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AF447 wreckage found

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Old 30th May 2011, 04:42
  #961 (permalink)  
 
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Early Airbus controversies recalled

When the Airbus A-320 was still in planning stages, I remember a presentation in a conference on aviation psychology relating all the combinations of circumstances software code writers had to consider, such as what warnings to inhibit on takeoff when they could be a nuisance, etc., which presentations were appropriate and when, and which might not be.

The speaker said there were many combinations of events the software could not anticipate, that it would be impossible to write software for unforeseen events, and that doubtless the software itself would probably cause some problems.

Add to that the reticence of some pilot unions (was one Air France's?) about the "fly by wire" concept at the outset, with no mechanical controls whatsoever,and it seems this recent nightmare situation is an example of expressed fears of just such unknowns.

All this speculation is premature. As many have said, it seems really more a matter of "there but for the grace..." etc.

It all makes the QANTAS A-380's crew's performance, augmented by the extra pilots who were all busy, just that much more remarkable.
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Old 30th May 2011, 06:33
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If there is one piece of unambiguous information this crew could have used to save their lives it is a display of AOA.


It is nothing short of negligent that this information is easily read on the flight recorder after the crash but was not accessible to the crew.


AOA information is available on every jet transport, it should be displayed constantly, at least on each EADI and additionally on a dedicated, independently powered standby instrument.
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Old 30th May 2011, 06:36
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I whose screwed up mind can a life be worth more or less depending on how long the descent was and when in that process they all died?
The legal community, who make the awards, see

64 New York University Law Review 1989 Final Moments: Damages for Pain and Suffering Prior to Death

You will see in the reference that the extra damages are intended to have a deterrent effect.

I'm not a lawyer, so please don't shoot the messenger.
 
Old 30th May 2011, 06:42
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@Greybeard
What is max displayed on AI EFIS?
We didn't have ISIS on the A332 but on the A333 and the A343. I don't know if AF had the same ISIS, but ours only displayed the following datas:

The ISIS system displays the following information:
- Attitude
- Airspeed and mach
- Altitude
- Barometric pressure
- LS function
- Bugs
(OM B A343 - Vol 1 / OM B A333 - Vol 1)

Therefore no VS indication on the ISIS.
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Old 30th May 2011, 06:54
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It is nothing short of negligent that this information is easily read on the flight recorder after the crash but was not accessible to the crew.
That's what I said earlier. I read somewhere that AoA display is/was an option on certain Boeing products, not sure about Airbus. It would be sickening to know that, in those dire moments, the single most important parameter, while present and available to the system, wasn't displayed because the customer had't ordered the software feature to do so.
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Old 30th May 2011, 07:20
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It would be sickening to know that, in those dire moments, the single most important parameter, while present and available to the system, wasn't displayed because the customer had't ordered the software feature to do so.
IMHO, one of the outcomes/goals of the investigation, and a focus of this thread should be to make it mandatory for the AoA to be on all commercial aircraft...no exceptions.
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Old 30th May 2011, 07:23
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They didn't need an AOA display on their PFD to fly the Aircraft.

I'm getting sick of repeating myself but here goes again.

This is not a new event

Let me say it again

This is not a new event

It's happened before and ALL OPERATORS HAVE PUBLISHED PROCEDURES FROM AIRBUS TO COPE WITH THE PROBLEM OF UNRELIABLE AIRSPEED.
These procedures detail what you can expect to hear and see during the event. They detail explicitly what to do.

Most competent Airline Pilots would have read about this problem, been shown the problem in the Simulator and hopefully bothered to have a think about what they would do if faced by the same event. I know I've put a lot of thought into it and so should have the AF crew.



Ok, so now we are clear.
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Old 30th May 2011, 07:35
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Originally Posted by Me Myself
The Air Caraïbe incident wasn't exactly a walk in the park, nor the Northwest one.
I doubt AF will ever bother to find this crew and ask them how they did it.
I had no problem finding out something about this, including a memo by the flight safety officer.

Air Caraibes Atlantique memo details pitot icing incidents

An Air France air safety message to its pilots last November talks of six related incidents on A330/A340s resulting in incorrect airspeed indications, numerous warning messages, and sometimes configuration alerts.

It urges pilots to be vigilant at high altitude when icing and turbulence are encountered, and to fly the aircraft gently if they take manual control.
And the Air Caribes memo itself, which is in French:
Air Caraibes Airbus A330 memo
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Old 30th May 2011, 07:36
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Ok, so now we are clear.
oh, it's been clear before, no problem with that!

however, every indicator other than the AoA gives you secondary information with respect to a stall condition. In a dire situation like this with a tsunami of information, warning, system errors, failing systems, unreliable systems etc rolling over your head, it can be very hard to correctly interpret secondary information. Having the root cause shown to you would shortcut through the cognitive dissonance and help gain correct situational awareness.
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Old 30th May 2011, 07:44
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An experienced crew would know for their a/c:--

1/ what pitch attitude they must fly AND WHAT IS NOT NORMAL
2/ what thrust setting they must fly AND WHAT IS NOT NORMAL
3/ What noise levels constitute "normal" for their cruise speed
4/ That it is simply not possible to climb 3,000 feet at heavy weights at high altitude quickly ( 7000 fpm apparently ) without Stalling the damn plane
5/ That if they entered the area at a normal speed and power settings then all they had to do was keep the pitch attitude somewhere around 2 deg nose up ( lower wouldn't matter too much, but higher does ) and the thrust around 78 to 80% N1 and they would be ok.

6/ keep the wings level and BE SMOOTH ON THE SIDESTICK.
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Old 30th May 2011, 07:46
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1. A/c enters cloud with high concentration of super-cooled droplets.
2. Faulty pitot ices over on PF side "freezing" dynamic pressure sent to ADC.
3. Sudden convective event induces a climb reducing static pressure to ADC.
4. PF responds to perceived Mmo excedence with stick back.
5. Static pressure reduces causing airspeed increase.
6. Auto-trim blindly complies with pilot input increasing nose up towards maximum.
7. Repeat steps 4 to 6 until stall....
8. Stall warning stops but comes back on if PF does the right thing.
9. Software has turned off auto trim with stab trim stuck 13 deg up.
10. Software has turned off the bird, just when it would has improved S.A.
11. Checkmate to the software....

In all error chains there's always a bit of man + a bit of machine. But once this kicked off, the man didn't really stand a chance, now did he?

Last edited by Pininstauld; 30th May 2011 at 08:02.
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Old 30th May 2011, 07:47
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Cool

Hi,

They didn't need an AOA display on their PFD to fly the Aircraft.
I disagree ...
You can't be so affirmative.
Methink the AF447 case is enough to understand that some pilots or aircraft under certain condition need a AOA display.
So ... the solution is to go to the most safe side and have a AOA display
And also needed a stall alarm who sound with no interrupt when aircraft is in stall condition
Save lifes first .. with experienced or inexperienced pilot is a noble task
Foolproof .. as always.

Was in 2006
By Joelle Barthe
Flight Operations Engineer

Quote:
6 Conclusion
An unreliable speed situatio may be difficult to identify, due to the multiple scenarios that can lead to it. Therefore, training is a key element: indeed the flight crew's ability to rapid detected the abnormal situation, and to correctely handle it, is cricial.
In case of any doubt, the pilot should apply the pitch/thrust memory items, and then refer to the QRH to safely fly the aircraft, and to positively determine the faulty source(s) before eliminating it (them).
In addition, to further assit the pilot in detecting the failure and safely fly the aircraft, Airbus has developed the BUSS, which provides a safe flying range indication.
Finaly, to reduze the probally of experiencing unreliable speed situations, on-ground actions, such as comprehensive maintenance and through pre-flight exterior inspection, should be stressed.
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Old 30th May 2011, 07:50
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well I think it reasonable to expect that this crew might have ignored that piece of information ( AOA display ) just like they ignored 3 fully serviceable BIG ATTITUDE INDICATORS right in front of their noses.
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Old 30th May 2011, 07:53
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AOA

There is no AOA display in the A330.
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Old 30th May 2011, 07:56
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Yes we know that thanks.

Actually if you have time ( they didn't ) you can call up AOA in the CMC maintenance pages.
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Old 30th May 2011, 07:56
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@ Pininstauld: This scenario doesn't work in alternate law...
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Old 30th May 2011, 07:57
  #977 (permalink)  
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Absolutely with nitpcker. Until the BEA tell us WHY the aircraft was climbed so rapidly we are all 'groping in the dark'
Originally Posted by aston
This scenario doesn't work in alternate law
- which bit and why please?
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Old 30th May 2011, 07:57
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Mainstream media coverage

TO ME IT IS WAY TOO EARLY TO SPECULATE ON A PROBABLE CAUSE BECAUSE ALL OF THESE DISCUSSIONS ARE BASED ON DATA THAT IS SELECTIVELY RELEASED. TOO MANY ISSUES ARE YET TO BE RESOLVED.

Pilot control versus Computer control. Flight into hazardous conditions. Simulator training. Pilot qualifications.

Too many questions. No conclusions.

Way too early for the public to be involved in hip-shot resolutions.
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Old 30th May 2011, 07:58
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@nitpicker That would be the same as driving on the highway while looking down while shifting gear.
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Old 30th May 2011, 08:01
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A side comment about AOA indication, valuable info for such operation:
a. It can be measured directly with a vane, but is subject to icing.
b. It can be calculated from INS measurements, generally it is the difference between flight path angle and fuselege pitch attitude.

Its absence was not a factor. A pilot can see the altitude dropping rapidly and the nose pointing up, which is sufficient information to deduct a very high AOA. A push of the sidestick forward would have been enough.

What to me is unacceptable, is an aircraft changing its response to my flight control inputs, due to some laws switching to and fro. In an ideal world it could be regarded advanced, but in the given circumstances it makes the pilot a deputy assistant to the autoflight system, as opposed to the pilot in command.
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