AF447 final crew conversation - Thread No. 1
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Once STALL occurred, the flight becomes conjectural.
AV Flyer. The part of the upset and LOC that is important has to do with what the PF saw, determined, and did post a/p drop, prior to STALL.
You have DFDR data, Period. You do NOT know what the PF saw, He certainly had no access to the recorded data, and his screen was NOT recorded. This is where you demand I explain why he did not give over control. I have, you missed it, and move on.
You have avoided any possibility of doubt re: the Crash? Not even BEA have a conclusion, nor do they have data that eliminates doubt, and if they do, they have not released it.
I am done re-explaining that you and others are ignorantly blind to possibilities, that you have eaten the fruit of bias, and you need to have a dead crew so singularly stupid that nothing like it could ever happen again. Dream on.
BEA is bluffing, and you are too soft headed to call, you lose the pot.
AV Flyer. The part of the upset and LOC that is important has to do with what the PF saw, determined, and did post a/p drop, prior to STALL.
You have DFDR data, Period. You do NOT know what the PF saw, He certainly had no access to the recorded data, and his screen was NOT recorded. This is where you demand I explain why he did not give over control. I have, you missed it, and move on.
You have avoided any possibility of doubt re: the Crash? Not even BEA have a conclusion, nor do they have data that eliminates doubt, and if they do, they have not released it.
I am done re-explaining that you and others are ignorantly blind to possibilities, that you have eaten the fruit of bias, and you need to have a dead crew so singularly stupid that nothing like it could ever happen again. Dream on.
BEA is bluffing, and you are too soft headed to call, you lose the pot.
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BOAC, even if they had all instruments available, I hardly doubt that they could have recovered, considering that they were in a "deep stall" (we don't know if they were). There are several instances of stall incidents that make me vary (KAL 747 near SFO, unconfirmed "test flights" described in this forum)
Without the instruments, I really wouldn't want to find out how a recovery works: When you push your nose down, when do you start to recover? If you pull too early, you stay stalled, if you pull too late, you end up in real overspeed. Rememember they didn't have airspeed all the time.
Without the instruments, I really wouldn't want to find out how a recovery works: When you push your nose down, when do you start to recover? If you pull too early, you stay stalled, if you pull too late, you end up in real overspeed. Rememember they didn't have airspeed all the time.
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well... it truly sounds amazing that THREE people did not recognize a stalled situation for minutes. with a massive descend rate , simultanous high pitch and lack of airspeed it should be clear for every pilot what is happening. airbus is to blame that it did not firmly and continiously informed the pilots that they are in a stall.
so in the first moment we all could think we would made better, the aircraft from that high altitude surely was recoverable from a technical point ov view.
on the other hand it is always easy to discuss NOT being in an direct life danger. they were at night conditions, thunderthorms in the area, turbulence , no visual horizon reference, erratic airdata informations, and they panicked in a situation they never saw before.
all in all it nevertheless seems to be an massive pilots error- they could be able to keep out of the stall or recover one .
so in the first moment we all could think we would made better, the aircraft from that high altitude surely was recoverable from a technical point ov view.
on the other hand it is always easy to discuss NOT being in an direct life danger. they were at night conditions, thunderthorms in the area, turbulence , no visual horizon reference, erratic airdata informations, and they panicked in a situation they never saw before.
all in all it nevertheless seems to be an massive pilots error- they could be able to keep out of the stall or recover one .
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Dani - I think it is probably a language issue that is causing a little confusion here. I assume you mean "I really doubt that they could have recovered,"? Otherwise the sentence does not make sense. I would also dispute the words 'deep stall' - they were 'fully stalled', and in all probability NOT in a 'deep stall'.
Regarding recovery - yes - it would not be easy, and is not trained, but remember IAS indications returned fairly quickly..
Regarding recovery - yes - it would not be easy, and is not trained, but remember IAS indications returned fairly quickly..
Known facts :
- some planes (particularly T-tail designs) may encounter a "deep" stall; as the definition of a "deep stall" isn't the same for everybody, let's describe it as a stall-in-which-you-cannot-unstall-the-aircraft-by-pushing-on-your-pitch-control-because-your-elevators-don't-have-any-authority-anymore.
- it is not proven (and, in my opinion, it is unlikely) that the A330 is prone to this kind of stall.
- sims tests cannot be representative (why? because uncharted aerodynamic territory = sim emulates, not simulates accurately)
- AF447 proved that pushing the stick and/or reducing thrust => less AoA, even on a stalled A330, cf FDR traces; it did not prove that the stall was (or wasn't) recoverable, because no sustained attempt was made.
- some planes (particularly T-tail designs) may encounter a "deep" stall; as the definition of a "deep stall" isn't the same for everybody, let's describe it as a stall-in-which-you-cannot-unstall-the-aircraft-by-pushing-on-your-pitch-control-because-your-elevators-don't-have-any-authority-anymore.
- it is not proven (and, in my opinion, it is unlikely) that the A330 is prone to this kind of stall.
- sims tests cannot be representative (why? because uncharted aerodynamic territory = sim emulates, not simulates accurately)
- AF447 proved that pushing the stick and/or reducing thrust => less AoA, even on a stalled A330, cf FDR traces; it did not prove that the stall was (or wasn't) recoverable, because no sustained attempt was made.
Some good objectivity.
AZR:
Is there any advantage to exposing crews to an A330 'full' stall in a Level D simulator at this time?
Or maybe more correctly put, is there any disadvantage to doing this?
Or should this be put off until the final report is made available or possibly not done at all?
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I truly cannot believe the bulls*hit I'm reading here.
Dani said,
Yes we do know. This aircraft was NOT susceptible to a deep stall. A deep stall affects aircraft with a T-tail, with a horizontal stabilizer capable of being aerodynamically 'blanked off' by separated air from a stalled wing. That is, Sea Vixen, B727, HS Trident.
The modern Airbus and Boeing aircraft are NOT prone to deep stall.
A deep stall is a stall which is unrecoverable except with the deployment of a tail-chute. This stall was induced by the pilot pulling the nose up into and beyond 'coffin corner', and then wilfully holding it there as though wishing to commit suicide.
On 18th June 1972, G-ARPI entered a (real) deep stall departing LHR. I recall hearing that a pitch down of -60 degrees would have been required to recover the aircraft, but the horizontal stabilizer was blanked off and didn't work! THAT is a deep stall.
This aircraft could have been recovered with an even half-qualified pilot at the controls.
I know, I know, it's hard to criticize departed colleagues, but any dispassionate observer must ask why this guy yanked the stick hard back when he experienced an ASI failure. Even if you're in a panic - a total funk, maxed-out (been there) - it is not logical or sensible.
But please, can we stop talking about 'deep stalls'?
This stall was caused by the PF, and maintained by the PF all the way down to MSL.
Dani said,
BOAC, even if they had all instruments available, I hardly doubt that they could have recovered, considering that they were in a "deep stall" (we don't know if they were)
The modern Airbus and Boeing aircraft are NOT prone to deep stall.
A deep stall is a stall which is unrecoverable except with the deployment of a tail-chute. This stall was induced by the pilot pulling the nose up into and beyond 'coffin corner', and then wilfully holding it there as though wishing to commit suicide.
On 18th June 1972, G-ARPI entered a (real) deep stall departing LHR. I recall hearing that a pitch down of -60 degrees would have been required to recover the aircraft, but the horizontal stabilizer was blanked off and didn't work! THAT is a deep stall.
This aircraft could have been recovered with an even half-qualified pilot at the controls.
I know, I know, it's hard to criticize departed colleagues, but any dispassionate observer must ask why this guy yanked the stick hard back when he experienced an ASI failure. Even if you're in a panic - a total funk, maxed-out (been there) - it is not logical or sensible.
But please, can we stop talking about 'deep stalls'?
This stall was caused by the PF, and maintained by the PF all the way down to MSL.
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they were confused
A discussion of handling an airplane in an emergency has to center around maintaining control while fighting to get out from under what I term the "Dome of Confusion".
One expert quoted in "High Altitude Upset Recovery" referenced using pitch and power as the right method of maintaining control during instrument malfunctions. The Air Force drilled into us where to look to ensure we were using those tools. We had steps to start working out of the confusion when the probability of what just occurred went to “one."
The instruments on every airplane panel are divided among three purposes: (1) control via the ADI and tachs; (2) performance, with altimeter, airspeed and heading indicators and VVI; and (3) navigation, using the HSI, RMI, GPS, VOR, ILS and ADF. This is an excellent concept as it prioritizes where to look.
When you are trying to maintain or regain control, you go to the two control instruments. Even though some, including me, fault certain auto-throttle systems for their lack of tactile feedback, the tachs still report what the engines are doing.
Looking at the attitude indicator and the tachs will give you a basis for either maintaining or regaining your control given that you have not yet stalled the airplane. I had an instructor once tell me in the F-4 Phantom that if you depart controlled flight (stall), you use the g meter to fly. “Keep it at zero and hope the rest of the gauges eventually come back to where they belong. If not, step smartly over the side at 10,000 ft.” Unfortunately, we don’t have the "step over the side” option in our world, so our job is to avoid departing controlled flight.
Our modern airplanes have the ability to greatly increase confusion when we start working on the back side of the information power curve. We can be presented with so much "performance” and “navigation” data, that "control" information may not be processed. As with engine thrust being ineffective when behind the power curve, the amount of data coming at the pilot in a high-stress situation is so massive that it can overwhelm the ability to process and therefore result in less and less output.
Here’s a personal example ofthe "Dome” at work. On a recent recurrency simulator session at CAE, instructor Bob Hare told us, "I’m going to give you an ADS [Air Data System] problem that you’ll have to solve. Pm just going to try and put you into a confused state in which I Want you to handle a simple problem. I’m going to give it to you on downwind, in night VFR conditions."
Of course we rolled our eyes at Hare’s unwillingness to let even a simple VFR landing sim go by without missing the opportunity to embarrass us, but hey, "Bring it on." Embarrassments at his hand have always resulted in knowledge gained. Besides, what could he do to our ADSes that we couldn’t handle in VFR conditions, and after he told us about it, no less?
What he did was introduce an "ADS 3 mis-compare" fail light in the panel. Our checklist said basically that if left and right ADS presentations were valid, to ignore the light. Swallowing the bait in one gulp, we unwittingly replaced the word "valid” with "the same" and continued on. We immediately assumed that something was wrong with the ADS 3 system since both the pilot’s and copilot’s presentations were identical. And for that reason, we also didn’t lend proper weight to what the standby system, indicator Number 4, was doing. It was accelerating. But here again, we didn’t give that information the processing it needed because the two "main" indications agreed we were OK.
That anchor of reasonableness – that the two big screens were good — led us down the path and caused us to write off the clue coming from the standby system. In our minds, Number 3 was bad, because Numbers 1 and 2 agreed, and the warning light on the panel had a "3" in it. Although Number 4 had a problem, too, we ignored it and continued on downwind. Then, after a few seconds, we noticed that there seemed to be an awful lot of noise for the airspeed we were showing.
At that point, Hare mentioned something about the flaps (he never rests) and we considered moving them in case our speed was actually slower than we thought. Finally we began, through basic pitch and power, to fight through the confusion while maintaining control. We were in level flight on the ADI, not nose high as we would have been had flaps been needed, and the power was more than sufficient to maintain flight.
I’m proud to say that at least we spit out the flap hook. Finally, amidst the what’s- going-on-here? confusion, we looked to the Number 3 ADS and saw that it was reading about 100 kt. higher than the indications on the panels in front of us. Number 3 was high, but Numbers l and 2 were low and within a knot of each other. The “decider" finally became the standby instrument panel (Number 4), which also showed us to be at a very high airspeed —- an airspeed that agreed with our attitude, power settings and Number 3.
In the Falcon 7X there are four ADS systems. Number 1 for the pilot, Number 2 for the copilot and Number 3 as a monitor/comparator. Number 3 can be switched to the Number 1 or 2 position or will automatically go to Number 4 (standby) if needed. When we got the Number 3 mis-compare our assumption was Number 3 was bad, but that was unimportant since we weren’t using it anyway. (Something tells me Hare has seen crews make this assumption before.)
What it was actually telling us was that Number 3 "disagreed" with the primaries. It was only as we continued, in confusion, wondering why things weren’t right and so noisy with normal power and attitude, that we caught it. The point of the demo was to show how the introduction of confusion can make a simple problem much more difficult to solve.
One expert quoted in "High Altitude Upset Recovery" referenced using pitch and power as the right method of maintaining control during instrument malfunctions. The Air Force drilled into us where to look to ensure we were using those tools. We had steps to start working out of the confusion when the probability of what just occurred went to “one."
The instruments on every airplane panel are divided among three purposes: (1) control via the ADI and tachs; (2) performance, with altimeter, airspeed and heading indicators and VVI; and (3) navigation, using the HSI, RMI, GPS, VOR, ILS and ADF. This is an excellent concept as it prioritizes where to look.
When you are trying to maintain or regain control, you go to the two control instruments. Even though some, including me, fault certain auto-throttle systems for their lack of tactile feedback, the tachs still report what the engines are doing.
Looking at the attitude indicator and the tachs will give you a basis for either maintaining or regaining your control given that you have not yet stalled the airplane. I had an instructor once tell me in the F-4 Phantom that if you depart controlled flight (stall), you use the g meter to fly. “Keep it at zero and hope the rest of the gauges eventually come back to where they belong. If not, step smartly over the side at 10,000 ft.” Unfortunately, we don’t have the "step over the side” option in our world, so our job is to avoid departing controlled flight.
Our modern airplanes have the ability to greatly increase confusion when we start working on the back side of the information power curve. We can be presented with so much "performance” and “navigation” data, that "control" information may not be processed. As with engine thrust being ineffective when behind the power curve, the amount of data coming at the pilot in a high-stress situation is so massive that it can overwhelm the ability to process and therefore result in less and less output.
Here’s a personal example ofthe "Dome” at work. On a recent recurrency simulator session at CAE, instructor Bob Hare told us, "I’m going to give you an ADS [Air Data System] problem that you’ll have to solve. Pm just going to try and put you into a confused state in which I Want you to handle a simple problem. I’m going to give it to you on downwind, in night VFR conditions."
Of course we rolled our eyes at Hare’s unwillingness to let even a simple VFR landing sim go by without missing the opportunity to embarrass us, but hey, "Bring it on." Embarrassments at his hand have always resulted in knowledge gained. Besides, what could he do to our ADSes that we couldn’t handle in VFR conditions, and after he told us about it, no less?
What he did was introduce an "ADS 3 mis-compare" fail light in the panel. Our checklist said basically that if left and right ADS presentations were valid, to ignore the light. Swallowing the bait in one gulp, we unwittingly replaced the word "valid” with "the same" and continued on. We immediately assumed that something was wrong with the ADS 3 system since both the pilot’s and copilot’s presentations were identical. And for that reason, we also didn’t lend proper weight to what the standby system, indicator Number 4, was doing. It was accelerating. But here again, we didn’t give that information the processing it needed because the two "main" indications agreed we were OK.
That anchor of reasonableness – that the two big screens were good — led us down the path and caused us to write off the clue coming from the standby system. In our minds, Number 3 was bad, because Numbers 1 and 2 agreed, and the warning light on the panel had a "3" in it. Although Number 4 had a problem, too, we ignored it and continued on downwind. Then, after a few seconds, we noticed that there seemed to be an awful lot of noise for the airspeed we were showing.
At that point, Hare mentioned something about the flaps (he never rests) and we considered moving them in case our speed was actually slower than we thought. Finally we began, through basic pitch and power, to fight through the confusion while maintaining control. We were in level flight on the ADI, not nose high as we would have been had flaps been needed, and the power was more than sufficient to maintain flight.
I’m proud to say that at least we spit out the flap hook. Finally, amidst the what’s- going-on-here? confusion, we looked to the Number 3 ADS and saw that it was reading about 100 kt. higher than the indications on the panels in front of us. Number 3 was high, but Numbers l and 2 were low and within a knot of each other. The “decider" finally became the standby instrument panel (Number 4), which also showed us to be at a very high airspeed —- an airspeed that agreed with our attitude, power settings and Number 3.
In the Falcon 7X there are four ADS systems. Number 1 for the pilot, Number 2 for the copilot and Number 3 as a monitor/comparator. Number 3 can be switched to the Number 1 or 2 position or will automatically go to Number 4 (standby) if needed. When we got the Number 3 mis-compare our assumption was Number 3 was bad, but that was unimportant since we weren’t using it anyway. (Something tells me Hare has seen crews make this assumption before.)
What it was actually telling us was that Number 3 "disagreed" with the primaries. It was only as we continued, in confusion, wondering why things weren’t right and so noisy with normal power and attitude, that we caught it. The point of the demo was to show how the introduction of confusion can make a simple problem much more difficult to solve.
The challenges the crew of Air France 447 must have been facing on the night of June 1, 2009, over the South Atlantic are known. Sensory systems appear to have iced up, negating their input. From what I’ve read, the airplane was held in a high angle of attack (AOA) position due to back stick pressure being exerted. With a frozen pitot static system, indicated altitude does not change and indicated airspeed increases with altitude. So they may have initially thought they were going fast and maintaining altitude. If true, that might explain why they continued raising the nose.
Did they remain in "controlled” flight all the to the water because the FBW wouldn’t let the airplane exceed the stall AOA? I’m not recommending stalling and spinning down through a thunderstorm when you ice up, but a pre-stall shudder and roll off would have at least given them the clue that they were going down. They may never have had that clue.
What other confusions could be added to this situation? Were they wondering if the airplane’s FBW system was functioning correctly? Was it causing them to pitch up because it, not them, thought they were going too fast? Did FBW add to the confusion by making inputs of its own? When FBW systems ice up, what do the computers think is happening and how will that affect the possibility of “putting the nose where you want it”? I’m not saying that’s what happened because I don’t know and no one else has pointed to that fact, but it could sure add to the confusion.
Did they remain in "controlled” flight all the to the water because the FBW wouldn’t let the airplane exceed the stall AOA? I’m not recommending stalling and spinning down through a thunderstorm when you ice up, but a pre-stall shudder and roll off would have at least given them the clue that they were going down. They may never have had that clue.
What other confusions could be added to this situation? Were they wondering if the airplane’s FBW system was functioning correctly? Was it causing them to pitch up because it, not them, thought they were going too fast? Did FBW add to the confusion by making inputs of its own? When FBW systems ice up, what do the computers think is happening and how will that affect the possibility of “putting the nose where you want it”? I’m not saying that’s what happened because I don’t know and no one else has pointed to that fact, but it could sure add to the confusion.
Trapped again.
Please don't misinterpret my poorly phrased post that got stuck in there between AD & LR. It was only a comment on AD's tidy summation.
There's a lot of loud, but not a lot of clear.
I think AD's post is somewhat presumptuous when it comes to this aircraft's aero characteristics.
We (he) know(s), I don't.
Please don't misinterpret my poorly phrased post that got stuck in there between AD & LR. It was only a comment on AD's tidy summation.
There's a lot of loud, but not a lot of clear.
I think AD's post is somewhat presumptuous when it comes to this aircraft's aero characteristics.
Yes we do know. This aircraft was NOT susceptible to a deep stall.
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Deep-Stall-able?
Quote:
Yes we do know. This aircraft was NOT susceptible to a deep stall.
We (he) know(s), I don't.
Yes we do know. This aircraft was NOT susceptible to a deep stall.
We (he) know(s), I don't.
Aerodynamic Principles of Large-Airplane Upsets
Beg all of your pardons if this has already been linked in this thread.
Certainly begs the question: when was upset recovery training started? And then.....when was it stopped/reduced?
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The battle between our 'DNA of flying' and machine management
This is my first post on this AF447 thread and one of the few I’ve made on PPRuNe. I am a private pilot with around 700 hours collected intermittently over a 25 year period. My experience is all single engine by day from C152 through to C210, Mooney 201, Piper Comanche with an aero endorsement, tail wheel and floating hull. My only air transport experience has been as SLF (on many business trips all over the world) and as an SLF that managed to talk my way into many cockpits to ride on the check /observers seat (in the glory days pre 9/11) so I am grossly unknowledgeable about the world of the commercial cockpit and the complex aircraft many of you here fly. The most amazing and wonderful flying I’ve done by far has been in a Lake Renegade amphibian. This go anywhere machine (for me) is the ultimate freedom aircraft and blends aviation and marine skills in a unique fashion that brings a whole other dimension to flying. If you’ve never experienced the wonder of a flying boat and all the amazing places you can go with one, you can’t begin to comprehend what it’s like.
Likewise, I can’t begin to comprehend the tragedy and chaos of the final moments of these pilots’ lives. I’ve read this entire thread from the beginning and would like to thank all the contributors for bringing a dozen salient points to the table. There’s much passion on display, much insight into what might have happened and much disbelief that this crew flew this aircraft into a stall and had no comprehension that that’s what they’d done and stalled it all the way down to the sea at 10,000 feet per minute. What’s been mentioned here, but perhaps not entirely clearly articulated, is the fundamental glaringly obvious issue with the Airbus’ FBW system’s entirely different approach to the control of an aircraft against the backdrop of everything most commercial fixed wing aircraft have been up to this point.
Does anyone remember those early computer video games from the late 70s/early 80s where you had a space ship that had to shoot other objects on the screen and you had to ‘”steer” the craft using keyboard arrows (or a joystick if you had a really swish setup)? I think it might have been called Spacewars. The “space ship” was represented as an arrow on the screen and you could rotate it through 360 degrees, and move around by using positive or negative thrust. It took some time to get used to how to move it because every control input required a counteractive input to stop the movement that was started (i.e. rotate to left required some rotate to right counteraction to stop the rotation. Move forward required some ‘reverse thrust’ to counter and stop the movement. Thrust movement plus rotation resulted in strange oversteer or understeer which could see you careering out of control). In fact the entire control of the spaceship was in effect what one might consider would truly happen out in space where Newton’s 3rd law is perfectly on display and not hampered by other things such as airflow. It took considerable time to conquer the techniques to move around and the ‘no gravity, no friction’ movement of the space craft was almost impossible for some people to get their minds around.
Now, all professional pilots, A & B drivers, please feel free to shoot my observations down in flames, but if the side stick of an Airbus behaves (sometimes, always or only occasionally such as perhaps when the aircraft is fully stalled) in a manner not dissimilar or even a little bit like the old video game I’ve mentioned above (i.e. the pilot makes an input such as ‘stick fully back’ and a substantial forward stick counteracting input is required to negate the state that the first input leaves the aircraft in) then this is just the most fundamentally different flying quality to virtually every other fixed wing aircraft, be it a large commercial jet or the tiniest recreational micro-lite. The many posts in this thread that are indicating the AB’s computers are recognising pilot input much like a ‘request’ for a certain pitch angle or for a certain G loading takes the manner in which an aircraft is controlled into an entirely different realm which would require a wholly different mode of thinking (no news here….but hear me out for a moment). In fact, the simple stick-position/attitude/power concepts we’ve all learned and are the currency of basic flying skills are not relevant for the skills required to fly an AB (if this concept of the operation of the control stick being so completely different is actually how it is).
My point is that EVERYTHING we have ever learned about how a fixed wing aircraft flies and the use of the control wheel/stick throughout all phases of flight, our ‘DNA of flying’ if you will, is embedded and inculcated into our ‘flying thinking’, our skill-sets, our survival instincts, our love of flight and our automatic reactions. Our ability to spatially conceptualise ourselves in space and time and to extend our bodies to the control surfaces of an aircraft is all tied to our first few experiences of flying. Just like taking our first few steps as a toddler, riding a bicycle as a youngster, learning to hit a ball with a bat or racquet, taking to the wheel of a car, those first few lessons when we started flying have gone into the subconscious and the feelings, sensations and sounds have formed an unchangeable and immovable level of ‘knowing’ about how to fly. For anyone that learned in a Cessna 152 or 172, who could forget those early experiences of stalling? The sound of the wind howling and ‘wailing’ through the vents up near the corners of the windscreen as your instructor encouraged you to keep holding the control wheel right back and keep it straight with rudder whilst waiting for the buffet and nose drop? The feeling and sensation of the aircraft struggling to fly and its nose drop demonstrating it was effectively ‘giving up’ is something you don’t forget as you ease off holding the control wheel back and add power (whilst, as a new student, frantically using rudder to prevent a wing drop) with your instructor either admonishing your good handling or castigating you for losing hundreds of feet!
And it’s this ‘DNA of flying’ that is most likely in a battle with the analysis/machine-interpretation skills that appear to be all important when flying these FBW airliners that are, in effect, very complicated computers with a whole raft of rules and ‘laws’ that keep the machines safe for 99% of the time but expose the operators to a baffling and overly complex environment for that 1% of time when conditions and malfunction take them outside the norm.
These AF447 pilots (and I would hazard to guess a substantial number of current AB drivers) can’t possibly have been trained well enough to deal with the conditions they found themselves in that night (dark, IMC, turbulence), the complexities of the flight data systems being compromised by the pitot malfunction and responses of the aircraft to the extremity of the a/p & auto throttle disconnect. It’s just so easy to blame them and say things “like the PF held the nose up at 35 degrees all the way down! Who would do such a stupid thing…!?” I would reckon many ‘would do’ the same (and the PF in fact may not have ‘held’ the stick back anyway) as there was clearly way too much complexity, way too many possibilities of the AB’s system’s reporting incorrect situation (and them needing to consider that simplistic conclusions are likely to be wrong because of the system’s compromise) and they had to deal with potentially just the most basic of fundamental conflict between their ‘DNA of flying’ knowing and the ‘laws’ and rules that the Airbus 330 had been keeping them safe with and then suddenly dropped them outside of the cocoon to fend for themselves.
I think we owe it to the memory of these guys to be aware that the situation they ended up in was just so confusing, so hopeless and so desperate, their loss (and our ability to know something of what happened) is likely to be the start of a major initiative to deal with the need to bridge this great divide between the art of flying (as it has been for the first 90 or so years) and this relatively new world of machine management that requires so much more knowledge and ability to get into the mind of the designer/programmer in order be ahead of it and not come unstuck.
Unfortunately this is the world we’re all moving into more and more. Technology is creating wonderful benefits for ordinary people where the users of the technology don’t need to understand the underlying operatives. And business leaders see great efficiency and profitability in building complex machines where technology that’s getting closer and closer to the goal of artificial intelligence keeps us safe and ‘inside the envelop’. The problem is that as this technology takes more and more hold, generations of users, proponents and ‘visionaries’ start to misunderstand man’s need to still be one step ahead of it and maintain the skills and knowledge to take back control when the technology fails (as it inevitably does because it’s just a reflection of our human condition).
I hope post has made sense; sorry for it being so long winded . I’m less than thrilled about travelling in these complex machines as I can see that this is about man-machine interface psychology, economics, politics and big business needing to come clean and invest more dollars into research and training rather than just about this particular crew's lack of ability, perceived or otherwise.
Likewise, I can’t begin to comprehend the tragedy and chaos of the final moments of these pilots’ lives. I’ve read this entire thread from the beginning and would like to thank all the contributors for bringing a dozen salient points to the table. There’s much passion on display, much insight into what might have happened and much disbelief that this crew flew this aircraft into a stall and had no comprehension that that’s what they’d done and stalled it all the way down to the sea at 10,000 feet per minute. What’s been mentioned here, but perhaps not entirely clearly articulated, is the fundamental glaringly obvious issue with the Airbus’ FBW system’s entirely different approach to the control of an aircraft against the backdrop of everything most commercial fixed wing aircraft have been up to this point.
Does anyone remember those early computer video games from the late 70s/early 80s where you had a space ship that had to shoot other objects on the screen and you had to ‘”steer” the craft using keyboard arrows (or a joystick if you had a really swish setup)? I think it might have been called Spacewars. The “space ship” was represented as an arrow on the screen and you could rotate it through 360 degrees, and move around by using positive or negative thrust. It took some time to get used to how to move it because every control input required a counteractive input to stop the movement that was started (i.e. rotate to left required some rotate to right counteraction to stop the rotation. Move forward required some ‘reverse thrust’ to counter and stop the movement. Thrust movement plus rotation resulted in strange oversteer or understeer which could see you careering out of control). In fact the entire control of the spaceship was in effect what one might consider would truly happen out in space where Newton’s 3rd law is perfectly on display and not hampered by other things such as airflow. It took considerable time to conquer the techniques to move around and the ‘no gravity, no friction’ movement of the space craft was almost impossible for some people to get their minds around.
Now, all professional pilots, A & B drivers, please feel free to shoot my observations down in flames, but if the side stick of an Airbus behaves (sometimes, always or only occasionally such as perhaps when the aircraft is fully stalled) in a manner not dissimilar or even a little bit like the old video game I’ve mentioned above (i.e. the pilot makes an input such as ‘stick fully back’ and a substantial forward stick counteracting input is required to negate the state that the first input leaves the aircraft in) then this is just the most fundamentally different flying quality to virtually every other fixed wing aircraft, be it a large commercial jet or the tiniest recreational micro-lite. The many posts in this thread that are indicating the AB’s computers are recognising pilot input much like a ‘request’ for a certain pitch angle or for a certain G loading takes the manner in which an aircraft is controlled into an entirely different realm which would require a wholly different mode of thinking (no news here….but hear me out for a moment). In fact, the simple stick-position/attitude/power concepts we’ve all learned and are the currency of basic flying skills are not relevant for the skills required to fly an AB (if this concept of the operation of the control stick being so completely different is actually how it is).
My point is that EVERYTHING we have ever learned about how a fixed wing aircraft flies and the use of the control wheel/stick throughout all phases of flight, our ‘DNA of flying’ if you will, is embedded and inculcated into our ‘flying thinking’, our skill-sets, our survival instincts, our love of flight and our automatic reactions. Our ability to spatially conceptualise ourselves in space and time and to extend our bodies to the control surfaces of an aircraft is all tied to our first few experiences of flying. Just like taking our first few steps as a toddler, riding a bicycle as a youngster, learning to hit a ball with a bat or racquet, taking to the wheel of a car, those first few lessons when we started flying have gone into the subconscious and the feelings, sensations and sounds have formed an unchangeable and immovable level of ‘knowing’ about how to fly. For anyone that learned in a Cessna 152 or 172, who could forget those early experiences of stalling? The sound of the wind howling and ‘wailing’ through the vents up near the corners of the windscreen as your instructor encouraged you to keep holding the control wheel right back and keep it straight with rudder whilst waiting for the buffet and nose drop? The feeling and sensation of the aircraft struggling to fly and its nose drop demonstrating it was effectively ‘giving up’ is something you don’t forget as you ease off holding the control wheel back and add power (whilst, as a new student, frantically using rudder to prevent a wing drop) with your instructor either admonishing your good handling or castigating you for losing hundreds of feet!
And it’s this ‘DNA of flying’ that is most likely in a battle with the analysis/machine-interpretation skills that appear to be all important when flying these FBW airliners that are, in effect, very complicated computers with a whole raft of rules and ‘laws’ that keep the machines safe for 99% of the time but expose the operators to a baffling and overly complex environment for that 1% of time when conditions and malfunction take them outside the norm.
These AF447 pilots (and I would hazard to guess a substantial number of current AB drivers) can’t possibly have been trained well enough to deal with the conditions they found themselves in that night (dark, IMC, turbulence), the complexities of the flight data systems being compromised by the pitot malfunction and responses of the aircraft to the extremity of the a/p & auto throttle disconnect. It’s just so easy to blame them and say things “like the PF held the nose up at 35 degrees all the way down! Who would do such a stupid thing…!?” I would reckon many ‘would do’ the same (and the PF in fact may not have ‘held’ the stick back anyway) as there was clearly way too much complexity, way too many possibilities of the AB’s system’s reporting incorrect situation (and them needing to consider that simplistic conclusions are likely to be wrong because of the system’s compromise) and they had to deal with potentially just the most basic of fundamental conflict between their ‘DNA of flying’ knowing and the ‘laws’ and rules that the Airbus 330 had been keeping them safe with and then suddenly dropped them outside of the cocoon to fend for themselves.
I think we owe it to the memory of these guys to be aware that the situation they ended up in was just so confusing, so hopeless and so desperate, their loss (and our ability to know something of what happened) is likely to be the start of a major initiative to deal with the need to bridge this great divide between the art of flying (as it has been for the first 90 or so years) and this relatively new world of machine management that requires so much more knowledge and ability to get into the mind of the designer/programmer in order be ahead of it and not come unstuck.
Unfortunately this is the world we’re all moving into more and more. Technology is creating wonderful benefits for ordinary people where the users of the technology don’t need to understand the underlying operatives. And business leaders see great efficiency and profitability in building complex machines where technology that’s getting closer and closer to the goal of artificial intelligence keeps us safe and ‘inside the envelop’. The problem is that as this technology takes more and more hold, generations of users, proponents and ‘visionaries’ start to misunderstand man’s need to still be one step ahead of it and maintain the skills and knowledge to take back control when the technology fails (as it inevitably does because it’s just a reflection of our human condition).
I hope post has made sense; sorry for it being so long winded . I’m less than thrilled about travelling in these complex machines as I can see that this is about man-machine interface psychology, economics, politics and big business needing to come clean and invest more dollars into research and training rather than just about this particular crew's lack of ability, perceived or otherwise.
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Renegade man - good post, however I do feel it's a bit of an airbus bashing. You have to remember that even though the airbus has loads of protections, the control surfaces still work in a normal sense. Stick forward, nose goes down. Stick back, nose comes up. There is no need to put in opposit control to stop or control the movement either, the aircraft just trims for you, so you can set the exact attitude you want then release the stick. So the stall recovery is still the same as for a light aircraft, with the exception that you may actually have to reduce thrust to remove the pitch power couple. I hope that helps you understand the airbus a bit more.
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BOAC, language critic well accepted.
Stall: Yes, the pitot got ice-free quickly, but did they know? They couldn't trust their instruments anymore. How could they know that speed is indicating correctly, once they remained around and below 60kts? It's a very disturbing indication. The likelihood that they are wrong is bigger, if you find yourself in this situation. Because it is not possible that you are in the air and indications show zero. Even vertical speed (-10000 fpm) they did not trust, and I can understand that they didn't.
I stand with my initial statement: After they inadvertently stalled the plane, their chances of recovering was very low. The only chance would have been to push down, check GPS speed, then pull. (G load should not be a problem as long as speed is in a normal range). I'm pretty sure we will be presented with some kind of data about how it is possible (BEA final report?).
That's also why Airbus training guidelines now concentrate on Unreliable Speed and stall recognition, not on stall recovery. It's much more important not to get into stall than to get out of it.
Stall: Yes, the pitot got ice-free quickly, but did they know? They couldn't trust their instruments anymore. How could they know that speed is indicating correctly, once they remained around and below 60kts? It's a very disturbing indication. The likelihood that they are wrong is bigger, if you find yourself in this situation. Because it is not possible that you are in the air and indications show zero. Even vertical speed (-10000 fpm) they did not trust, and I can understand that they didn't.
I stand with my initial statement: After they inadvertently stalled the plane, their chances of recovering was very low. The only chance would have been to push down, check GPS speed, then pull. (G load should not be a problem as long as speed is in a normal range). I'm pretty sure we will be presented with some kind of data about how it is possible (BEA final report?).
That's also why Airbus training guidelines now concentrate on Unreliable Speed and stall recognition, not on stall recovery. It's much more important not to get into stall than to get out of it.
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I'm not qualified to answer that.
As far as personal opinions go, I cannot see why it would be a disadvantage to do this (from a flying skills point of view).
But there are not so many Level D simulators, perhaps they are better used at something else (that they do accurately). If the goal is to train crews to push stick & decrease thrust, a more simple sim/trainer may be enough... and cheaper, pending the final report & recommendations.
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Very informative thread.
I think the psychological key might be the PNF's statement at 2:10:17 "we've lost the the speeds..." which implies he thinks the failure is more than one, and communicates that to the PF. With such extreme values when they are all working its easy to understand why they might be sceptical of what they were reading. Unfortunately we will never know for sure because we don't know what the PF was seeing.
Also at 2:10:22 the PNF just says "Alternate law protections" to the PF without specifying which. This seems a recipe for pilot confusion, particularly in such a stressful situation when the ECAM hasn't said why the ap has disconnected and control switched to alt2. Again psychologically, if you have different states, far better to have different names for them to avoid exactly this sort of potential misunderstanding which is the last thing you need in a time critical environment.
I think the psychological key might be the PNF's statement at 2:10:17 "we've lost the the speeds..." which implies he thinks the failure is more than one, and communicates that to the PF. With such extreme values when they are all working its easy to understand why they might be sceptical of what they were reading. Unfortunately we will never know for sure because we don't know what the PF was seeing.
Also at 2:10:22 the PNF just says "Alternate law protections" to the PF without specifying which. This seems a recipe for pilot confusion, particularly in such a stressful situation when the ECAM hasn't said why the ap has disconnected and control switched to alt2. Again psychologically, if you have different states, far better to have different names for them to avoid exactly this sort of potential misunderstanding which is the last thing you need in a time critical environment.
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For those that keep going on about the requirement for force feedback because nothing is apparent to the pilot when the sidestick is moved, have you flown the type? I doubt it because to achieve the 15 degrees nose up that the Pf achieved requires a SUBSTANTIAL and CONSTANT back stick and the FORCE required to do so SIGNIFICANT! It is NOT just a little blip on the sidestick that you would NOT know you were applying.
worrier
The fact you have lost the speeds does NOT mean you will fall out of the sky just hold the attitude, that is why we have a big Primary Flight Display. The ECAM does not need to tell you why the AP has disconnected as it is apparent due to loss of airspeed indications and the PFD will show some of the protections that are NOT available. So all the PF has to do is hold the attitude through any turbulence until the PM can run the ECAM and before you know it the speeds recover.
LYMAN
You are clutching at straws with
You are trying to say that the PF's PFD was not available to him because it is not on the DFDR. Well you are actually saying that the PF is incompetent as he was trying to fly the aircraft without a PFD, when he should have handed over control immediately if that was the case.
RenegadeMan
Wrong I am afraid as the Instrument rating is designed for flight in the dark or heaven forbid IMC! The A/C was NOT at any "extremity" when the AP and A/THR disconnected they were virtually STRAIGHT and LEVEL, one of the first things we were taught as PILOTS!
I will say again that once they were in the stall they were then poorly placed to recognise and recover, confusion reigned, HOWEVER they should NOT have been in that situation in the first place. If the stall warning had been programmed to keep operating below 60 kts I doubt it would have helped them as they did not "hear" it, in the zoom climb, when it would have saved them, so I doubt they would have "heard" it in the actual stall!
As an aside, why on earth would any designer / regulator of a transport category aircraft, never mind the pilot, expect an aircraft of that size to get below 60kts in flight, without a stall recovery being attempted a long time before is beyond me!
worrier
The fact you have lost the speeds does NOT mean you will fall out of the sky just hold the attitude, that is why we have a big Primary Flight Display. The ECAM does not need to tell you why the AP has disconnected as it is apparent due to loss of airspeed indications and the PFD will show some of the protections that are NOT available. So all the PF has to do is hold the attitude through any turbulence until the PM can run the ECAM and before you know it the speeds recover.
LYMAN
You are clutching at straws with
The part of the upset and LOC that is important has to do with what the PF saw, determined, and did post a/p drop, prior to STALL.
You have DFDR data, Period. You do NOT know what the PF saw, He certainly had no access to the recorded data, and his screen was NOT recorded.
You have DFDR data, Period. You do NOT know what the PF saw, He certainly had no access to the recorded data, and his screen was NOT recorded.
RenegadeMan
can't possibly have been trained well enough to deal with the conditions they found themselves in that night (dark, IMC, turbulence), the complexities of the flight data systems being compromised by the pitot malfunction and responses of the aircraft to the extremity of the a/p & auto throttle disconnect.
I will say again that once they were in the stall they were then poorly placed to recognise and recover, confusion reigned, HOWEVER they should NOT have been in that situation in the first place. If the stall warning had been programmed to keep operating below 60 kts I doubt it would have helped them as they did not "hear" it, in the zoom climb, when it would have saved them, so I doubt they would have "heard" it in the actual stall!
As an aside, why on earth would any designer / regulator of a transport category aircraft, never mind the pilot, expect an aircraft of that size to get below 60kts in flight, without a stall recovery being attempted a long time before is beyond me!
As an aside, why on earth would any designer / regulator of a transport category aircraft, never mind the pilot, expect an aircraft of that size to get below 60kts in flight, without a stall recovery being attempted a long time before is beyond me!
A lot of your argument, iceman, relies of pilots being competent "stick and rudder" pilots. Can't you see that that is rapidly becoming not the case any more?
As for the two FOs, I wonder if the chap in the left hand seat ever did much hand flying from that seat. With the captain, the FOs would always "fly" from the RHS. The two FOs would probably only ever be together with the AP engaged. Here we have the aeroplane out of control, with one crewmember not sitting in his normal "poling" seat and the other not being able to work out what was going on, or at least recover. A setup for a stuffup, me thinks.
Training
Is this a case of limited stick and rudder skills or a failure to read and interpret instruments.
Knowledge base ?
Skill base?
or
Error base ?
It makes a difference in how we train to prevent a repeat of this accident
Knowledge base ?
Skill base?
or
Error base ?
It makes a difference in how we train to prevent a repeat of this accident