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

AF 447 Thread no. 4

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

AF 447 Thread no. 4

Old 4th Jul 2011, 08:20
  #741 (permalink)  
 
Join Date: Dec 2001
Location: England
Posts: 1,389
Likes: 0
Received 0 Likes on 0 Posts
Forgive me if this is wide of the mark but I haven't seen it discussed here..

Is it possible the pilots seat position contributed to the incident? For example if he left it in the position the captin had set it to, and that was a bit far back for him, could that have caused him to in advertantly apply back stick?

At least one problem with this theory is that I don't think the PF was the one that took over from the captain.
cwatters is offline  
Old 4th Jul 2011, 08:41
  #742 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes on 0 Posts
Cool

Hi,

Quite simply, there is no "Relief Pilot" slot in AF crews : the two F/Os should be fully qualified for all phases.
So .. it's possible Air France will have some problems
jcjeant is offline  
Old 4th Jul 2011, 08:50
  #743 (permalink)  
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jcjeant
So .. it's possible Air France will have some problems
Says jcjeant.
But the investigation is obviously pointing at the contrary on this specific point.
takata is offline  
Old 4th Jul 2011, 09:45
  #744 (permalink)  
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 77
Posts: 2,107
Received 4 Likes on 4 Posts
Crew composition

For the reason PJ2 has stated pilot development it makes absolute sense to ensure that all copilots remain fully qualified in the R/H Seat. I now infer from takata that Air France may not have had a formal system for training copilots to act as PF in the L/H seat. There is no doubt that using the sidestick with the hand you don't normally use results in a very different "feel". This left/right discrepancy also applies to all switch selections.

This may not be relevant to AF447, because the pilot in the R/H seat appears to have been the PF almost to the end. However, in the event that the more experienced pilot was occupying the L/H seat as relief pilot, he MIGHT have been discouraged from taking control because he had not been trained to fly with the L/H sidestick. I suggest this merely as a tentative possibility, because in any two-pilot operation (which this was, in a sense) one has to cover the incapacitation case.

I remain curious why, in the present absence of CVR evidence in the public domain, takata is emphatic that the more-experienced copilot was in the R/H seat. I appreciate that ground staff at GIG would be aware who was occupying which seats just before departure.

It needs to be said that, AFAIK, there is no evidence that Air France procedures were inferior to those of other airlines.
Chris Scott is offline  
Old 4th Jul 2011, 09:55
  #745 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
While you all debate FDRs etc, is there any merit in prioritising PF' s data rather than LHS?
BOAC is offline  
Old 4th Jul 2011, 10:14
  #746 (permalink)  
 
Join Date: Jun 2009
Location: Germany
Age: 71
Posts: 776
Received 3 Likes on 1 Post
Why the pitch up?

It might have been a mix of several factors causing the pitch up.
As i´m unable to think in bits and bytes i´ll do the traditional approach (aerodynamics and human behaviour).

My first thing to do after takeover from autopilot or student (i have the aircraft) was o get a feel for the flightcontrols. Grip the stick and do some small inputs to see if it acts correctly and autopilot is deactivated or the other guy has his hands of the stick. That was an automated habit.

Flightcontrol response is different depending on speed, altitude, CG, and in case of FBW on LAW. As somebody stated before the flightcontrol response of the A330 is more sensitive in ALt2 than in normal, and CG in cruise is more aft then during TO and LDG, where stick time is more present.

AF447 was not flying in undisturbed air, also there is no proved evidence yet that it was turbulence in a significant severity. However, the possibility that there was turbulence affecting smooth flight can be taken as assured.

Hand flying in FL350 seems to be a seldom live expierience by an FO, if it gets necessary in an event the CPT probably will do the flying and then the problem will be quickly solved or the flightlevel will be reduced to get better lifties. So it can be assumed, that whoever was flying at 02:10 could not rely on a lot of handflying expierience in Alt LAW in FL350, and not at all in less than smooth air.

Let me get to my point.
2:10:05 - 2:10:20
AP and AThr disconnect and Alt Law, and a PF / FO with minimal handflying expierience gets the AC in his lap with a roll to the right, takes the stick and tries to get a feel for it like in lower altitude, intends to counter the roll and to set the pitch 5° NU for the UAS procedure, simultaneously trying to counteract some mild or not so mild turbulence. He gets it wrong, his input is to big aggrevated by some outside lifties, and the pitch gets higher then intended. AOA being 4° at the beginning, raised quickly to above 10, triggering the stall warning (yes, i think that was a valid stall warning). Same time he is distracted by the cacophonie of the warning systems while trying to figure out what´s happening.
Only 15 sec passed, we are now at FL375 and Pitch is 10°, AOA not known but somewhere around 10°.

Imho it does not need any technical glitch to get in this high pitch there, not enough expierience for such a situation, some turbulence and a bad day will be sufficient.

02:10:20 - 02:10:45
Now the nose is up and PF tries to get it down again, but PF is over cautious from unintentional NU expierience and his ND input is not big enough to get the nose down quickly, but sufficient to keep the aircraft in an somewhat less then 1G slight upward trajectory. There is again speed indication at 215 Kts, but is it valid? The aircraft looks stable, time to sort out the warnings, ecam.....
Only 20 sec have passed, speed is down to 200 and the climb stopped around FL 375, balistic trajectory basically ended and AOA increased and trigggerd the stall warning in the end. AOA at the beginning before unloading somewhere around 10, then down to 4 after unloading, increasing above 6 again due to decaying airspeed and stopping of climbrate (change of relative wind).

Everything is gone haywire within 45 seconds from routine to nightmare (actually we dont see it that way from our armchair, but the PF might have seen it that way). AF447 is now off track off heading turning to the bad zone of the WX area, 2.500 feet above cleared altitude without contact to ATC, at low speed and all good helpers for cruise flight are on leave when mostly needed. Aditionally the most expierienced help, the captain unfortunately is not on the flightdeck.

02:10:51 - 02:11:40
Stall warning sounds again and the indicateing valid speeds are decreasing through 200kts, and (BEA does not state it, but it looks logical to me, therefore i take that guess) the altitude starts to decrease despite the fact, that pitch is still 10° NU. Natural instinct says power (TOGA) and keep the ship from falling into the bad WX area below (SS up), also we know, that this was the big mistake. The aditional thrust kept the altitude from decreasing initally and brought the ship even to FL380 (again overcommanding of SS and THS trimming), but now gravity strikes again, even the pitch increased from 10 to 16°, the aircraft starts its fall in this attitude (stall) out of FL380 down through FL350 at 02:11:45, at what time the captain entered the cockpit.

I stopp there, because the question was why pitchup. If there are computer glitches aiding this pitchup, we will know later. I for myself stated my oppinion how the events happened above, using A33Zab´s very helpfull chronology of events.

Last edited by RetiredF4; 4th Jul 2011 at 11:41.
RetiredF4 is offline  
Old 4th Jul 2011, 10:30
  #747 (permalink)  
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Likes: 0
Received 0 Likes on 0 Posts
Hi Chris,
Originally Posted by Chris Scott
I remain curious why, in the present absence of CVR evidence in the public domain, takata is emphatic that the more-experienced copilot was in the R/H seat.
Simply because it was supposed to be the procedure when the Captain is taking his rest: the new PF, acting as Captain, should be the most senior F/O from the RHS following what AF believed to be the best use of its crews when two F/Os are left alone in the flight deck. Note that, in this case, the PNF (junior F/O) is also acting from the seat he is not used to (hence, more F/O training for LHS after AF447).
Originally Posted by Chris Scott
I appreciate that ground staff at GIG would be aware who was occupying which seats just before departure.
At take-off time, those slots could have been filled differently as the junior F/O could have been PF with the Captain PNF (as he was, see report). The next cruise leg was nonetheless flown by the same PF (senior F/O) as during the second cruise leg (when acccident happened). The junior F/O was certainly resting after the climb and came back for the second cruise leg, sitting in Captain's seat. The Captain seems to have been PNF all the time until his rest.
There is no hard evidence of that: it is based on AF routine and clues from the meteo briefing. If the first cruise leg has been flown by the junior F/O, the Captain would have made the briefing to his replacement (senior F/O). The pilot talking (PF) is obviously the same one that is in charge once the Captain is resting: hence he is also the one flying (senior F/O) and this is fully consistent with known AF routine.
takata is offline  
Old 4th Jul 2011, 10:51
  #748 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Folks - why waste time on speculation? It is not rocket science to find out who was in the RHS. I guess that IF we need to know BEA will tell us. In any case, does it really matter?
BOAC is offline  
Old 4th Jul 2011, 10:51
  #749 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes on 0 Posts
Cool

Hi,

First BEA report:

1.5 Renseignements sur le personnel
Compte tenu de la durée de vol prévue et conformément au manuel d’exploitation d’Air France et à la réglementation en vigueur, l’équipage de conduite était renforcé.
La réglementation définit l’équipage renforcé comme suit :
« Un équipage de conduite dont le nombre de membres est supérieur au nombre minimal requis pour l’exploitation de l’avion et au sein duquel chaque membre de l’équipage de conduite peut quitter son poste et être remplacé par un autre
membre de l’équipage de conduite ayant la qualification appropriée »(4).
Les procédures de la compagnie aérienne(5) précisent que pour renforcer la fonction de pilotage, un membre d’équipage doit posséder la même qualification que le membre d’équipage qu’il vient renforcer et, qu’en outre, durant la période de repos du commandant de bord, un pilote possédant la même licence que lui doit être aux commandes. En l’état actuel des données rassemblées, il n’est pas possible de déterminer quelle était la composition de l’équipage de conduite en fonction au moment de l’événement.

And I read nothing more in the second preliminary report ... and nothing in the last note about who is who ...
Maybe they will know for the end of this month ?
Very important to know ... remind the number of people life hanging in the hands of the PF
jcjeant is offline  
Old 4th Jul 2011, 11:05
  #750 (permalink)  
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jcjeant
And I read nothing more in the second preliminary report ... and nothing in the last note about who is who ...
Maybe they will know for the end of this month ?
Well...
Usual stuff from you aimed at the very same goal. Please, just read the last findings in the last BEA note and you'll see it written black on white:
New findings
At this stage of the investigation, as an addition to the BEA interim reports of 2 July and 17 December 2009, the following new facts have been established:
*The composition of the crew was in accordance with the operator’s procedures.
Which mean that they obviously perfectly know who was where.... they just didn't tell it to you for some very reasonable reasons at this stage of the investigation. Remember those previous press headlines (Times, etc.) about "Baby AF pilot killed 228!".

Nonetheless, the only relevant part of your quote is this one:
durant la période de repos du commandant de bord, un pilote possédant la même licence que lui doit être aux commandes.
Which mean that during the Captain resting time, the Pilot Flying (PF) must be the one having the same licence as the Captain (ATPL), hence the PF must have been the senior F/O and it seems also that he really was, despite those news headlines, because that is what the BEA is already saying about it (read it again and again): The composition of the crew was in accordance with the operator’s procedures.

Clear enough, isn't it?

Last edited by takata; 4th Jul 2011 at 11:34.
takata is offline  
Old 4th Jul 2011, 11:44
  #751 (permalink)  
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Likes: 0
Received 0 Likes on 0 Posts
Hi BOAC,
Originally Posted by BOAC
While you all debate FDRs etc, is there any merit in prioritising PF' s data rather than LHS?
Basic common sense would call for all the cockpit displayed informations to be recorded. I don't know if it is possible but they should try it, especially whith today machines that are using all the sources for their flight systems.
But I guess they would have collected more than DFDR data in AF447 case.
takata is offline  
Old 4th Jul 2011, 12:56
  #752 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
BEA interim reports of 2 July
- can we have a link please or is it a typo?

Takata- we understand PF's ASI readings were not recorded.
BOAC is offline  
Old 4th Jul 2011, 13:06
  #753 (permalink)  
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 77
Posts: 2,107
Received 4 Likes on 4 Posts
cwatters, quote:
"Is it possible the pilots seat position contributed to the incident?
"For example if [...] that was a bit far back for him, could that have caused him to inadvertantly apply back stick?"

It's possible but, as you note, the PF was apparently in the R/H seat, and had been for some time. Some pilots move their seats back during meals, but not normally when the PF. Seat position is adjusted fore/aft and up/down either electrically or mechanically (the latter being inadvisable in turbulence). The seat is manoeuvred so that the pilot's eyes line up two balls suspended on the frame between the two windshields. The elevation and rake of the sidestick armrest is also very important. Accurate sidestick control is difficult without it.

takata
,
Thanks. Can you clarify what you mean by first cruise leg and second cruise leg, just in case I am misunderstanding your terminology?

BOAC, Sir,
Perhaps you would be so kind as to provide us with a list of subjects that we can discuss in advance of the next BEA report, without occasioning your displeasure? Or perhaps we should merely suspend our conversations altogether? Pray forgive us simple Airbus folk.
Chris Scott is offline  
Old 4th Jul 2011, 13:33
  #754 (permalink)  
 
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes on 0 Posts
Cool

Hi,

BEA interim reports of 2 July - can we have a link please or is it a typo?
FLIGHT AF 447
English version:
http://www.bea.aero/docspa/2009/f-cp...90601e1.en.pdf
French version:
http://www.bea.aero/docspa/2009/f-cp...cp090601e1.pdf

Which mean that they obviously perfectly know who was where.... they just didn't tell it to you for some very reasonable reasons at this stage of the investigation. Remember those previous press headlines (Times, etc.) about "Baby AF pilot killed 228!".
Indeed .. and so BEA for the "reasonable reasons" .. don't negate it ... and let the rumour run .....
I wonder if it's reasonable
BEA communicate .. yes .. but don't inform .. at least not in better way than the tabloids ..

Last edited by jcjeant; 4th Jul 2011 at 13:45.
jcjeant is offline  
Old 4th Jul 2011, 13:49
  #755 (permalink)  
 
Join Date: Jun 2009
Location: Paris
Posts: 691
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Chris Scott
takata,
Thanks. Can you clarify what you mean by first cruise leg and second cruise leg, just in case I am misunderstanding your terminology?
Flight details:
a) from take-off to top of climb -> all 3 pilots are in the flight deck
b) the cruise flight time is then divided in three parts ("legs") for resting.
. 1st: one pilot is resting (junior F/O)
. 2nd: one pilot is resting (Captain) => event start at the begining of it.
. 3rd: one pilot is resting (senior F/O)
c) from top of descent to landing -> all three pilots are in the flight deck.
Does it make sense?
takata is offline  
Old 4th Jul 2011, 14:54
  #756 (permalink)  
PJ2
 
Join Date: Mar 2003
Location: BC
Age: 76
Posts: 2,486
Received 2 Likes on 2 Posts
My thanks, Takata - I should know better than to estimate! I flew the RR on an A333.

Thanks for the information on AF cruise procedures. It is important to understand that there are no "Relief Pilots" but all F/Os are fully-licensed on the airplane and can take off and land.

Canada has seen fit to create the CRP - Cruise Relief Pilot License, a non-flying position where the RP sits in the front seat during cruise only and never handles the aircraft. I don't think that's appropriate but we lost that battle years ago. They have ATPLs and get the full airplane course but competency on the aircraft is not renewed and instead, recurrent training covers the basics and the Emergency Descent, which the RP must be able to do from the LS when replacing the captain. The RPs I flew with were superb crew members but to me the creation of the "CRP" license comes from the same thinking that permitted the creation of the MCPL: It just doesn't cut it when the going gets tough. It's part of the same kind of thinking that states that demonstrating and training the approach to the stall is not required for FBW aircraft. It's all about the illusion that automation solves all the problems of flight. And....it's all about money.

It's not the aircraft that is the problem. It is the hubris engendered by "automation" that fools those who don't fly but who think they understand aviation.

Last edited by Jetdriver; 4th Jul 2011 at 17:42.
PJ2 is offline  
Old 4th Jul 2011, 15:06
  #757 (permalink)  
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,579
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Chris Scott
Perhaps you would be so kind as to provide us with a list of subjects that we can discuss in advance of the next BEA report, without occasioning your displeasure?
- entirely up to you 'Airbus folk', but I would prefer anything RELEVANT and based on known facts for a start?.
BOAC is offline  
Old 4th Jul 2011, 17:04
  #758 (permalink)  
 
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by RR_NDB
The current FDR concept deals with this "crew member" considering it as an Engineering black box.
I think you're wrong there.

As an ancient (Concorde...) I'm not too familiar with the data the current AB 'FBW' systems passes on to the FDR, or the exact way this is done.

On Concorde, with an AFCS easily as complex as those of the various ABs we're talking about - even if it was analogue rather than digital - we 'had our fingers' on a lot of signals (both analogue and logic) inside each of those 'black boxes'. All of those went to the flight test recorders (been there, done that, haven't got the T-shirt, but I still have the G-BSST tie), and AFAIK all the essential ones went to the FDRs on the production aircraft.

I am entirely open to further clarify to you or (anyone) any point before going deeper into the "probable need for more data" to fully "understand" the behavior of the "complex crew member" in an investigation of accidents involving "advanced planes"
BTW, Concorde was 'advanced', even if implemented with 1960s technology. And yes, the data we recorded allowed us to fully understand the behavior of the "complex crew member". Like why she 'twitched the rudder' whenever somebody talked on HF... (ancient anecdote).

A discussion about FDRs and FDR data might be interesting, but I think it's totally outside the scope of an internet forum, even one like PPRuNe.
I 'did' FDRs late in my engineering career, so at least I'm familiar with the concepts.
ChristiaanJ is offline  
Old 4th Jul 2011, 18:34
  #759 (permalink)  
 
Join Date: Jan 2008
Location: Blighty (Nth. Downs)
Age: 77
Posts: 2,107
Received 4 Likes on 4 Posts
Quote from BOAC:
"...I would prefer anything RELEVANT and based on known facts for a start?."

Known facts are still in fairly short supply, and some may never be known. As you evidently think you are an important arbiter in these matters despite your lack of any Airbus experience please provide a list of what topics YOU THINK are relevant. And we'll give it our usual polite consideration.

Otherwise, put a sock in it?
Chris Scott is offline  
Old 4th Jul 2011, 18:35
  #760 (permalink)  
 
Join Date: Jun 2009
Location: Bedford, UK
Age: 70
Posts: 1,320
Received 40 Likes on 24 Posts
'The stall warning sounded twice in a row. The recorded parameters show a sharp fall from about 275 kt to 60 kt in the speed displayed on the left primary flight display (PFD)'

What does 'twice in a row' mean - why not continuously ? Doesn't the warning continue until the a/c is unstalled (or switched off at <60kts, though why it isn't latched if V is initially valid eludes me).
Mr Optimistic is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.