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AF447 Thread No. 3

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AF447 Thread No. 3

Old 30th May 2011, 18:13
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Conversely rudderrudderrat, might I suggest you find a place in the FCOM reference where it says trim will be shown under any conditions. (Your wording implied you are sure such a statement would not be there because trim is always shown. I've seen no evidence so far that it is ever show.)
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Old 30th May 2011, 18:19
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Can airliners recover from a stall?

Discussion of mixed type, but worth revisiting.

Interesting, particularly post #18 and further pages.

http://www.pprune.org/tech-log/17316...ver-stall.html
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Old 30th May 2011, 18:24
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"Further, and sadly, Airbus has assured us it is almost impossible to "lose control" of that jet. That assertion seems to permeate the crew training and design corrective actions by Airbus following certain incidents.

I'll let that aspect of my observations recede and prolly not raise it again for a long time."

Allow me. A casual view of the history of the Airbus leaves a few undigested morsels. Question the electrics, and the software side gets indignant. Some flyers get indignant that the a/c seems "arrogant" (sic).

An airplane cannot be arrogant, and software cannot be defended when it is garbage.

After all this time, if there is a remotely valid question raised (There are), something is wrong with the approach.

The honeymoon was over long ago, and this airplane has worn long pants for years. To be able to get away with calling it a "work in progress" at this point is beyond absurd.

Training? Confidence? User friendly? Who gives a crap, Fix it.
 
Old 30th May 2011, 18:31
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Post #34 from the link:

Stall recovery does not normally require violent manoeuvres (zero g push / then pulling lots of g). A fully developed stall may require more nose down attitude, but the certification requirements require civil aircraft to have a nose drop at the stall anyway.

Could an a/c be too well behaved in a stall ?. Presumably the =/- 40 degree of roll could have been interpreted as turbulence.

20k feet doesn't seem to go a long way.

Bear: there is no reason to think the software was at fault in this instance is there? Necessarily limited perhaps, but isn't it more to do with the presentation of information which is at issue ?

Last edited by Mr Optimistic; 30th May 2011 at 18:43.
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Old 30th May 2011, 18:52
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Originally Posted by sensor_validation
BEAs statement is a careful selection of established facts which must have been checked out carefully by legal opinion - so I think I think it is worth looking carefully at the words used - albeit in the English translation - does the French read the same? Maybe reading in too much?

the Captain woke the second co-pilot
Suggesting he was asleep, and could have been for a couple of hours - but within 5 minutes he was in front of the controls as PNF.
He was briefing his replacement 10 minutes prior to the PNF trying to call him to the cockpit.
Captain attended the briefing
that was nice...
It was also about 10 minutes prior to the wakeup call. And you quoted it too disproving your first statement.
... - he could have just said bye? OK a lot more would have been said in the 3 minute handover, but who was Responsible, Accountable, or just Consulted/Involved. (yes management consultant speak - RACI analysis).
Whereas I am only a lowly lifeform known as an engineer. What this appears to plainly say is that the Captain followed proper procedure before leaving the cockpit. (Is there a reason you are altering the time line?)

PF said
we cant climb much for the moment because the temperature is falling more slowly than forecast" and that "the logon with Dakar failed"
shows he knows near max alt, and not authorized to climb, and that they all knew that.
More proper procedure.

At 2 h 08 min 07 , the PNF said "you can maybe go a little to the left []".
tentative subservient, he didn't like what he saw ahead.
I am not sure about subservient unless that is something you read from the French. Subservient is not present in the English. He had to suggest as he was not PF. But he was not sniveling about it. He was not sure the radar showed a clear path and could not suggest a better alternative because of too large a deviation or a significant climb.

(I note that this is a place the radio could help - identify flight, location, direction, and planned deviation to all within hearing of the VHF radio. Then do what is really needed. Yeah - me and my radios again.)

From 2 h 10 min 50, the PNF tried several times to call the Captain back.
Repeating a comment in this thread too many pages back. PNF not happy with what PF is doing - but doesn't have authority to question?
Maybe that is YOUR personality, sir. If I were PNF and unhappy I'd bitch and worry about the consequences later. AND I would try to get Captain up front for his good advice. PF is in command. But I reserve the right to bitch and call attention to items that may appear to be forgotten. But then, I am an ugly American.

At around 2 h 11 min 40 , the Captain re-entered the cockpit. The altitude was then about 35,000 ft,
Did they tell the captain that they had been to 38,000 ft and were now on the way down?
Damnifino - that is not in the partial transcript. Could they have recovered if the captain had been instantly right on it? Maybe. That's why I'd voice my concerns over continued climb. I'd be aware. Captain would need a minute or two to come up to speed. (I hope they did not try to swap seats or something like that. I doubt it - PF never handed over to PNF for the captain to swap in safely.

Unless the Captain was really over tired he'd not had time to fall asleep. He probably visited the head and stretched a bit before moving back to his private curtained off area.
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Old 30th May 2011, 18:52
  #746 (permalink)  
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"Bear: there is no reason to think the software was at fault in this instance is there? Necessarily limited perhaps, but isn't it more to do with the presentation of information which is at issue ? "

I think that's covered (displays) in Training, Confidence, and User Friendly??

Yes?
 
Old 30th May 2011, 18:54
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Call Captain X at three a.m. for a sim session, "now". Then throw a few nasties at him.
I think the unions would go berserk.... even if it might produce some "interesting" results.

When I think of what military pilots go through during military campaigns, lack of sleep and all that, I just wonder why commercial pilots are unable to perform their duties without rest periods and having to have a 'wake-up' time before resuming their assigned tasks. Just what do they do when they are off duty? Do they not sleep before going to work? Okay maybe I am ignorant of facts, and will hold my hands up if criticized.
But I just wonder what public opinion would be if a doctor was woken up at three am and told one of his patients was 'crashing'. And he replied that he would have to wake himself up properly before he could give orders, so call back in fifteen minutes or so? Many doctors in ER work 24 hour shifts. But they do not have unions of course.
Sorry but I consider that airline staff have an easy life.

edited for spelling
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Old 30th May 2011, 19:00
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llagonne66, a closer reading reveals that the PF was the right hand seat with the captain being PNF. The captain's replacement sat in the captain's seat as PNF. So there's no good reason for grogginess on the part of the PF. And when the captain was awoken later he'd not really had time to fall asleep unless he should not have been in the plane at all.
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Old 30th May 2011, 19:02
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I'm going to volunteer my 2 centavos to the following question raised by Mr. Optimistic.
there is no reason to think the software was at fault in this instance is there? Necessarily limited perhaps, but isn't it more to do with the presentation of information which is at issue ?
From the events I have seen so far, there is no cause yet to question the performance of the flight control software with relation to it's specification. In other words, it appears to have worked as designed.

One of the problems appears to be that there are a few holes in the design. The concept of "it can't possibly stall" appears to have stopped the specification effort a few clicks short of completion.

The aircraft probably needs a manual lateral trim control switch that is active only in roll direct modes. Lets see what BEA says about that!
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Old 30th May 2011, 19:02
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JD-EE:
Quote:
Originally Posted by sensor_validation
BEAs statement is a careful selection of established facts which must have been checked out carefully by legal opinion - so I think I think it is worth looking carefully at the words used - albeit in the English translation - does the French read the same? Maybe reading in too much?

Quote:
the Captain woke the second co-pilot
Suggesting he was asleep, and could have been for a couple of hours - but within 5 minutes he was in front of the controls as PNF.

He was briefing his replacement 10 minutes prior to the PNF trying to call him to the cockpit.
The relief pilot was asleep for a couple of hours not the PIC. The point being that the relief pilot (PNF)) may have been slow to recognize the stall.

BTW: The relief pilot was denied two critical, valid (most of the time anyway) bits of informatation.

A: The AOA sensor output.

B: The control inputs by the PF

Both of these 'could' probably be displayed given a moderate SW update.
The AOA as a simple # and the control inputs as a vector with length corresponding to deflection.

Last edited by MurphyWasRight; 30th May 2011 at 19:07. Reason: Typos, clarity.
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Old 30th May 2011, 19:05
  #751 (permalink)  
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"Sorry but I consider that airline staff have an easy life."

I'll not argue that, but what is important is that this was a flight of 11? hours? The enemy is not SA, but the ennui that can degrade it. It would take Clarence Darrow to absolve this crew of the last bit of 'nonchalance'. Rest is more than being able to quickly recapture SA. It has to do with the time before and after the flight. There is no black, no white, I think, but shades of grey?

There is a larger topic in this, embracing more than the Airbus, Boeing, Bombardier, or other a/c. Being always ready takes almost as many calories as being in performance?
 
Old 30th May 2011, 19:13
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AoA indicator, as on Boeing would have save them.

Plane knowed it but was censured for pilots.
Investigators talk about it almost every line of report, post mortem.

But it has been censured for pilots. What an irony.
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Old 30th May 2011, 19:21
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Originally Posted by Mr Optimistic
Bear: there is no reason to think the software was at fault in this instance is there? Necessarily limited perhaps, but isn't it more to do with the presentation of information which is at issue ?
Agreed, and I hope I'll be forgiven here for stating things more bluntly.

Originally Posted by bearfoil
Allow me. A casual view of the history of the Airbus leaves a few undigested morsels. Question the electrics, and the software side gets indignant. Some flyers get indignant that the a/c seems "arrogant" (sic).

An airplane cannot be arrogant, and software cannot be defended when it is garbage.

After all this time, if there is a remotely valid question raised (There are), something is wrong with the approach.

The honeymoon was over long ago, and this airplane has worn long pants for years. To be able to get away with calling it a "work in progress" at this point is beyond absurd.

Training? Confidence? User friendly? Who gives a crap, Fix it.
Bear, I deliberately stepped back from this thread when I realised a few days ago that all I was doing by posting was repeating myself - and in doing so getting far more worked up than I should. So unless you have new information may I respectfully request that you consider the same?

Now, if you'll allow me to refer to your points:
  • No-one on the "software side" has become "indignant" in this thread. You have a few skilled electrical engineers (not all of whom are familiar with the system's design) positing theories, but that's about it.
  • Flyers are allowed to think what they like - and they seem to be about fairly divided on their opinions towards automation (though understandably some are a little short on the facts and some are unable/unwilling to understand certain aspects of it).
  • Sometimes they get the presence of automation confused with how some airlines are using that automation - and how it affects their jobs. Again, this is understandable, if sometimes a little frustrating
  • At no point has any piece of evidence been raised that points to a failure in the aircraft systems, over and above the loss of airspeed information. What little we have suggests that it was behaving as designed.

My personal opinion, for what it's worth, is that all this talk of control laws will turn out to be a red herring. What sounds complicated on paper is in fact not all that complicated. With all systems functioning, you are in Normal Law. When certain systems components fail, you are in Alternate Law. If basic flight data becomes unavailable, you are in Alternate Law 2 (which for the sake of argument should be thought of as Alternate Law without protections).

In Alternate Law 2 the pilots have complete control over all aspects of the aircraft, though you're commanding pitch and roll rate unlike in Direct Law which commands deflection. In short - the pilot is in charge and the computers are specifically programmed to do whatever the pilot asks.

Autoflight is already out, so the computers cannot command anything that the pilot is not already commanding. In this law, Autotrim will answer commands from the sidestick, if the sidestick remains deflected past the limit of elevator authority. In this aspect it is not unlike the old DLC system in the TriStar, which linked all flying surfaces to the controls to better stabilise the aircraft. Autotrim can be disabled in this mode simply by grabbing the trim wheel and moving it, just like in any other airliner - if this aspect is not being trained by airlines then it is a *serious* omission.

So - what we have so far is the aircraft's trajectory during the accident sequence, and a set of "point-in-time" status reports of what was going on and being said in the flight deck. Other than that we know *nothing* - even CONF iture is holding back on blaming the aircraft, which is almost unheard of (even if he is making up for that by bashing the BEA)!

Take out all this discussion over laws and automation and what you're left with is a crew over the ocean in the middle of the night (low circadian time and - perhaps even more importantly - no visible horizon or external reference) who suddenly find all airspeed information gone, a plethora of warnings they've got to figure out and a few minutes to make the correct choice. This is not the first time it's happened, and it's not the first time it's killed people.

Right, now back to radio silence on this thread for a bit...

@peplow - The ADI (artificial horizon) would have given them enough attitude information to work with - and even with a working AoA indicator, experienced pilots have failed to heed it in this situation.

Last edited by DozyWannabe; 30th May 2011 at 19:35.
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Old 30th May 2011, 19:25
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Originally Posted by JD-EE
.... (I hope they did not try to swap seats or something like that. I doubt it - PF never handed over to PNF for the captain to swap in safely...
There may be more to come out on this - who took the controls in the last minute? An assumption made elsewhere is that it was the captain, presumably displacing the 2nd co-pilot PNF in the left seat.
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Old 30th May 2011, 19:28
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Originally Posted by promani
bearfoil

"BEA know exactly what happened, and could explain it in layman's terms yesterday."

How right you are. If their reason for only releasing the limited info was to placate the media and stop leaks, I fear that the opposite will happen. I can't imaging Le Figaro et al sitting back and waiting for July.
I can see Euros being waved under the noses of those 'in the know'.
I wonder if mm43 can relocate to France to get some insider info, which he seems to be good at?
I'm not willing to say "BEA know(s) exactly what happened...." They may suspect it. But knowing what happened and why it happened requires careful analysis. What happened does not necessarily tell you why it happened and what corrective action must be taken. They are working with a vastly richer data set than before. But they do not know what the radar screen showed. That's not recorded (quality video uses IMMENSE bandwidths compared to FDR standards.) So there is still guesswork.

I hope they avoid the "quick solution" you and bearfoil seem to be implying we could have and instead drill down to the real factors that contributed to the crash. If fault is needed for some emotional reason get it right.

And be sure to accept that sometimes "stuff" just happens. If I had to apportion blame at this moment that is exactly what I'd blame. A situation that was "rumored" and "suggested by past events" struck this hapless plane with more force than any other plane that may have experienced it. After that crew reactions may have made a bad situation worse. And the cause for that seems to this SLF to be training, inexperience with real control of aircraft at that level, and basic primal human reactions.

What happened apportions blame. Why it happened discovers how it can be prevented, which is infinitely more important. If we never learn why 228 people went to a watery grave for nothing. And THAT would leave me furious - not that I as a person matter that much. The Internet does give some leverage here, though.
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Old 30th May 2011, 19:30
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Call Captain X at three a.m. for a sim session, "now". Then throw a few nasties at him.
I think the unions would go berserk.... even if it might produce some "interesting" results.

When I think of what military pilots go through during military campaigns, lack of sleep and all that, I just wonder why commercial pilots are unable to perform their duties without rest periods and having to have a 'wake-up' time before resuming their assigned tasks. Just what do they do when they are off duty? Do they not sleep before going to work? Okay maybe I am ignorant of facts, and will hold my hands up if critized.
But I just wonder what public opinion would be if a doctor was woken up at three am and told one of his patients was 'crashing'. And he replied that he would have to wake himself up properly before he could give orders, so call back in fifteen minutes or so? Many doctors in ER work 24 hour shifts. But they do not have unions of course.
Sorry but I consider that airline staff have an easy life.
I have no wish to make fun of what airline crews have to do to earn a living. The following is for comparison only.

Short Sea Story.Combat operations.
Fly 2-3 flights per 12 hour Carrier flight cycle. During off cycle, there is a requirement for a 5 minute fighter alert. Each squadron assigns a crew for a 4 hour stint. There you are strapped in, switches set, but power off waiting for the call to launch. The back seater has enough time before he has to function that he can lie down on the wing. Yours truly could only unlock his shoulder harness, take off helmet-put on top of stick, take off kneeboard, put on top of helmet, put head on kneeboard and fall asleep. Meanwhile adjacent E-2 is doing a maintenance turn.
One thing I knew. No matter how clobbered the flight deck looked, they could clear a catapult and launch inside of 5 minutes. Next day, you were on the schedule for 2 more flights. I was very thankful that I wasn't actually called on for a night cat shot on 5 minute notice.
Sea story over.
Back to your regularly scheduled discussion.
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Old 30th May 2011, 19:32
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@Dozy
Take out all this discussion over laws and automation and what you're left with is a crew over the ocean in the middle of the night (low circadian time) who suddenly find all airspeed information gone, a plethora of warnings they've got to figure out and a few minutes to make the correct choice. This is not the first time it's happened, and it's not the first time it's killed people.
I'm not sure how you know that they found all airspeed information gone. There is no indication in the report that the airspeed information was false at any point. Only that for a minute the standby didn't agree with the PFD. I also don't see and indication of a "plethora of warnings".

If you ignore all the previous speculations and just read the new report there isn't much wrong with the jet except an AP-AT disconnect in turbulence.
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Old 30th May 2011, 19:32
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40 AoA, read a such value and i guaranty the guy would have push all his weight on the stick ..
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Old 30th May 2011, 19:33
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I stand by post#1 here, posted nearly two years ago, and would repeat another post somewhere else that an easily accessible big button on this type of system is needed to enable direct control
Why? So they could pitch further nose-up?
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Old 30th May 2011, 19:33
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"...Take out all this discussion over laws and automation and what you're left with is a crew over the ocean in the middle of the night (low circadian time) who suddenly find all airspeed information gone, a plethora of warnings they've got to figure out and a few minutes to make the correct choice. This is not the first time it's happened, and it's not the first time it's killed people..."

From three years ago, I have said pretty much the same thing, and after your last post I admitted to that very thing. The problem aisi, is the interface twixt a/c and PF's caress.
 

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