AF447 wreckage found
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3 questions regarding Air France 447
1. What were they doing flying through huge CBs when everyone else was going around them???
2. Was the Air Data Ice Protection switched on, and if not, why ???
3. So if you have unreliable airspeed indications, don't you revert to Attitude and Power?
2. Was the Air Data Ice Protection switched on, and if not, why ???
3. So if you have unreliable airspeed indications, don't you revert to Attitude and Power?
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Quote:
What makes me wonder is why a expirenced and well trained crew did these actions. I simply can not believe they ignored what seems to be SOP and standard pilot knowledge.
For some unknown reason they must have lost thier situation awareness and reacted the way they did with the known consequences.
After the auto pilot disengaged thier understanding of the situation seems to be very different from realtiy.
I hope the recovered data help us to understand why this happened.
3/ pilot for reasons the majority doesn't want to picture, pulls nose up. 7000 ft / min at FL 350 ! Some kind of pull ! 10 deg pitch ! Plane bleeds off all its speed and STALLS. by that time, still functionning trim has done its job.......it's trimed the aircraft since somebody was pulling !
4/ by that time, speed is back and shows an horrific 215 kt.....pilot pulls some more adding full thrust making things a lot worse than they already were.
I write this as a none pilot. 4/ by that time, speed is back and shows an horrific 215 kt.....pilot pulls some more adding full thrust making things a lot worse than they already were.
What makes me wonder is why a expirenced and well trained crew did these actions. I simply can not believe they ignored what seems to be SOP and standard pilot knowledge.
For some unknown reason they must have lost thier situation awareness and reacted the way they did with the known consequences.
After the auto pilot disengaged thier understanding of the situation seems to be very different from realtiy.
I hope the recovered data help us to understand why this happened.
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Stall warning inop
I don't know if someone said, but the Stall Warning was automatically cancel due to auto cancelation of angle of attack sensor because speed was showing bellow 60 kt.
Stall warning is the first and basic warning in aircrafts. Maybe a modern Airbus fell from 37000 ft because the crew didn't know they were stalling. I can imagine the workload, the storming and the IMC falling thinking they were in over speed or high speed stall.
That's my conclusion, it may be wrong but can somebody tell me why no stall warning during a stall?
In Airbus Manuals is said clearly that during a Unruialbe speed RELAY on Stal warning and Overspeed.
Stall warning is the first and basic warning in aircrafts. Maybe a modern Airbus fell from 37000 ft because the crew didn't know they were stalling. I can imagine the workload, the storming and the IMC falling thinking they were in over speed or high speed stall.
That's my conclusion, it may be wrong but can somebody tell me why no stall warning during a stall?
In Airbus Manuals is said clearly that during a Unruialbe speed RELAY on Stal warning and Overspeed.
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747-400 Hi Alt Stall Recovery Training Video
Below link shows a sim 747-400 at FL400 cruising with A/P.
The thrust is reduced to approach stall. Note that the the plane pitches up automatically to try and maintain FL400 as power is reduced. Until finally it approaches stall with 5% pitch. In this case the Training Capt (Don Grange ) applies full thrust. This prevents a stall however the A/P is unable to correct its nose up attitude and is unable to increase its IAS. It can only be recovered by a gentle descent.
See link below and skip to about 5:15 min.
The thrust is reduced to approach stall. Note that the the plane pitches up automatically to try and maintain FL400 as power is reduced. Until finally it approaches stall with 5% pitch. In this case the Training Capt (Don Grange ) applies full thrust. This prevents a stall however the A/P is unable to correct its nose up attitude and is unable to increase its IAS. It can only be recovered by a gentle descent.
See link below and skip to about 5:15 min.
Last edited by xcitation; 9th Jun 2011 at 23:25.
CP, #1558
1. ‘They were in a CB’’. There is no evidence that the aircraft was in a CB; the crew had seen and planned / turned to deviate around weather.
2. ‘Air data ice protection on’. A feature of pitot blocking due to ice crystals is that there has to be a heated surface on which some crystals can accumulate / melt. The water becomes the glue for other crystals to build up on, or the water ice mix can stabilize around freezing and block the pipes / vents.
3. ‘Fly attitude / power’. This depends on what the crew see and understand about the situation, and then depending on complex circumstances the ability to fly accurately, all in a very sudden, surprising, and complex situation.
1. ‘They were in a CB’’. There is no evidence that the aircraft was in a CB; the crew had seen and planned / turned to deviate around weather.
2. ‘Air data ice protection on’. A feature of pitot blocking due to ice crystals is that there has to be a heated surface on which some crystals can accumulate / melt. The water becomes the glue for other crystals to build up on, or the water ice mix can stabilize around freezing and block the pipes / vents.
3. ‘Fly attitude / power’. This depends on what the crew see and understand about the situation, and then depending on complex circumstances the ability to fly accurately, all in a very sudden, surprising, and complex situation.
CP, #1558
1. ‘They were in a CB’’. There is no evidence that the aircraft was in a CB; the crew had seen and planned / turned to deviate around weather.
1. ‘They were in a CB’’. There is no evidence that the aircraft was in a CB; the crew had seen and planned / turned to deviate around weather.
PEI, wouldn't it be true to state that there is no evidence that they weren't in, or in the vicinity of, either a CB or a significant vertical development? I may be stretching the boundary of inference here, but there has been ample anecdotal evidence of possible "blind spots" with Wx radar, from people who operate and operated them. The possibility of locale specific weather/metro surprise remains open, and may remain an unknown forever. The metro conditions along the flight path route were sketched out by Mr. Vasquez. What was locally experienced remains unclear, beyond the BEA release of some conversation about turbulence before the event.
2. ‘Air data ice protection on’. A feature of pitot blocking due to ice crystals is that there has to be a heated surface on which some crystals can accumulate / melt. The water becomes the glue for other crystals to build up on, or the water ice mix can stabilize around freezing and block the pipes / vents.
Gonna save that one in a text file.
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Hi,
I skipped all .. ROFL cause videos no more available due to copyright claim
EDIT:
Thank's for edit !
EDIT:
jcjeant and others
The training video link is fixed.
The training video link is fixed.
Last edited by jcjeant; 10th Jun 2011 at 00:15.
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NigelOnDraft:
My comments Re 'classic 747s' was not meant to suggest that they were impervious to accidents, although the cases you referenced differ quite markedly to the Air France and QANTAS incidents. My point was, does a cascade of automated system failures distract / confuse a pilot from his most important job...flying the aircraft? Are these aircraft too complex? In the QANTAS incident the pilots became very task saturated trying to clear the multitude of system errors, and I wonder how they would have fared had they not had an additional two pilots on the flight-deck that day to assist.
I'm not Airbus bashing BTW, and as Iceman kindly responded to my query, both major manufacturers have their good and bad points. I'm merely posing a question for discussion.
Iceman, thanks for your reply. I'd love to hear your theory, but understand that it's probably not prudent to do so until more info comes to light. Will be interesting to hear how close you were when we do learn more...
My comments Re 'classic 747s' was not meant to suggest that they were impervious to accidents, although the cases you referenced differ quite markedly to the Air France and QANTAS incidents. My point was, does a cascade of automated system failures distract / confuse a pilot from his most important job...flying the aircraft? Are these aircraft too complex? In the QANTAS incident the pilots became very task saturated trying to clear the multitude of system errors, and I wonder how they would have fared had they not had an additional two pilots on the flight-deck that day to assist.
I'm not Airbus bashing BTW, and as Iceman kindly responded to my query, both major manufacturers have their good and bad points. I'm merely posing a question for discussion.
Iceman, thanks for your reply. I'd love to hear your theory, but understand that it's probably not prudent to do so until more info comes to light. Will be interesting to hear how close you were when we do learn more...
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Hi,
Tireless I read and reread the BEA note .........
15 seconds after 2H10Min51Sec the speed is coherent
So at 2H11Min06Sec the speed is coherent
It's also noted that the inconsistency between the speeds lasted a little less than ONE minute.
So for the sake of accuracy I will take the "less than ONE minute" as 59Sec.
So this indicate that the inconsistency between speeds appears (the earliest) at 2H10Min07Sec
So before 2H10Min07Sec the speeds are coherent
Or the BEA note that at 2H10Min05Sec the autopilot and auto-thrust disengage and the pilot tell he is in control..
So .. the autopilot and auto-thrust disengage before the apparition of incoherent speeds 
Where is the logic in the BEA chronology ?
Around fifteen seconds later
Why using the word around when they are accurate at the Sec for the other times in the note ...they have the accurate times or not ?
Can we take this BEA note as serious ?
Tireless I read and reread the BEA note .........
From 2 h 10 min 50, the PNF tried several times to call the Captain back.
At 2 h 10 min 51 , the stall warning was triggered again. The thrust levers were positioned
in the TO/GA detent and the PF maintained nose-up inputs. The recorded angle of attack, of
around 6 degrees at the triggering of the stall warning, continued to increase. The trimmable
horizontal stabilizer (THS) passed from 3 to 13 degrees nose-up in about 1 minute and
remained in the latter position until the end of the flight.
Around fifteen seconds later, the speed displayed on the ISIS increased sharply towards 185 kt;
it was then consistent with the other recorded speed. The PF continued to make nose-up
inputs. The airplane’s altitude reached its maximum of about 38,000 ft, its pitch attitude and
angle of attack being 16 degrees.
Note: The inconsistency between the speeds displayed on the left side and on the ISIS lasted a little less
than one minute.
At 2 h 10 min 51 , the stall warning was triggered again. The thrust levers were positioned
in the TO/GA detent and the PF maintained nose-up inputs. The recorded angle of attack, of
around 6 degrees at the triggering of the stall warning, continued to increase. The trimmable
horizontal stabilizer (THS) passed from 3 to 13 degrees nose-up in about 1 minute and
remained in the latter position until the end of the flight.
Around fifteen seconds later, the speed displayed on the ISIS increased sharply towards 185 kt;
it was then consistent with the other recorded speed. The PF continued to make nose-up
inputs. The airplane’s altitude reached its maximum of about 38,000 ft, its pitch attitude and
angle of attack being 16 degrees.
Note: The inconsistency between the speeds displayed on the left side and on the ISIS lasted a little less
than one minute.
So at 2H11Min06Sec the speed is coherent
It's also noted that the inconsistency between the speeds lasted a little less than ONE minute.
So for the sake of accuracy I will take the "less than ONE minute" as 59Sec.
So this indicate that the inconsistency between speeds appears (the earliest) at 2H10Min07Sec
So before 2H10Min07Sec the speeds are coherent
Or the BEA note that at 2H10Min05Sec the autopilot and auto-thrust disengage and the pilot tell he is in control..
From 2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the
controls".
controls".
Where is the logic in the BEA chronology ?
Around fifteen seconds later
Why using the word around when they are accurate at the Sec for the other times in the note ...they have the accurate times or not ?
Can we take this BEA note as serious ?
Last edited by jcjeant; 9th Jun 2011 at 22:29.
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It's time to close this thread now, I'm totally overdosed on the same arguments, and newcomers asking the same questions, until more information is made available, which I frankly doubt will ever happen, IMHO the 'final' report will just be a padded out version of what has already been released. Hope I'm wrong, and it would be nice to have a complete voice transcript.
My thanks to those with Scairbus experience for some insight, but even they differ - recent sidestick 'feel' - or 'no feel' - opinions for instance.
Goodbye.
My thanks to those with Scairbus experience for some insight, but even they differ - recent sidestick 'feel' - or 'no feel' - opinions for instance.
Goodbye.
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Hi,
Another already posted PDF
http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf
It's ironical that the emphasize is put on the AOA ... when we know that the Airbus A330 had not a AOA indicator
I'm totally overdosed on the same arguments,
http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf
It's ironical that the emphasize is put on the AOA ... when we know that the Airbus A330 had not a AOA indicator
Lonewolf, “…what they saw in front of them what was actually there”
I think it best to credit the crew with appropriate use of the WXR until evidence is presented otherwise. Plotting the proposed deviation on some weather charts suggest that it was in keeping with the general weather situation.
Also, assuming ice crystals were a major factor; these are more likely to be encountered around Cbs – up to 15nm away, although the Cb core probably has high concentrations. The analogy is that the Cb core is the chimney, and the crystals / grauple is the soot / smoke. The heavier particles fall out of the high-level cloud, whereas the light particles travel downwind in / under the anvil. In both instances, they are not easily detected with WXR (if at all).
Re #1549 “… were they set up to fail? If so, how?”
First I don’t think that we should pursue crew failure – you probably did not mean any negative connotation.
Like most accidents, the findings will probably fall into three broad categories: technical, human, and organisational.
There is insufficient evidence to judge any technical aspects at this time, but there are indications of complexities in the human / technical interface. Not that this implies technical failure or poor design, just different; and thus this requires a different way of looking at systems, different operations, and differences in required human behaviour.
The human behaviour is crucial. The crew were faced with a surprising and complex failure situation, challenged by weather, time, and changing circumstance. Unfortunately we cannot know what they thought, at best we might only speculate, based on what was presented to them, but even that might be less than normally certain from an FDR.
The organisational aspects might focus on airworthiness. The authority knew of the problem but judged the risk of simultaneous ADC failure as being remote (but warranting remedial action), and that the intervening ‘at risk’ period could be mitigated by crew performance, which was supported by evidence of previous events.
This was a failure of risk management, but a failure at or beyond the limits of probability, and based on reasonable assumptions. Yet perhaps a difference which was overlooked was that a modern aircraft with highly augmented controls might not be as easy to fly with pitch /power as previously assumed based on a conventional aircraft, or that the crew may not have had had the appropriate training / experience. Were the regulators ‘set up’; – by life, aviation; probably yes.
How long did it take to read the text above, to understand, to formulate any reaction … 3.5 mins? That’s all that AF447 crew had, and whilst we have had 2 years to define the major themes of the situation and improve our general understanding of systems, weather, operations; the crew only had blanks on the screen.
Such is human performance – variable. We are never set-up, only faced with the limits of our capability in a given situation, assuming first that the situation is understood.
I think it best to credit the crew with appropriate use of the WXR until evidence is presented otherwise. Plotting the proposed deviation on some weather charts suggest that it was in keeping with the general weather situation.
Also, assuming ice crystals were a major factor; these are more likely to be encountered around Cbs – up to 15nm away, although the Cb core probably has high concentrations. The analogy is that the Cb core is the chimney, and the crystals / grauple is the soot / smoke. The heavier particles fall out of the high-level cloud, whereas the light particles travel downwind in / under the anvil. In both instances, they are not easily detected with WXR (if at all).
Re #1549 “… were they set up to fail? If so, how?”
First I don’t think that we should pursue crew failure – you probably did not mean any negative connotation.
Like most accidents, the findings will probably fall into three broad categories: technical, human, and organisational.
There is insufficient evidence to judge any technical aspects at this time, but there are indications of complexities in the human / technical interface. Not that this implies technical failure or poor design, just different; and thus this requires a different way of looking at systems, different operations, and differences in required human behaviour.
The human behaviour is crucial. The crew were faced with a surprising and complex failure situation, challenged by weather, time, and changing circumstance. Unfortunately we cannot know what they thought, at best we might only speculate, based on what was presented to them, but even that might be less than normally certain from an FDR.
The organisational aspects might focus on airworthiness. The authority knew of the problem but judged the risk of simultaneous ADC failure as being remote (but warranting remedial action), and that the intervening ‘at risk’ period could be mitigated by crew performance, which was supported by evidence of previous events.
This was a failure of risk management, but a failure at or beyond the limits of probability, and based on reasonable assumptions. Yet perhaps a difference which was overlooked was that a modern aircraft with highly augmented controls might not be as easy to fly with pitch /power as previously assumed based on a conventional aircraft, or that the crew may not have had had the appropriate training / experience. Were the regulators ‘set up’; – by life, aviation; probably yes.
How long did it take to read the text above, to understand, to formulate any reaction … 3.5 mins? That’s all that AF447 crew had, and whilst we have had 2 years to define the major themes of the situation and improve our general understanding of systems, weather, operations; the crew only had blanks on the screen.
Such is human performance – variable. We are never set-up, only faced with the limits of our capability in a given situation, assuming first that the situation is understood.
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The difficult thing for me to understand is why didn't they just disengage the autopilot as soon as the nose started pitching up? And a jet will descend at a safe speed with the thrust off at 2.5 to 3 degrees nose down. I guess we'll learn all about it in CRM next time."
On the L-1011 there was a situation that could occur only during ground operations. If the stabilizer was moved abruptly a fuselage osculation could be set up. To stop the osculation all you had to do was let go of the column. Lots of luck trying to convince the crew to do nothing!
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Poit, which airplane would you rather be in if you were in turbulence, at night, iced up pitot tubes with unreliable airspeed trying to hold pitch and power using the unreliable airspeed checklist? A 747 classic with a yoke and direct throttle or a side stick and a lot of broken automation? Would you pitch the 747 up into a 10 degree plus nose up stall?
That is why I never bid the Airbus so never had to fly it and never learned all the laws, even though it paid more. I never cared if the AP or AT disengaged because the automation was just a help when it worked and when it failed it just increased the workload slightly. I'm thinking pilots are now depending too much on automation and it failing isn't just a small inconvenience.
I am waiting for the BEA to finally tell us what they know because so far the info has been scant so it is hard for us to really know what happened. The CVR would tell a lot of the story and they have all of that.
Just because you don't trust an airplane doesn't necessarily mean you dispise it by the way. I just happened to love and trust my B757 because I had total control over it no matter what the computer thought.
That is why I never bid the Airbus so never had to fly it and never learned all the laws, even though it paid more. I never cared if the AP or AT disengaged because the automation was just a help when it worked and when it failed it just increased the workload slightly. I'm thinking pilots are now depending too much on automation and it failing isn't just a small inconvenience.
I am waiting for the BEA to finally tell us what they know because so far the info has been scant so it is hard for us to really know what happened. The CVR would tell a lot of the story and they have all of that.
Just because you don't trust an airplane doesn't necessarily mean you dispise it by the way. I just happened to love and trust my B757 because I had total control over it no matter what the computer thought.
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jcjeant:
Excuse me for saying so, but that FAA/Airbus pitch seems pretty elementary to me. About the only aspect a PPL holder might find unfamiliar is the pitch-up moment generated by underwing engines - and even that is obvious after a moment's thought.
So - I must ask why the ATP world has become so disconnected from this very basic flying lesson?
http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf
It's ironical that the emphasize is put on the AOA ... when we know that the Airbus A330 had not a AOA indicator
It's ironical that the emphasize is put on the AOA ... when we know that the Airbus A330 had not a AOA indicator
So - I must ask why the ATP world has become so disconnected from this very basic flying lesson?
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iceman50
Thanks again, iceman50. Only word I'd (gently ) query is 'emphasised,' though - surely, at the time of AF447, the 'old' drill had been completely replaced by the 'new' one>?
So the old 'nose down and add power carefully' rule wasn't even there to be 'emphasised'? it had been completely replaced by the new - and, in my view, flawed - new 'full power and stay level' one?
xcitation
Thanks, xcitation - shows exactly why the 'standard operating procedure' in operation at the time of AF447 appears to have been flawed - or, at best, inadequate.
So the AF447 PF appears to have done exactly what 'the book' (and his instructors) said at the time - applied TO/GA power and tried to maintain level flight. But, looking at the various press stories, and many comments on this thread, a lot of people (possibly already a majority of people) already think that he was guilty of 'pilot error.'
Maybe the investigators will invent a completely-new accident cause in this case, though - something like 'handbook error'..........?
It was not just Airbus that re-stated the "new / old" stall procedure, Boeing did as well. I believe that Boeing, Airbus, other manufacturers and the regulators got together and the "new/old" procedures were emphasised.
) query is 'emphasised,' though - surely, at the time of AF447, the 'old' drill had been completely replaced by the 'new' one>?
previous advice was along the lines of 'full power and seek to maintain assigned altitude'?
xcitation
In this case the Training Capt (Don Grange ) applies full thrust. This prevents a stall however the A/P is unable to correct its nose up attitude and is unable to increase its IAS. It can only be recovered by a gentle descent.
So the AF447 PF appears to have done exactly what 'the book' (and his instructors) said at the time - applied TO/GA power and tried to maintain level flight. But, looking at the various press stories, and many comments on this thread, a lot of people (possibly already a majority of people) already think that he was guilty of 'pilot error.'
Maybe the investigators will invent a completely-new accident cause in this case, though - something like 'handbook error'..........?
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Yet another link...
http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf
Given the assertion of Basil: "the AB should be handled as a video game"... (great post for sure)...
I have a nasty question: Why was the AB logic (software), unaware of its deep-stall condition?
Why did the logic not kicked into Direct Law instead of Alternate? Conditions to do so were not met? The proper parameters weren´t reached would many say... Still, it may had saved the a/c and the guys in it... Or not? A simple: "YOU NEED TO TRIM MANUAL" may had made a difference...
I have a lot of respect to AB, French goverment, investors and all of you in this forum... I´m just addressing some aspects which may go beyond training... And at the end: Life can always surprise you!
I hope that many (I won´t name no-one), will further show some respect for the guys which were doomed in this particular event...
As TheShadow said in his post #1219, (It was #1222 or something like that a while ago... index change here also...): I´m also sick of defenceless pilots who aren´t here to tell what really happened and have to carry the can... Cheers.
http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf
Given the assertion of Basil: "the AB should be handled as a video game"... (great post for sure)...
I have a nasty question: Why was the AB logic (software), unaware of its deep-stall condition?
Why did the logic not kicked into Direct Law instead of Alternate? Conditions to do so were not met? The proper parameters weren´t reached would many say... Still, it may had saved the a/c and the guys in it... Or not? A simple: "YOU NEED TO TRIM MANUAL" may had made a difference...
I have a lot of respect to AB, French goverment, investors and all of you in this forum... I´m just addressing some aspects which may go beyond training... And at the end: Life can always surprise you!
I hope that many (I won´t name no-one), will further show some respect for the guys which were doomed in this particular event...
As TheShadow said in his post #1219, (It was #1222 or something like that a while ago... index change here also...): I´m also sick of defenceless pilots who aren´t here to tell what really happened and have to carry the can... Cheers.
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Quote:"Why using the word around when they are accurate at the Sec for the other times in the note ...they have the accurate times or not ?
Can we take this BEA note as serious ?"
Not being familiar with the specific FDR output characteristics, it could conceiveably be the FDR data sampling intervals, for instance- write every 5 seconds...
Can we take this BEA note as serious ?"
Not being familiar with the specific FDR output characteristics, it could conceiveably be the FDR data sampling intervals, for instance- write every 5 seconds...