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AF 447 Thread No. 5

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AF 447 Thread No. 5

Old 29th Jul 2011, 13:28
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AF statement:

At this stage, there is no reason to question the crew’s technical skills
From the BBC:

A statement from Air France rejected the BEA's findings, saying that "nothing at this stage can allow the crew's technical competence to be blamed" for the crash.
Personally I find it hard to agree with either statement.

The BEA recommendations don't seem to support these statements either....

- GY
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Old 29th Jul 2011, 13:36
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Cool

Hi,

From the flight recorder data, it has been established that the combination of multiple improbable factors led to the disaster in less than four minutes: the icing of the Pitot probes
Are they serious ?
Improbable factors ?
The icing of pitot tubes is not a improbable factor
This icing was well know .. cause many anterior accidends before the AF447 event
Anyways I hope a more complete interim report will be posted on BEA site.
Weird behaviour that posting the synthesis before the 3 interim report if it's any one ........
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Old 29th Jul 2011, 13:38
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- regarding AF statement

Originally Posted by FE Hoppy
Could not be? Wasn't would be more accurate wouldn't it?
I would agree - bear in mind it's probably gone through translation though.

The statement (at least in english) then goes on to contradict itself by saying that the stop-start stall alarm contributed to failure to analyse situation. Why would that have any relevance if the situation "could not be" recovered !?

It also states that pitot icing "led to" the roll excursions - new one on me, how

Personally I think AF are grasping at straws, particularly given the comments on training. Also, AF blames the pitots, but they were advised (in plenty of time to prevent this) to change them by AB, and they delayed/refused. I think AF are in trouble on this one.
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Old 29th Jul 2011, 13:52
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Cool

Hi,
Warning: crude statement
So with this synthesis report .. we know the technical event starting the tragedy
The icing of the pitots tubes
And we know the human factor
Incompetent pilots in the situation cause lack of training (not training at all !!)
Methink AF is in BIG trouble cause this report.
And me think the BEA and DGAC are also in BIG trouble for the reasons above !
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Old 29th Jul 2011, 14:08
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Disappointing report!

Is it just me, or is this report really useless? I would have expected plots of the DFDR data and a CVR transcript! Bloody hell, there's nothing new of relevance in there!

Very disappointing. BEA should just dish out the facts!
 
Old 29th Jul 2011, 14:14
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Hello HarryMann

There is at least one instance that shows that a member of the A300 family has been recovered from a stall, from a lot lower altitude, 4100ft.

A A310, Tarom, approaching Orly, France, 1994 has been recovered at 800 ft, and landed safely, with no injuries or damage, from an uncontrolled climb and stall at 4100ft, pitch of 60 degrees, and airspeed of 30knots.
But it was a very well understood stall situation though, with very quick, proper ND, and roll, aggressive reactions from the pilots.

So, based on that one could even say that at 10000ft there was hope.

Originally Posted by HarryMann

...I find it quite incredible that so many are suggesting (albeit frequently doing it between the lines), that the aircraft may have been irrecoverable once fully stalled soon after reaching the apogee.

It's a fairly conventional aerod. design, and I see no reason we should start comparing it to a 'T' tailed a/c operating with an aft c.g.

The fact it stayed at a stable AoA (probably determined by the THS setting) and just rocked its wings (+/- 20° max), maintained a reasonable airflow and forward speed component, make me think all was definitely not lost until say, at a guess, 25 > 20,000 ft.
One element I don't have an answer yet about the Stick, is what is the effect of "duration" in a certain position of the stick.

a. Is the actuating of a control surface proportional with the duration of the stick in a certain position?

or,

b. Is the actuating of a control surface, proportional only with the position of the stick, regardless of its duration?

One other thing, and I know this will not be accepted immediately by all Airbus cockpit crew .. I am not convinced that the airbus sidestick design is optimum for all situations (I'll leave it at that for now!).

Last edited by airtren; 29th Jul 2011 at 14:30.
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Old 29th Jul 2011, 14:20
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Originally Posted by FE Hoppy
Could not be? Wasn't would be more accurate wouldn't it?
No.
Based on the pilots actions, it was not possible to recover the plane.
The verb and sentence conveys what it is meant: airplane COULD not be recovered.
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Old 29th Jul 2011, 14:30
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Airtren,

I agree with your semantics but I think that Af are obfuscating. A clearer statement would be "the pilots were unable to recover from the stall" for whatever reason whether it be lack of training, not realisung they were fully stalled, simple panic or a combination of these and other factors.

"Could not" might imply what I wrote or that given the situation nobody could recover the plane, something that has not even been suggested yet.
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Old 29th Jul 2011, 14:38
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I am tempted to say the report contains a lot more valuable information than the AF statement does.

What a shame AF is only thinking of keeping her slate clean rather than to enhance flight safety.

I find AF's comments shameful.
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Old 29th Jul 2011, 14:53
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Air France défend ses pilotes (from Le Nouvel Observateur)
Air France, a répondu à ces résultats dans un communiqué en défendant le "professionnalisme" des pilotes, mettant en cause de leur côté la fiabilité de l'alarme de décrochage de l'avion, dont "les multiples activations et arrêts" ont "fortement contribué à la difficulté pour l'équipage d'analyser la situation".
Air France responded to these results in a press release defending the "professionalism" of the pilots,for its part blaming the reliability of the stall warning with "multiple stops and starts" which strongly contributed to the difficulties the flight team had in analysing the situation.

Personally, although AF is not impartial I think this point is very important. I think the pilots disbelieved the stall warning from the start. In fact I think the very first stall warning, which came only a few seconds after AP disconnect, was a bogus warning caused by UAS.
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Old 29th Jul 2011, 14:54
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Originally Posted by badgerh
Airtren,

I agree with your semantics but I think that Af are obfuscating. A clearer statement would be "the pilots were unable to recover from the stall" for whatever reason whether it be lack of training, not realisung they were fully stalled, simple panic or a combination of these and other factors.

"Could not" might imply what I wrote or that given the situation nobody could recover the plane, something that has not even been suggested yet.

Andrew from Addis
It's a "press release", and the number of words used is an important consideration. Sentences are crafted, so that they're short, while they convey the information, which you've noted. Excluding misinterpretations is a lesser consideration, and it is left to the reader.
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Old 29th Jul 2011, 14:57
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What about this document?

http://www.bea.aero/docspa/2009/f-cp...cp090601e3.pdf
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Old 29th Jul 2011, 15:01
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Interim Report #3, 117 pages (French) , mirror site link:
http://media.webcastor.fr/web/bea/f-cp090601e3.pdf
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Old 29th Jul 2011, 15:03
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Cool

Hi,

Thank you ... downloading as I write ...
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Old 29th Jul 2011, 15:06
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Thanks, assume it will also be in English. Hopefully it appears that this report will be more telling.
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Old 29th Jul 2011, 15:15
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Originally Posted by glenbrook
In fact I think the very first stall warning, which came only a few seconds after AP disconnect, was a bogus warning caused by UAS.
From the BEA press release:
Each time the stall w arning was triggered, the angle of attack exceeded its theoretical trigger value
To achieve a rate of climb of 7000 ft/min, then reduce it to 700 ft/min in the time allocated in BEA's note, requires a level of "gee" that brought the AoA very close to the "theoretical trigger value". A little bit of turbulence could have done the rest, which explains the intermittent nature of the first two s/w occurrences. Nothing 'bogus' about that.
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Old 29th Jul 2011, 15:16
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Hello PJ2,

I am sorry if there is any perception in a negative sense. I am not the good writer that you are.

Nevertheless, please take my post, as a long thought out positive feedback, and an additional clarification to the ones you've already posted recently in your replies. As I've noticed the possible misinterpretation along time ago, in the repeated instances of that text, I think such clarifications were long due. I hope will help for future posts.

The Forum, and these threads are a learning and information source for many. The audience is a lot wider than just airmen.


Originally Posted by PJ2
airtren;

If I may, I've clarified the meaning of "do nothing" and I think you're turning it into something I never meant and that no airman would mis-interpret.

I would have thought that all pilots who fly transports would have understood what I meant and wouldn't think of it as "advice", or take it literally - no pilot would actually "do nothing" and just sit there waiting for the automatics.
As I posted earlier, I've expected the BEA recommendations to target both manufacturers and operators. They are in the right direction. What we see is just a summary.

I am looking forward though to the transcript of the CVR, and an accurate/precise time line of A/C states, and state changes, and pilot actions.

Edit: >>> Finally, got the report...... Yes, the transcript of the CVR speaks: the PNF calls the attention of the PF several times to do a ND, during the ascent. Furthermore, it calls the attention of the PF to use very fine stick controls. That's what you've recommended, isn't it?

Finally the CVR shows that Captain does not make too much of a difference.....

The problem with the Stall Warning is brought forward strongly, which was one of my major issues with the A/C.

The graph of the PF stick almost shows that the PF kept the stick in NU, instead of Neutral.

Training, training, training is an issue.

The PF had a "Glider Pilot License" from 2001, and the AF330 license from December 2008....
>>>>
End Edit

Originally Posted by PJ2
As for the BEA effort, it's disappointing, but there it is. Some interesting points regarding SOPs and some obvious safety recommendations. I guess we'll have to wait til October.

Last edited by airtren; 29th Jul 2011 at 18:02.
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Old 29th Jul 2011, 15:17
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and there is a recommendation for an AoA display, which will be down to Airbus and Boeing to implement
IIRC from our discussions a few threads ago, AoA can be called up already on one of the pages (maintenance?). Perhaps a short term fix is to use the software to add AoA to the opening of the F/CTL page which shows position of the THS and Rudder, etc. Granted, that puts the PNF in the role of advising PF of AoA, rather than putting it into scan. While that's not how I would do it, might be a decent short term fix. (Opinions?)

Second: where on the vertical display real estate is a good place for an AoA gauge? Opinions will differ.

Gratifying to see the BEA seems to agree with something that had me scratching my head.

Note: the training issue leaps to the fore.

PostScipt:
Seeing as captain off duty happens rather frequently on long haul, it's slightly suprising (well, to me...) that there is no CRM training for the rest of the crew in that situation. Poor CRM is then unsuprising.
CRM shortfall in terms of "Captain's at rest, how do we coordinate our efforts when we need him" an interesting point I had not thought about. I would have assumed that AF has a drill for that case. Good for the analysis effort to consider that area.
It should be noted that the misleading stopping and starting of the stall warning alarm, contradicting the actual state of the aircraft, greatly contributed to the crew’s difficulty in analyzing the situation.
Begins to look like the compound emergency/malfunction scenario, perhaps, in the eye of the crew.
"Crap, the AS is going squirrely, look, SW is sounding, must be from bad AS, look, x is wrong ... "
A A310, Tarom, ... recovered at 800 ft, ... from an uncontrolled climb and stall at 4100ft, pitch of 60 degrees, and airspeed of 30knots ... very quick, proper ND, and roll, aggressive reactions from the pilots ... one could even say that at 10000ft there was hope.
I doubt that aircraft developed a 10,000 fpm rate of descent. (And good thing, the pilots reacted promptly! Overcoming that 10,000 fpm from first unstalling, then getting knots on, then recovering with a nice firm pull without heading toward accelerated stall, since you are not in Normal Law ... how much altitude that takes is a question worth thinking through.
A clearer statement would be "the pilots were unable to recover from the stall" for whatever reason whether it be lack of training, not realisung they were fully stalled, simple panic or a combination of these and other factors.
That's a clue to what the crew were seeing and understanding from what they saw. (Was PNF head down in ECAMS pages or was his scan on flight instruments? We will probably never know. Is that how PNF's roles are trained? )
Personally, although AF is not impartial I think this point is very important. I think the pilots disbelieved the stall warning from the start. In fact I think the very first stall warning, which came only a few seconds after AP disconnect, was a bogus warning caused by UAS.
How well does this sort of malfunction get covered in the sim training?

When interrelated elements of a system both go bad, what logic tree or symptom troubleshooting is taught?

Last edited by Lonewolf_50; 29th Jul 2011 at 17:22.
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Old 29th Jul 2011, 15:34
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OK, this is the real report. It is very clear that PF was confused from the start and disbelieved airspeed. PNF kept telling him to descend, at one point saying "all three say you are climbing so descend";.
At one point PNF says ";we still have engines so whats happening"; presumably referring to the low airspeed.
2:12:27 PNF You're climbing (Stall warning), Descend descend descend descend
PF I was descending then?
PNF, Descend
Captain: No, you're climbing
PF: There I am climbing, ok now descend

The focus herein should be why the PF & PNF got so confused, although I am wondering how the PNF and Captain could not notice the PF's input. They realised they were climbing and knew they shouldn't be.
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