs of feeling approach to stall through the primary flight controls, the other signs (including buffet) can definitely still be felt, and because thet's not enough, there's a very loud aural "STALLSTALL" warning. What the design made obsolete with one aspect was replaced with others - the change in design did not make it harder to recognise approach to stall in real terms.
The stability question is being bounced around quite a lot in the most recent Tech Log thread on the subject. I'd suggest having a peek in there to get a better idea of what those paragraphs state.
The idea that standards were "relax[ed]" is a contentious one - they were simply changed to accommodate changes in technology, as they have been for every iteration of airliner design from the beginning.
While the design removes the traditional signs of feeling approach to stall through the primary flight controls, the other signs (including buffet) can definitely still be felt, and because thet's not enough, there's a very loud aural "STALLSTALL" warning. What the design made obsolete with one aspect was replaced with others - the change in design did not make it harder to recognise approach to stall in real terms.
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- no. I suspect the 'put down' referred to was under another of svhar's usernames.
Only today you have managed to insult a few posters with your attitude. On various threads. Go play golf or something.
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@ svhar,
This is a legitimate question. Although you show only 23 posting, you are actually credited with a total of 466. Most coming on JB, "Where in the world?"
Suggest you log on, click on your name on one of your posts and then click on "See more posts by svhar", and see for yourself. Are you the only one or is there another? Who is the real svhar?
Your quote: What other usernames?
Suggest you log on, click on your name on one of your posts and then click on "See more posts by svhar", and see for yourself. Are you the only one or is there another? Who is the real svhar?
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Ridiculous design
The report suggests
Diagnosis : the pilots never diagnosed "unreliable air speed". Analysis of the dozen or so similar incidents where pitot tubes froze suggest that most of those crews did not diagnose it either.
Stall warning: did they comprehend it? The report provides references suggesting that in a confusing environment, humans can be cognitively deaf to aural stimuli, and tend to prefer and respond to visual stimuli much better.
Diagnosis : the pilots never diagnosed "unreliable air speed". Analysis of the dozen or so similar incidents where pitot tubes froze suggest that most of those crews did not diagnose it either.
Stall warning: did they comprehend it? The report provides references suggesting that in a confusing environment, humans can be cognitively deaf to aural stimuli, and tend to prefer and respond to visual stimuli much better.
Technically it is VERY EASY to detect and report IMMEDIATELY and PRECISELY to the crew the UAS. Airbus SAS prefer delegate it to the crew.
(A paper from Airbus SAS designers, etc. shows that)
A big part of this was the human-machine interface, which did an extremely poor job of letting the pilots know what was actually going on.
IMO F-GZCP had a ridiculous design (WRT to Air Speed) AND An ABSURD man machine interface.
So, from a cognitive perspective, the accident makes sense.
This accident was "designed" by Airbus SAS. No redundancy at all (AS probing) and misleading indications presented to crew.
Are they entirely, or even primarily to blame? Far from it.
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DW, it always seems you are making excuses for a bad design. This is a travesty of engineering - an airplane that can't be felt, only interpreted.
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Most of us abandoned the concept of aviation as terminally unique ages ago. For the simple reason that those who wished high profit could claim "complexity" to hide their greed and demands for special treatment from regulators and the public.
Airbus and BEA insult all of us who are capable of understanding not only flight, but controls and failures, with this entirely unsatisfactory report.
Concierge? Thus started the patronizing and fallacious nonsense....
Airbus and BEA insult all of us who are capable of understanding not only flight, but controls and failures, with this entirely unsatisfactory report.
Concierge? Thus started the patronizing and fallacious nonsense....
Per Ardua ad Astraeus
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Turbine - I assume he/she is still going on about it. As I said, I don't see his/her posts. I did exactly what you posted a while back but could find no post where I had put 'svhar down' (oh to be a vet). I have a vague memory that some way back he/she claimed exclusive evidence that AF447 had been struck by lightning to which I replied (I think I may have mentioned the 'O' bird, but got away with it), but I assume a mod sensibly deleted the post. Hey ho. Time to move on, I think. Bigger fish to fry.
). I have a vague memory that some way back he/she claimed exclusive evidence that AF447 had been struck by lightning to which I replied (I think I may have mentioned the 'O' bird, but got away with it), but I assume a mod sensibly deleted the post. Hey ho. Time to move on, I think. Bigger fish to fry.
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Special Conditions and Interpretative Material
From the FAA Regulatory and Guidance Library:
Special conditions are often a precursor to later general rulemaking proposals. Although originally specific to an airplane make, other manufacturers in a similar situation may elect to use them for their projects.
Interpretative material is published by the regulatory authority to illustrate one or several ways to meet a requirement that have been found acceptable in past certifications, for example FAA Advisory Circulars or EASA ACJ/AMJ material.
A Special Condition is a rulemaking action that is specific to an aircraft make and often concerns the use of new technology that the Code of Federal Regulations do not yet address. Special Conditions are an integral part of the Certification Basis and give the manufacturer permission to build the aircraft, engine or propeller with additional capabilities not referred to in the regulations.
Interpretative material is published by the regulatory authority to illustrate one or several ways to meet a requirement that have been found acceptable in past certifications, for example FAA Advisory Circulars or EASA ACJ/AMJ material.