AF 447 Thread No. 5
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Garage Years
Do you have access to the traces of the autopilot's inputs prior to its loss to the crew? Just a question. (A comparison, an overlay, might help give some scale to PF's inputs?)
Is there a slight possibility that the PF may have been reacting to airframe positions, including ones he had created?
Mr. Optimistic
Could the Pitot #1 (Captain's) have been inop for the duration? If so, why?
TyroPicard
If so, then there is friction, perhaps fatal friction, in the cockpit? PNF's call for Captain's return, was that a call for his Authority as well as his skill? Was PNF too timid to overrule the PF? (perhaps?).......
Do you have access to the traces of the autopilot's inputs prior to its loss to the crew? Just a question. (A comparison, an overlay, might help give some scale to PF's inputs?)
Is there a slight possibility that the PF may have been reacting to airframe positions, including ones he had created?
Mr. Optimistic
Could the Pitot #1 (Captain's) have been inop for the duration? If so, why?
TyroPicard
If so, then there is friction, perhaps fatal friction, in the cockpit? PNF's call for Captain's return, was that a call for his Authority as well as his skill? Was PNF too timid to overrule the PF? (perhaps?).......
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Hi,
takata
And why he can't be irritated cause the captain not come more quickly on the flight deck ?
He make not one .. but some calls .. so this show his impatience for see the captain on the flight deck
We can argue for years only on those words .. but I think it's not significant words for the main event ...
takata
It is obvious that he is irritated by PF way of flying and slow corrections. PNF is very authoritative and PF seems quite stubborn.
So, I would interpret this sentence related to aircraft control, not to the captain: it sounds like an exprimed PNF concern about aircraft response time to imputs from the PF:
- have you got a response or not? (implying: I'm asking you to correct your pitch for a while but I can't see that we are going down)
So, I would interpret this sentence related to aircraft control, not to the captain: it sounds like an exprimed PNF concern about aircraft response time to imputs from the PF:
- have you got a response or not? (implying: I'm asking you to correct your pitch for a while but I can't see that we are going down)
He make not one .. but some calls .. so this show his impatience for see the captain on the flight deck
We can argue for years only on those words .. but I think it's not significant words for the main event ...
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Hi,
AFAIK .. you can see the AP commands in the graphics in the report N°3 (longitudinal and lateral axis commands and surfaces controls responses are shown)
The graphics timeline begin before the AP tell goodbye
Garage Years
Do you have access to the traces of the autopilot's inputs prior to its loss to the crew? Just a question. (A comparison, an overlay, might help give some scale to PF's inputs?)
Do you have access to the traces of the autopilot's inputs prior to its loss to the crew? Just a question. (A comparison, an overlay, might help give some scale to PF's inputs?)
The graphics timeline begin before the AP tell goodbye
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A bit of punctuation in the BEA report would have helped, but I'm aware that's difficult to clearly define from a colloquial discussion on a CVR tape...
"Là je sais pas. Là, ça descend"
Expanded and interpreted: "From what I see, I don't know. As far as I can see, we're going down."
"Là je sais pas là. Ça descend"
Expanded and interpreted: "There I haven't got a clue" (repeating the first "là" to stress it). "But we're going down".
Just putting a comma or caps would have made the intonation and meaning clearer.
And literally of course "ça descend" = "it's going down", which can refer to a lot of things, even instrument indications.
I doubt we, as outsiders, will ever get to hear the original tape.
And I would expect even the BEA is still battling today to match up the real meaning of those CVR 'cockpit voice messages' with what they think the pilots were seeing.
Only a detail, but IMHO maybe in a full transcript, expletives should not be deleted..... They often indicate a state of mind, or fury, or bafflement, or a first reaction to a totally unexpected event. And the exact intonation often speaks volumes....
For the francophones among here, I'm just thinking of the difference between the short-and-sharp "merde" (as when burning your fingers on the stove) and the long-and-slow "ohhh meeerrrddde" (when the soufflé coming out of the oven has totally collapsed).
I expect my anglophone friends can come up with exactly similar examples.
I gather in the current BEA CVR transcript, expletives have already been deleted. Too bad.
"Là je sais pas. Là, ça descend"
Expanded and interpreted: "From what I see, I don't know. As far as I can see, we're going down."
"Là je sais pas là. Ça descend"
Expanded and interpreted: "There I haven't got a clue" (repeating the first "là" to stress it). "But we're going down".
Just putting a comma or caps would have made the intonation and meaning clearer.
And literally of course "ça descend" = "it's going down", which can refer to a lot of things, even instrument indications.
This was in reply to a question as to what should be done. Is the Captain's reply to be taken as 'I don't know why we are descending' ie that he accepted they were but couldn't figure out why - if so, not very encouraging to the PF, or that he didn't believe that they were descending ?
And I would expect even the BEA is still battling today to match up the real meaning of those CVR 'cockpit voice messages' with what they think the pilots were seeing.
Only a detail, but IMHO maybe in a full transcript, expletives should not be deleted..... They often indicate a state of mind, or fury, or bafflement, or a first reaction to a totally unexpected event. And the exact intonation often speaks volumes....
For the francophones among here, I'm just thinking of the difference between the short-and-sharp "merde" (as when burning your fingers on the stove) and the long-and-slow "ohhh meeerrrddde" (when the soufflé coming out of the oven has totally collapsed).
I expect my anglophone friends can come up with exactly similar examples.
I gather in the current BEA CVR transcript, expletives have already been deleted. Too bad.
Last edited by Jetdriver; 1st Aug 2011 at 23:55.
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I'd been meaning to ask you about that as it happens, because that's exactly what I said!
Did you read 'pitots' as 'pilots'? (In any case it's my fault for using 'pitots' as a contraction of 'pitot tubes')
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First, for what is worth: the French pronouns ("prenomes"), like the nouns they replace, have in French two genres: masculine, or feminine. "il' is the masculine form, so it would translate into the English "he" for a person, or "it" for an object or animal.
In this case, I have NO doubts, that the PNF's ""il vient ou pas" - "is he coming or not?" is "Lonewoolf_50's" interpretation, in terms of referring to the Captain.
Indeed, it seem to show the frustration in regards to the PFs actions, but also with his limitations as well in changing the situation, without the Captain's presence
But, it's quite a long stretch to say that he refers to the "a/c controls response", instead of the Captain. That's something a non fluent French speaker would not know.
The "il descend ou non?" would be first on the list, with others as well, while, "il viens ou non?" would not even be on the list, not only in terms of meaning, but also in the context of an emergency call placed shortly before with the Captain, and in the context of using "descend/monte" relative to the "a/c" and PF actions shortly before.
airtren
This is based on something said by the PNF, I presume. But it is not the meaning I understood myself from the context:
- 2 h 11 min 06 : (…) il vient ou pas
The French pronom "il" is undefined, it may be related to something or someone. But all the discussion between pilots is about aircraft control up to this point and after this point. PNF wanted the PF to control his pitch during the climb. It is obvious that he is irritated by PF way of flying and slow corrections. PNF is very authoritative and PF seems quite stubborn.
So, I would interpret this sentence related to aircraft control, not to the captain: it sounds like an exprimed PNF concern about aircraft response time to imputs from the PF:
- have you got a response or not? (implying: I'm asking you to correct your pitch for a while but I can't see that we are going down)
In this case, I have NO doubts, that the PNF's ""il vient ou pas" - "is he coming or not?" is "Lonewoolf_50's" interpretation, in terms of referring to the Captain.
Indeed, it seem to show the frustration in regards to the PFs actions, but also with his limitations as well in changing the situation, without the Captain's presence
But, it's quite a long stretch to say that he refers to the "a/c controls response", instead of the Captain. That's something a non fluent French speaker would not know.
The "il descend ou non?" would be first on the list, with others as well, while, "il viens ou non?" would not even be on the list, not only in terms of meaning, but also in the context of an emergency call placed shortly before with the Captain, and in the context of using "descend/monte" relative to the "a/c" and PF actions shortly before.
airtren
Originally Posted by Lonewoolf-50
I just had a weird thought:
The PNF was wondering "why is captain not back in the cockpit?" at some point. Perhaps, on his way back to his rest station, he had to visit the lavatory, ...
The PNF was wondering "why is captain not back in the cockpit?" at some point. Perhaps, on his way back to his rest station, he had to visit the lavatory, ...
- 2 h 11 min 06 : (…) il vient ou pas
The French pronom "il" is undefined, it may be related to something or someone. But all the discussion between pilots is about aircraft control up to this point and after this point. PNF wanted the PF to control his pitch during the climb. It is obvious that he is irritated by PF way of flying and slow corrections. PNF is very authoritative and PF seems quite stubborn.
So, I would interpret this sentence related to aircraft control, not to the captain: it sounds like an exprimed PNF concern about aircraft response time to imputs from the PF:
- have you got a response or not? (implying: I'm asking you to correct your pitch for a while but I can't see that we are going down)
Last edited by airtren; 1st Aug 2011 at 17:17.
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@RetiredF4:
THS:
IN FLIGHT
In flight, on all fly-by-wire aircraft, the position of the pitch trim surface
automatically adjusts in order to maintain the flight path with no deflection of the elevators.
The position of the pitch trim surfaces that is required to maintain Flight
Level depends obviously on the center of gravity of the aircraft.
However, it also depends on several other parameters, such as altitude, speed,
aircraft weight and aircraft configuration
In flight, on all fly-by-wire aircraft, the position of the pitch trim surface
automatically adjusts in order to maintain the flight path with no deflection of the elevators.
The position of the pitch trim surfaces that is required to maintain Flight
Level depends obviously on the center of gravity of the aircraft.
However, it also depends on several other parameters, such as altitude, speed,
aircraft weight and aircraft configuration
Elevator:
If a very small deflection of the elevator causes "a lot of g", the efficiency of the elevator is very high.
The aircraft is considered to be very sensitive to maneuver.
The maneuver point is the CG, for which the elevator is infinitely effective.
The CG must obviously be as far forward from the maneuver point as possible.
This distance is defined by a maneuverability criteria, that determines that
"at least 1 ° of elevator deflection is required to pull 1 g load factor".
This condition defines the aft CG limit in terms of maneuverability.
But the CG must not be too far forward.
The maximum elevator deflection must enable at least the maximum
acceptable load factor (e.g. 2.5 g) to be pulled.
This condition defines the forward CG limit in terms of maneuverability.
If a very small deflection of the elevator causes "a lot of g", the efficiency of the elevator is very high.
The aircraft is considered to be very sensitive to maneuver.
The maneuver point is the CG, for which the elevator is infinitely effective.
The CG must obviously be as far forward from the maneuver point as possible.
This distance is defined by a maneuverability criteria, that determines that
"at least 1 ° of elevator deflection is required to pull 1 g load factor".
This condition defines the aft CG limit in terms of maneuverability.
But the CG must not be too far forward.
The maximum elevator deflection must enable at least the maximum
acceptable load factor (e.g. 2.5 g) to be pulled.
This condition defines the forward CG limit in terms of maneuverability.
Maximum elevator deflection and extern load factor:
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Originally Posted by vanHork
CAP: "Là je sais pas là ça descend"
in no way is this one single sentence. I was raised partly in French, the second "là" is out of place within one sentence. It suggests a second sentence, therefore:
Là je sais pas. Là ça descend
or to put it differently:
Là je sais pas .............. Là ça descend
Whatever the conclusion is, this sentence is crucial alongside the decisions or not of the PNF or the CDB (not) to take control
in no way is this one single sentence. I was raised partly in French, the second "là" is out of place within one sentence. It suggests a second sentence, therefore:
Là je sais pas. Là ça descend
or to put it differently:
Là je sais pas .............. Là ça descend
Whatever the conclusion is, this sentence is crucial alongside the decisions or not of the PNF or the CDB (not) to take control
What makes the link is that it seems obvious that the captain is answering the PNF previous questions:
2 h 12 min 13
PNF: - Qu’est-ce que tu en penses... qu’est-ce que tu en penses, qu’est-ce qu’il faut faire ?
2 h 12 min 15 -> 2 h 12 min 19
CAP: - Là... je sais pas là... ça descend...
2 h 12 min 13
PNF: - What do you think... what do you think, what should we do?
2 h 12 min 15 -> 2 h 12 min 19
CAP: - Hmm... no idea up to this point... aircraft is going down... [free interpretation of the meaning]
And the reason why the captain seems so puzzled is to be find on what the aircraft was doing after his arrival in the cockpit (0211:43 - 0212:15) added to the lack of informations reported to him by near panicked F/Os.
He did not find a stable situation at all: pitch, roll, alarms, thrust... everything could look incoherent to him during this time window.
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Originally Posted by Mr Optimistic
Any particular significance to AoA sensor #1 consistently reading low ?
It has to be add to the complexity of the situation - Beside the known disparities of indicated airspeed, did it trigger a silent rejection of the ADR 1 anemometric values ?
How confused was the system ?
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Originally Posted by airtren
In this case, I have NO doubts, that the PNF's ""il vient ou pas" - "is he coming or not?", is "Lonewoolf_50's" interpretation, in terms of referring to the Captain.
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Hello RetiredF4,
This can be a major catch !!! Your question is indeed very important!!!
I still don't have an answer to my question, which is somewhat along the lines of yours:
"Is the actuating of the control surfaces proportional to the duration of a control SS command", which could also be a contributor to the amplifying of control surface action, if the perception of the control surface action by the PF is delayed.
This can be a major catch !!! Your question is indeed very important!!!
I still don't have an answer to my question, which is somewhat along the lines of yours:
"Is the actuating of the control surfaces proportional to the duration of a control SS command", which could also be a contributor to the amplifying of control surface action, if the perception of the control surface action by the PF is delayed.
i had asked that question at least two times before, and your answer motivates me to try it a third time:
If the SS input to the flightcontrols, in this case to the elevators (and the THS???) is modulated according to speed, what speed source is used and is that a gradual change or a change of lets say 2 or three different datum values?
I think this question is very important, as we see a drastic drop of IAS after AP dropout while PF was (mis)handling the SS. If this new "false speed" changed the modulation of the SS input to the extreme low speed regime (wich at that time was not cosistant with the real speed), then the SS inputs of the PF would suddenly cause much greater flightcontrol deflections than moments before. It would explain part of the initial SS control problems and if THS travel is speed dependent as well we should look into THS travel to NU in relation to later (when speeds where valid again)THS travel ND also.
If the SS input to the flightcontrols, in this case to the elevators (and the THS???) is modulated according to speed, what speed source is used and is that a gradual change or a change of lets say 2 or three different datum values?
I think this question is very important, as we see a drastic drop of IAS after AP dropout while PF was (mis)handling the SS. If this new "false speed" changed the modulation of the SS input to the extreme low speed regime (wich at that time was not cosistant with the real speed), then the SS inputs of the PF would suddenly cause much greater flightcontrol deflections than moments before. It would explain part of the initial SS control problems and if THS travel is speed dependent as well we should look into THS travel to NU in relation to later (when speeds where valid again)THS travel ND also.
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Originally Posted by CONF iture
There is a little something of Perpignan here.
It has to be add to the complexity of the situation - Beside the known disparities of indicated airspeed, did it trigger a silent rejection of the ADR 1 anemometric values ?
How confused was the system
It has to be add to the complexity of the situation - Beside the known disparities of indicated airspeed, did it trigger a silent rejection of the ADR 1 anemometric values ?
How confused was the system
Even for stall alarm, the higher value of three is triggering the alarm. An under-reading probe is a sign of something (ice, probe issue) but not something that could "confuse" the system (when was it confused, by doing what?).
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First, for what is worth: the French pronouns ("prenomes"), like the nouns they replace, have in French two genres: masculine, or feminine. "il' is the masculine form, so it would translate into the English "he" for a person, or "it" for an object or animal.
In this case, I have NO doubts, that the PNF's ""il vient ou pas" - "is he coming or not?" is "Lonewoolf_50's" interpretation, in terms of referring to the Captain.
In this case, I have NO doubts, that the PNF's ""il vient ou pas" - "is he coming or not?" is "Lonewoolf_50's" interpretation, in terms of referring to the Captain.
You should have SOME doubts....
In French it's "un avion", so an aircraft is "il".
I've had regular problems explaining this to anglophone firends...
"Why do the French refer to a Concorde as "he" or "it", rather than "she" ?"
That said, you may have a valid point... "il vient ou pas" is more likely to refer to the captain than to the response of the aircraft. I would have expected "ça vient ou pas ?" in the latter case (still too colloquial to translate unequivoqually without the full context)
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@Conf iture & Mr. Optimistic:
Quote:
Originally Posted by Mr Optimistic
Any particular significance to AoA sensor #1 consistently reading low ?
There is a little something of Perpignan here.
It has to be add to the complexity of the situation - Beside the known disparities of indicated airspeed, did it trigger a silent rejection of the ADR 1 anemometric values ?
How confused was the system ?
Originally Posted by Mr Optimistic
Any particular significance to AoA sensor #1 consistently reading low ?
There is a little something of Perpignan here.
It has to be add to the complexity of the situation - Beside the known disparities of indicated airspeed, did it trigger a silent rejection of the ADR 1 anemometric values ?
How confused was the system ?
For SW the highest value of the 3 AOA's is the trigger.
FWIW currently an AOA sensor replacement program is active.
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Originally Posted by airtren
This can be a major catch !!! Your question is indeed very important!!!
I still don't have an answer to my question, which is somewhat along the lines of yours:
"Is the actuating of the control surfaces proportional to the duration of a control SS command", which could also be a contributor to the amplifying of control surface action, if the perception of the control surface action by the PF is delayed.
I still don't have an answer to my question, which is somewhat along the lines of yours:
"Is the actuating of the control surfaces proportional to the duration of a control SS command", which could also be a contributor to the amplifying of control surface action, if the perception of the control surface action by the PF is delayed.
Alternate law 2 is just doing that; C* law is modified; imputs are treated differently with less gain (meaning that default values are used instead of real air data). There is no proportionality between surface deflection and stick imputs until direct law. Those imputs are translated into load-factor demand, and system will deliver them up to the limits (2.5g/-1 g in clean conf.).
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Lonewolf, in the English version of the BEA note, the time it takes for the captain to return to the cockpit from his rest is less than a minute.
While we await the English version, the PNF presumably asking where is the captain is said at 2h 10 min 49.
2 h 10 min 49
PNF: (…) il est où euh ?
Uh, where is he?
The timing suggests three things:
1.) The PNF expected that the movements of the plane would have brought the captain back to the cockpit.
2.) The PNF had already called the captain but the BEA did not include that call in its sequence.
3.) The PNF thought he had called the captain, but had not.
We do not have a transcript of the phrasing used by the PNF to summon the captain back to the cockpit, but I don't think even resting pompiers would get to the pompe floor within a minute after the alarm sounds.
From 2 h 10 min 50, the PNF tried several times to call the Captain back.
At 2 h 11 min 42, the Captain came back into the cockpit
2 h 10 min 49
PNF: (…) il est où euh ?
Uh, where is he?
The timing suggests three things:
1.) The PNF expected that the movements of the plane would have brought the captain back to the cockpit.
2.) The PNF had already called the captain but the BEA did not include that call in its sequence.
3.) The PNF thought he had called the captain, but had not.
We do not have a transcript of the phrasing used by the PNF to summon the captain back to the cockpit, but I don't think even resting pompiers would get to the pompe floor within a minute after the alarm sounds.
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Originally Posted by Saturn V
2 h 10 min 49
PNF: (…) il est où euh ?
Uh, where is he?
The timing suggests three things:
1.) The PNF expected that the movements of the plane would have brought the captain back to the cockpit.
2.) The PNF had already called the captain but the BEA did not include that call in its sequence.
3.) The PNF thought he had called the captain, but had not.
PNF: (…) il est où euh ?
Uh, where is he?
The timing suggests three things:
1.) The PNF expected that the movements of the plane would have brought the captain back to the cockpit.
2.) The PNF had already called the captain but the BEA did not include that call in its sequence.
3.) The PNF thought he had called the captain, but had not.
1. the sentence is unfinished, "euh" at the end means that PFN missed the word and did not bother to complete it later.
2. "Where is it... uh..."
He is looking at something that disapeared or that he did not found. And it could be a part of the documentation if the captain left with it.
The clues:
a) he is calling the captain right after saying that..
b) when the captain came back, one of his first word is "here it is, use that".
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Thanks CJ. Do you remember a few weeks back when everyone just wanted the cvr as it would answer everything ! Can understand the editing, but it would help if BEA explained their policy to what they were showing and not showing. A simple <expletive> mark in the transcript would help show tension without loss of anyone's integrity.
Still don't know what the PNF and PF knew about their initial altitude excursion, think it is important as the failure of the Captain to be made aware of the climb is I think crucial to his failure to appreciate what the situation was. If they didn't know, then their failure to brief him wasn't a separate failure on their parts.
As for AoA sensor #1, well it could be a bit of ice counterbalancing I suppose but I rather expected to be told that it was likely due to an airflow issue owing to its location and the unusual wind vector.
Still don't know what the PNF and PF knew about their initial altitude excursion, think it is important as the failure of the Captain to be made aware of the climb is I think crucial to his failure to appreciate what the situation was. If they didn't know, then their failure to brief him wasn't a separate failure on their parts.
As for AoA sensor #1, well it could be a bit of ice counterbalancing I suppose but I rather expected to be told that it was likely due to an airflow issue owing to its location and the unusual wind vector.
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takata and A33Aab
I don't really mind about the color of the REMUS that was used. But if an AoA sensor seemed to be blocked for a while, I do think it is worth a clear mention.
Where is that mention ?
If one alpha probe is blocked and the two remaining vary together, would it change a glitch in the ADR rejection process ?
I don't really mind about the color of the REMUS that was used. But if an AoA sensor seemed to be blocked for a while, I do think it is worth a clear mention.
Where is that mention ?
Originally Posted by takata
One alpha probe doesn't change a glitch until a second one is drifting
