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AF447 wreckage found

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AF447 wreckage found

Old 8th Aug 2011, 08:37
  #2741 (permalink)  
 
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All aircraft are developed and certified so as to ensure that their control is easy and well-behaved throughout their operating envelope. Testing to ensure these good handling characteristics assumes that pilots are utilizing typical piloting techniques during routine line operations.
The advancement of technology in today’s modern airplanes has brought us flight directors, autopilots, autothrottles, and flight management systems. All of these devices are designed to reduce the flight crew workload. When used properly, this technology has made significant contributions to flight safety. But technology can include complexity and lead to trust and eventual complacency.
The systems can sometimes do things that the flight crew did not intend for them to do. Industry experts and regulators continue to work together to find the optimal blend of hardware, software, and pilot training to ensure the highest possible level of system performance
Aircraft are designed, tested, and certified based on accepted assumptions of how pilots will operate them, together with various environmental and technical constraints (e.g., gusts, engine failure dynamics). These assumptions drive the regulatory certification requirements and are validated through in-service experience. The certification flight test process examines the entire flight envelope of the aircraft, including that area beyond which the airline pilot normally operates. Examples would be a fully stalled aircraft or airspeed exceeding Vmo. The process even explores how the aircraft could possibly be inappropriately operated; however, the testing assumes fundamental flying skills are known and understood. A primary assumption regarding pilot inputs is that they are based on control inputs that are measured (the result of experience), analyzed, then fine-tuned to achieve a desired result. Exaggerated rates and amounts of control deflection (overcontrolling) may cause an accelerating divergence of flight path control until the input is countered.
Pilots are expected to make control inputs based on desired aircraft reaction. Control deflections at one point in the flight envelope might not be appropriate in another part of the flight envelope. Pilots must have a fundamental understanding of flight dynamics in order to correctly make these choices. They should not make mechanical control deflections and rote reactions to dynamic situations that require an understanding of these flight fundamentals.
Extract from Boeing Document entitled Airplane Upset Recovery dated August 2004

Last edited by Owain Glyndwr; 8th Aug 2011 at 08:54.
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Old 8th Aug 2011, 09:44
  #2742 (permalink)  
 
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From Post #2738

90% of my flying is with a competent crew with us.
May I inquire about the other 10%?
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Old 8th Aug 2011, 10:23
  #2743 (permalink)  
 
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Deleted this post as I made a mistake with the time line.
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Old 8th Aug 2011, 10:55
  #2744 (permalink)  
 
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The missing clue in all this may be what the flight directors were demanding.

There are just two seconds between the autopilot disconnect and the F/Ds becoming unavailable but during that time the change in measured pressure saw an indicated loss of altitude - 300 feet. The F/D bar may well have shown a fly up indication before it disappeared completely and the PF may have "blindly" followed it.

Later the F/D is restored in HDG/ALT* modes and HDG/VS modes which may have briefly confirmed to both pilots that their actions were correct.

It was only later that the PNF saw that the aircraft was climbing.

Also very telling is the autothrust disconnect, the realisation that climb thrust has been inadvertantly applied and then the subsequent reduction in thrust.

The PF didn't want to climb otherwise he would have remained in climb thrust.

By then he is really confused and doesn't really know what pitch attitude to set without F/D guidance.
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Old 8th Aug 2011, 12:11
  #2745 (permalink)  
 
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Mountain Bear wrote:

If the technology can't correct for pilot error then it's rubbish technology. That's what FBW is all about. What part of the word "protection" in "flight envelope protections" doesn't you understand. The software is to protect the pilot from screwing up. It didn't. It failed.

People keep talking about pilot error as if that's the conclusion of the matter. Pilot error is just the beginning. Every single major advance in flight safety over the last hundred years has happened because "pilot error" was not an acceptable answer. The fact that the pilots in AF447 screwed up is as obvious as it is irrelevant. The pilot is just one cog in the system. If the system cannot compensate for errors in the system then it isn't a robust system.
While I agree with the general sentiment of your post and that pilot error is just the beginning, you are, in this case, going too far.

Yes: the system should compensate for errors from the pilot but you can't blame the engineers for thinking that a pilot who made it to the right seat of a heavy had mastered stall recovery about 5 hours into his basic flight training.

This isn't a "pilot error" accident. Maintaining nose-up for four minutes in a stall from 37000' is not an ERROR!
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Old 8th Aug 2011, 13:00
  #2746 (permalink)  
 
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The statistics however highlight that if we wish to eliminate accidents, then there is only one path to follow, the technology path
This line could have been a direct quote out of "Brave New World".

How many times have we heard that "only one path" thesis in history?
It always lead to disaster.
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Old 8th Aug 2011, 13:30
  #2747 (permalink)  
 
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" The statistics however highlight that if we wish to eliminate accidents, then there is only one path to follow, the technology path "

This line could have been a direct quote out of "Brave New World".

How many times have we heard that "only one path" thesis in history?
It always lead to disaster.
Depends on how you read it

I agree with its message but interpreted it as;

reduce accidents (we can't seem to elimnate anything to zero)

and

There is far more room in technology improvements per year than reducing human error per year.

and

Since a human is likely to still be involved for the direction that they provide to using the technology, we still have to keep them in the loop or they will cancel out the technology improvements.

We should strive to make human error less critical.
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Old 8th Aug 2011, 14:39
  #2748 (permalink)  
 
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eliminate was a bit strong but you interpreted my post correctly
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Old 8th Aug 2011, 17:08
  #2749 (permalink)  
 
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It is actually really sad to see so much ab apologists. Ab philosophy is clearly that of reducing costs, pilots costs included, and if that has so much flaws seems it doesnt matter, there are still a lot of short sighted people believing everything the bea says and shouting pilot error anytime they can
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Old 8th Aug 2011, 17:13
  #2750 (permalink)  
 
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If not understanding how thye a/c keeps trimming, this is Pilot error.

If a fundamentsl trap, this is aircrafts error. If Pilots know the trim is happening, and cannot feel it, where do they see it?
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Old 8th Aug 2011, 18:36
  #2751 (permalink)  
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Many years ago I posted on full automation. I suggested pilots were already redundant and electronics would take over within the next 20 years. Public sensibilities? We could employ actors. Then I quipped, "Oh, we already do."

It was meant to cut. I again referred to Davis' 'Handling the Big Jets' - later edition. Hey, I haven't seen a quote from that yet. Is there a single first officer that doesn't carry it with him these days?

It was all meant to shout: If humans are on the flight-deck, they MUST be able to fly the aircraft. Really fly it. Oh, and be allowed to fly it.

Twenty years on and every incident, let alone accident, will be built into the logic of civil airliners' control systems. All that will remain is what to tell the passengers. Frankly, if they believe half the horse-feathers they're fed now, they'd believe anything. They don't matter. Conveying the aircraft to destination with perfect safety is all that matters.

The entire problem that faces the industry now is how to bridge the gap from the human nervous system controlling the kit, to a total black-box industry. That really is not an easy question to answer.

Today I read of a new alloy. A molecular seeding that will make aluminum/aluminium very, very much stronger. Plastic aircraft are a stop-gap, in the same way the hybrid human/electronics control interface is. It's just getting over these years.

As an electronics bod who was later forced to fly the Zero-Reader, I know how difficult this transition period is going to be. The Zero-Reader was a smoldering pile of valves/tubes and melting rubber insulation. How the heck did it find itself advising human captains of civil aircraft?
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Old 8th Aug 2011, 18:59
  #2752 (permalink)  
 
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I again referred to Davis' 'Handling the Big Jets' - later edition. Hey, I haven't seen a quote from that yet. Is there a single first officer that doesn't carry it with him these days?
Sadly, yes.
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Old 8th Aug 2011, 19:23
  #2753 (permalink)  
 
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It was all meant to shout: If humans are on the flight-deck, they MUST be able to fly the aircraft. Really fly it. Oh, and be allowed to fly it.
Your words in gods ear!

The reality is that whenever the automatics are no longer capable of handling, due to invalid signals they need, they throw the aircraft back at the human.

- Perfect - It will be him screwing up finally.
Good for statistics and engineers.

Second reality is that even when the automatics switch off autopilot and autothrust, it can still intervene with pilot inputs, through automatic protections, and therefore limit his authority.

Why on earth? ?
It had detected itself incapable of handling the aircraft, but still messes with controls.

Isn't that a paradoxon?


I am not entirely against automation and technology to improve safety. But the implemented systems must work flawlessly.
Otherwise I don't need them.
So before introducing even more protections, please fix the technology that's already on board.

Concerning statistics, lots of contributors just love those, I am still missing a serious one about automation induced pilot errors. This would give a clearer picture than the one containing just plain pilot error. Not that it would excuse any such error, eliminating those should be just as noble a cause, but it would point back at the magic automatics that benefit from too big a confidence and a lack of genuine criticism, as it would mean responsibility (meaning doe) from you who I mean.
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Old 8th Aug 2011, 19:28
  #2754 (permalink)  
 
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I ask myself

Over and over again I ask: did these 2 FOs do any better than an average, armchair, MS Flt Sim "pilot"?

We'll never know, but they were paid big bucks to do better.
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Old 8th Aug 2011, 19:38
  #2755 (permalink)  
 
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Originally Posted by dlcmdrx View Post
It is actually really sad to see so much ab apologists. Ab philosophy is clearly that of reducing costs, pilots costs included, and if that has so much flaws seems it doesnt matter, there are still a lot of short sighted people believing everything the bea says and shouting pilot error anytime they can
That's a pretty serious accusation - where's your evidence?
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Old 8th Aug 2011, 20:00
  #2756 (permalink)  
 
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Here, the poster has said, "We the computer have some ill readings, so you pilot must fly, out." But the computer stays close, and interferes....

For Gretchenfrage then a new word, '.Paradoxicon..' A smiley airbus?
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Old 8th Aug 2011, 20:04
  #2757 (permalink)  
 
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Concerning statistics, lots of contributors just love those, I am still missing a serious one about automation induced pilot errors. This would give a clearer picture than the one containing just plain pilot error
Spot on Gretchenfrage.

About one week ago I opened a thread about this subject at this very place.
It was deleted within minutes for whatever reason.....

AF447, TAM 3054, XL 888T, etc. etc.
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Old 8th Aug 2011, 20:24
  #2758 (permalink)  
 
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KWATEOW
and for three hundred grand plus one would have expected the captain to be on the flight deck during THE critical part of the enroute phase!
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Old 8th Aug 2011, 20:25
  #2759 (permalink)  
 
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somebody asked about statistics. well no accidents involving european airlines during 2010. safety levels the best they have ever been.

its time to look forward. automation has improved safety but isn't quite perfect yet.
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Old 8th Aug 2011, 21:38
  #2760 (permalink)  
 
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@JCJEANT : Right Seat vs Left Seat ; how do you manage ?

I apologize if my last post appeared to point out a pilot error again. It is not my point.

My point is that you have two co-pilots with equal rights giving dual inputs.

If the two pilots have to hand-flight because of a mechanical problem, then:

- Can the plane detect and decide who's of the pilot it has to obey yet it has problems and gave the control to the pilots ?
- Can the designers predict in which seat will be the good pilot vs the bad and therefore, allow this seat to take control of the plane and withdrow this possibility to the other seat ?

In AF447, if the PNF or the Captain had not a mean to prevent the PF from giving inputs, since this PF didn't obey his Captain, what should have they do?

Knock Down the PF ?

OK : but what if it has been the PF that was right ?

This has nothing to do with the stall warning or the SS, since the PF'brain was stuck at nosing up whatever would be the stall warning !.

IMO, in the actual state of the art, only a human action could have stop the PF, not the plane.

In particular, it is wrong to say that the Capt and the PNF didn't recognized a stall. Not only they did but they gave the good advices to the PF, only 21s after the PF took control !

And they keep on asking the PF to go down for minutes.

But when the PNF took control, the PF re-took it, several times and again in the last seconds.

Without a knock down he would'have stoped.nosing up.

Should the Capt. have had a billy ?
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