AF447 wreckage found
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I note the report talks of 'nose up input'.
It may seem a daft question but what is the correlation between what the computer saw and what the pilot(s) joy sticks were doing? Are both the joy stick positions recorded?
It may seem a daft question but what is the correlation between what the computer saw and what the pilot(s) joy sticks were doing? Are both the joy stick positions recorded?
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Where are the Air Caraibes guys now?
Edmund......This is not new, before the Air Caraibis incident my Airline had a similar thing occur over the South China sea in an A330. They had their pitot probes ice up from super cooled water and they then had all the same things happen.
AP A/THR dropped out
Simultaneous overspeed AND under speed warnings
Alternate Law
Etc etc
They were initial hung out to dry but the union proved the Radar was at fault and the crew hadn't actually exceeded any limitations.
So, the Airline changed the Radars on all the 330's and changed the Pitot tubes to the newer model.
This is not a new thing..
AP A/THR dropped out
Simultaneous overspeed AND under speed warnings
Alternate Law
Etc etc
They were initial hung out to dry but the union proved the Radar was at fault and the crew hadn't actually exceeded any limitations.
So, the Airline changed the Radars on all the 330's and changed the Pitot tubes to the newer model.
This is not a new thing..
Regarding the initial sudden climb:
"'The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started to climb. The PF made nose-down control inputs and alternately left and right roll inputs. The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left. The speed displayed on the left side increased sharply to 215 kt (Mach 0.68). The airplane was then at an altitude of about 37,500 ft and the recorded angle of attack was around 4 degrees."
So obviously to some extent the aircraft was climbing despite the pilot's attempts to lower the nose. Keep in mind that with a whale of a plane like this, there is a lot of inertia. It is not a maneuverable fighter jet.
__________________
On the question of using GPS as a substitute for pitot tubes - here's why it isn't useful (apologies to the 98% of pilots who already know this), especially at 35,000 ft.
The behavior of an aircraft is determined by effective or INDICATED airspeed. How much air is flowing over the airfoils and controls.
An aircraft at 35,000 feet flying at 500 kts, may show an indicated (pitot) airspeed of about 260 kts (depends on temperature) - because the air is so thin. More importantly, it will BEHAVE as though it is only going 260 kts, because there are fewer air molecules to hold up the wings or have an effect on the control surfaces.
The "magic" of the pitot system is that it measures the EFFECTIVE airflow at any given altitude, thereby fairly accurately reflecting how the plane will handle as the air gets thinner. (At least up to the point where Mach effects kick in - getting close to the speed of sound introduces its own issues.)
A GPS cannot do this. It only reports how fast the plane is actually moving, which says nothing directly about how much airflow the pilot has to work with. In addition, it figures in wind effects, which also have no direct usefulness in controlling the plane.
Pop quiz:
You are at 35,000 feet. The GPS says you are traveling at 400 kts due north over the ground, decreasing at 1 kt per second. There is a 60-kt jet stream blowing from the southwest (217°). Your stall speed (no flaps) would be 167 kts INDICATED, but your airspeed indicator isn't working. Your heading is 356°. Barometric pressure is 29.75 (but your altimeter is set to 29.92 as in all flights above 18,000 feet.) The air outside is -42° C.
Tell me how close you are to a stall. (You have 10 seconds to calculate this).
Doesn't work.
The reason planes still use a 160-year-old instrument for airspeed is that it remains the best tool for the job.
"'The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started to climb. The PF made nose-down control inputs and alternately left and right roll inputs. The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left. The speed displayed on the left side increased sharply to 215 kt (Mach 0.68). The airplane was then at an altitude of about 37,500 ft and the recorded angle of attack was around 4 degrees."
So obviously to some extent the aircraft was climbing despite the pilot's attempts to lower the nose. Keep in mind that with a whale of a plane like this, there is a lot of inertia. It is not a maneuverable fighter jet.
__________________
On the question of using GPS as a substitute for pitot tubes - here's why it isn't useful (apologies to the 98% of pilots who already know this), especially at 35,000 ft.
The behavior of an aircraft is determined by effective or INDICATED airspeed. How much air is flowing over the airfoils and controls.
An aircraft at 35,000 feet flying at 500 kts, may show an indicated (pitot) airspeed of about 260 kts (depends on temperature) - because the air is so thin. More importantly, it will BEHAVE as though it is only going 260 kts, because there are fewer air molecules to hold up the wings or have an effect on the control surfaces.
The "magic" of the pitot system is that it measures the EFFECTIVE airflow at any given altitude, thereby fairly accurately reflecting how the plane will handle as the air gets thinner. (At least up to the point where Mach effects kick in - getting close to the speed of sound introduces its own issues.)
A GPS cannot do this. It only reports how fast the plane is actually moving, which says nothing directly about how much airflow the pilot has to work with. In addition, it figures in wind effects, which also have no direct usefulness in controlling the plane.
Pop quiz:
You are at 35,000 feet. The GPS says you are traveling at 400 kts due north over the ground, decreasing at 1 kt per second. There is a 60-kt jet stream blowing from the southwest (217°). Your stall speed (no flaps) would be 167 kts INDICATED, but your airspeed indicator isn't working. Your heading is 356°. Barometric pressure is 29.75 (but your altimeter is set to 29.92 as in all flights above 18,000 feet.) The air outside is -42° C.
Tell me how close you are to a stall. (You have 10 seconds to calculate this).
Doesn't work.
The reason planes still use a 160-year-old instrument for airspeed is that it remains the best tool for the job.
Last edited by pattern_is_full; 29th May 2011 at 19:25.
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The stall warning discontinued when the speed was BELOW 60 Kts. How in blazes do you fly a large jet at 35000 ft at a speed of 60 Kts ?? At that height the speed has to be above 270 Kts. The stall warning is of no use to the pilot below 60 Kts
This is not a feature, it is a bloody stupid design error.
If the stall warning sounds all pilots are trained from PPL level to expect it to continue until the stall has been recovered. Stopping the horn while the aircraft is still stalled is dangerously misleading and IMHO is a major contributing factor in this accident.
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If the stall warning sounds all pilots are trained from PPL level to expect it to continue until the stall has been recovered. Stopping the horn while the aircraft is still stalled is dangerously misleading and IMHO is a major contributing factor in this accident.
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Dumb, single engine piston instructor here.
It would appear that everyone agrees that erroneous data from Pitot/Static/AOA gauge was a (the?) significant causal factor here. So, assuming that is the case and also assuming that pilots will remain fallible, doesn't the multi-billion dollar air transport industry owe it to the numerous casualties of many accidents to sort the sensor issue once and for all? We have achieved so much in aviation but continue to rely on a small tube (or set of) and some pin holes to measure dynamic & static pressure.
It would appear that everyone agrees that erroneous data from Pitot/Static/AOA gauge was a (the?) significant causal factor here. So, assuming that is the case and also assuming that pilots will remain fallible, doesn't the multi-billion dollar air transport industry owe it to the numerous casualties of many accidents to sort the sensor issue once and for all? We have achieved so much in aviation but continue to rely on a small tube (or set of) and some pin holes to measure dynamic & static pressure.
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Dairy guy here cows. Remember, a lack of respect for the Physics is only very occasionally punished with such an outcome as 447's plunge. The Bottom line is what you see in equipment is not the best, but the best, considering.
keep the greasy side down
keep the greasy side down
For ST27:
Perhaps. The report definitely notes that when the PF lowered the nose a couple of other times, the silenced stall alert CAME ON again - and the PF STOPPED lowering the nose in response to the alarm (or at least, at the moment the alarm came on - cause and effect is strongly circumstantial).
If you do something, and someone or something starts yelling "No, no, no!" - it is basic human nature to STOP doing whatever it was - even though it was the correct thing to do.
Shades of Buffalo - when the alarms went off, the FO "undid" the last thing she'd done before the alarm (raised the flaps she'd just lowered.)
The design of this alarm taught the AF PF in a very short period of time that "if you lower the nose, you will get yelled at. If you don't lower the nose, the alarm will stay quiet."
That is not good design.
Perhaps. The report definitely notes that when the PF lowered the nose a couple of other times, the silenced stall alert CAME ON again - and the PF STOPPED lowering the nose in response to the alarm (or at least, at the moment the alarm came on - cause and effect is strongly circumstantial).
If you do something, and someone or something starts yelling "No, no, no!" - it is basic human nature to STOP doing whatever it was - even though it was the correct thing to do.
Shades of Buffalo - when the alarms went off, the FO "undid" the last thing she'd done before the alarm (raised the flaps she'd just lowered.)
The design of this alarm taught the AF PF in a very short period of time that "if you lower the nose, you will get yelled at. If you don't lower the nose, the alarm will stay quiet."
That is not good design.
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Basic Observations
At 1 h 55, the Captain woke the second co-pilot and said "[…] he’s going to take my place". Between 1 h 59 min 32 and 2 h 01 min 46, the Captain attended the briefing between the two co-pilots, during which the PF said, in particular "the little bit of turbulence that you just saw […] we should find the same ahead […] we’re in the cloud layer unfortunately we can’t climb much for the moment because the temperature is falling more slowly than forecast" and that "the logon with Dakar failed". The Captain left the cockpit.
From 2 h 10 min 05, the autopilot then auto-thrust disengaged and the PF said "I have the controls". The airplane began to roll to the right and the PF made a left nose-up input. The stall warning sounded twice in a row. The recorded parameters show a sharp fall from about 275 kt to 60 kt in the speed displayed on the left primary flight display (PFD), then a few moments later in the speed displayed on the integrated standby instrument system (ISIS).
Note 1: Only the speeds displayed on the left PFD and the ISIS are recorded on the FDR; the speed displayed on the right side is not recorded.
Note 2: Autopilot and auto-thrust remained disengaged for the rest of the flight.
At 2 h 10 min 16, the PNF said "so, we’ve lost the speeds" then "alternate law […]".
Note 1: The angle of attack is the angle between the airflow and longitudinal axis of the airplane. This information is not presented to pilots.
Note 2 : In alternate or direct law, the angle-of-attack protections are no longer available but a stall warning is triggered when the greatest of the valid angle-of-attack values exceeds a certain threshold.
Note 1: Only the speeds displayed on the left PFD and the ISIS are recorded on the FDR; the speed displayed on the right side is not recorded.
Note 2: Autopilot and auto-thrust remained disengaged for the rest of the flight.
At 2 h 10 min 16, the PNF said "so, we’ve lost the speeds" then "alternate law […]".
Note 1: The angle of attack is the angle between the airflow and longitudinal axis of the airplane. This information is not presented to pilots.
Note 2 : In alternate or direct law, the angle-of-attack protections are no longer available but a stall warning is triggered when the greatest of the valid angle-of-attack values exceeds a certain threshold.
The PF response to the right roll is problematic. The nose-up component started a climb, which he already knew he did not have excess power for. We have no information that he increased power at this time. Why he pulled nose-up is a mystery. Maybe he thought the 2 brief stall warnings were false, maybe he wanted to try and climb above the icing or the turbulence. However he did not have reliable airspeed indication in these moments, to attempt this.
The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started to climb. The PF made nose-down control inputs and alternately left and right roll inputs. The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left. The speed displayed on the left side increased sharply to 215 kt (Mach 0.68). The airplane was then at an altitude of about 37,500 ft and the recorded angle of attack was around 4 degrees.
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.
At around 2 h 11 min 40, the Captain re-entered the cockpit. During the following seconds, all of the recorded speeds became invalid and the stall warning stopped. Note: When the measured speeds are below 60 kt, the measured angle of attack values are considered invalid and are not taken into account by the systems. When they are below 30 kt, the speed values
themselves are considered invalid. The altitude was then about 35,000 ft, the angle of attack exceeded 40 degrees and the vertical speed was about -10,000 ft/min. The airplane’s pitch attitude did not exceed 15 degrees and the engines’ N1’s were close to 100%. The airplane was subject to roll oscillations that sometimes reached 40 degrees. The PF made an input on the sidestick to the left and nose-up stops, which lasted about 30 seconds.
themselves are considered invalid. The altitude was then about 35,000 ft, the angle of attack exceeded 40 degrees and the vertical speed was about -10,000 ft/min. The airplane’s pitch attitude did not exceed 15 degrees and the engines’ N1’s were close to 100%. The airplane was subject to roll oscillations that sometimes reached 40 degrees. The PF made an input on the sidestick to the left and nose-up stops, which lasted about 30 seconds.
I could go on, but I'll stop here. The great mystery for me is the persistent nose-up inputs. The later nose-down inputs might have worked if they had remembered to manually trim the THS. Too many holes in the Swiss cheese here.
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It really amazes me that there are so many super god like pilots opining here, all with super hindsight acting as if the data released so far give them a crystal clear picture of all the cockpit indications in this tragic flight. I can bet my last dollar that if we are ever able to simulate all the chaos and mess that had happened on this cockpit and throw them at a super airbus ace caught unaware, the outcome would have been no different.
In another life as a checker, after completing the sim check of a super ace to a very high standards we used the remaining time to conduct some extra excercises on really unusual attitudes with combinations of other failures...the plane went belly up, ace or no ace. We repeated it twice, same results. 2 years later, another sim check and super ace asked for another go at that exercise...he managed to save the plane but barely. He admitted he thought long and hard about it coming out with all the possible solutions in his head before the session. He was truly humbled and conceded that there were combinations of failures that are almost impossible to handled when one is caught unaware with not much time on one's side.
So, sky gods hold your peace. Thank your lucky stars that it did not happened to you. Hope that the manufacturers come up with equipments without all those design flaws; get the designers to think like average sensible pilots, not anal retentive hardnose savants who think that handling an inflight emergency is as easy as having brainstorming piss up in some soothing sequestered karaoke joint.
In another life as a checker, after completing the sim check of a super ace to a very high standards we used the remaining time to conduct some extra excercises on really unusual attitudes with combinations of other failures...the plane went belly up, ace or no ace. We repeated it twice, same results. 2 years later, another sim check and super ace asked for another go at that exercise...he managed to save the plane but barely. He admitted he thought long and hard about it coming out with all the possible solutions in his head before the session. He was truly humbled and conceded that there were combinations of failures that are almost impossible to handled when one is caught unaware with not much time on one's side.
So, sky gods hold your peace. Thank your lucky stars that it did not happened to you. Hope that the manufacturers come up with equipments without all those design flaws; get the designers to think like average sensible pilots, not anal retentive hardnose savants who think that handling an inflight emergency is as easy as having brainstorming piss up in some soothing sequestered karaoke joint.
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Again, if PF had not made himself aware of Law change, and was functionally still in Normal, these inputs would not do harm. (Roll left, full aft stick).
Dropping a/p does not command degradation out of Normal Law. Could he have been that far behind? It takes AD disagrees to autoselect ALTLAW. So at what point were they aware of AD disagree , and how long after that before they acclimated there 'get'/'got' to new parameters?
Dropping a/p does not command degradation out of Normal Law. Could he have been that far behind? It takes AD disagrees to autoselect ALTLAW. So at what point were they aware of AD disagree , and how long after that before they acclimated there 'get'/'got' to new parameters?
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My 0.02:
The pilots must have thought they were in an overspeed situation. Horns blaring, rate of descent 10000+ fpm, no reliable speed indication, dark night, in severe weather, stall warning suddenly went off after pitching the nose up for sometime and then coming back on after pitching the nose down...
It's a pity they got it wrong. When in confused state, one would try everything to save the situation. They must have thought stick aft at full thrust was working since the stall warning actually stopped blaring. The thing they couldn't resolve was why were they still descending at a rapid rate? That's when one of them pushed the stick forward, which unfortunately re-trigger the stall warning. So they pulled the stick back to silence the horn, and the action did silence it. And all the while, they didn't have a valid 'speedometer'...
The pilots must have thought they were in an overspeed situation. Horns blaring, rate of descent 10000+ fpm, no reliable speed indication, dark night, in severe weather, stall warning suddenly went off after pitching the nose up for sometime and then coming back on after pitching the nose down...
It's a pity they got it wrong. When in confused state, one would try everything to save the situation. They must have thought stick aft at full thrust was working since the stall warning actually stopped blaring. The thing they couldn't resolve was why were they still descending at a rapid rate? That's when one of them pushed the stick forward, which unfortunately re-trigger the stall warning. So they pulled the stick back to silence the horn, and the action did silence it. And all the while, they didn't have a valid 'speedometer'...
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Wonder what the r/h asi tape was reading. Amazed it is not recorded. If it was very high it may explain the back stick inputs. However use of the QRH would of been useful. Too distracted to get it out I guess.
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Back to Basics (2)
Oh yes, pmansion, I HAVE read that!
The first ND inputs were recorded between 02:10:05 and 02:10:51 -- the Captain re-entered the cockpit at 02:11:40.
The PF obviously wanted to bleed off some of the incredible VS of the airplane (and did so: 7000 to 700 ft./ min.). Why were they climbing so fast? I would say, because the PF inadvertendly induced a little nose up pitch, when correcting the right roll (02:10:05). Used to AP flying when at night and/or IMC it is not so easy to fly a clean straight line on instruments by hand. PLUS the startle of the AP+AThr disengage and the Wx-induced stress.
The stall warning in that phase must have been triggered by the erroneous airspeed breakdown. The pilots dealt with that by doing NOTHING (= nothing wrong). No need to.
Shortly before 02:10:51 they were nearly fine (but probably at their mental limits): 37500 fts and climbing with 700 fts/min with an AOA of 4° -- no trouble, but now speed down to around 215kts. That means stall and I think that is the moment when they lost the plane (first mentally, shortly after actually).
This time they didn't question the warning (by plausibility check), they simply followed procedures, they were behind their plane -- and flew into the deep stall. When the Captain entered the cockpit again; they were back down to 35000 and in the 'no-airspeed'-zone again.
Then, the second ND-input-phase (02:12:17), which could have changed everything. But, due to the lack of situational overview, at the next stall warning signal, they followed procedures again -- and threw their last chance away.
The PF said: 'Go ahead, You have control'. The wording is clearly NOT a confirmation, but a request: For me proof of the PF giving up. The procedure he (and two other pilots too!) were trained for doesn't work out. The end is known.
And there I am again: Do we overtrain pilots, do we encourage them to stop thinking and only follow procedures? There will always at some time arise a situation, where there is no procedure to be followed, because the situation is new, where common (flying-) sense is necessary and MAY save lives.
And there's my point again: Back to Basics!
The first ND inputs were recorded between 02:10:05 and 02:10:51 -- the Captain re-entered the cockpit at 02:11:40.
The PF obviously wanted to bleed off some of the incredible VS of the airplane (and did so: 7000 to 700 ft./ min.). Why were they climbing so fast? I would say, because the PF inadvertendly induced a little nose up pitch, when correcting the right roll (02:10:05). Used to AP flying when at night and/or IMC it is not so easy to fly a clean straight line on instruments by hand. PLUS the startle of the AP+AThr disengage and the Wx-induced stress.
The stall warning in that phase must have been triggered by the erroneous airspeed breakdown. The pilots dealt with that by doing NOTHING (= nothing wrong). No need to.
Shortly before 02:10:51 they were nearly fine (but probably at their mental limits): 37500 fts and climbing with 700 fts/min with an AOA of 4° -- no trouble, but now speed down to around 215kts. That means stall and I think that is the moment when they lost the plane (first mentally, shortly after actually).
This time they didn't question the warning (by plausibility check), they simply followed procedures, they were behind their plane -- and flew into the deep stall. When the Captain entered the cockpit again; they were back down to 35000 and in the 'no-airspeed'-zone again.
Then, the second ND-input-phase (02:12:17), which could have changed everything. But, due to the lack of situational overview, at the next stall warning signal, they followed procedures again -- and threw their last chance away.
The PF said: 'Go ahead, You have control'. The wording is clearly NOT a confirmation, but a request: For me proof of the PF giving up. The procedure he (and two other pilots too!) were trained for doesn't work out. The end is known.
And there I am again: Do we overtrain pilots, do we encourage them to stop thinking and only follow procedures? There will always at some time arise a situation, where there is no procedure to be followed, because the situation is new, where common (flying-) sense is necessary and MAY save lives.
And there's my point again: Back to Basics!
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Again, if PF had not made himself aware of Law change, and was functionally still in Normal, these inputs would not do harm. (Roll left, full aft stick).
Dropping a/p does not command degradation out of Normal Law. Could he have been that far behind? It takes AD disagrees to autoselect ALTLAW. So at what point were they aware of AD disagree , and how long after that before they acclimated there 'get'/'got' to new parameters?
Dropping a/p does not command degradation out of Normal Law. Could he have been that far behind? It takes AD disagrees to autoselect ALTLAW. So at what point were they aware of AD disagree , and how long after that before they acclimated there 'get'/'got' to new parameters?
"2 h 10 min 05 , the autopilot then auto-thrust disengaged and the PF said "I have the controls"."
"At 2 h 10 min 16, the PNF said "so, we’ve lost the speeds" then "alternate law […]"."
So the PF should have been aware of the change within seconds.
There is no indication in the report of any other input recognized by the PF, other than putting the nose down as the stall warning sounded the first times.
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It's a pity they got it wrong. When in confused state, one would try everything to save the situation. They must have thought stick aft at full thrust was working since the stall warning actually stopped blaring. The thing they couldn't resolve was why were they still descending at a rapid rate? That's when one of them pushed the stick forward, which unfortunately re-trigger the stall warning. So they pulled the stick back to silence the horn, and the action did silence it. And all the while, they didn't have a valid 'speedometer'...
The ASI only were out for a matter of 60 seconds, according to the report, so they had valid indications for the last 2 1/2 minutes of flight, though they may not have recognized it or trusted it.
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'Human error' makes SLF feel better/safe
From SLF perspective it would be so much easier to swallow 'human error' as sole/major factor. That means when one flies over the ocean in the dark we can reassure ourselves with the thought that the pilots of this plane won't make the same mistake because... they're smarter/more experienced/not arrogant/not French/will have learned from AF447....
But reading all these posts two things stand out for me:
- Yes, clearly this accident COULD have been avoided, if the right action had been taken BUT who is to say any of you pilots would do the right thing?
- If the stall warning is (a) intermittent and (b) alarming when you do the right thing and silent when you do the wrong thing, it is human nature to be confused - question your actions, especially under stress.
That combined with the statements in this discussion by professional pilots that express arrogance, defensiveness, fear/"there but for..."/lack of trust in aircraft/technology... makes this SLF question the very people in the front seat who we depend on to get us there safely; the training provided by airlines and modern cockpit design.
Not a happy place to be
But reading all these posts two things stand out for me:
- Yes, clearly this accident COULD have been avoided, if the right action had been taken BUT who is to say any of you pilots would do the right thing?
- If the stall warning is (a) intermittent and (b) alarming when you do the right thing and silent when you do the wrong thing, it is human nature to be confused - question your actions, especially under stress.
That combined with the statements in this discussion by professional pilots that express arrogance, defensiveness, fear/"there but for..."/lack of trust in aircraft/technology... makes this SLF question the very people in the front seat who we depend on to get us there safely; the training provided by airlines and modern cockpit design.
Not a happy place to be
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Why he pulled nose-up is a mystery. Maybe he thought the 2 brief stall warnings were false, maybe he wanted to try and climb above the icing or the turbulence. However he did not have reliable airspeed indication in these moments, to attempt this.
Could he have felt the floor fall out from under him as a result of turbulence, and as a reflex reaction thought he needed to pull the nose up to maintain altitude?