AF 447 Thread No. 9
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Hi,
Turbine D
Ref
PJ2
Turbine D
Ref
PJ2
and not at cruise altitude which didn't require any action at all as the "safe conduct of the flight" was not in question
What is "unsafe condition"
The definition of "unsafe condition" is given in the AMC 21 A 3b (b):
a) event likely to cause victims, usually with the destruction of
plane or likely to reduce the capacity of the aircraft or crew to manage
degraded conditions that lead to:
A significant reduction in safety margins or functional capabilities;
Physical distress or excessive workload which no longer allows
crew to perform its tasks accurately or to complete them;
The occurrence of death or serious injury to at least one occupant of the aircraft.
Unless it is shown that the probability of this event is within the limits defined
by certification standards.
Note: The equipment must operate an aircraft throughout its flight and admits that
there can be failures whose probability does not exceed a threshold defined by the
severity of the risk (minor, major, hazardous, catastrophic). In the case of blockage of the Pitot probes, it
may be withheld probability of occurrence because it is not a failure but a failure. the
manufacturer and the regulator have the obligation to eliminate all the defects of an aircraft.
The definition of "unsafe condition" is given in the AMC 21 A 3b (b):
a) event likely to cause victims, usually with the destruction of
plane or likely to reduce the capacity of the aircraft or crew to manage
degraded conditions that lead to:
A significant reduction in safety margins or functional capabilities;
Physical distress or excessive workload which no longer allows
crew to perform its tasks accurately or to complete them;
The occurrence of death or serious injury to at least one occupant of the aircraft.
Unless it is shown that the probability of this event is within the limits defined
by certification standards.
Note: The equipment must operate an aircraft throughout its flight and admits that
there can be failures whose probability does not exceed a threshold defined by the
severity of the risk (minor, major, hazardous, catastrophic). In the case of blockage of the Pitot probes, it
may be withheld probability of occurrence because it is not a failure but a failure. the
manufacturer and the regulator have the obligation to eliminate all the defects of an aircraft.
September 8, 2009: The FAA conducts emergency disposal of the AA Pitot probe
AD 2009-18-08 (Appendix 49) stating that it is the response to an "unsafe
condition "(In the document 14 CFR part 39.5, the FAA states that" airworthiness
Directive "is published in response to an" unsafe condition ") to eliminate all the defects of an aircraft.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the
Member States of the European Community, has issued a Notification of a Proposal to
Issue an Airworthiness Directive (PAD), PAD 09‐099, dated August 10, 2009 (referred to
after this as “the EASA PAD”), to correct an unsafe condition for certain Airbus Model
A330‐200 and ‐300 series airplanes, Model A340‐200 and ‐300 series airplanes, and
Model A340‐541 and ‐642 airplanes.
“ we have reviewed the numerous airspeed anomalies recently reported on Model
A330 and A340 airplanes. Based on our review, we have determined that an unsafe
condition exists and immediate airworthiness action for the Model A330 and A340 fleet
is warranted.”
Because an unsafe condition exists that requires the immediate adoption of this AD, we
find that notice and opportunity for prior public comment hereon are impracticable and
that good cause exists for making this amendment effective in less than 30 days.
AD 2009-18-08 (Appendix 49) stating that it is the response to an "unsafe
condition "(In the document 14 CFR part 39.5, the FAA states that" airworthiness
Directive "is published in response to an" unsafe condition ") to eliminate all the defects of an aircraft.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the
Member States of the European Community, has issued a Notification of a Proposal to
Issue an Airworthiness Directive (PAD), PAD 09‐099, dated August 10, 2009 (referred to
after this as “the EASA PAD”), to correct an unsafe condition for certain Airbus Model
A330‐200 and ‐300 series airplanes, Model A340‐200 and ‐300 series airplanes, and
Model A340‐541 and ‐642 airplanes.
“ we have reviewed the numerous airspeed anomalies recently reported on Model
A330 and A340 airplanes. Based on our review, we have determined that an unsafe
condition exists and immediate airworthiness action for the Model A330 and A340 fleet
is warranted.”
Because an unsafe condition exists that requires the immediate adoption of this AD, we
find that notice and opportunity for prior public comment hereon are impracticable and
that good cause exists for making this amendment effective in less than 30 days.
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One Outsider ...
The cabin altitude is limited to a maximum of 7350 feet, it is not set to it.
The cabin altitude is limited to a maximum of 7350 feet, it is not set to it.
I hadn't referred to the FCOM; just remembered the figure from eons ago.
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@Dozy
"Except that Direct Law throws the crew into a situation where the aircraft handles differently in *every axis* compared to what they are used to, which would likely be more risky than the current design."
You are suggesting the crew are better off with a "hybrid" control Law, Direct in Roll, and Load factor in Longitudinal.
That makes no sense, PF handled the Direct axis, but had consummate trouble with his "familiar".
The facts belie your proposal....
@infrequentflyer789
"How are you programming in a 3deg THS limit in your sim when there is not one on the a/c - are you using a THS-failure setup of some sort or are you physically holding the trim wheel to override the autotrim or what?"
The THS did not move for 43 seconds between the two STALL warnings, 1 and 2.
Shouldn't that be programmed into the sim, when replicating the climb?
It stopped at three degrees, then resumed at the top, to smoothly go to MaxNU, where it stayed til impact. This is AUTOTRIM? Ascending, was PF's elevator limited? After the beginning of Autotrim at STALLWARN 2, did he regain elevators fully?
"Except that Direct Law throws the crew into a situation where the aircraft handles differently in *every axis* compared to what they are used to, which would likely be more risky than the current design."
You are suggesting the crew are better off with a "hybrid" control Law, Direct in Roll, and Load factor in Longitudinal.
That makes no sense, PF handled the Direct axis, but had consummate trouble with his "familiar".
The facts belie your proposal....
@infrequentflyer789
"How are you programming in a 3deg THS limit in your sim when there is not one on the a/c - are you using a THS-failure setup of some sort or are you physically holding the trim wheel to override the autotrim or what?"
The THS did not move for 43 seconds between the two STALL warnings, 1 and 2.
Shouldn't that be programmed into the sim, when replicating the climb?
It stopped at three degrees, then resumed at the top, to smoothly go to MaxNU, where it stayed til impact. This is AUTOTRIM? Ascending, was PF's elevator limited? After the beginning of Autotrim at STALLWARN 2, did he regain elevators fully?
Last edited by Lyman; 17th Aug 2012 at 23:17.
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Originally Posted by mm43
Semantics.
Just as a general remark, these threads have run way past they sell by date and there are several posters who would have done themselves a great service had they stopped some time ago.
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Post Stall is irrelevant. Stop trying to cape the Bull. Your suggestion of support for the hybrid Control Law does not hold water.
Roll was mastered as Machinbird has eloquently posted. What have you to say re: hibernating Horizontal?
Roll was mastered as Machinbird has eloquently posted. What have you to say re: hibernating Horizontal?
Quote:
OK465
In practice, in ALT LAW, if the THS is somehow stopped at any position, when further movement would be commanded, the FCPC treats this as a jammed stab and will only exercise about 1/2 of the remaining elevator movement automatically, leaving the pilot about 1/2 of the elevator movement for manual control.
OK465
In practice, in ALT LAW, if the THS is somehow stopped at any position, when further movement would be commanded, the FCPC treats this as a jammed stab and will only exercise about 1/2 of the remaining elevator movement automatically, leaving the pilot about 1/2 of the elevator movement for manual control.
That seems counter intuitive. Do you mean other than a manual input to the Trim Wheel?
Whether you 'hold' the trim wheel or 'fail' the system internally, if you then change airspeed, the ECAM message concerning a THS 'jam' will be displayed when the elevator reaches about half travel and that's the limit to which the FCS will take the elevator.
This gives the pilot both manual nose up and manual nose down elevator authority thru the SS, whereas an elevator at the actual travel limit provides for nose authority in only one direction.
This actually seems intuitive to me.
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Originally Posted by One Outsider
Just as a general remark, these threads have run way past they sell by date and there are several posters who would have done themselves a great service had they stopped some time ago.
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Roll was mastered as Machinbird has eloquently posted.
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Piloting 101 (or Air Training Corps Leading Cadet exam c. 1992).
When stalled, the airflow over the wings is insufficiently stable to allow the ailerons to behave in a stable and predictable way. The only way to stabilise roll when stalled is to use the rudder.
When stalled, the airflow over the wings is insufficiently stable to allow the ailerons to behave in a stable and predictable way. The only way to stabilise roll when stalled is to use the rudder.
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Dozy
Quote:
Roll was mastered as Machinbird has eloquently posted.
He spent a long time on PIO roll. The PF did control Roll in DIRECT in the climb...
By using aileron, spoilers.......
"When stalled, the airflow over the wings is insufficiently stable to allow the ailerons to behave in a stable and predictable way. The only way to stabilise roll when stalled is to use the rudder."
Or spin, careful........
Quote:
Roll was mastered as Machinbird has eloquently posted.
He spent a long time on PIO roll. The PF did control Roll in DIRECT in the climb...
By using aileron, spoilers.......
"When stalled, the airflow over the wings is insufficiently stable to allow the ailerons to behave in a stable and predictable way. The only way to stabilise roll when stalled is to use the rudder."
Or spin, careful........
Last edited by Lyman; 18th Aug 2012 at 00:07.
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Whether the PF started to get control of the roll in the climb or not is neither here nor there - the point is that the pitch inputs were all wrong from beginning to end. As CONF iture likes to point out, I have no line experience at all - and yet I did not inadvertantly add roll input to my pitch control during the sequence (in fact I had to work hard to do so), despite trying to settle the roll with the ailerons during the climb.
It took the TRE shouting at me to control the roll with rudder post-stall to make me do so (sadly I forgot a lot of what I once knew), but even then we managed to recover.
Spinning is hard to induce in a swept-wing design - they tend to develop a spiral dive instead. Birgenair 301 *did* spin towards the end of the sequence, but the DFDR proved that was caused by an asymmetric engine compressor stall rather than flight control input.
It took the TRE shouting at me to control the roll with rudder post-stall to make me do so (sadly I forgot a lot of what I once knew), but even then we managed to recover.
Spinning is hard to induce in a swept-wing design - they tend to develop a spiral dive instead. Birgenair 301 *did* spin towards the end of the sequence, but the DFDR proved that was caused by an asymmetric engine compressor stall rather than flight control input.
Last edited by DozyWannabe; 18th Aug 2012 at 00:16.
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Hi jcjeant,
If you live in the USA and watch the early 1/2 hour evening national news, you agonize through 6-8 pharmaceutical commercials in the non-political season. The first 15 seconds extol the benefits of the product, the next 45 seconds is a legal disclaimer listing all the things that could go wrong up to and including death. It is what is known as "legal speak". It protects the pharmaceutical company from damages should you die taking their product, because they told you so. So the FAA and EASA develops wording (legal speak) defining "unsafe condition" or proposing a PAD for a condition for which there is no 100% remedy, now or in the future (our lifetime). This is legal speak to relieve themselves of responsibility should and when the next event occurs and at least one person dies. It is the way things work these days. Lets say you are zooming down the unregulated speed section of the autobahn in you BMW or Porsche at 240 KPH and you suffer LOC. Your estate will not be able to sue the government as they somewhere have a disclaimer (travel at your own risk). However, your estate may be able to sue BMW or Porsche for designing and building a car that goes so fast thereby causing your LOC. Such is the state of the legal business in the Western world. If either the FAA or EASA were really concerned they would have addressed this problem years ago, in fact they are not because there isn't a solution. A substantial part of my career was spent working with lawyers, supporting lawyers or working against lawyers. I know how the system works, at least in the US.
If you live in the USA and watch the early 1/2 hour evening national news, you agonize through 6-8 pharmaceutical commercials in the non-political season. The first 15 seconds extol the benefits of the product, the next 45 seconds is a legal disclaimer listing all the things that could go wrong up to and including death. It is what is known as "legal speak". It protects the pharmaceutical company from damages should you die taking their product, because they told you so. So the FAA and EASA develops wording (legal speak) defining "unsafe condition" or proposing a PAD for a condition for which there is no 100% remedy, now or in the future (our lifetime). This is legal speak to relieve themselves of responsibility should and when the next event occurs and at least one person dies. It is the way things work these days. Lets say you are zooming down the unregulated speed section of the autobahn in you BMW or Porsche at 240 KPH and you suffer LOC. Your estate will not be able to sue the government as they somewhere have a disclaimer (travel at your own risk). However, your estate may be able to sue BMW or Porsche for designing and building a car that goes so fast thereby causing your LOC. Such is the state of the legal business in the Western world. If either the FAA or EASA were really concerned they would have addressed this problem years ago, in fact they are not because there isn't a solution. A substantial part of my career was spent working with lawyers, supporting lawyers or working against lawyers. I know how the system works, at least in the US.
It took the TRE shouting at me to control the roll with rudder post-stall to make me do so (sadly I forgot a lot of what I once knew), but even then we managed to recover.
Post stall "beta'' effects in a Level D simulator at this point in time are essentially worthless.
Last edited by OK465; 18th Aug 2012 at 01:06. Reason: added quote
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A quote from Captain William Wainright, Chief Pilot Airbus Industry
USE OF RUDDER We also spent a lot of time dis-cussing the use of rudder. The exist-ing training courses all emphasised using rudder for roll control at low speeds. It is true that the rudder re-mains effective down to very low speeds, and fighter pilots are accustomed to using it for “scissor” e v asive ma-noeuvres when flying not far from the stall. But large airlin-ers, with all the inertias that they pos-sess, are not like fighter aircraft. Based on our experience as test pilots we are very wary of using rudder close to the stall. It is the best way to provoke a loss of control if not used very carefully, particularly with flaps out. We finally got the training managers to agree to play down the use of rudder in their existing courses. But we do not say never use the rudder at low speed. We say that, if necessary, the aileron inputs can be assisted by coordinated rudder in the direction of the desired roll. However, we also caution that “ex-cessive rudder can cause excessive sideslip, which could lead to departure from controlled flight”.
End quote.
That can be found in FAST #24, a discussion of aircraft upset.
If rudder is the best way to " provoke a loss of control" in an upset, how could it be beneficial in the stall? I do agree with you were we discussing straight wing low speed trainers, but not large swept wing turbojets.
USE OF RUDDER We also spent a lot of time dis-cussing the use of rudder. The exist-ing training courses all emphasised using rudder for roll control at low speeds. It is true that the rudder re-mains effective down to very low speeds, and fighter pilots are accustomed to using it for “scissor” e v asive ma-noeuvres when flying not far from the stall. But large airlin-ers, with all the inertias that they pos-sess, are not like fighter aircraft. Based on our experience as test pilots we are very wary of using rudder close to the stall. It is the best way to provoke a loss of control if not used very carefully, particularly with flaps out. We finally got the training managers to agree to play down the use of rudder in their existing courses. But we do not say never use the rudder at low speed. We say that, if necessary, the aileron inputs can be assisted by coordinated rudder in the direction of the desired roll. However, we also caution that “ex-cessive rudder can cause excessive sideslip, which could lead to departure from controlled flight”.
End quote.
That can be found in FAST #24, a discussion of aircraft upset.
If rudder is the best way to " provoke a loss of control" in an upset, how could it be beneficial in the stall? I do agree with you were we discussing straight wing low speed trainers, but not large swept wing turbojets.
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As we all know, roll wasn't the problem, pulling up into a stall was. Never pull up into a 15 degree pitch angle in any airliner and expect the ailerons to work once you stall. Only very inexperienced pilots would attempt this at FL350 because you will stall and ailerons are the least of your worries.
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Originally Posted by studi
We are waiting for your well thought out explanation why autotrim OVERALL is such a bad feature to have after Clandestino very well showed how hard it is to deal on a conventional plane with stall situations.
No – Quote me please.
Autotrim should withdraw in case of known dubious data ?
Absolutely.
The guys did not trim in the 737 when they should have – Fair enough – Pretty sure they have learned the lesson and everybody smart enough to read their adventure will have also.
But what I like is the unambiguous rule : If manual flight trim is on you (the PF).
To the contrary on the Airbus confusion is around (Airplane talking) :
- If manual flight trim is on me
- Sometimes I won’t trim for you but I will advise
- But sometimes I may forget …
- Or some other times I will trim when I should not
- Or I won’t even if I should.
To my understanding one type of alternate law would not have trimmed further as the AoA reached a critical value, but the alternate law on which was AF447 just kept trimming … Go and figure ?
... how hard it is to deal on a conventional plane with stall situations
CONF, you are becoming pathetic. Play the ball, not the man.
The man fully deserves that little extra and don’t worry he’s very much able to take it, but pathetic I am ... you may be right.