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AF447 wreckage found

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AF447 wreckage found

Old 9th Jun 2011, 05:31
  #1521 (permalink)  
 
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Old Airplane with Control Problem

About ten years ago, the Roll Channel went to sleep on an Evergreen 747-1 cargo plane one night over Canada enroute KJFK-KANC. It was well beyond 30 degrees roll when the pilot caught it. They went something like 1.06 M in the recovery.

SperryWell could find nothing wrong with the roll channel, so it became a boat anchor. EV installed 30 degree bank limit alarms in the fleet after that.
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Old 9th Jun 2011, 05:54
  #1522 (permalink)  
RWA
 
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Iceman 50

Altitude is the least of your concerns at that point in time, ATTITUDE and POWER are the life savers. If you have stalled, you MUST unstall the wing and add power progressively to be able to counteract any pitch up due to the low slung engines.
Agree, Iceman50. I wonder, though, whether that procedure (attitude first, then power) was 'in force' at the time of AF447? I ask because I recall reading this a while back - a 'new' approach (well, actually, the 'old' one) published by Airbus in 2010, long after the AF447 accident? According to the poster, and many of those who replied to him, previous advice was along the lines of 'full power and seek to maintain assigned altitude'?

http://www.pprune.org/tech-log/41537...procedure.html


As for never being trained in stalling, you never train to stall in the simulator, but most regulators require approach to the stall recovery training as part of the Type rating requirements.
Thanks for that information. Obviously you couldn't have pilots in training practise actual stalls in a real transport category aircraft, but up to now I'd been assuming that some sort of 'simulated stall' could be practised in the simulator.

So, on the face of it, pilots can only be taught 'stall avoidance,' and there's no way to train them in actual 'stall recovery' - except, of course, that they'll have practised it in light aircraft in their early flying lessons?
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Old 9th Jun 2011, 06:41
  #1523 (permalink)  
 
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Stall recovery procedure

Shouldn't it include checking you aren't trimmed fully nose up?
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Old 9th Jun 2011, 07:48
  #1524 (permalink)  
 
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studi,

With respect, read the report.

The protections were not available because the aeroplane had reverted to Alternate Law 2. That means that the pilot is fully responsible for the aeroplane's course except load factor limitations which are still applied.

The A/P and A/TH failed at the moment that the probes froze over and the airspeed readings became unreliable.

The F/O took control.

The F/O made persistent nose-up inputs - not the autopilot.

I reiterate that now the mystery is why he made those inputs.

Any alternative discussion on this thread or any other is quite frankly, irrelevant.
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Old 9th Jun 2011, 07:55
  #1525 (permalink)  
 
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For all you current Air Bus pilots. Is this guy telling it correctly?

AVmail: June 6, 2011
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Old 9th Jun 2011, 08:06
  #1526 (permalink)  
 
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Not according Iceman50. But like you Aterpster, I am very interested in the opinion of experienced and objective Airbus pilots.
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Old 9th Jun 2011, 08:24
  #1527 (permalink)  
 
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Poit

I have my own theory but it will stay that until the report is out, no point in posting it here as it would be speculation.

There are differences between Boeing and Airbus philosophy and on both there are some good things and some not so good things. The whole point is you have to "learn" the aircraft you are flying and not continually think back to previous types, didn't do that on a ......... (insert A/C type here). That's what we as "pilots" are supposed to do. Any A/C with the AP / A/THR (Autothrottle) off are still aircraft and subject to the same rules of flight as your small cessna or chipmunk.

RWA

It was not just Airbus that re-stated the "new / old" stall procedure, Boeing did as well. I believe that Boeing, Airbus, other manufacturers and the regulators got together and the "new/old" procedures were emphasised. This was after events like Turkish in AMS (with moving throttles) and Colgan at Buffalo. The same thing happened when the revised procedures for Smoke and Fumes were changed a couple years ago. Manufactures and regulators assessing the most likely causes of Smoke and Fumes and devising a checklist priority, with reminders that an off field landing may be required should the fire escalate.

aterpster

Good memories beat me to it!
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Old 9th Jun 2011, 09:09
  #1528 (permalink)  
 
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Cool

Hi,

I have my own theory but it will stay that until the report is out, no point in posting it here as it would be speculation.
"Sarcastic mode open"
What a great contribution from a A330/A340 expert
"Sarcastic mode closed"
But of course it's your right to have an opinion and not post it !
I wonder why you post here in the first place ? (Rumours and news)
BTW Bubbers44 have also the right to have an opinion (despise Airbus) .. and he post it.
Why fallen in love with a girl you don't like ?
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Old 9th Jun 2011, 10:20
  #1529 (permalink)  
 
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jcjeant

I have not posted my opinion as I / we do not have all the facts.

I posted as I am fed up with the total nonsense that is sometimes spouted and do not want to add to the "speculation / Airbus bashing frenzy".

Just in case you are still unsure, I get great pleasure flying the A330 / A340 and do not wish to return to Mr Boeing. A blue cockpit is so much nicer than brown!

Yes, Bubbers has a right to an opinion but the endless Airbus sniping is boring and does not bring anything to the debate.
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Old 9th Jun 2011, 11:34
  #1530 (permalink)  
 
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Just in case you are still unsure, I get great pleasure flying the A330 / A340 and do not wish to return to Mr Boeing
I would never have guessed that judging by your previous post.

There are some very open-minded Airbus pilots on this thread who accept and acknowledge the best and the worst of the aircraft they fly.Post 1491 confirms what I have always believed about this aircraft.I say "believed" because having never flown it(and never will) I must step carefully having been burned on a previous thread.
NOD's reference to Air China upset(and others) is not so open-minded and unbiased if hes attempting to use it to compare the two designs.The Air China upset was a clear case of pilot error.The culprit was the pilot.We dont know yet to what extent(if any) system design played a part in 447.The jury is out.The BEA is that jury and it will be interesting to see if they can remain totally impartial and unbiased.I doubt it but lets wait and see.
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Old 9th Jun 2011, 12:41
  #1531 (permalink)  
 
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PPRuNe should really be renamed "Arm Chair and Flight SIM Wanna Be Airline Pilots" because the vast majority of the so called "experts" on these forums are exactly that and not current professional airline pilots.

Studi,

The aeroplane reverts to Alternate Law whenever a "dual" failure is detected. The failure of the A/P, A/THR and reversion to Alternate 2 Law all occurred simultaneously.

Ironically perhaps but the aeroplane reverts back to being a Cessna 150 whenever the failures are such that the automation feels that it can no longer cope. I say Ironically because it is on these rare occassions when the protections are probably most needed.

In this case the autopilot had at least two or more unreliable airspeed indications and it would be unsafe for the autopilot to continue to fly the aeroplane when it is being fed unreliable information. The protections are also abandoned because they too rely on this information. What's the difference then between the autopilot flying and the pilot flying when both will receive the same limited, reduced and unreliable information? Because the pilot is human and hopefully has the ability to recognise and reason out the solution based on the evidence available. First and foremost he must take control and fly the aeroplane.

If you bother to read the other interim reports produced by the BEA then you will know that the very many previous occurrences of this issue have resulted in the same symptoms and an almost immediate stall warning occurring. Partly due to the abrupt change in measurements (pressure) and also due to the turbulence that was encountered.

The margins that an airliner flies within at 35000' are pretty small and a pitch attitude of 10 degrees nose up would never be seen in normal everyday operations at this altitude.
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Old 9th Jun 2011, 13:18
  #1532 (permalink)  
 
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"NOD's reference to Air China upset(and others) is not so open-minded and unbiased if hes attempting to use it to compare the two designs.The Air China upset was a clear case of pilot error.The culprit was the pilot.We dont know yet to what extent(if any) system design played a part in 447.The jury is out.The BEA is that jury and it will be interesting to see if they can remain totally impartial and unbiased.I doubt it but lets wait and see. "

So, let me guess. If the BEA faults the plane, you will judge that it remained impartial. But if it faults the pilot, it is clearly because it is biaised.

I mean it is so transparent from your posts that you are the biaised party that is starting from a preconceived position. In other words, if Boeing crash, always a pilot error. If airbus, the suggestion of pilot error should be discounted. If BEA goes into another direction it is because it is biaised to protect French interests. For its part, US authorities are always totally unbiaised and never whithewash Boeing (here, allow to laugh for a good five minutes.).
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Old 9th Jun 2011, 13:37
  #1533 (permalink)  
 
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Exclamation Quit the Airbus bashing, puhlease.

OK. So this thread again degenerates into Airbus bashing. No surprise there then.

Let's just step back a minute and consider the frequent calls to ditch all that fancy automation and put full authority back into the hands of a human pilot.

Consider what the objective of the Airbus laws are - from first principals.

They allow a pilot to control the aircraft with maximum performance when the muck hits the fan. Prevent a stall, keep the aircraft flying, even on the brink of maximum AoA. Prevent overloading the airframe. Prevent overspeed. If you are faced with looming CFIT, pull back, all the way, and the Airbus will deliver maximum performance to avoid it.

Case in point: The Hudson river incident. The media loves a hero pilot, but by rights they should have been equally applauding a bunch of anonymous engineers in France. Because they are just as responsible for delivering a 100% survivable ditching as the men in the cockpit. The reason everyone walked (floated?) away from that incident was because of excellent CRM, a very good call by Sully (He activated the APU which kept the aircraft in Normal Law) and Airbus' Alpha protections.

So what's the downside? We'll I'm not a pilot - I'm an experienced Control Engineer - servo systems, process control, you name it - the kind of safety critical systems you find in an Airbus are found everywhere from a Nuclear power station to your Toyota Prius. If you ever crash you car into a power pole and bring down the high voltage lines, there's a good chance that my own software kept you from being fried. Even electric wheelchairs can kill you - should one suddenly propel you off the curb and into traffic. For fun I work out Laplace Transforms.

The problem with all safety critical systems is that you want them to fail-safe. And, when you consider protections and they priorities, you need to start off with a bit of FMECA analysis. The trouble is that some systems cannot fail-safe - you have to compromise by "failing-as-safe-as-you-can"

Another case in point, related to a relatively simple system I developed: You're a skydiver. Your reserve canopy has a microcontroller AAD (Automatic Activation Device). It has one simple objective. If you are going to hit the ground, and haven't deployed your main canopy, or for some other reason, it has not deployed correctly - the AAD will deploy the reserve canopy for you. But while you're freefalling, the AAD self-tests and detects a fault. So what should it do while you fall at 120mph directly toward the ground? What's the *safest* thing for it to do? I'll leave it open for you. But it's not as simple as you think.

Back to Airbus. The downside of an automatic protection system is that it adds a layer of complexity to debug if it fails. Though Airbus' fallbacks are well designed - this is going to mean you have a tougher task to manage when there is a fault. This means Airbus Pilots have to be smart.

But given the huge safety benefits of their automated protections, the answer is not to remove them - the answer is to improve their robustness, refine their fallback modes and ensure that failure conditions are adequately trained and simulated.

To round off in line with my argument about protections and in a roundabout way come back on topic: I don't understand why Air France didn't purchase BUSS (Back Up Speed Scale) - designed specifically for loss of speed data incidents.
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Old 9th Jun 2011, 13:48
  #1534 (permalink)  
 
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I don't understand why Air France didn't purchase BUSS (Back Up Speed Scale) - designed specifically for loss of speed data incidents.
Because it wasn't developed until after this accident.
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Old 9th Jun 2011, 13:52
  #1535 (permalink)  
 
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Cool

Hi,

Because it wasn't developed until after this accident.
Ohhh .. this is completely wrong statement.
Why do you post such disinformation ? ignorance I hope ....
Was already available during the 90
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Old 9th Jun 2011, 14:05
  #1536 (permalink)  
 
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Was never a mod on the airbus until recently.
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Old 9th Jun 2011, 14:06
  #1537 (permalink)  
bearfoil
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For this aircraft, both BUSS and steam AHI were available. Air France did not select either. This was established in the original thread, as I recall.
 
Old 9th Jun 2011, 14:09
  #1538 (permalink)  
 
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Originally Posted by jcjeant
Why do you post such disinformation ? ignorance I hope ....
You should acquaint yourself with the difference between disinformation and misinformation.

BUSS have certain limitations that makes it questionable whether it adds anything safety wise.
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Old 9th Jun 2011, 14:15
  #1539 (permalink)  
 
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Cool

Hi,

Google Vertaling

This press article from l'Express had not yet triggered any official reactions or any reactions in the other medias.
It is to notice that the author of this article is Christophe Barbier
This journalist is well know journalist and chief editor and he is exposed everydays ...
I would be astonished if what he write is false.
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Old 9th Jun 2011, 15:28
  #1540 (permalink)  
 
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jc, that article doesn't do much to unlock the mystery of why, all it does is report that a finger has been pointed.

Not a very productive link.
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