Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

AF 447 Thread No. 12

Tech Log The very best in practical technical discussion on the web

AF 447 Thread No. 12

Reply

Old 27th May 2014, 00:29
  #41 (permalink)  
Moderator
 
Join Date: Apr 2001
Location: various places .....
Posts: 6,202
80% of pilots will instinctively pull up when sufficiently alarmed

I don't doubt that for a moment.

However, in the absence of anything else going the pilot's way in extremis ... configuration, attitude and thrust is a good place to start when nothing much makes sense - unload the fear and then there is a chance for rational thought to occur. It follows that such data MUST be a memory item .. there is no time to pull out the QRH when the aircraft is at risk of toppling.

In my insular view, training and more training in the basics is the best way to cause a quasi-automatic but reasonable response to fright to occur.

That this may not have happy results in some cases is part of the cost of doing business .. we are concerned with maximising the overall probability of a successful outcome.

Sioux City was an exemplar for how to approach a lost cause, I suggest. A lot of the folks were killed but the miracle that any survived remains ..

Whether the beancounters acknowledge it or not .. when all the aces have disappeared, only the flightcrew remains to sort it out.



Certainly would echo those comments which look to new discussion rather than a rehash of what is contained in the archived megathread on this mishap.
john_tullamarine is offline  
Reply With Quote
Old 27th May 2014, 19:13
  #42 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
Originally Posted by john_tullamarine View Post
However, in the absence of anything else going the pilot's way in extremis ... configuration, attitude and thrust is a good place to start when nothing much makes sense - unload the fear and then there is a chance for rational thought to occur.
Right - totally agree. But what makes startle effect especially insidious in an aviation context is that it takes time to "unload the fear", as you put it - even when the person concerned is very well-versed, experienced and trained to automatically respond, sometimes it can overwhelm even that. Making it even more dangerous is the fact that if the person afflicted is PF at the time, then they only have a limited amount of time to overcome the mental overload before the aircraft cannot be recovered. As a result, on top of a greater focus on drilling basic responses and handling, I think it would be an extremely good idea to train pilots on diagnosis of startle effect in colleagues and a cast-iron method of safely dealing with it - even taking control if necessary - until they have calmed down.

Sioux City was an exemplar for how to approach a lost cause, I suggest.
Indeed, and I would add to that example BA038, BA009, Cactus 1549 and the DHL A300 hit by SAM fire over Baghdad.

In the case of Sioux City I think that while the primary crew performed brilliantly by any standard, the addition of the late Capt. Fitch improved their chances significantly, not least because he brought a fresh pair of eyes and analysis to the situation - but also because his presence allowed Capt. Haynes to delegate the task of handling the throttles to him, reducing the task load on the rest of the crew.

I occasionally hear CRM dismissed as a "touchy-feely" exercise, to which I like to point to the UA232 CVR as a rebuttal. I've heard it said that the recording is one of the best existing examples of CRM used in extremis, and I wholeheartedly agree. Not only that, but there's nothing "touchy-feely" about the recording at all!

A lot of the folks were killed but the miracle that any survived remains ..
Indeed, and - while it's a sign of the man Denny Fitch was - I always found it very sad that in every interview given he was still clearly troubled by the fact that not everyone survived.

Whether the beancounters acknowledge it or not .. when all the aces have disappeared, only the flightcrew remains to sort it out.
Absolutely, but management in aviation needs to recognise it too - if not more so.
DozyWannabe is offline  
Reply With Quote
Old 28th May 2014, 00:51
  #43 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 755
Originally Posted by DozyWanabee
I think what confuses the issue slightly is that translation from the French tends to mix up whether the PNF in particular is referring to pitch angle or altitude (hence the translation into "go up" and "go down" can refer to either). That said, whenever any of the pilots refers to the altimeter specifically after the stall has developed, they consistently say "You're going down", or words to that effect.
I'm finding a difficulty to understand that sentence in French, not first about attitude/altitude (in French from professional pilots it is probably altitude , reference to attitude would mostly use the word "assiette"="pitch") but a greatest ambiguity - and I cannot imagine professional pilots using that expression - is one of the fact which lets me reject the CVR written in a fantasy language, I have NEVER seen by the worst french professional pilot :
In french, when you are saying "tu montes" it has two OPPOSITE meanings, 1. You are climbing ; 2. I'm requesting you to climb, unsaid you are descending. Idem with the expression "tu descends".
Edit add : Inflection of the voice should perhaps help to discriminate, but the BEA did not deliver the vocal tape, and the text is rewritten...

Last edited by roulishollandais; 28th May 2014 at 01:28. Reason: [, add, é, -, r
roulishollandais is offline  
Reply With Quote
Old 28th May 2014, 02:11
  #44 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 755
Originally Posted by john_tullamarine
However, in the absence of anything else going the pilot's way in extremis ... configuration, attitude and thrust is a good place to start when nothing much makes sense - unload the fear and then there is a chance for rational thought to occur. It follows that such data MUST be a memory item .. there is no time to pull out the QRH when the aircraft is at risk of toppling.

In my insularview, training and more training in the basics is the best way to cause a quasi-automatic but reasonable response to fright to occur.

That this may not have happy results in some cases is part of the cost of doing business .. we are concerned with maximising the overall probability of a successful outcome.

Sioux City was an exemplar for how to approach a lost cause, I suggest. A lot of the folks were killed but the miracle that any survived remains ..

Whether the beancounters acknowledge it or not .. when all the aces have disappeared, only the flightcrew remains to sort it out.
Your description of the heart of the philosophy of french PROFESSIONAL pilots "education" is exactly this one. Doing the student able to resist to the many pressures he will be the focus in his profession, corruption, fatigue, fear, surprise.

@DozyWanabee,
Where is the 80% figure coming from? In any case when you are seeing the speed decreasing instinctive action is to PUSH not to PULL and immediatly after come back to the HSI if speed continues to decrease, to avoid overspeed. If now a roll PIO is starting in alt2B sub-law instinctive action is away, and specialy with an autotrimmed plane you don't grip the stick, more the joy-stick! as if you were on a roller-coaster
roulishollandais is offline  
Reply With Quote
Old 28th May 2014, 02:38
  #45 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 755
DECORATED AIR FORCE VETERANS

Originally Posted by DozyWanabee
I think it's worth pointing out that in the Birgenair and West Caribbean accidents, it was the Captain on each flight - both of whom were decorated Air Force veterans - who misjudged the situation, pulling up into the stall and holding it there. In both cases, the younger F/Os correctly diagnosed the stall
It's a shame for civilian aviation to kill these decorated Air Force Veterans who proved their ability to face much more difficult situations in war and who hàd no more the adequate and enough training once in airlines to avoid a stall.
Beancounters and chief pilots must not be proud of that, to get money of insurance despite their inhumanity and irresponsible behaviour.
DozyWanabee, once more you are showing usa cold cynism.
roulishollandais is offline  
Reply With Quote
Old 28th May 2014, 11:43
  #46 (permalink)  
 
Join Date: Jun 2011
Location: Devonshire
Age: 90
Posts: 300
THAT 80 % !

In 1949, as a very new "Joy-riding" pilot flying an Auster I was asked to " Loop the Loop" by some of my passengers. This was NOT allowed - by those in authority. ( We did have lap-straps.)


Instead I would push the stick forward and some of the young ladies would squeal. On pulling the stick back, they became silent again.
I ought to have collected, and kept, the statistics. But PPRuNe did not exist to tell .


Perhaps fear of the unknown, how far will I drop, is worse than a hardening cushion!


80 % would seem right... It must have been much more than 50%.
Linktrained is offline  
Reply With Quote
Old 1st Jun 2014, 23:15
  #47 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
Should point out that the above linked blog is that of a former head of the SNPL union (notable for their long-standing adversarial stance towards Airbus), so therefore his comments (also downloadable from the page) will likely have a degree of bias to them.

I've had a quick squiz on his commentary via Google Translate, and I don't think his comments cover anything that was not already covered by the archived "mega-thread" on the subject.
DozyWannabe is offline  
Reply With Quote
Old 2nd Jun 2014, 13:22
  #48 (permalink)  
 
Join Date: Feb 2008
Location: somewhere
Posts: 92
Compare

@ winerhofer :

When you will get the contre expertise and its Air Caraibes incident comparaison , do not miss a comparaison with their internal report, bottom of pages 3, 12 and 13..sorry for the non french readers..

http://fr.slideshare.net/Unusualatti...rbus-a330-memo
VNAV PATH is offline  
Reply With Quote
Old 2nd Jun 2014, 13:57
  #49 (permalink)  
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 65
Posts: 3,338
If startled, 80% of pilots pull back on the controls, training has serious problems. Doing nothing is better than that.
galaxy flyer is offline  
Reply With Quote
Old 2nd Jun 2014, 17:30
  #50 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
@VNAV_PATH:

I think the primary discrepancy between the (valid) points made in the Air Caraibes memo and what we later learned of AF447 via the CVR is that in the case of AF447, neither pilot makes any reference (or indeed any reaction) to the Stall Warning even though it sounds continuously for around a minute. In fact, there's no evidence to suggest that the crew attempted to apply any known procedure at all.

@galaxy flier:

That figure came from this report on YR-LCA - an A300 on approach to Orly airport in 1994:

YR-LCA

(Use your browser's "Find" to look for the relevant section with '80%')

I believe the conclusions and recommendations included more thorough explanation via training of how inappropriate reactions can occur and for pilots to take extra care in guarding against them.
DozyWannabe is offline  
Reply With Quote
Old 2nd Jun 2014, 20:09
  #51 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 755
80% of pilots

Originally Posted by report Tarom
The PF does not seem to have noticed the THS pitch down movement, particularly given that a movement of the THS commanded by the automated systems is not announced by the “whooler”. This triggered a reduction in pitch attitude. The aircraft did, however, stall; the “Cricket” stall warning signal and stick shaker were only activated later during descent (see paragraph 2.3.2 below).

Immediately before, during and after the stall, due the unreliability of the total pressure, the ADC no longer provided speed data, resulting in automatic disconnection of the ATHR, with the throttle levers remaining in the maximum thrust position.

Just before the stall, the Captain pulled the control column* fully back, bringing the elevator to 23 degrees nose up. He then pushed it fully forward, while continuing to counter the roll of 75 degrees to the right with the ailerons. The statistical data shows that, when confronted by a stall, in 80% of cases, pilots pull back the control column, in a sort of reflex movement, which continues the loss of control.

The aircraft was subjected to a series of four full and rapid rolls. The first was attributed to the force brought to bear by the pilot on the left part of the control column; the following ones were due to pilot overcompensation on the roll then the stall. Having pulled the control column fully back and thus caused maximum nose up pitch, the pilot rectified this by pushing the control column fully forward. The aircraft dipped, with its nose going under the horizon by 32°. The roll-off from +50 to –32° in seven seconds was remarkable.
We can't know in that quote :
- which stat data ? Who ? Sim/plane ? Type ? Size and type of population ? Have these results been published in a controlled research paper, etc.
- which pilots ? (Licence, experience, recent training, fatigue, which flight school if any ? etc.
- which stall ? N? Thrust ? Other anomaly (roll, oscillations, ths, spin, aso) ? etc.
- other
roulishollandais is offline  
Reply With Quote
Old 2nd Jun 2014, 21:50
  #52 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
@roulis:

I think it would be fair to presume that the experiments would have been performed as part of the investigation. The context gives two points - when confronted by a stall in that scenario, 80% of the pilots who took part in the experiment reflexively pulled up. If so, then it was an adjunct to the investigation itself rather than a scientific study in its own right. I'd imagine the pilots were taken from a reasonably broad cross-section of those available.

As far as I'm concerned, quibbling over the parameters of the experiments would have been far less concerning at the time than the significant number of those tested who did indeed pull up! I also think that the lack of surprise at the figure from posters known to be experienced pilots is rather telling.

Going back to a previous reply of yours - the point I was making regarding other incidents in which ex-military captains were responsible for pulling up was simply to highlight that it would be unwise to "write off" the actions of the AF447 PF as being purely down to inexperience.
DozyWannabe is offline  
Reply With Quote
Old 3rd Jun 2014, 17:12
  #53 (permalink)  
 
Join Date: Jun 2011
Location: france
Posts: 755
@DozyWanabee
1. It has been said again and again that training was a major factor in AF447. I don't remember that inexperience has been pointed as such a point. Why don't Airlines maintain the level from skilled pilots like these Vétérans ?

2. You know that math was my first learning. In that immense matter, I used "some" time in stats ! Real stats. Not what we are used to read in magazines, because stats are not very pleasant to understand nor to read... And no aviation investigation wants to give you a pleasant reading ! or a complete demonstration.

Please watch, about Airliners stall, on one hand we are reading that test pilots don't stall airlines, on the other hand we should accept that airlines pilots (likeTarom) should have done an experimentation with 80% pilots pulling the stick at any startle factor... Where are these experimentations ? they don't exist !
roulishollandais is offline  
Reply With Quote
Old 3rd Jun 2014, 18:04
  #54 (permalink)  
 
Join Date: Aug 2005
Location: fl
Posts: 2,563
When we were hired as new FO's on my first airline job not one of us needed training to instinctively release back pressure and lower the nose if we encountered a stall. We were way beyond that basic stuff at that time.

Yes, it was covered again in training for the 737 but it was just a review. Blaming airline training for this accident would only apply to inexperienced pilots that aren't ready for the job yet.
bubbers44 is offline  
Reply With Quote
Old 3rd Jun 2014, 18:35
  #55 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
Originally Posted by bubbers44 View Post
Blaming airline training for this accident would only apply to inexperienced pilots that aren't ready for the job yet.
You might be inclined to think so, but of 5 incidents I can think of involving airliners where the crew pulled up into a stall, 4 of them had the Captain as PF and at least 2 of those captains were ex-mil veterans.

The "inexperienced/magenta line" argument doesn't seem to hold with the historical record here.
DozyWannabe is offline  
Reply With Quote
Old 8th Jun 2014, 02:01
  #56 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
@Winnerhofer - to be honest, for the most part I disagree.

In general, the article seems to be based around the assertion that the flight crew are being assigned primary responsibility for the accident - which is, as stated before, fiction. In fairness, it does at least seem to acknowledge that the BEA report enumerates the known contributing factors without assigning responsibility. But it seems to ignore the fact that the Judicial Experts' Reports are also just a preliminary phase in the ongoing legal process - and nothing has as yet been set in stone regarding responsibility.

Forgive Google Translate, it's the best I can do for now:

THALES - . Failure design Pitot probes
Failure of these sensors seems to be the root cause of the air crash, leading to the sequence of events (including errors of representation drivers) to unrecoverable stall the Airbus Air France.
While the icing of the pitot probes was undoubtedly the initiating factor in the accident, referring to it as a "root cause" is inaccurate. The article itself goes on to mention 30-odd other incidents where these probes iced over, yet in all those cases the aircraft was not lost.

EASA (European Aviation Safety Agency) - Lack of certification of the Pitot probes...
The Thales AA probes met certification requirements - not just for EASA but for all international regulatory bodies. The problem arose because aircraft on the line were encountering scenarios which exceeded the regulatory limits.

AIRBUS - Failure design of embedded & automation flight control software
- Lack of understanding of man / machine interface:
AIRBUS did not properly assess the criticality of the event of failure of the Pitot probes, nor the stall could s 'result. Consequently, it did not set the appropriate procedures for dealing with these degraded modes. It was not planned special training to recover from a stall because the system prohibits any such situation even disabling the PA...
This assertion doesn't make sense. If the crew of AF447 were seen to apply a known procedure in response to the loss of airspeed data, then the article might have a point. This would consist of the crew setting the pitch angle to 5 degrees nose up etc. If that had led to a crash then yes - the procedure would be at fault.

But the procedure was not followed, and the PF pulled the nose up to a pitch angle closer to 15 degrees before even taking time to assess the situation.

AF - The procedure "IAS questionable" (procedure for the blocking probes) - Failure to pilot training -. Lack of feedback
Given multiple flight incidents involving Pitot probes Thales brand before the accident, the company had indeed asked Airbus to replace these probes by BF Goodrich probes (deemed less susceptible to icing), but had not stopped the aircraft for this operation. The procedure called "IAS questionable", defined at the time for processing cases of failure of the Pitot probes was inappropriate (it has also been changed since). Finally, Air France would not properly trained its pilots to the case of failure or recovery stall that could ensue (in his defense stall was deemed impossible by the manufacturer).
The replacement of the Thales AA pitot tubes was ongoing, and in fact it was the airlines that requested the work be a service bulletin as opposed to an airworthiness directive. As discussed above, the existing UAS procedure was primarily aimed towards scenarios involving a lower altitude - but that procedure was not followed in the case of the accident. If it had been, even though it was not tailored for a cruise-level scenario, it is extremely unlikely that the aircraft would have been lost.

Furthermore, Airbus's documentation has *always* been clear on the point that the aircraft can be stalled if the flight control law has degraded from "Normal", so the last sentence is a complete fabrication.

DGCA & BEA - Failure to take into account events precursors :
These bodies have not given the feedback on Thales Pitot probes. 32 incidents of blocking Pitot probes, listed on the world fleet between 2003 and 2009, 28 involve Thales probes. They have not issued the necessary recommendations to AIRBUS, regarding essential to guarantee flight safety modifications on its devices. Moreover, after the disaster, Thales Pitot probes complained were changed urgently on all devices.
This statement seems to be worded to imply that the 32 other incidents must have been handled by the BEA (inferring F-registered aircraft) when this is not the case. The outcome of the worldwide case history regarding Thales AA probes did indeed result in an ongoing program to replace them, and supplementary information was supplied to airlines to handle the problem in the interim. 28 incidents were logged with a positive outcome, so the idea that the aircraft would likely be endangered on every occasion is something of an exaggeration.

Crew - pilot inappropriate Reactions :
Their responsibility rests only on the basis of arguments that seem very light. The pilots of the 447 are scapegoats (too) easy no longer here to defend himself.
Not true - there has been no definitive action as yet which determines that the crew bear primary responsibility.
DozyWannabe is offline  
Reply With Quote
Old 9th Jun 2014, 23:25
  #57 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
Originally Posted by Winnerhofer View Post
AF and DGAC knowingly knew that for the last 25-odd years that training was sub-par.
The warning signs were ignored despite victims being sacrificed at the altar of political expediency.
3 fatal crashes ignored: Habsheim, St Odile and Roissy and many non-fatal disasters...
The fast-tracking of F/As on to the RH-seat due Union pressure over more qualified crew is scandalous as well as unsackable incompetence.
Sorry, but with all due respect those conclusions are drawn too simplistically.

For one thing, the crashes you refer to were all flown by experienced (civil) veteran crews. Additionally, the Mt. St. Odile accident was an Air Inter flight, not AF.

For another, I believe that the only member of the flight crew on AF447 who had come up from being a former FA was F/O Robert - and based on the evidence we have I'm convinced that he was probably the most aware of the flight crew as to what was happening, though, tragically, he seems unaware that was the case, and did not assert himself accordingly.

To be fair, I think there's enough evidence doing the rounds to suggest that at the time of AF447, AF was not a "happy" airline and had not been for some time. Furthermore I make no secret of my opinion that the SNPL union is in many ways - and to put it mildly - misguided.

That said, I think that drawing an inference - as you seem to be - that these events mean that the DGAC is somehow deliberately turning a blind eye is not supported by the evidence. At the very least, the DGAC are by no means the only offenders when it comes to not noticing airlines pushing the boundaries of regulations - the US FAA and their regional airlines' working practices are another infamous example.

Last edited by DozyWannabe; 10th Jun 2014 at 00:28.
DozyWannabe is offline  
Reply With Quote
Old 10th Jun 2014, 00:53
  #58 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 61
Posts: 1,809
At the very least, the DGAC are by no means the only offenders when it comes to not noticing airlines pushing the boundaries of regulations - the US FAA and their regional airlines' working practices are another infamous example.
We must never excuse the bad practices of one by taking as exemple the bad practices of another
It goes back to both apologize and in fact approving bad practices !
jcjeant is offline  
Reply With Quote
Old 10th Jun 2014, 01:04
  #59 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 61
Posts: 1,809
For another, I believe that the only member of the flight crew on AF447 who had come up from being a former FA was F/O Robert
The best that Google can do

Recruitment of Drivers with Air France: Officially described today, three streams feeding pilot hiring in Co.
Drivers Cadets, ENAC, Drivers Air Force and Naval Aviation, Business Drivers
Drivers Cadets: These are men and women recruited Contest (Bac +2) and not strictly have no aviation background. They are intended to complete training at Air France, under the educational and cultural responsibility Instruction Air France. First flight on light aircraft and private pilot license (flying club) they evolve to the Professional Driver license accompanied by the qualification of flight instrument now called CPL / IR for Commercial Pilot License / Instrument Rules.
If successful this cycle, and after completing flight simulator (Airbus A300) a general adaptation training flight on Jet, including capacity building in terms of "basic skills" (keeping speed with the use of thrust in manual control with only classical instruments ie artificial horizon, airspeed indicator, altimeter, vertical speed indicator, "needle and ball" they are offered for a qualification on Airbus A320, which marks their entry into the Co. .
During this adaptation Jet (conventional aircraft: Airbus A300 Simulator) stall is studied and shown in various configurations.
Contrary to the destroyers Airbus from this so-called "generic aircraft" phase, the stall is studied, taught, and practiced the most universal manner, which "requires" priority to the reduction of incidence, and prudence in setting thrust ...
It is also clear in the Instruction formal document that this practice output approaching the stall is valid for all types of aircraft, including aircraft FBW (Fly By Wire "as the Airbus A320/330 / 340 and B777.
Pilot Pierre-Cedric Bonin and Frederic Naud (crash Toronto for the latter) have never been recruiting from "Cadet" said yet
"Ab Initio". Never! For the simple reason that they have both joined Air France as Steward, and enjoyed enormous benefits of Enterprise Committee of Air France to perform at the flying club their first Air France flight hours privately.
AIR FRANCE : Sélection des Pilotes et recrutement interne
jcjeant is offline  
Reply With Quote
Old 10th Jun 2014, 01:34
  #60 (permalink)  
 
Join Date: Jul 2002
Location: UK
Posts: 3,181
Originally Posted by jcjeant View Post
We must never excuse the bad practices of one by taking as exemple the bad practices of another
Agreed, and that's not what I'm saying. What I'm saying is that the conclusion Winnerhofer is drawing - namely that the DGAC knew of issues at AF and wilfully ignored them - is not supported by the evidence.

Regarding former FAs on the flight deck, I'll confess I was incorrect and Robert was never a FA. However, according to the Final Report neither was Bonin - the only flight crew member noted as having converted from CC was in fact Capt. Dubois - and the process of conversion lasted from 1979 to 1982 - hardly a recent event!
DozyWannabe is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service