AF 447 Thread No. 6
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airtren
Again, I would have to defer to proper pilots, but from a strictly aerodynamic point of view I can't see any advantage in being in Direct Law other than the obvious fact that there would not have been any autotrim deflection of the THS - something that IMHO needs sorting anyway.
It depends a bit on where you consider 'Stall' to be. By the time the stall was fully developed the actual details of how the system would respond to control inputs are far less important than the fact that there were no control inputs. If you are considering the actual entry to stall in the first place then the better pitch damping given by Alternate might have been a factor for good.
I don't think much of the harmonisation of roll and pitch given by Alt2, but I suspect that a 'double whammy' of direct law in both axes might have led to even worse results. But I trespass into pilot territory
Without having a Normal Acceleration in the picture, is there any indication that in order to being able to quickly and effectively react and have full control of the control surfaces at Stall, would have been better achieved by being in Direct Law?
It depends a bit on where you consider 'Stall' to be. By the time the stall was fully developed the actual details of how the system would respond to control inputs are far less important than the fact that there were no control inputs. If you are considering the actual entry to stall in the first place then the better pitch damping given by Alternate might have been a factor for good.
I don't think much of the harmonisation of roll and pitch given by Alt2, but I suspect that a 'double whammy' of direct law in both axes might have led to even worse results. But I trespass into pilot territory
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I don't think it would stall, because even at 40 deg aircraft AOA the THS AOA was only about 10 deg. After all, you don't very often see wings stalling at that sort of AOA with plain flaps deflected do you?
Your previous proviso that the downwash rule of thumb (0.4 * mainplane alpha) you used still applies in the flow-field behind a fully stalled wing (typ alpha, 35 ~ 45 degrees); nevertheless, expect your conclusion is right though.
Additionally: Significant drag is contributing to NU trim when and if the tail does stall
Overall, there are several here pretty confident now that this aircraft was not locked into a stall.
That's not to say I would be happy (if asked) with the THS logic at these Mach Nos and altitudes.. this style of 'g' -demand hands-off trimming, is surely never intended for cruise or high altitude flight such as this?
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Qwain Glyndwr,
Thanks for your quick answers. On my way out, I will make some quick clarifications, and perhaps have some more quick questions.
So, the Elevator to THS surface ratio is 3:7, which is 1: 2.33. .... ...
I like that...
Or the THS overcoming the Elevators....
Your focus on THS alone is fine. The THS is slaved to the Elevator - I take that in terms of Auto-trim, as the Elevators move first, and then the THS move follows.
But in terms of rotation and angle, I take that the Elevator is slave to the THS, in that it is hinged to the THS.
As the Elevator is hinged onto the THS, if the THS were FIX, its move/angle would be "simple".
But as the THS moves itself, the Elevators move/angle is relative to the THS, and absolute to the a/c body, and thus "complex" - it has two components: its own, and that of the THS.
At this quick writing I am not sure if I am clear.
As the pitching momentum depends on the angle, the complex angle has a complex effect on the pitching momentum.
Are you sure?
I am not.... but will have to come back to this later....
Imagine cruise AoA, and THS and Elevators at corresponding position.
What would Manual Trim NU of THS do?
Let's ignore it for now, as it is included in the rest, and I may have mistyped...
Yes, it's easiest I agree, ... but it is so, because it is a "simplification".
It considers only:
max NU, with both THS and Elevators at max NU, and
max ND with both THS and Elevators at max ND,
and leaves out the other two combinations, which are part of the set of possible positions see my original post bellow:
5. At AoA 40 degrees, are the THS + Elevator, Thrust, (and Cg) the only (force) factors contributing to the pitching momentum?
It is usual to take moments around the CG, so that doesn't figure in the calculation of moments except through variations in the relevant moment arms. The pitching moment is then affected by THS+elevator, Thrust and pitch rate, although this last is a minor term compared to the others.
I am not sure how to read, or connect your answer to my question.
So, I will rephrase.... each participant moment is a force and an arm. .. I added the Thrust, and Cg in my question to explicitly refer to them, although you've implicitly included them in your sentence I think, or if I understand correctly.
question:
are there any other forces (with their respective arms) involved? at that AoA?
Sorry, for the speed I am typing it,... the temperature of the seat, reminds me I was supposed to leave it a while ago,
Thanks.
Thanks for your quick answers. On my way out, I will make some quick clarifications, and perhaps have some more quick questions.
I know this has been said, but I think it is based on a misinterpretation of the facts (as is quite a lot said here)
)
.... I rather suspect people have been thinking of the ability of the elevator to overcome the THS when they are in opposition, but since the THS is slaved to the elevator it is difficult to see how this could in any way be relevant particularly when you consider the main thrust of my arguments on THS behaviour
Your focus on THS alone is fine. The THS is slaved to the Elevator - I take that in terms of Auto-trim, as the Elevators move first, and then the THS move follows.
But in terms of rotation and angle, I take that the Elevator is slave to the THS, in that it is hinged to the THS.
As the Elevator is hinged onto the THS, if the THS were FIX, its move/angle would be "simple".
But as the THS moves itself, the Elevators move/angle is relative to the THS, and absolute to the a/c body, and thus "complex" - it has two components: its own, and that of the THS.
At this quick writing I am not sure if I am clear.
As the pitching momentum depends on the angle, the complex angle has a complex effect on the pitching momentum.
Are you sure?
I am not.... but will have to come back to this later....
What would Manual Trim NU of THS do?
Let's ignore it for now, as it is included in the rest, and I may have mistyped...
It considers only:
max NU, with both THS and Elevators at max NU, and
max ND with both THS and Elevators at max ND,
and leaves out the other two combinations, which are part of the set of possible positions see my original post bellow:
Originally Posted by airtren
Elevators max NU (absolute) angle is at
- maximum at THSmax NU
- minimum at THSmax ND
and
b) the Elevators max ND (absolute) angle is
- minimum at THS max NU,
and
- maximum at THS max ND.
- maximum at THSmax NU
- minimum at THSmax ND
and
b) the Elevators max ND (absolute) angle is
- minimum at THS max NU,
and
- maximum at THS max ND.
Originally Posted by airtren
Originally Posted by Qwain Glyndwr
The nose was being held up by the application of elevator.
So, I will rephrase.... each participant moment is a force and an arm. .. I added the Thrust, and Cg in my question to explicitly refer to them, although you've implicitly included them in your sentence I think, or if I understand correctly.
question:
are there any other forces (with their respective arms) involved? at that AoA?
Sorry, for the speed I am typing it,... the temperature of the seat, reminds me I was supposed to leave it a while ago,
Thanks.
Last edited by airtren; 26th Aug 2011 at 22:46.
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Harry Mann. "Locked in Stall", given the difference in language spoken here, and semantics, is a highly "loaded" phrase.
The bottom line, for 447, seems to me to be, is the STALL recoverable with NOSE UP elevators and a planted FULLNU THS? (For those hiding in the weeds, and ready to pounce, this is rhetorical).....
Do we know? because for 447, that is the KEY. The PILOTS were committed to NU, without judgment, and hopefully w/o further comment. So for me, what was the role of the THS and 'g' demand control, in a potential 447 recovery?
On its face, it would appear that THS prevented a potential recovery.
Similarly, without 1g demand control for the climb, PF would have STALLED the airframe sooner, much sooner, with NOSE DROP CUE, and perhaps BUFFET CUE.
So, empirically only, and without going straight into who's who, and what needs be DONE, what are your thoughts re: survivability (in best practice recovery), W/O TRIM? IN PITCH DIRECT? (elevator LIMITED).
airtren. "The most powerful control surface on the a/c"? Only because it moves. If the wing could change its Angle of Incidence, it would be far more powerful as a control surface. Surface area that articulates relative the airstream is ad lib powerful, and potentially lethal.
I am starting to think more folks than I thought don't see the THS as HYBRID. It changes the ASPECT ratio radically, automatically, and here, lethally. I think new pilots are shown how she flies, but not why.
What will the training become when the wings of a new iteration of BUS articulate, AOI? "DON'T TOUCH THAT?"
F-8, variable incidence.
The bottom line, for 447, seems to me to be, is the STALL recoverable with NOSE UP elevators and a planted FULLNU THS? (For those hiding in the weeds, and ready to pounce, this is rhetorical).....
Do we know? because for 447, that is the KEY. The PILOTS were committed to NU, without judgment, and hopefully w/o further comment. So for me, what was the role of the THS and 'g' demand control, in a potential 447 recovery?
On its face, it would appear that THS prevented a potential recovery.
Similarly, without 1g demand control for the climb, PF would have STALLED the airframe sooner, much sooner, with NOSE DROP CUE, and perhaps BUFFET CUE.
So, empirically only, and without going straight into who's who, and what needs be DONE, what are your thoughts re: survivability (in best practice recovery), W/O TRIM? IN PITCH DIRECT? (elevator LIMITED).
airtren. "The most powerful control surface on the a/c"? Only because it moves. If the wing could change its Angle of Incidence, it would be far more powerful as a control surface. Surface area that articulates relative the airstream is ad lib powerful, and potentially lethal.
I am starting to think more folks than I thought don't see the THS as HYBRID. It changes the ASPECT ratio radically, automatically, and here, lethally. I think new pilots are shown how she flies, but not why.
What will the training become when the wings of a new iteration of BUS articulate, AOI? "DON'T TOUCH THAT?"
F-8, variable incidence.
Last edited by Lyman; 26th Aug 2011 at 18:18.
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Was it not considered proper behaviour, some time ago, for a/c to "naturally" pitch nose-down when stalled? And when this was not the case, then a "stick pusher" had to be fitted? For FBW (Airbus only?) this was not enforced because the aircraft was to be protected anyway, and never come close to actually being stalled?
If you trim your Cessna full NU and Pull the yoke all the way back you will not see much Nose drop either. Do that in a swept wing and you're lucky if you don't go into a flat spin directly.
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Hi Henra,
In Direct Law - I agree.
In ALT LAW - when stick free, the FBW computers would maintain the same attitude and probably apply more nose up elevator and trim in an attempt to maintain 1g during the stall.
I'm quite confident this aircraft would have dropped the Nose upon stall if this hadn't been so vigorously countered by the massive NU inputs and subsequent THS following.
In ALT LAW - when stick free, the FBW computers would maintain the same attitude and probably apply more nose up elevator and trim in an attempt to maintain 1g during the stall.
However, the drag resulting from a stall of the tail would induce a Nose Down pitching moment rather than Nose Up.
Regarding the recoverability of the stall: Please count me in in the camp of the 'it was technically very likely recoverable' camp.
The A332 is statically stable had a moderate Cg in the given case, has a low tail and a rather short forward fuselage. It is aerodynamically a through and through conventional airliner.
It is no F-16 with negative static stability and massive forebody strakes and Delta wing.
It was Elevator + Trim which enabled it to keep the Nose up.
Regarding behaviour close to the stall in Alt 2 that is an interesting one.
Assumed the control logic is a pure C* it would indeed first try to maintain 1g slowly switched to maintaining of pitch below a certain speed (should be somewhere between 210 and 230 kts for the A330 where the switch from g demand to pitch rate demand occurs).
Where I'm actually not sure is the question if that is all they do in the control logic or if they switch to another logic (eg.g AoA) below another threshold.
which points me to a kind request:
It would be great if someone with access to a level D sim for an A330 could try what happens in Alt2 if you point the Nose 10° NU and let go of the stick. Will it fly attitude right into the stall ?
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With Owain Glyndwr's dissertation on the THS / Elevator relationship, a reposting of a graphic from a previous thread may help. The Attitude represents the aircraft's longitudinal center-line, and the THS angle is referenced to that, while the Elevator is referenced to the THS chord line.
As depicted, the THS has a slight negative camber.
As depicted, the THS has a slight negative camber.
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Hi,
Personally I do not think the AF447 accident has any relation (or could be explained) by trigonometry .. geometry or other formulas .. academic or by the curvature of THS
The accident was related to the actions of the pilot(s)
This aircraft was built according to specifications and apparently he has met these requirements since it was authorized to make commercial flights.
And since the AF447 accident he continue to perform commercial flights
This aircraft is equipped with up to date flight and navigation aids
So .. it indicates to pilots (in the case of 447) that there may stall ... or if this warning is not followed by appropriate reactions of the pilots .. he will warn that the aircraft is experiencing stall
The pilot did not have appropriate responses to deal with the event and did not have appropriate responses to correct his first mistake
The aircraft systems were all put in place to prevent the pilot from his mistake
The stall alarm has been running for 54 seconds continuously
The artificial horizon presented a large blue area
The altimeter showed a rapid loss of altitude
The origin of the event is the icing three pitot probes at the same time (same manufacturer .. same type .. no luck for redundancy)
There was also 3 pilots icing (brain icing) ....
The three pilots, however, were of different types .. but of the same brand (AF)
Even there .. redundancy has not worked ...
Personally I do not think the AF447 accident has any relation (or could be explained) by trigonometry .. geometry or other formulas .. academic or by the curvature of THS
The accident was related to the actions of the pilot(s)
This aircraft was built according to specifications and apparently he has met these requirements since it was authorized to make commercial flights.
And since the AF447 accident he continue to perform commercial flights
This aircraft is equipped with up to date flight and navigation aids
So .. it indicates to pilots (in the case of 447) that there may stall ... or if this warning is not followed by appropriate reactions of the pilots .. he will warn that the aircraft is experiencing stall
The pilot did not have appropriate responses to deal with the event and did not have appropriate responses to correct his first mistake
The aircraft systems were all put in place to prevent the pilot from his mistake
The stall alarm has been running for 54 seconds continuously
The artificial horizon presented a large blue area
The altimeter showed a rapid loss of altitude
The origin of the event is the icing three pitot probes at the same time (same manufacturer .. same type .. no luck for redundancy)
There was also 3 pilots icing (brain icing) ....
The three pilots, however, were of different types .. but of the same brand (AF)
Even there .. redundancy has not worked ...
Hello OwainG,
Following on from your responses to airtren's questions, excuse me checking my own understanding of the relative authorities of THS and elevator, and your 3:2 ratio. I note that your graph combines the two (Dqt and Dq) into an equivalent combined Dq.
If I understand correctly, your method results in, for examples:
THS 0 (Zero) with Elevator -15 (UP) -> equivalent Dq -15
THS -10 (NU) with Elevator 0 (Zero) -> equivalent Dq -15
THS -10 (NU) with Elevator -20 (UP) -> equivalent Dq -35
In the second example above, 100% of the HS surfaces (THS and elevator) are at -10 deg relative to the longitudinal axis of the A/C. In the third, 70% of them are at -10 deg and only 30% at -30 deg. Can you confirm that this is equivalent to a (notional) Dq of -35 (Elevator 35 deg UP) with the THS at zero, in which case only 30% of the surface area is considered to be at -35 deg?
Similarly, picking convenient figures, would:
THS -13.3 (NU) with Elevator +20 (DOWN) -> equivalent Dq zero?
Following on from your responses to airtren's questions, excuse me checking my own understanding of the relative authorities of THS and elevator, and your 3:2 ratio. I note that your graph combines the two (Dqt and Dq) into an equivalent combined Dq.
If I understand correctly, your method results in, for examples:
THS 0 (Zero) with Elevator -15 (UP) -> equivalent Dq -15
THS -10 (NU) with Elevator 0 (Zero) -> equivalent Dq -15
THS -10 (NU) with Elevator -20 (UP) -> equivalent Dq -35
In the second example above, 100% of the HS surfaces (THS and elevator) are at -10 deg relative to the longitudinal axis of the A/C. In the third, 70% of them are at -10 deg and only 30% at -30 deg. Can you confirm that this is equivalent to a (notional) Dq of -35 (Elevator 35 deg UP) with the THS at zero, in which case only 30% of the surface area is considered to be at -35 deg?
Similarly, picking convenient figures, would:
THS -13.3 (NU) with Elevator +20 (DOWN) -> equivalent Dq zero?
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@ Lyman (re: #478)
I understand your first question as this:
"If the THS had (for whatever reason) remained in its previous (cruise) position of 3° NU (afther the aircraft stalled), and considering the crew would have made the same inputs (NU, mainly) as they indeed did, would the plane have by itself unstalled?"
Am I correct there?
I think the answer is no, but I'm not enough qualified to affirm it.
I'm not sure this question is really what matters, but anyway, why not?
---
About the moving wings (re: F-8 Crusader). The fact is that the AoA don't change when the wing moves. It's the plane (the fuselage) which moves. The AoA is relation between the airflow and the wing main chord. Not between the airflow and the plane attitude.
The F-8 wing was built so only to allow the (long) fuselage of the plane not to tail-crash on carrier landings (and perhaps also to ehance the pilot's visibility). That wing stalled at the same AoA, regarless of it's position (incidence) relative to the fuselage.
Take care: apples & oranges aren't the same
---
@ jcjeant (re: #485)
I do agree, for once.
But I'm still sure the plane can be made safer, with some "tweaks". That doesn't imply I think it is not safe now (I think it is), but that ehancements may (must?) be made, in the light of AF447's tragedy: The more holes in the cheese are resealed, the better.
I understand your first question as this:
"If the THS had (for whatever reason) remained in its previous (cruise) position of 3° NU (afther the aircraft stalled), and considering the crew would have made the same inputs (NU, mainly) as they indeed did, would the plane have by itself unstalled?"
Am I correct there?
I think the answer is no, but I'm not enough qualified to affirm it.
I'm not sure this question is really what matters, but anyway, why not?
---
About the moving wings (re: F-8 Crusader). The fact is that the AoA don't change when the wing moves. It's the plane (the fuselage) which moves. The AoA is relation between the airflow and the wing main chord. Not between the airflow and the plane attitude.
The F-8 wing was built so only to allow the (long) fuselage of the plane not to tail-crash on carrier landings (and perhaps also to ehance the pilot's visibility). That wing stalled at the same AoA, regarless of it's position (incidence) relative to the fuselage.
Take care: apples & oranges aren't the same
---
@ jcjeant (re: #485)
I do agree, for once.
But I'm still sure the plane can be made safer, with some "tweaks". That doesn't imply I think it is not safe now (I think it is), but that ehancements may (must?) be made, in the light of AF447's tragedy: The more holes in the cheese are resealed, the better.
Last edited by AlphaZuluRomeo; 26th Aug 2011 at 20:51.
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It would be great if someone with access to a level D sim for an A330 could try what happens in Alt2 if you point the Nose 10° NU and let go of the stick. Will it fly attitude right into the stall ?
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Owain
Re: your opinion v/v AL2 v. DIRECT LAW at climb (handoff). You neglect to mention the negation of g command. PITCH, DIRECT, would have well defined suggestions as to 'recovery'?
As in, do you have an opinion on what to then do with elevators? That would be important, should they be limited? RATE + DEFLECTION?
Not just the AUTOTRIM would be missing, NO?
I hope I am not being simplistic, but I see a very definite (dis)connection between the "Helpful" bits of AL2 verse the DIRECT behaviour of DIRECT.
Simply put, and given that she "Did what was commanded", had she been DIRECT, she would not have pissed away her energy in a g commanded climb, and the PF would quick like a mouse had a STALL, with NOSE DROP, BUFFET, and a very focused PNF. Captain would not have been called. As it was, Captain's ultimate presence was not helpful. Recovery? I can't be sure, but as a pilot which would you prefer?
The honesty of DIRECT LAW, or the "HELPS" of AL2?
Your CALL?
Q1:
AZR Your quote did not look familiar, so I went back, and don't see in my post a question such as you quoted.
edit. OK, I think I mean what you see. Would the A/C have STALLED, conventionally, with FULLNU elevators, and -3 THS? I think yes, You? I also think recovery would have been straightforward, though of course wicked challenging, I'll give it a miss!
Q2:
AZR, that is my point, but I disagree that the AoA will not change, as the Cl does, and the a/c will accomodate the "new" fuselage orient, with Tail. The relationship is dynamic, very dynamic. That is why the difference twixt AoA and Longitudinal alignment is critical, altering the "comfort zone" of the system (aspect) changes relative to all the surfaces, and a moving lift surface changes the balances with greatly divergent rates, as it moves. imo.
Re: your opinion v/v AL2 v. DIRECT LAW at climb (handoff). You neglect to mention the negation of g command. PITCH, DIRECT, would have well defined suggestions as to 'recovery'?
As in, do you have an opinion on what to then do with elevators? That would be important, should they be limited? RATE + DEFLECTION?
Not just the AUTOTRIM would be missing, NO?
I hope I am not being simplistic, but I see a very definite (dis)connection between the "Helpful" bits of AL2 verse the DIRECT behaviour of DIRECT.
Simply put, and given that she "Did what was commanded", had she been DIRECT, she would not have pissed away her energy in a g commanded climb, and the PF would quick like a mouse had a STALL, with NOSE DROP, BUFFET, and a very focused PNF. Captain would not have been called. As it was, Captain's ultimate presence was not helpful. Recovery? I can't be sure, but as a pilot which would you prefer?
The honesty of DIRECT LAW, or the "HELPS" of AL2?
Your CALL?
Q1:
AZR Your quote did not look familiar, so I went back, and don't see in my post a question such as you quoted.
edit. OK, I think I mean what you see. Would the A/C have STALLED, conventionally, with FULLNU elevators, and -3 THS? I think yes, You? I also think recovery would have been straightforward, though of course wicked challenging, I'll give it a miss!
Q2:
AZR, that is my point, but I disagree that the AoA will not change, as the Cl does, and the a/c will accomodate the "new" fuselage orient, with Tail. The relationship is dynamic, very dynamic. That is why the difference twixt AoA and Longitudinal alignment is critical, altering the "comfort zone" of the system (aspect) changes relative to all the surfaces, and a moving lift surface changes the balances with greatly divergent rates, as it moves. imo.
Last edited by Lyman; 26th Aug 2011 at 21:00.
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Hi Chris,
Yes, your understanding of what I intended is correct.
I see the difficulty that you and airtren might have and I think it stems from my not specifying that the THS and elevator contributions can be calculated separately and then added together (at least up to the point where significant nonlinearity/stall becomes important).
What the theory says is that the whole THS deflected through 10 deg will produce the same lift force as the last 30% of the chord deflected through 15 deg. If you then take the whole surface at 10 deg and deflect the last 30% by another 20 deg say the total lift will be the same as the surface at zero AOA and the controls deflected through 35 deg, although of course that last bit of chord will actually only be deflected 30 deg to freestream.The difference is the lift generated on the fixed bit of THS ahead of the elevators.
You will I'm sure appreciate this is an artifice introduced to allow one to collapse the data onto a single line, but it does give an appreciation of the aerodynamics without the complication of worrying about what angle a particular surface is to whatever reference ...
Yes, your understanding of what I intended is correct.
I see the difficulty that you and airtren might have and I think it stems from my not specifying that the THS and elevator contributions can be calculated separately and then added together (at least up to the point where significant nonlinearity/stall becomes important).
What the theory says is that the whole THS deflected through 10 deg will produce the same lift force as the last 30% of the chord deflected through 15 deg. If you then take the whole surface at 10 deg and deflect the last 30% by another 20 deg say the total lift will be the same as the surface at zero AOA and the controls deflected through 35 deg, although of course that last bit of chord will actually only be deflected 30 deg to freestream.The difference is the lift generated on the fixed bit of THS ahead of the elevators.
You will I'm sure appreciate this is an artifice introduced to allow one to collapse the data onto a single line, but it does give an appreciation of the aerodynamics without the complication of worrying about what angle a particular surface is to whatever reference ...
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jcjeant,
The work, data and discussion that you've alluded to is relevant particularly to the Stall, and Stall Recovery, which was part of what was described as Phase 3 of the events analyzed in the BEA Report.
The elements discussed are a help in understanding better the conditions that persisted during the Stall, and understanding better the elements that could have contributed to making the Stall Recovery easier, or more difficult. Some of that is science.
The type of Stall Recovery the AF 447 would have required is particularly difficult at the size and weight of an A330, and even more so because of the night conditions, and use of instruments as only indications of attitude, altitude and speed of the plane I am not aware of any Airbus Stall Recoveries during the night. It requires most talent, training, and practice.
I hope this explanation helps.
airtren
The work, data and discussion that you've alluded to is relevant particularly to the Stall, and Stall Recovery, which was part of what was described as Phase 3 of the events analyzed in the BEA Report.
The elements discussed are a help in understanding better the conditions that persisted during the Stall, and understanding better the elements that could have contributed to making the Stall Recovery easier, or more difficult. Some of that is science.
The type of Stall Recovery the AF 447 would have required is particularly difficult at the size and weight of an A330, and even more so because of the night conditions, and use of instruments as only indications of attitude, altitude and speed of the plane I am not aware of any Airbus Stall Recoveries during the night. It requires most talent, training, and practice.
I hope this explanation helps.
airtren
Last edited by airtren; 26th Aug 2011 at 23:28.
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Lyman:
Q1: It was not a quote, but a re-phrasing. The purpose was to check if I understood what you were seeking for. Based on your last post, it seems not, but I still don't see where you're going. Hope you do, still...
Sidenote: About (and there follows a quote):
I don't have to think, here. Neither do you. The aircraft did stall at ~02:10:25. At that time, the THS was at its cruise value of 3° NU. And the elevators weren't even full NU.
So it's not about thinking, only reading the FDR traces. And deducing (OK, that's a tought stricly speaking) that of course with full NU elevators the stall would have occured too.
=> That was never a question (to me).
=> I cannot phrase more accurately that I did in my post #488 the question I thought you were asking. Sorry.
Q2: My point was direct relation or not (yes, dynamic link, but no direct relation). Anyway, let's drop it, it's out of topic here.
Did you see my last MP, and the question it contained?
Q1: It was not a quote, but a re-phrasing. The purpose was to check if I understood what you were seeking for. Based on your last post, it seems not, but I still don't see where you're going. Hope you do, still...
Sidenote: About (and there follows a quote):
Would the A/C have STALLED, conventionally, with FULLNU elevators, and -3 THS? I think yes, You?
So it's not about thinking, only reading the FDR traces. And deducing (OK, that's a tought stricly speaking) that of course with full NU elevators the stall would have occured too.
=> That was never a question (to me).
=> I cannot phrase more accurately that I did in my post #488 the question I thought you were asking. Sorry.
Q2: My point was direct relation or not (yes, dynamic link, but no direct relation). Anyway, let's drop it, it's out of topic here.
Did you see my last MP, and the question it contained?
Join Date: Aug 2011
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I am without proper quoting skills, I too rely on memory to paraphrase, and I frequently stream my thoughts one post to the next.
It is not in disregard of others, nor meant to be complicated. Only one thing, I was discussing these things in relation to a similar entry to STALL but with DIRECT LAW. She would Stall, of course. Also, without the g commanded Pitch up, she'd have STALLED far sooner, I think that would have made things a bit more straightforward for our crew. Not to mention a stowed and unavailable THS (but by hand).
Sorry for my confused state, and thanks for your thoughts.
It is not in disregard of others, nor meant to be complicated. Only one thing, I was discussing these things in relation to a similar entry to STALL but with DIRECT LAW. She would Stall, of course. Also, without the g commanded Pitch up, she'd have STALLED far sooner, I think that would have made things a bit more straightforward for our crew. Not to mention a stowed and unavailable THS (but by hand).
Sorry for my confused state, and thanks for your thoughts.