AF447 wreckage found
No I haven't but I don't think it would be a lot different to the stalls I have done at 22,000'. It would be a little more sensitive perhaps and i would need to be careful not to over control but the principles of stall recognition and recovery defined by Airbus in their FCTM and QRH would be the same:-
1/ reduce AOA
2/ increase energy.
1/ reduce AOA
2/ increase energy.
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The more I read, the more clear it gets: the poor guys failed to recognize they were flying a full stalled plane, got absolutely scared by the bells and whistles blaring all the time, rocking wings, winding down altimeters, a panicked captain shouting instructions and simply frozen at the controls, failing to do the only thing that would have saved the day. Pure lack of proper training, basic airmanship & situation awareness. It's hard to admit that a lot of us could have reacted exactly the same way.
A perfectly flyable aircraft turned into a gigantic coffin.
Of course there'll be endless theories about A330 systems, speculations on Boeing x Airbus, if this, if that etc... "
A perfectly flyable aircraft turned into a gigantic coffin.
Of course there'll be endless theories about A330 systems, speculations on Boeing x Airbus, if this, if that etc... "
Here comes to play a major role of Airbus system design, like it or not. With substantial personal experience in both own circumstances and other's, there must follow-on a drastic system redesign:
a. A human is unlikely to adapt well to changing control laws. Why is someone, used to not trimming, start trimming all of a sudden while he is already task-overloaded.
b. Why would anyone have an autoflight system obstructing/ overruling pilot control inputs and decisions, in a stable transport aircraft. Believe me I have likely much more experience than most of you flying variable stability aircraft and rotorcraft. There is no need to override a pilot control motion, just to properly design the flight control system such that there is almost no likelihood of the pilot damaging the aircraft to become unflyable. This must be coupled with proper pilot selection and training. Too expensive for the airline? choose another.
The CSS (Control Stick Steering) Boeing design, an arrangement I flew as example on the Douglas A-4H Skyhawk, enables autopilot flight during which the pilot can make desired changes, small or substantial, by synchronizing autopilot feedback signal (nullifying it) in the channel the pilot has applied force onto, such that it recognizes the new desired attitude upon pilot control pressure release. Simple and natural for the human in flight, during blue skies and in emergencies.
I would never pilot an aircraft with not only a mind of its own, such as trimming, but also limiting my AOA command, whether within the flight envelope or out of it. As captain it is my call, I know how to fly it better than any lead system engineer, fill reports later, in 36 years of flying they were few but all very well accepted and approved.
The current modern pilot flight displays are overly saturated such that no regular apt and trained human can quickly build in his mind a dynamic aerial situation. 60 year old captains would need at least double the time for that. In research simulator flights, 18 out of 19 seasoned and young pilots alike, failed to recognize and act upon erroneous FMA readings and below glidepath approaches. To me this is more than obvious, and leads to e.g. a Boeing 737-800 flying an auto-ILS with 1:50 of idle throttles just to stall it before the threshold, without pilot reaction, till it was too late. You guys fly them and should be well aware of this.
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?somatogravic disorientation - pitch down illusion?
Sounds like the common sense immediate response to the stall warning was ignored, but the deceleration could have created a somatogravic illusion ,shared by all, for false nose down pitch sensation, hence the repeated and probably confused "pitch up" commands.
If thats the case, everyone would have had to be ignoring the AI, the stall warning, and the angle of attack indicator....very very strange....
A worst case scenario would combine it with a tail heavy loading configuation but that doesnt appear to be the case.
Sadly, they just couldn't work out out how to fly a stalled aircraft, no ASI, albeit in very bad weather which was avoidable...
If thats the case, everyone would have had to be ignoring the AI, the stall warning, and the angle of attack indicator....very very strange....
A worst case scenario would combine it with a tail heavy loading configuation but that doesnt appear to be the case.
Sadly, they just couldn't work out out how to fly a stalled aircraft, no ASI, albeit in very bad weather which was avoidable...
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Ask21,
good thoughts, especially about the trim effect on aoa of the stab. I fly only small planes, but I guess the report is simply not providing enough information for a sound judgement.
I would not be surprised if the final conclusion will be that this stall, fully developed, was unrecoverable. I doubt if such a scenario was ever flight tested during certification. Certainly not without a drag chute installed.
good thoughts, especially about the trim effect on aoa of the stab. I fly only small planes, but I guess the report is simply not providing enough information for a sound judgement.
I would not be surprised if the final conclusion will be that this stall, fully developed, was unrecoverable. I doubt if such a scenario was ever flight tested during certification. Certainly not without a drag chute installed.
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Never the computer will prevent you from recovering from a stall
Human factor is the only cause of the stall.
Whatever is the configuration of the computer, when stall warning : nose down.
Never a computer will prevent you from recovering from a stall if you nose down.
Both american and european authorities says that 80% of the crews earing a stall warning don't nose down at first bacause of a human factor.
The challenge is to train the crews to react like a top gun and not like a civil servant.
Whatever is the configuration of the computer, when stall warning : nose down.
Never a computer will prevent you from recovering from a stall if you nose down.
Both american and european authorities says that 80% of the crews earing a stall warning don't nose down at first bacause of a human factor.
The challenge is to train the crews to react like a top gun and not like a civil servant.
Dropping a wing is taught in unusual attitude recoveries on Boeings if you find yourself with a very high nose attitude and the speed rapidly heading south. ( and at the same time reducing thrust to help to help the nose down pitching moment )
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There could have been a deceleration somatogravic pitch down illusion causing the erroneous pitch up commands. But 3 minutes or so is a long time to keep that up - I'd be surprised if the artificial horizon and the angle of attack indicator were not functioning, and even more surprised if they werent referenced automatically in the stall.
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To recover a stall, forward sidestick control motion is required. It was recovered once then the pilot longitudinal control moved aft and stayed there. The rest about such things like anti-spin chute, recoverability etc... may be important but irrelevant to the specific stall recovery.
Cricky do any of you fellas read previous posts?
Yes all the Attitude indicators where fully functioning.
The problem was with the Air Data Modules receiving crap info from the iced up Pitot tubes....
Some Aircraft have AOA displayed on the Primary Flight Display but in this case I don't think AF do. Certainly my Airline and many others do not on any of our Aircraft types.
Yes all the Attitude indicators where fully functioning.
The problem was with the Air Data Modules receiving crap info from the iced up Pitot tubes....
Some Aircraft have AOA displayed on the Primary Flight Display but in this case I don't think AF do. Certainly my Airline and many others do not on any of our Aircraft types.
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I'm sorry, I'm losing the overview.
Can somebody please remind me, what the margins were in the given conditions?
Obviously, the air was relatively warm yet below dew point. How can we interpret that they couldn't climb higher because of the temperature gradient being shallower than expected? Was that just referring to the tops of the cb being above their ceiling at that time?
What's the speed margin between Vmmo and Vs?
What's the AoA in normal flight at that altitude and what's the Stall AoA? (did I see it's only 6°?)
What triggered the 13° nose up trim on the THS? What impact would that setting have, along with fuel trim aft, on their chances of recovering from a stall if they had positively identified it in the first place?
With so many indicators being unreliable or not available, what "direct", that is aerodynamic or "seat of the pants" feedback would you have in a machine of that size with FBW controls? Obviously, there's no feedback from the control surfaces, there's no stick force to overcome (or rather to soften when the control surfaces get into turbulent air from the stalled wings)
Can the turbulent flow be felt through the airframe?
I honestly have no idea if those guys would have had any primary means of identifying the stall, given that the secondary means (read: instruments) were unreliable.
Also, I've read a lot about "law changes" in this thread, how does an AB pilot stay aware of what law what control axis is in at any given point? I'm sure there's nice flow charts in the documentation, but I wonder how many distinct states of flight law degradations there are and how often the system is allowed to change between them.
If, and it might, this turns out to be a case of "loss of situational awareness" (or rather: they never gained awareness of the situation they were in), it begs the question how complex the situation was when it was presented to them. A simple AoA indicator might have made all the difference to them.
The interface between the automation systems and the pilots seem to be the most difficult part of any design these days. How does the system present all the relevant information while not overwhelm the pilots? And this in a situation where the system is forced to give up since it's parameters are outside what it knows to handle. We could interpret such situations as the design engineers saying "this is a situation we have not considered / thought possible, over to you, pilots". This almost necessarily also means that it's hard or even impossible to say what information is relevant and what can be withheld. As a system designer, you are faced with the decision to possibly withhold information that might be meaningful to interpret the situation or to present information overload which doesn't help either.
I don't envy you guys who poke around at the levels >300.
ps: the system "knows" the AoA. If getting AoA display is an optional item on the aircraft order and AoA is not automatically displayed when the stall warning goes off because the feature wasn't ordered, that would seem sickening to me.
Can somebody please remind me, what the margins were in the given conditions?
Obviously, the air was relatively warm yet below dew point. How can we interpret that they couldn't climb higher because of the temperature gradient being shallower than expected? Was that just referring to the tops of the cb being above their ceiling at that time?
What's the speed margin between Vmmo and Vs?
What's the AoA in normal flight at that altitude and what's the Stall AoA? (did I see it's only 6°?)
What triggered the 13° nose up trim on the THS? What impact would that setting have, along with fuel trim aft, on their chances of recovering from a stall if they had positively identified it in the first place?
With so many indicators being unreliable or not available, what "direct", that is aerodynamic or "seat of the pants" feedback would you have in a machine of that size with FBW controls? Obviously, there's no feedback from the control surfaces, there's no stick force to overcome (or rather to soften when the control surfaces get into turbulent air from the stalled wings)
Can the turbulent flow be felt through the airframe?
I honestly have no idea if those guys would have had any primary means of identifying the stall, given that the secondary means (read: instruments) were unreliable.
Also, I've read a lot about "law changes" in this thread, how does an AB pilot stay aware of what law what control axis is in at any given point? I'm sure there's nice flow charts in the documentation, but I wonder how many distinct states of flight law degradations there are and how often the system is allowed to change between them.
If, and it might, this turns out to be a case of "loss of situational awareness" (or rather: they never gained awareness of the situation they were in), it begs the question how complex the situation was when it was presented to them. A simple AoA indicator might have made all the difference to them.
The interface between the automation systems and the pilots seem to be the most difficult part of any design these days. How does the system present all the relevant information while not overwhelm the pilots? And this in a situation where the system is forced to give up since it's parameters are outside what it knows to handle. We could interpret such situations as the design engineers saying "this is a situation we have not considered / thought possible, over to you, pilots". This almost necessarily also means that it's hard or even impossible to say what information is relevant and what can be withheld. As a system designer, you are faced with the decision to possibly withhold information that might be meaningful to interpret the situation or to present information overload which doesn't help either.
I don't envy you guys who poke around at the levels >300.
ps: the system "knows" the AoA. If getting AoA display is an optional item on the aircraft order and AoA is not automatically displayed when the stall warning goes off because the feature wasn't ordered, that would seem sickening to me.
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Well this is a discussion forum after all, and just as Nitpicker has pointed out is anyone reading previous posts at all??!! I am no authority at all, but having just done a shiney new Airbus rating I just practised Unreliable Airpeed last week(!), all the alerts are going off left right and centre, with 3 different airspeed indications in the cockpit, so putting TOGA on and pitching up 15deg (sounding familiar yet anyone?!!) you have a manouver which gives you an airspeed that should be at least what you get on initial climbout, then its time to see which speed tape has what you think it should have and compare with the G/S for at least ball park ideal.
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Opherben
With all due respect, we basicly agree on the fundamentals: more training, more situation awareness.
Systems redesign? Very unlikely.
I cannot envisage a better scenario for this ill fated plunge into the ocean than the described.
I have some good thousands of hours on both designs: Boeing and Airbus.
Both have their virtues and flaws.
It's very unlikely that systems control design have anything to do with the outcome.
The lack of 'aviate' certainlly have...
If they ever trained high altitude stall recognizing and recovering everybody would be probably at thome at this time.
Systems redesign? Very unlikely.
I cannot envisage a better scenario for this ill fated plunge into the ocean than the described.
I have some good thousands of hours on both designs: Boeing and Airbus.
Both have their virtues and flaws.
It's very unlikely that systems control design have anything to do with the outcome.
The lack of 'aviate' certainlly have...
If they ever trained high altitude stall recognizing and recovering everybody would be probably at thome at this time.
Remember there a 3 different phases mentionedJoin Date: May 2001
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Hi Delta!
No offense: are you sure you're Bus rated?
Were in the earth you're taught to TOGA and rotate to 15 degrees, upon a loss of speed indication and stall warning at 35.000'??
Please, go back to your FS.
Were in the earth you're taught to TOGA and rotate to 15 degrees, upon a loss of speed indication and stall warning at 35.000'??
Please, go back to your FS.
You know what I think is that a lot of Pilots don't know the normal performance to expect on their Aircraft. ie normal CLB pitch and N1, Normal CRZ pitch and N1 and normal DES pitch and N1 ( yeah yeah idle !! )
If don't really know what's normal how could you know what to set when the **** hits the fan? Like in Iced Pitots or Volcanic ash flameouts etc...
I've asked FO's in the past what pitch attitude and N1 should we have in cruise now, don't look ( cheater
) Quite a few got it wrong by quite a bit.....
If don't really know what's normal how could you know what to set when the **** hits the fan? Like in Iced Pitots or Volcanic ash flameouts etc...
I've asked FO's in the past what pitch attitude and N1 should we have in cruise now, don't look ( cheater
) Quite a few got it wrong by quite a bit.....
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Anybody of YOU ...
anybody of you fellow pilots out there have been through this
(or something similar)?
technicalities, can (has it been shown somewhere else)
a large A/C survive this encounter? With what probability?
I remember a similar encounter: Pulkovo 612 which
came out of a large CB in a flat spin (is this still valid?),
where the PF tried to "fly over" the mess and failed.
Would AF447 PF try to "overfly" the "turbulence" that
he (obviously) didn't know what it really was (otherwise,
he wouldn't be heading straight into it).
This is a question of a layperson, so please pardon
any wrong assumptions.
Thanks & regards
(or something similar)?
- approaching CB killer cell without seeing it (why?, wx radar fault?, too-fast buildup?)
- entering the outer downdraft surprisingly (cpt woke up?), (ice)
- entering low-pressure inner updraft (water)
- back in the outer zone (N.E.) with new massive downdraft
technicalities, can (has it been shown somewhere else)
a large A/C survive this encounter? With what probability?
I remember a similar encounter: Pulkovo 612 which
came out of a large CB in a flat spin (is this still valid?),
where the PF tried to "fly over" the mess and failed.
Would AF447 PF try to "overfly" the "turbulence" that
he (obviously) didn't know what it really was (otherwise,
he wouldn't be heading straight into it).
This is a question of a layperson, so please pardon
any wrong assumptions.
Thanks & regards
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Been following this and my amateur .02 is:
who has not fallen victim to the tyranny of the urgent at some time or other? - but tres dangerous in a cockpit..
who has not fallen victim to the tyranny of the urgent at some time or other? - but tres dangerous in a cockpit..
Oh another one........
To save you from reading previous posts that have addressed your question I'll answer it for you again.
Yes, this has happened before in much the same circumstances as AF 447.
Other Airbus and Boeing types have entered CB's by mistake and lived to tell the tail. CB's large enough to injure Pax and freeze the pitot tubes with super cooled water......
To save you from reading previous posts that have addressed your question I'll answer it for you again.
Yes, this has happened before in much the same circumstances as AF 447.
Other Airbus and Boeing types have entered CB's by mistake and lived to tell the tail. CB's large enough to injure Pax and freeze the pitot tubes with super cooled water......
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Re: Oh another one.....
nitpicker330:
I read the posts, a lot of them, but not all 850+, so
sorry for missing some important parts.
I read many of your posts too and I'd like to ask
you as an AB driver: can you understand, why the
PF pulled with N1 100%? Did he try to get out?
Sometimes, subjective assessments by the right
people are more instructive than loads of technical
detail.
But: maybe I'm completely on the wrong track.
I read the posts, a lot of them, but not all 850+, so
sorry for missing some important parts.
I read many of your posts too and I'd like to ask
you as an AB driver: can you understand, why the
PF pulled with N1 100%? Did he try to get out?
Sometimes, subjective assessments by the right
people are more instructive than loads of technical
detail.
But: maybe I'm completely on the wrong track.
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Hi Graybeard
We can assure you: they didn't tried to pass over the CB.
One explanation why they pulled back an already stalled airplane is confusion, lack of proper training, panicking, etc.
One explanation why they pulled back an already stalled airplane is confusion, lack of proper training, panicking, etc.