AF447 wreckage found
'What else then a reaction to the stall warning should have motivated the crew to apply TOGA thrust?'
'If they were unaware of Stall, they would select TOGA exactly, why?'
I am not convinced they knew/thought/suspected they were continuously stalled. Perhaps belief in the reliability of the messages and warnings left them and in a fog of doubt they tried to 'climb out'. Nose up and lots of thrust. What was in their minds ...structural anomaly, inexpliable control faults, heavy icing...we don't know, but.......
Edit: 'We have no valid indications...' was it ? Not we are still stalled or try this, that or the other. Yes I know the CVR was heavily parsed but without use of the word 'stall' I think the first question is did they know, and perhaps the second may be, knowing that why did they...........
'If they were unaware of Stall, they would select TOGA exactly, why?'
I am not convinced they knew/thought/suspected they were continuously stalled. Perhaps belief in the reliability of the messages and warnings left them and in a fog of doubt they tried to 'climb out'. Nose up and lots of thrust. What was in their minds ...structural anomaly, inexpliable control faults, heavy icing...we don't know, but.......
Edit: 'We have no valid indications...' was it ? Not we are still stalled or try this, that or the other. Yes I know the CVR was heavily parsed but without use of the word 'stall' I think the first question is did they know, and perhaps the second may be, knowing that why did they...........
Mr Optimistic
I am not convinced they knew/thought/suspected they were continuously stalled. Perhaps belief in the reliability of the messages and warnings left them and in a fog of doubt they tried to 'climb out'. Nose up and lots of thrust.
I am not convinced they knew/thought/suspected they were continuously stalled. Perhaps belief in the reliability of the messages and warnings left them and in a fog of doubt they tried to 'climb out'. Nose up and lots of thrust.
It´s one of the first lessons learned with TS and buildups: Don´t try to outclimb one, it might rise faster than your machine is able to climb. Aditionally, there was no danger from below or from the FL they where flying at, which would have disappeared when flying 2000 feet higher. At least i dont know one.
An intentional climb is a "no option" for my thinking.
Also this was posted before, i think it is appropriate to look at this article again.
Some points out of it:
The value of the AoA SW depends
on the Mach number. At high Mach
number, the AoA SW is set at a
value such that the warning occurs
just before encountering the pitch
up effect and the buffeting.
Typically, in cruise at high Mach
number and high altitude, at or
close to the maximum recommended FL, there is a small margin between the actual cruise AoA
and the AoA STALL. Hence, in
ALTERNATE or DIRECT LAW,
the margin with the AoA SW is
even smaller
Equally, in similar high FL cruise
conditions, in particular at turbulence
speed, if the pilot makes significant
longitudinal inputs, it is not unlikely
that it reaches the AoA SW value.
For those reasons, when in ALTERNATE or DIRECT LAW, it is recommended to fly at a cruise flight
level lower than the maximum recommended. A 4,000 ft margin is to
be considered. Then, for the same
cruise Mach number, the IAS will
be higher, the AoA will be lower,
and therefore the AoA margin
towards AoA SW will be significantly increased.
A practical exercise done in flight
in DIRECT LAW on an A340-600
and well reproduced in the simulator consists in performing a low altitude level flight deceleration at idle
until the SW is triggered, and then to
push the THR levers to TOGA while
continuing to pull on the stick in order to maintain the altitude.
The results of such a manoeuvre
are:
q In clean configuration, even if
the pilot reacts immediately to the
SW by commanding TOGA, when
the thrust actually reaches TOGA
(20 seconds later), the aircraft
stalls.
This shows that increasing the
thrust at the SW in order to increase
the speed and hence to decrease the
AOA is not the proper reaction in
many cases (this will be developed
in the following chapter).
In addition, it is to be noticed that,
at high altitude, the effect of the
thrust increase on the speed rise is
very slow, so that the phenomenom
described above for the clean configuration is exacerbated.
Obviously, such a procedure leads
to potentially unrecoverable situations if it is applied once the aircraft has reached the aerodynamic
stall (see next chapter).
Even if the traditional procedure
can work in certain conditions if
the pilot reacts immediately to the
SW, or if he is not too adamant on
keeping the altitude, the major issue comes from the fact that once
the Stall Warning threshold has
been crossed, it is difficult to know
if the aircraft is still approaching to
stall or already stalled. Difference
between an approach to stall and an
actual stall is not easy to determine,
even for specialists.
The AoA decrease may be obtained
indirectly by increasing the speed,
but adding thrust in order to increase
the speed leads to an initial adverse
longitudinal effect, which trends to
increase further the AoA (fig. 4).
It is important to know that if such
a thrust increase was applied when
the aircraft is already stalled, the
longitudinal effect would bring the
aircraft further into the stall, to a
situation possibly unrecoverable
Well, enough said from my point of view, i´ll go back to my armchair, hope i didn´t produce too much garbage.
Some points out of it:
The value of the AoA SW depends
on the Mach number. At high Mach
number, the AoA SW is set at a
value such that the warning occurs
just before encountering the pitch
up effect and the buffeting.
Typically, in cruise at high Mach
number and high altitude, at or
close to the maximum recommended FL, there is a small margin between the actual cruise AoA
and the AoA STALL. Hence, in
ALTERNATE or DIRECT LAW,
the margin with the AoA SW is
even smaller
Equally, in similar high FL cruise
conditions, in particular at turbulence
speed, if the pilot makes significant
longitudinal inputs, it is not unlikely
that it reaches the AoA SW value.
For those reasons, when in ALTERNATE or DIRECT LAW, it is recommended to fly at a cruise flight
level lower than the maximum recommended. A 4,000 ft margin is to
be considered. Then, for the same
cruise Mach number, the IAS will
be higher, the AoA will be lower,
and therefore the AoA margin
towards AoA SW will be significantly increased.
A practical exercise done in flight
in DIRECT LAW on an A340-600
and well reproduced in the simulator consists in performing a low altitude level flight deceleration at idle
until the SW is triggered, and then to
push the THR levers to TOGA while
continuing to pull on the stick in order to maintain the altitude.
The results of such a manoeuvre
are:
q In clean configuration, even if
the pilot reacts immediately to the
SW by commanding TOGA, when
the thrust actually reaches TOGA
(20 seconds later), the aircraft
stalls.
This shows that increasing the
thrust at the SW in order to increase
the speed and hence to decrease the
AOA is not the proper reaction in
many cases (this will be developed
in the following chapter).
In addition, it is to be noticed that,
at high altitude, the effect of the
thrust increase on the speed rise is
very slow, so that the phenomenom
described above for the clean configuration is exacerbated.
Obviously, such a procedure leads
to potentially unrecoverable situations if it is applied once the aircraft has reached the aerodynamic
stall (see next chapter).
Even if the traditional procedure
can work in certain conditions if
the pilot reacts immediately to the
SW, or if he is not too adamant on
keeping the altitude, the major issue comes from the fact that once
the Stall Warning threshold has
been crossed, it is difficult to know
if the aircraft is still approaching to
stall or already stalled. Difference
between an approach to stall and an
actual stall is not easy to determine,
even for specialists.
The AoA decrease may be obtained
indirectly by increasing the speed,
but adding thrust in order to increase
the speed leads to an initial adverse
longitudinal effect, which trends to
increase further the AoA (fig. 4).
It is important to know that if such
a thrust increase was applied when
the aircraft is already stalled, the
longitudinal effect would bring the
aircraft further into the stall, to a
situation possibly unrecoverable
Well, enough said from my point of view, i´ll go back to my armchair, hope i didn´t produce too much garbage.
Yes, I see that. As SLF who am I to know, however climb is exactly what they did in the first instance and subsequently they were faced with rapidly unwinding height by which time their previous height limit was a fading memory. Two possiblities then, they were stalled, knew it and didn't begin to start a plausible recovery owing to what.....bad training/inappropriate SOP's, bad execution or second, didn't get the diagnosis right and were then flummoxed ? Had the Captain got all the facts when he returned (about which there is doubt) perhaps he could have illuminated the fog. If (biggish if I grant you), even he couldn't get at least a timely start to a stall recovery going isn't the simplest explanation that they didn't realise they were stalled ?
Sorry, just saw the subsequent post !
Sorry, just saw the subsequent post !
Join Date: Jul 2007
Location: Argentina
Age: 66
Posts: 38
Likes: 0
Received 0 Likes
on
0 Posts
Be patient
Greetings,
I keep asking myself (slegde hammer)... Why don´t we wait till friday or even more... Read what the ppl involved in this investigation have to say? We haven´t that much data so far... Neither did those involved ever sinds 2009 till now...
I hope you stop fighting each other, coz the goal is to solve the problem... Nothing else. You will contribute to that goal (and you already did without notice), by thinking toghether, not the other way around...
I keep asking myself (slegde hammer)... Why don´t we wait till friday or even more... Read what the ppl involved in this investigation have to say? We haven´t that much data so far... Neither did those involved ever sinds 2009 till now...
I hope you stop fighting each other, coz the goal is to solve the problem... Nothing else. You will contribute to that goal (and you already did without notice), by thinking toghether, not the other way around...
Join Date: May 2003
Location: USA
Posts: 83
Likes: 0
Received 0 Likes
on
0 Posts
Challenging ones teachers
If I may briefly chime in and then return to lurking: In my own profession of medicine we strongly encourage students to challenge old dogmas and procedures; in so doing they really can wrap their heads around why "the rules" evolved the way they did. More often than not, in surgery/aviation lessons learned are hard won, and sometimes fatally so. Rules of thumb can help when one is overwhelmed with sensory input from sophisticated technology.
As time goes on, and our understanding of deeper mechanisms evolves, so can our hard learned drills and emergency procedures. IMHO this needs to happen slowly and cautiously with attention to what has been learned in the past.
As time goes on, and our understanding of deeper mechanisms evolves, so can our hard learned drills and emergency procedures. IMHO this needs to happen slowly and cautiously with attention to what has been learned in the past.
Guest
Posts: n/a
Hello averow.
Unfortunately, all too often the attention paid to sincere questions is directly proportional to the standing of the questioner.
To the extent that this is not so, your post is compelling. Surgery especially has a relationship to your sentiments; for a long standing aviation protocol has been given some attention in the last few years. Briefly, the Operating room is starting to be understood as a sort of flight deck, where decisions and actions are critical, and time sensitive, to put it mildly. Two concepts are assigned a new perspective: CRM, and Lists.
Cockpit Resource Management, and the checklist. Perhaps a PM, I was recently deleted for mentioning an object that I assume is available at some price.
Unfortunately, all too often the attention paid to sincere questions is directly proportional to the standing of the questioner.
To the extent that this is not so, your post is compelling. Surgery especially has a relationship to your sentiments; for a long standing aviation protocol has been given some attention in the last few years. Briefly, the Operating room is starting to be understood as a sort of flight deck, where decisions and actions are critical, and time sensitive, to put it mildly. Two concepts are assigned a new perspective: CRM, and Lists.
Cockpit Resource Management, and the checklist. Perhaps a PM, I was recently deleted for mentioning an object that I assume is available at some price.
Join Date: Jan 2011
Location: London, UK
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
In a simulator test .. the plane was recoverable ....
Press "France Infos" (french)
Vol Rio-Paris : la catastrophe reconstituée dans un simulateur de vol - international - toute l'actualité internationale - France Info
In a simulator test .. the plane was recoverable ....
Press "France Infos" (french)
Pour France Info, notre spécialiste aéronautique, Frédéric Béniada, a pu lors d’une séance en simulateur de vol, revivre minute par minute le scénario de la catastrophe. Il nous livre ses conclusions.
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
And we've already been through the difference between the simulator and the plane in that part of the flight envelope.
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes
on
0 Posts
Hi;
That's a interesting statement
How does the pilots "in reality" don't know they are in a stalling aircraft ?
Airbus instruments and systems are wrong to the point to not show valuables indications to the pilots ?
Are the Airbus simulators better than the real thing ?
The pilots in the simulators were able to see they were in a stalling aircraft .. why not the AF pilots ?
The conclusion anyways reality or not is a good point for Airbus ....
No. The author (pilot?) states clearly they succeeded in recovering the simulator from the 'stall' because they knew exactly what was happening. He does not say tne plane was recoverable in reality.
How does the pilots "in reality" don't know they are in a stalling aircraft ?
Airbus instruments and systems are wrong to the point to not show valuables indications to the pilots ?
Are the Airbus simulators better than the real thing ?
The pilots in the simulators were able to see they were in a stalling aircraft .. why not the AF pilots ?
The conclusion anyways reality or not is a good point for Airbus ....
I listened to the conversation and to me it is not clear what they are getting to... A lot of talking but no clear answers.
The one theme that does come back a lot is the relationship or interface between aircraft and humans and how Airbus may have to rethink it big time.
It seems the two pilots perhaps three when the captain comes back into the cockpit didn't know what was going on or what was wrong. They were confused and did not know how to solve the problem(s) and how to apply a solution to get them out of it.
At one point they say the aircraft stalled but then say the systems worked because the Airbus cannot stall? Apparently they had access to the cockpit transcripts because they say you can hear the "Stall warning" and that there was no panic in the cockpit all was calm and professional.
They claim from their test in the sim that the crew had about only 40 seconds to figure out and save the aircraft that after that they were going to go for a ride until it crashed.
Not being an Airbus pilot I am totally shocked that these pilots did not know they were in a high altitude stall scenario and could not just apply common sense and fly the aircraft out of it.
What is it with the Airbus that a pilot cannot just push the nose over to a 5 degree nose down and apply MCT and fly out of this stall?
BTW, one of their so called aeronautic experts is a pilot but there is no mention of his background/experience or what type of license he holds and if he is typed on any aircraft in the conversation. The other is or was at one point an Airbus 330 pilot but that's all we know.
I guess it would be prudent to take what is said in this conversation with a grain of salt because there are a lot of unknowns.
Best wait for the July 29th report from BEA.
The one theme that does come back a lot is the relationship or interface between aircraft and humans and how Airbus may have to rethink it big time.
It seems the two pilots perhaps three when the captain comes back into the cockpit didn't know what was going on or what was wrong. They were confused and did not know how to solve the problem(s) and how to apply a solution to get them out of it.
At one point they say the aircraft stalled but then say the systems worked because the Airbus cannot stall? Apparently they had access to the cockpit transcripts because they say you can hear the "Stall warning" and that there was no panic in the cockpit all was calm and professional.
They claim from their test in the sim that the crew had about only 40 seconds to figure out and save the aircraft that after that they were going to go for a ride until it crashed.
Not being an Airbus pilot I am totally shocked that these pilots did not know they were in a high altitude stall scenario and could not just apply common sense and fly the aircraft out of it.
What is it with the Airbus that a pilot cannot just push the nose over to a 5 degree nose down and apply MCT and fly out of this stall?
BTW, one of their so called aeronautic experts is a pilot but there is no mention of his background/experience or what type of license he holds and if he is typed on any aircraft in the conversation. The other is or was at one point an Airbus 330 pilot but that's all we know.
I guess it would be prudent to take what is said in this conversation with a grain of salt because there are a lot of unknowns.
Best wait for the July 29th report from BEA.
Join Date: Jan 2005
Location: France
Posts: 2,315
Likes: 0
Received 0 Likes
on
0 Posts
BTW, one of their so called aeronautic experts is a pilot but there is no mention of his background/experience or what type of license he holds and if he is typed on any aircraft in the conversation. The other is or was at one point an Airbus 330 pilot but that's all we know.
I guess it would be prudent to take what is said in this conversation with a grain of salt because there are a lot of unknowns.
I guess it would be prudent to take what is said in this conversation with a grain of salt because there are a lot of unknowns.
Feldzer did fly as an Airbus captain... then became director of the Le Bourget museum. Now retired, and mostly known as a "talking head"/"expert" the moment French TV needs one.
He's the one that came up with the moronic idea of starting up the engines of one of the French museum Concordes.... which should give you an idea of his "technical competence".
Join Date: Nov 2010
Location: FR
Posts: 477
Likes: 0
Received 0 Likes
on
0 Posts
france info
[...]
Also a desire to 'protect' the Airbus technology to the public eyes ... ?
"The airplane did not stall, il s'est enfoncé (it has gone deep ?), thanks to the protections."
"The protections have been effective but not understood by the pilots."
[...]
Also a desire to 'protect' the Airbus technology to the public eyes ... ?
"The airplane did not stall, il s'est enfoncé (it has gone deep ?), thanks to the protections."
"The protections have been effective but not understood by the pilots."
- the aircraft did stall
- most of the protections were inop (ALT LAW + rejected ADRs)
However, I think it's more a -very poorly phrased- attempt of vulgarization. Which by the way will indeed somehow "protect" the aircraft maker reputation, for sure.
In french, "décrocher" (to stall) may be heard as a "violent" phenomenon to the general public. OTOH "s'enfoncer" (to sink) is a "softer" thing... and may be more "meaningful" to an uneducated ear (no offense).
And protections seem to stand for some flight laws/FBW features, here (i.e. maintaining pitch when stick is released and/or maintaining 1g)... Bad phrasing again, using a precise, technically meaningful word in an "oblique" sense.
I listened to the entire interview (thanks for the link) and did not learn much (if not nothing). It is clearly intended for the "general public", hence my interpretation above. Too bad one doesn't think it's worth to explain correctly... I'm sure it's possible, with a little (more?) goodwill.
------
@ jcjeant : "The pilots in the simulators were able to see they were in a stalling aircraft .. why not the AF pilots ?"
That's not what is said. It is said they (those who take a sim tour) were able to recover because they knew [by the briefing] what was going on. Not because they saw it [from the instruments].
(my comments between [brackets])
I think your other (previous) questions were purely rethorical ones, and don't call for an answer.
Join Date: Aug 2009
Location: Germany
Age: 67
Posts: 1,777
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
The press again ....
They tell they had access to parts of the BEA report to be published in few hours..
AF*447*: le rapport d'enquête met en cause l'équipage* - Yahoo! Actualités
I read that the less experimented pilot was the PF ..
I read also that this crew had not have adequate training for the situation encountered by AF447 (loss of speed indications)
Read also that all commands of the pilot were perfectly executed by the plane system
And also read that never the crew know they were in a stall situation
Again and again all fingers are pointing to the lack of training of the pilots and some errors made in the event.
And immediate reaction of a AF union (Alter)
Les accusations contre les pilotes du Rio-Paris relancées - Le Point
Wait and see ....
The press again ....
They tell they had access to parts of the BEA report to be published in few hours..
AF*447*: le rapport d'enquête met en cause l'équipage* - Yahoo! Actualités
I read that the less experimented pilot was the PF ..
I read also that this crew had not have adequate training for the situation encountered by AF447 (loss of speed indications)
Read also that all commands of the pilot were perfectly executed by the plane system
And also read that never the crew know they were in a stall situation
Again and again all fingers are pointing to the lack of training of the pilots and some errors made in the event.
And immediate reaction of a AF union (Alter)
Les accusations contre les pilotes du Rio-Paris relancées - Le Point
Wait and see ....
Last edited by jcjeant; 28th Jul 2011 at 22:11. Reason: Added link
Join Date: Jun 2009
Location: NNW of Antipodes
Age: 81
Posts: 1,330
Received 0 Likes
on
0 Posts
You've got to wonder what goes on at Google Translate when the following is submitted for translation into English and German.
The result being:-
Le Figaro a obtenu, en avant-première, des éléments de l'investigation sur le vol Rio-Paris.
- The BBC has obtained a preview, elements of the investigation on the flight from Rio to Paris.
- Die BBC hat eine Vorschau, Elemente der Untersuchung auf dem Flug von Rio nach Paris erhalten.
Join Date: Aug 2005
Location: fl
Posts: 2,525
Likes: 0
Received 0 Likes
on
0 Posts
It seems a lot of people are making last minute statements before the report tomorrow. I agree with most of them because we have been saying that for months. Saying, I told you so, tomorrow, isn't much help right now.
Tomorrow, hopefully, we will get a meaningful report then we can talk about it with some facts.
Tomorrow, hopefully, we will get a meaningful report then we can talk about it with some facts.