AF447 wreckage found
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Zorin, hold on a sec. I did miss your prior question to me. So here goes an answer flown an AB aircraft;
Flight 296 in Paris. I do not think the pilots flew into those trees on purpose.
Flight 296 in Paris. I do not think the pilots flew into those trees on purpose.
Do you think the pilots wanted the THS to go full ANU or do you think the computer assumed one (not both) of the pilots wanted it?
I say both because who really has command when the side sticks are displaced in different locations? I really do not know.
In fairness to the PF (whichever one it was) the only 'nose-up input' he (The PF) applied at the onset of the accident was immediately after the sign-off. The BEA states that the 'zoom climb' started at least 11 seconds after that - and there is no mention of the PF moving the stick either way until he applies 'nose-down' to counteract the climb. Does this mean the PF did not cause the climb but it takes several seconds for the AB330 to respond to control movements?
Although this question wasn't addressed to me I'm going to answer it.
The question you ask is disingenuous. The complaint is not that the software didn't do what it was supposed to do
The question you ask is disingenuous. The complaint is not that the software didn't do what it was supposed to do
(a) When the airplane is within the flight envelope the stall warning provides an aural communication to the pilots: SILENCE.
(b) when the software decides the airplane is outside established parameters it provide an aural communication to the pilots: STALL STALL STALL
(c) when the software decides that the airplane has so drastically exceeded established parameters that the data should be considered invalid it provides an aural communication to the pilots: SILENCE.
(b) when the software decides the airplane is outside established parameters it provide an aural communication to the pilots: STALL STALL STALL
(c) when the software decides that the airplane has so drastically exceeded established parameters that the data should be considered invalid it provides an aural communication to the pilots: SILENCE.
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Sorry about that!
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CJ said:
Thanks CJ, that is the kind of communication I like to see.
It shows dignity...
Maybe is the wind tunnel as it is outdated as well... Maybe some kind of Cb sim could be developed for AFCS and/or IFCS testing... Improving weather satellite links in place of (or assisting), poor local radar systems may be helpful as well...
Todays certification standards for pitot tubes still date from the Stone Age.
Unless a real job is done to update those standards, and re-define the certification testing with regard to potential present-day (icing etc.) circumstances, "we" (the engineers) just try to do our best.... which, because of the lack of clearly defined design data, may not be good enough.
Unless a real job is done to update those standards, and re-define the certification testing with regard to potential present-day (icing etc.) circumstances, "we" (the engineers) just try to do our best.... which, because of the lack of clearly defined design data, may not be good enough.
It shows dignity...
Maybe is the wind tunnel as it is outdated as well... Maybe some kind of Cb sim could be developed for AFCS and/or IFCS testing... Improving weather satellite links in place of (or assisting), poor local radar systems may be helpful as well...
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Airspeed Input to Stall Warning
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Originally Posted by Graybeard
I cannot understand the logic of inhibiting Stall Warning based on low airspeed, unless it's meant as a redundancy to squat switch (WOW) discrete. It would be better to make the WOW more reliable, than add complication to SW logic, but that was an engineer's decision not vetoed by the AB pilots nor certification authorities.
DW replied: I suspect it was not a deliberately designed-in behaviour so much as a point so far outside the envelope that it was not considered. >60kts, in a heavy, at cruise altitude?
Originally Posted by Graybeard
I cannot understand the logic of inhibiting Stall Warning based on low airspeed, unless it's meant as a redundancy to squat switch (WOW) discrete. It would be better to make the WOW more reliable, than add complication to SW logic, but that was an engineer's decision not vetoed by the AB pilots nor certification authorities.
DW replied: I suspect it was not a deliberately designed-in behaviour so much as a point so far outside the envelope that it was not considered. >60kts, in a heavy, at cruise altitude?
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BOAC said:
See the clear announcement in front of you: USE MANUAL TRIM (blinking red if possible), you aren´t protected!
Speed prot wasn´t possible anyway... The system has no idea of speed... It seems...
So... Alternarte Law...?
Oldish or not, i like the idea too...
I still like your (oldish) idea of dropping straight to Direct Law in the 447 scenario, by the way - with a concomitant shift in training, of course....
Speed prot wasn´t possible anyway... The system has no idea of speed... It seems...
So... Alternarte Law...?
Oldish or not, i like the idea too...
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Tio Pablo
How is "Use Manual Trim Only" a Protection? It is a command. BUT, theoretically, it is unneeded for even STALL recovery if zeroed. Elevators are enough. It is a command also to CHECK THS' deflection, and zero it immediately? So, if THS is not necessary for Manual flight, (IT should not be- per certification?) How is THS allowed (commanded) to deploy to max NU in less than NORMAL LAW? And if in other than NORMAL, shouldn't the return to zero be auto as well? Remember, if PF needs its authority, it is available? "Use THS with Caution, Roll Direct, Pitch not protected")
Perhaps, rather than a big red Button to DIRECT, the button should be to ut back neutral the THS. Would not that have been enough in 447' case?
bear
How is "Use Manual Trim Only" a Protection? It is a command. BUT, theoretically, it is unneeded for even STALL recovery if zeroed. Elevators are enough. It is a command also to CHECK THS' deflection, and zero it immediately? So, if THS is not necessary for Manual flight, (IT should not be- per certification?) How is THS allowed (commanded) to deploy to max NU in less than NORMAL LAW? And if in other than NORMAL, shouldn't the return to zero be auto as well? Remember, if PF needs its authority, it is available? "Use THS with Caution, Roll Direct, Pitch not protected")
Perhaps, rather than a big red Button to DIRECT, the button should be to ut back neutral the THS. Would not that have been enough in 447' case?
bear
xcitation
They could have looked at ground speed and it would have helped.
So if you lost IAS and then you scanned GS and see it drop from >400kts to <50kts you would not worry?
So if you lost IAS and then you scanned GS and see it drop from >400kts to <50kts you would not worry?
These guys were on the edge or beyond it and they had very little time to decipher WTF was going on. Nowhere, to my knowledge, is keeping the Groundspeed, even if displayed, a requirement of a basic instrument scan. I'm sure, if the AF447 crew had unlimited time then they may well have noticed the G/S and made the connection.
I'll make the point I made a while back: unless you have experience of an aircraft coming "unglued" around you have no idea how idea how difficult it can be to comprehend (a) how little time you've got left and (b) how bad things have got. I suspect if we could listen to the CVR that would be very clear.
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@bear
I would expect overspeed warning to only disable if IAS was invalid or somewhere beyond Mach 1.0 (no wings then anyway).
My point is that cross referencing ground speed at the onset of lost IAS they would see it reducing during the bizarre zoom climb. Either way if ground speed gradually from 400kts to close to zero it would indicate more an underspeed than an over speed. Giving a profoundly different perception.
If AB disabled SW< 60knots, would they have likewise programmed no WARNING at OVERSPEED? Seems logical?
In a spin, one can have forward A/S, and negative G/S. Fact is, it will always be 'negative' save for still air.
In a spin, one can have forward A/S, and negative G/S. Fact is, it will always be 'negative' save for still air.
My point is that cross referencing ground speed at the onset of lost IAS they would see it reducing during the bizarre zoom climb. Either way if ground speed gradually from 400kts to close to zero it would indicate more an underspeed than an over speed. Giving a profoundly different perception.
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me:
Mike X:
No offense taken. But what has Roselawn to do with what I have said?
My line of argumentation has to do with feed-back and interface between machine and pilots. Of course pilots have to be proficient.
The question I am highlighting is a different one:
We fly FBW Airbuses in a different way from other aircraft. Although the same laws of aerodynamics apply, the "orders we give" to Airbus Flight Controls are: "You fly this way". We really "don't care how" the aircraft is going to "fly that way", but underneath that "order", a number of systems will try to cope with that "order", and will move all the necessary flight controls surfaces (including THS) in order to cope with that "demand". The protections are used to prevent pilots to "order" unrealistic or stupid demands, when in normal law. But when those protections are lost in alternate law, pilots must be very careful when "asking" for unrealistic "orders" (from a degraded FBW aircraft). Unfortunately, the fact that pilots are now used to "ask" for what they "want" from FBW aircraft, without having to actually "fly" the aircraft, has lead them to a false sense of safety. Moreover, the fact that pilots now have no feed-back on the sticks has turned them senseless and complacent. We, FBW pilots have left ourselves tend to be taken by the Principle of Least Effort. And the only way to cope with that, is to try to keep proficient on basic flying skills. I have the fortune of having my own Pitts (together with a couple of friends). Others, just take some spare time in the local aero club. But most think its just a waste of time. I would advise them to think again...and get back to basics.
those aircrafts are ultimately flown by men and that men revert to basics when in face of an outstanding dangerous situation.
No offence, but your statement is unqualified.
My line of argumentation has to do with feed-back and interface between machine and pilots. Of course pilots have to be proficient.
The question I am highlighting is a different one:
We fly FBW Airbuses in a different way from other aircraft. Although the same laws of aerodynamics apply, the "orders we give" to Airbus Flight Controls are: "You fly this way". We really "don't care how" the aircraft is going to "fly that way", but underneath that "order", a number of systems will try to cope with that "order", and will move all the necessary flight controls surfaces (including THS) in order to cope with that "demand". The protections are used to prevent pilots to "order" unrealistic or stupid demands, when in normal law. But when those protections are lost in alternate law, pilots must be very careful when "asking" for unrealistic "orders" (from a degraded FBW aircraft). Unfortunately, the fact that pilots are now used to "ask" for what they "want" from FBW aircraft, without having to actually "fly" the aircraft, has lead them to a false sense of safety. Moreover, the fact that pilots now have no feed-back on the sticks has turned them senseless and complacent. We, FBW pilots have left ourselves tend to be taken by the Principle of Least Effort. And the only way to cope with that, is to try to keep proficient on basic flying skills. I have the fortune of having my own Pitts (together with a couple of friends). Others, just take some spare time in the local aero club. But most think its just a waste of time. I would advise them to think again...and get back to basics.
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How is "Use Manual Trim Only" a Protection? It is a command. BUT, theoretically, it is unneeded for even STALL recovery if zeroed. Elevators are enough.
I hope nobody needs to explain that elevators autorithy is directly related to THS position...
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Seeing a +10 nose up with decreasing airspeed and obviously ground speed decrease should have told them something. I guess they were just bad pilots. What other explanation is there? They probably were never trained to hand fly at altitude. I don't understand why a pilot has to be trained to handfly an airplane. Is it a European thing? I thought hand flying was taught in the first five hours. That is how we do it here.
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Tio
A protection to me means a limit, something is prevented that could conceivably cause a serious problem, and not up to the Pilots in Normal Law. With Alternate Law, Protections are less, though some remain.
My point is that what occurred, for whatever reason, found the a/c climbing and peaking with a "trimming" HS, not a protection, a flight path mitigation re: elevator reduction of effort.
Of course elevators authority are related to PITCH of HS. That is my point, to the extent that it eases elevator pressure in one direction, it fights it in another. One of the reasons the a/c climbed so well, was the THS deflection NU. At apogee, and Stall, it remained full NU, making recovery either problematic or impossible? So it autoed in ALTERNATE LAW all the way up, and since the PF input little nose down, it remained in that position? What inputs he made ND he did not have the boost of the THS.
Now he should have recalled the flight LAW, and pushed (and held?) ND, to recover level flight. He did not.
So, whether he was cognizant of the trim NU or not, he was not cognizant of THS when he "tried" to drop the nose. Only in Direct does the warning appear "Manual Trim Only"? Add in that PITCH is not protected in ALTERNATE LAW, and whatever solution any PF would attempt is hampered with the THS' Position, yes? My simple point is that an annunciated migration of the THS back to neutral would make possible an elevators only solution, just that. That IS a protection, taking THS deflection out the problem. The THS is for continued flight at a certain PITCH, and it is not a maneuvering device, per se. In fact, it is anti maneuver, this time anti LOWER THE NOSE. Favoring the ship Nose Up is not a good thing in a Stall? Is it as simple as connecting the THS drive to STALL WARN? Auto return? Is that undoable? Too expensive? Hurt someone's pride? Or am I throwing Pooh?
A protection to me means a limit, something is prevented that could conceivably cause a serious problem, and not up to the Pilots in Normal Law. With Alternate Law, Protections are less, though some remain.
My point is that what occurred, for whatever reason, found the a/c climbing and peaking with a "trimming" HS, not a protection, a flight path mitigation re: elevator reduction of effort.
Of course elevators authority are related to PITCH of HS. That is my point, to the extent that it eases elevator pressure in one direction, it fights it in another. One of the reasons the a/c climbed so well, was the THS deflection NU. At apogee, and Stall, it remained full NU, making recovery either problematic or impossible? So it autoed in ALTERNATE LAW all the way up, and since the PF input little nose down, it remained in that position? What inputs he made ND he did not have the boost of the THS.
Now he should have recalled the flight LAW, and pushed (and held?) ND, to recover level flight. He did not.
So, whether he was cognizant of the trim NU or not, he was not cognizant of THS when he "tried" to drop the nose. Only in Direct does the warning appear "Manual Trim Only"? Add in that PITCH is not protected in ALTERNATE LAW, and whatever solution any PF would attempt is hampered with the THS' Position, yes? My simple point is that an annunciated migration of the THS back to neutral would make possible an elevators only solution, just that. That IS a protection, taking THS deflection out the problem. The THS is for continued flight at a certain PITCH, and it is not a maneuvering device, per se. In fact, it is anti maneuver, this time anti LOWER THE NOSE. Favoring the ship Nose Up is not a good thing in a Stall? Is it as simple as connecting the THS drive to STALL WARN? Auto return? Is that undoable? Too expensive? Hurt someone's pride? Or am I throwing Pooh?
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unless you have experience of an aircraft coming "unglued" around you have no idea how idea how difficult it can be to comprehend (a) how little time you've got left and (b) how bad things have got. I suspect if we could listen to the CVR that would be very clear.
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Bearfoil,
How will we find out weather the elevator had enough authority the bring the nose down at such a low speed and that immense sink rate. For me a test in the best simulator is no proof it has enough authority. It has to be simulated on the acft. , same weight, same altitude, same CG, 5000 kg in the stab tank. I think EADS is obliged to make a test like that with a test pilot and some normal line pilots with no aerobatic experience.
If this it not possible, maybe full rudder could have helped to bring her nose down, I think the air force pilots call it top rudder. I never heard of this until l was 50 and skipper on a 747. There was a video demonstration from a AA Captain about unusual attitudes. Only after my retirement flying gliders here in the Provence I did these maneuvers real time.
We are not all gifted like Scully and I was certainly not, still I was able to fly 21000 hrs accident and incident free.
It is therefor that I find the conclusion on this matter by the BEA very premature and greatly unfair towards the pilots.
I like Aquadelta's questioning and view on the matter in post nr. 2423.
To me it seems there is more knowledge and serious doubt in this forum than there is with the BEA or is it EADS?
How will we find out weather the elevator had enough authority the bring the nose down at such a low speed and that immense sink rate. For me a test in the best simulator is no proof it has enough authority. It has to be simulated on the acft. , same weight, same altitude, same CG, 5000 kg in the stab tank. I think EADS is obliged to make a test like that with a test pilot and some normal line pilots with no aerobatic experience.
If this it not possible, maybe full rudder could have helped to bring her nose down, I think the air force pilots call it top rudder. I never heard of this until l was 50 and skipper on a 747. There was a video demonstration from a AA Captain about unusual attitudes. Only after my retirement flying gliders here in the Provence I did these maneuvers real time.
We are not all gifted like Scully and I was certainly not, still I was able to fly 21000 hrs accident and incident free.
It is therefor that I find the conclusion on this matter by the BEA very premature and greatly unfair towards the pilots.
I like Aquadelta's questioning and view on the matter in post nr. 2423.
To me it seems there is more knowledge and serious doubt in this forum than there is with the BEA or is it EADS?
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The perfect crime ?
Either the PF was insane either he could have commited the perfect crime if AF, AB and the BEA had not spent millions to recover the boxes :
The PF managed - volontarly - to :
1/ Preparation of the action
- not to use the anti-icing;
- send the captain to rest yet the capt had a nasty feeling : "Do you (really) have your licence ?"
- unfasten his seat belt;
- disconnect from Rio;
- Not connect to Dakar;
2/ Action
- nose up to stall
- lost the plane
- when the PNF wants to take the command : disconnect his stick without telling him;
- when the PNF understand that the problem lies with the PF: he ask the Captain not for his skills but for his authority ;
- when the captain arrived, the PF had this incredible phrase : "we have the speed of a "fool"" so the captain can't understand the situation;
- when the PF his asked to put the wing "à plat" (horizontal) that clearly shows that the PNF had identify the stall, the PF seems to agree but lie and continue to nose up;
Conclusion : Air France is one of the company where the salaries are the higest in the profession and therefore, the selection is really severe. It is just impossible that a 32 years old qualified pilot had not the skill and the training.
In the contrary, many smart people have tried to kill their wife and suicide... ???
The conclusion of the BEA is to undertake a "psychological" inquiry. Then, the case will go to the Court.
The PF managed - volontarly - to :
1/ Preparation of the action
- not to use the anti-icing;
- send the captain to rest yet the capt had a nasty feeling : "Do you (really) have your licence ?"
- unfasten his seat belt;
- disconnect from Rio;
- Not connect to Dakar;
2/ Action
- nose up to stall
- lost the plane
- when the PNF wants to take the command : disconnect his stick without telling him;
- when the PNF understand that the problem lies with the PF: he ask the Captain not for his skills but for his authority ;
- when the captain arrived, the PF had this incredible phrase : "we have the speed of a "fool"" so the captain can't understand the situation;
- when the PF his asked to put the wing "à plat" (horizontal) that clearly shows that the PNF had identify the stall, the PF seems to agree but lie and continue to nose up;
Conclusion : Air France is one of the company where the salaries are the higest in the profession and therefore, the selection is really severe. It is just impossible that a 32 years old qualified pilot had not the skill and the training.
In the contrary, many smart people have tried to kill their wife and suicide... ???
The conclusion of the BEA is to undertake a "psychological" inquiry. Then, the case will go to the Court.
Last edited by JJFFC; 2nd Aug 2011 at 09:55.
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Originally Posted by jcjeant
Another dumb question (and maybe already asked .. no remember .. and the search engine of this forum kill my nerves 
)
Why the AP must absolutely disengage when the system detect incoherent speed datas ?
And consequently ..why the procedure for IAS can't be take in charge by the AP for some time ... (pilots alerted) and give to pilots the time to put their gloves before touch anything ?
)Why the AP must absolutely disengage when the system detect incoherent speed datas ?
And consequently ..why the procedure for IAS can't be take in charge by the AP for some time ... (pilots alerted) and give to pilots the time to put their gloves before touch anything ?
http://www.pprune.org/rumours-news/4...ml#post6582987
NASA is running a project to address that by prototyping "inteligent flight controls" which would adapt to particular degraded conditions whatever they might be. But this is for now just research project. And it's not finished yet, while it started in previous millenium. It's findings will probably first find their way into military UAV (meant to fly over enemy territory, so if one falls off the sky and hits someone on the head it's enemy who's hit so damage is acceptable), then into manned military equipment and only much later into transport category planes.
IMHO, what is conceivable now, not in some distant, undefined future, is making "staged" (or "preanounced") AP disconnect in some (but not all!) situations. I.E. have two thresholds for various parameters. When first threshold (let's call it warning threshold) is crossed there is a warning that AP "feels uneasy" about particular parametr(s) (which crossed that threshold). And the second threshold is exactly what is now AP disconnect threshold and causes the very same effect - disconnects AP.
That would not change current AP logic at all, it would add another system with logic similar the one which rules AP disconnection, but with lower preprogrammed thresholds.And that would help that guys and gals in front to bring themselves fully into the loop before airplane is handed to them.
Psychophysiological entity
How will we find out weather the elevator had enough authority the bring the nose down at such a low speed and that immense sink rate . . .
I again ask - is there any evidence one can be locked into an unrecoverable deeps stall in this aircraft type?
Good memories goes on to say:
For me a test in the best simulator is no proof it has enough authority. It has to be simulated on the acft. , same weight, same altitude, same CG, 5000 kg in the stab tank.
I think EADS is obliged to make a test like that with a test pilot and some normal line pilots with no aerobatic experience.
The suggestion funds might be diverted from executives luxury homes to advanced training is not going to - dare I say, 'fly.' But I'm left wondering just how much of Davis' handling training could have been bought with the costs of years of recovery and even more years of inquiries and the implementation of even more confusing workarounds and fixes.
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Originally Posted by GM
How will we find out weather the elevator had enough authority the bring the nose down at such a low speed and that immense sink rate.
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Originally Posted by BOAC
- NB I am still waiting for Wednesday to download the (English) report, but as I understand it the 'nose down' SS DID move the nose down?
Originally Posted by BOAC
Did the stall warning not 'restart' as the IAS increased? Had the input been continued recovery (from the stall) would probably have been assured. Any reduction in AoA is going the right way and would then rapidly reduce AA further as 'forward' IAS increased.