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Thread: Air Canada pulls a Hans Solo

  1. #81
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    Quote Originally Posted by elaw View Post
    God grant me the serenity to accept the things I cannot change, (Computer flying the airplane)
    Makes you wonder what all those knobs are for, doesn't it.

  2. #82
    Senior Member 3WE's Avatar
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    Quote Originally Posted by Evan View Post
    ...Knowing what it's doing now, and what it will be doing next. And what it won't be doing, ever, that you must do yourself. And what you should never do to it.
    You list 5 scenarios in the quote and then mention lots of knobs right above. I suggest this as a single, simple solution: Fly the GD plane (or at least check the instruments if it's flying itself).

    Quote Originally Posted by Evan View Post
    And that's all very teachable.
    I agree it's teachable.

    But I look at the long list of accidents (see post #70, Item #2) and ask why it wasn't taught, including the basic stuff that you say must have been taught way back in their history somewhere.
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  3. #83
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    Quote Originally Posted by 3WE View Post
    I agree it's teachable.
    Congrats Evan- you now have me arguing with myself.

    The issue is actually that it doesn't have to be taught.

    Gabriel and I are two, self-confessed, dumbasses. We have no business flying an airliner.

    BUT- with zero type specific training at all, whatsoever:

    -We would not have stalled Air France nor Colgan nor Pinnacle.

    -We would not have run Asiana's 777 out of airspeed, altitude and ideas on short final.

    -We might even be able to make a 737 go around at 400 feet and not enter a steep climb due to somatographic illusions and powerful underslung engines.

    We don't need shit in the way of 'teaching' for those particular incidents.

    God help us if we are called upon to legally navigate an airliner to a New York airport.

    Important note on that 737 go-around: It would indeed be dangerous of me to try to turn the autopilot back on during that go around- I am NOT properly trained in its use. To do so would be distracting and might make me miss it if an extreme-nose up attitude crept in...

    But hey, Gabe and I have got that covered too! We've been trained to fly the GD airplane and NOT BE DISTRACTED by automation...somewhere around 3000 feet...if things are stable, I'll call you up on the radio and you can help me with the automation.

    Yes, we were once taught basics. Yes, all pilots were once taught hand flying. Yes, we would need lots of type specific training. Yes, we have not forgotten the basics.

    But some pilots seem to forget the basics (and kill people) and some training programs seem to neglect the basics and some airplanes are designed to not need basics and some type-specific trainings tell you to not hand-fly above 250 feet...

    ...maybe some correlation?
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  4. #84
    Senior Member Gabriel's Avatar
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    Quote Originally Posted by Evan View Post
    Exactly my point. There is no safe, universal "I know how to fly an airplane". You have to know the specific systems if you don't want to end up eating those words.
    There IS a universal "I know how to fly an airplane", and then there IS specifics. (Did I say AND lately?)

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  5. #85
    Senior Member Gabriel's Avatar
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    Quote Originally Posted by Evan View Post
    Again, tell me where this was a factor in any of these crashes. None of this was about nuance. None of them failed due to unpolished handflying skills and flawed inputs.
    Lack of proper understanding, experience and skills in hand flying can result in worse than just "unpolished" performance, like pulling up to go up beyond the max lift that your wing will give, like not properly monitoring the flight parameters, like not realizing that you are not being pushed against your seat back and that means that something is wrong with the GA thrust...

    Air France: the extended inputs and apparent intention was entirely in conflict with 'basically need to know how to fly an airplane'. Same with Colgan. Same with Turkish. All of these pilots broke a cardinal rule taught to every pilot learning the basics of how to fly an airplane
    You seem not to understand the difference between being taught something, learning something theoretically, learning something in tageted practice (like " let's go and so some stalls), and having something really incorporated to your most intimate understanding (understanding with the whole soul and body, not just after a thought process). Do you drive a car? Have you ever learned to drive a car or were you born knowing how to do it? Does it feels NOW as if you were born knowing how to do it, as if it part of your self, or is it something that you learned and can reason around, like it could be maybe some calculus problem?

    Saying "this will never happen to me" is a big no-no in aviation, but I honestly feel that some things will never happen to me. Take Colgan. To begin with, even if I don't understand the effects of the "ice" switch in the stall warning and approach speeds, my first reaction on the stall warning would have been maybe to lower the nose a bit (especially since I knew that I had altitude to spare), but immediately after I would have said "wait a minute... pitch slightly nose up, airplane flying level, this is low AoA, this is NOT a stall". And it is not that I would have needed to think about. The thought would have come by itself. I might have become distracted or disoriented and crashed in some other way, Pulling up relentlessly against the stick shaker and stick-pusher and then keep pulling up all the way down? That would not have happened to me. Take Turkish. Not only they were I don't know how many seconds not realizing of the speed decay and that the throttles were at idle, all the engine instruments were showing idle, the engine noise was idle, and the airplane felt as at idle (you are being pushed "forward" by the deceleration). The stall warning sounded and, initially, they reacted correctly. The FO lowered the nose and advanced the thrust levers. At this point it was still recoverable. Then the Captain said "my plane". With that, the FO took his hands off the controls, including the throttles, and the captain didn't put the hands on the throttles. Seriously? You are hand-flying a stall recovery, where you were taken to by the automation (for reasons X, I don't care at THIS point in the accident sequence) and you let the automation do things? Some criticize them for not turning the AT off. I can't believe that the pilot flying the plane out of a stall didn't have one hand in the thrust levers all the time!!!! THIS would not have happened to me.

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  6. #86
    Senior Member Evan's Avatar
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    Quote Originally Posted by Gabriel View Post
    THIS would not have happened to me.
    Perhaps not.

    Or perhaps that is hubris. After studying the canon of literature known as the NTSB archive, amongst others, you find that there is something very humbling about human nature and proficiency. And clearly, there is something that happens to the mind under surprise and stress that seems quite random and inexplicable and unrelated to experience. As this becomes more apparent to us, we can't simply take refuge in confidence and denial.

    I think:

    a) Some pilots are inherently more susceptible than others to confusion under surprise and stress and sensory disorientation, while some are more apt to remain clear-headed and perform reliably.

    b) It is possible to screen for this susceptibility and to condition pilots to be more prepared for it, but the methods would be too extreme for the industry to accept (a la the USN inverted dunk test).

    c) Practiced proficiency under non-stressful, non-disorienting conditions may help but will not prevent the phenomena, as the phenomena itself momentarilly deprives pilots of their learned skills and reasoning.

    d) Since we can't prevent it, since we can't go to the extremes of testing and screening for this, and we can't reliably prevent this through non-extreme training, we must (as best as possible) prevent the things that cause it (this is similar to the existing design philosophy that, because we can't make airplanes crashworthy, we must build in better provisions and redundancies to prevent crashes from ever happening).

    e) We know many the things that cause surprise, stress and disorientation. They are sudden events and/or inverted expectations. Some of these events are open to chance and can't be overcome but inverted expectations can be through training because THEY ARE THE DIRECT RESULT OF INADEQUATE TRAINING. For example, a sudden, uncontained engine failure or a sudden decompression cannot be entirely prevented at this time. It's going to happen from time to time. Our best defense is rote training on memory procedures and practiced airmanship (executed in that order). But a sudden confusion and emergency recovery brought about by erroneous expectations concerning the behavior and capabilties of autoflight —which is behind quite a number of these events—CAN be entirely prevented through better training and a deeper type-specific understanding.

    f) Even veteran pilots experience these "brain farts" as we call them, and subsequently cannot account for them. Some never experience them. Some have a perfect history until that one day when they almost land on a crowded taxiway. But because we cannot screen for pilots who are immune to these human factors (assuming there really are any), we have to create an environment that provides for the ones who are not immune. We have to build in safeguards (TOO LOW GEAR) that might seem idiotic on the surface, and we have to make certain that nothing the aircraft is DESIGNED TO DO will ever confuse and thus distract and/or disorient the pilot entrusted with it.

    e) We are not currently doing that consistently, across the industry. In some cases it seems we are not doing that at all.

    f) Handflying skills and universal, fundamental airmanship, which are no less important, are a seperate issue which also needs to be addressed. But I'm not addressing that here, other than to point out that these things alone are not going to prevent the preventable aspects of the phenomena.

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    Quote Originally Posted by Evan View Post
    Perhaps not.

    Or perhaps that is hubris. After studying the canon of literature known as the NTSB archive, amongst others, you find that there is something very humbling about human nature and proficiency. And clearly, there is something that happens to the mind under surprise and stress that seems quite random and inexplicable and unrelated to experience. As this becomes more apparent to us, we can't simply take refuge in confidence and denial.

    I think:

    a) Some pilots are inherently more susceptible than others to confusion under surprise and stress and sensory disorientation, while some are more apt to remain clear-headed and perform reliably.

    b) It is possible to screen for this susceptibility and to condition pilots to be more prepared for it, but the methods would be too extreme for the industry to accept (a la the USN inverted dunk test).

    c) Practiced proficiency under non-stressful, non-disorienting conditions may help but will not prevent the phenomena, as the phenomena itself momentarilly deprives pilots of their learned skills and reasoning.

    d) Since we can't prevent it, since we can't go to the extremes of testing and screening for this, and we can't reliably prevent this through non-extreme training, we must (as best as possible) prevent the things that cause it (this is similar to the existing design philosophy that, because we can't make airplanes crashworthy, we must build in better provisions and redundancies to prevent crashes from ever happening).

    e) We know many the things that cause surprise, stress and disorientation. They are sudden events and/or inverted expectations. Some of these events are open to chance and can't be overcome but inverted expectations can be through training because THEY ARE THE DIRECT RESULT OF INADEQUATE TRAINING. For example, a sudden, uncontained engine failure or a sudden decompression cannot be entirely prevented at this time. It's going to happen from time to time. Our best defense is rote training on memory procedures and practiced airmanship (executed in that order). But a sudden confusion and emergency recovery brought about by erroneous expectations concerning the behavior and capabilties of autoflight —which is behind quite a number of these events—CAN be entirely prevented through better training and a deeper type-specific understanding.

    f) Even veteran pilots experience these "brain farts" as we call them, and subsequently cannot account for them. Some never experience them. Some have a perfect history until that one day when they almost land on a crowded taxiway. But because we cannot screen for pilots who are immune to these human factors (assuming there really are any), we have to create an environment that provides for the ones who are not immune. We have to build in safeguards (TOO LOW GEAR) that might seem idiotic on the surface, and we have to make certain that nothing the aircraft is DESIGNED TO DO will ever confuse and thus distract and/or disorient the pilot entrusted with it.

    e) We are not currently doing that consistently, across the industry. In some cases it seems we are not doing that at all.

    f) Handflying skills and universal, fundamental airmanship, which are no less important, are a seperate issue which also needs to be addressed. But I'm not addressing that here, other than to point out that these things alone are not going to prevent the preventable aspects of the phenomena.
    Oh no, is it to early in the morning or have I not had enough coffee yet? I am agreeing with Evan.

  8. #88
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    Quote Originally Posted by Gabriel View Post
    ...Take Colgan. To begin with, even if I were dog tired AND flirting with the opposite sex, I want to think that I'd peek at the airspeed a few times as the flaps and gear went out and the props went "flat". On these specific airplanes (almost all of them except Airbus) these things can cause a marked speed decay, leading to stall if you or the autopilot are holding altitude. But let's say I'm too tired and forget and I don't understand the effects of the "ice" switch in the stall warning and approach speeds, my first reaction on the stall warning would have been maybe to lower the nose a bit (especially since I knew that I had altitude to spare), but immediately after I would have said "wait a minute... pitch slightly nose up, airplane flying level, this is low AoA, this is NOT a stall". And it is not that I would have needed to think about. The thought would have come by itself. I might have become distracted or disoriented and crashed in some other way, Pulling up relentlessly against the stick shaker and stick-pusher and then keep pulling up all the way down? That would not have happened to me...
    Fixed.
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    Quote Originally Posted by BoeingBobby View Post
    Oh no, is it to early in the morning or have I not had enough coffee yet? I am agreeing with Evan.
    Do you agree to the point that "we" need an extra runway-alignment warning system?

    DFW is a most amazing place with who knows how many N-S strips of concrete...and most of them aren't runways.

    Or is 'always* tune a localizer, or check the magenta line when you line up' good enough...maybe even somehow stress it or 'sort-of-require it'?

    *Ok, almost always.
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    Quote Originally Posted by Evan View Post
    Exactly my point. There is no safe, universal "I know how to fly an airplane".
    1. Concur with Gabriel, yes there is.

    2. It would seem to be good practice to utilize this, as-appropriate, to maintain/improve safety.

    3. There is evidence that sometimes this has been deprioritized AND crashes where it appears it was sorely missing.

    4. There is evidence that you have disdain for these concepts.
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    Quote Originally Posted by 3WE View Post
    Do you agree to the point that "we" need an extra runway-alignment warning system?
    I'm not sure where the red word came from but it didn't come from me. I said it might not be a bad idea.

    Localizer signals get distorted, particularly by large metal objects on the taxiway near the array. GPS is more infallible and is already driving the predictive aspect of EGPWS. That system knows your track and where it is currently taking you. I, for one, cannot think of a normal scenario where the track would be to the adjacent taxiway in the final moments of the approach. Maybe you can. But, if we have EGWPS for vertical proximity issues DESPITE THE INSTRUMENTS AND THE WINDOWS, why not throw in a lateral aspect as well? Especially if it is a mere software revision.

    I don't think we desperately need it. I also don't think aviation got safer because we only pursued the absolutely necessary. It got safer because we looked at the potential dangers, used our imagination and applied safeguards where they were practical and not detrimental. And when that one-in-a-million plane was prevented from landing with the gear up, it paid off, didn't it...

  12. #92
    Senior Member Gabriel's Avatar
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    Evan, know what?

    UAS memory items is very easily scriptable. Build it into the automation. Hell, I don't even understand why UAS downgrades the flight controls from Direct to Alternate law, when having all gyros, accelerometers and AoA indicators in agreement, and leaves the pilot in the worst of the worlds for hand-flying: no protections and no feedback. Don't ever let automation fly into a low energy situation. If airspeed is getting too low, either increase thrust (like in the Airbus solution) or reduce pitch (like in a speed-keeping pitch mode). In any event, don;t ever let the autopilot pull up as far as the stick-shaker. This is a very easy fix. Make the necessary self and crosschecks by default between the different RAs to detect disagreement. If one is found not working properly, use the other one as reference to enter the FLARE mode, even if it belongs to the set of the "other" autopilot. If the pilot starts a go around by selecting the GA switch after touchdown, and he actually pulls up and starts to climb, make the AT to add thrust. Make all planes autoland capable, and make autoland more robust. Invent auto-take-off. Auto-taxi should be piece of cake, or ask Tesla for help. Do a bunch more of things like that, and remove the pilot from the front seat. Planes almost fly by themselves already. Pilots seldom touch the controls, in some flights the AP is turned on at 400 ft (some 15 seconds) after lift off and is disconnected when at taxi speed after landing.

    I am not the guy how says "I will never fly in a plane with no pilot". I know that technology goes on and cannot be stopped. I know that it will be eventually safer. We will have sporadic accidents by the automation doing unexpected things as result of programming bugs, poor system engineering, or simply combined failures beyond what the redundancy can stand. But the chance of those will be minimal and the accident rate will be less than today's record where most of them are still "pilot error" (which includes errors by messing with the automation and errors by not hand-flying the plane properly, or both in the same accident).

    IN THE MEANTIME, I WANT PILOTS NOT JUST SYSTEM MANAGERS BEHIND THE CONTROLS.
    Because the systems are very complex, have a lot of "if" branches, and are NOT intuitive. It's very complicated for a human to learn one in depth to the point of knowing what state the system is in among all the Logics tree, especially in times of stress where an action needs to be takes immediately.

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  13. #93
    Senior Member 3WE's Avatar
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    Quote Originally Posted by Evan View Post
    I'm not sure where the red word came from but it didn't come from me. I said it might not be a bad idea...
    Gray-area distinction noted.

    I do have another side that asks how we can add big, fat, obvious-but-not-intrusive 'safety checks' to the big TV screens. Dittos for TOPMS- some big, obvious, fairly early "on-track" "a little slow" "BAD SLOW!" depiction, without it being A WHOLE ADDITIONAL SYSTEM THAT WILL THROW OUT MORE WARNINGS AT BAD TIMES THAT BOBBY DISLIKES.

    Maybe "we" always get a GPS-generated localizer- with bold font words that clearly state what it is (to know if it's a true localizer or something..it's there to be glanced at when you are lining up with a lot of strips of concrete.

    I do have sympathy for what the view is like from a 3 degree angle...Throw in a little glare or darkness and the piano keys and really dim lights may not be all that obvious- AND there are those times when a pair of strips of concrete can fake you out and look like a pair of runways.
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    Quote Originally Posted by Gabriel View Post
    Hell, I don't even understand why UAS downgrades the flight controls from Direct to Alternate law, when having all gyros, accelerometers and AoA indicators in agreement, and leaves the pilot in the worst of the worlds for hand-flying.
    Pure ass-hat speculation...I think the programmers realized that there could be more than one cause of UAS and that the computer wasn't really the best 'person' to be making critical flight decisions when the flight management system is operating 'in the dark'.

    It's almost, "Oh shit, I give up, your airplane." (Or a more gentle version- "This might be complicated- so for the best safety, let's revert to those ultimate fundamentals of you (the one with the eyes, ears, and brain)...you fly the GD airplane").
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    Quote Originally Posted by 3WE View Post
    Do you agree to the point that "we" need an extra runway-alignment warning system?

    DFW is a most amazing place with who knows how many N-S strips of concrete...and most of them aren't runways.

    Or is 'always* tune a localizer, or check the magenta line when you line up' good enough...maybe even somehow stress it or 'sort-of-require it'?

    *Ok, almost always.
    Do you agree to the point that "we" need an extra runway-alignment warning system? No

    Or is 'always* tune a localizer, or check the magenta line when you line up' good enough...maybe even somehow stress it or 'sort-of-require it'? ​Yes

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    And I will tell you what Gabe, You get your butt up here to Miami, and I will get you in the 400 sim. I will put you on a 20 mile final, lined up and configured, and I will bet you with no automation, and no magenta line,no glide slope and no localizer,a handful of yoke and thrust levers, you won't make the field. A visual approach in a 600,000 pound airplane is not your Tomahawk.

  17. #97
    Senior Member Evan's Avatar
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    Quote Originally Posted by Gabriel View Post
    Evan, know what?

    UAS memory items is very easily scriptable. Build it into the automation. Hell, I don't even understand why UAS downgrades the flight controls from Direct to Alternate law, when having all gyros, accelerometers and AoA indicators in agreement, and leaves the pilot in the worst of the worlds for hand-flying: no protections and no feedback. Don't ever let automation fly into a low energy situation. If airspeed is getting too low, either increase thrust (like in the Airbus solution) or reduce pitch (like in a speed-keeping pitch mode). In any event, don;t ever let the autopilot pull up as far as the stick-shaker. This is a very easy fix. Make the necessary self and crosschecks by default between the different RAs to detect disagreement. If one is found not working properly, use the other one as reference to enter the FLARE mode, even if it belongs to the set of the "other" autopilot. If the pilot starts a go around by selecting the GA switch after touchdown, and he actually pulls up and starts to climb, make the AT to add thrust. Make all planes autoland capable, and make autoland more robust. Invent auto-take-off. Auto-taxi should be piece of cake, or ask Tesla for help. Do a bunch more of things like that, and remove the pilot from the front seat. Planes almost fly by themselves already. Pilots seldom touch the controls, in some flights the AP is turned on at 400 ft (some 15 seconds) after lift off and is disconnected when at taxi speed after landing.

    I am not the guy how says "I will never fly in a plane with no pilot". I know that technology goes on and cannot be stopped. I know that it will be eventually safer. We will have sporadic accidents by the automation doing unexpected things as result of programming bugs, poor system engineering, or simply combined failures beyond what the redundancy can stand. But the chance of those will be minimal and the accident rate will be less than today's record where most of them are still "pilot error" (which includes errors by messing with the automation and errors by not hand-flying the plane properly, or both in the same accident).

    IN THE MEANTIME, I WANT PILOTS NOT JUST SYSTEM MANAGERS BEHIND THE CONTROLS.
    Because the systems are very complex, have a lot of "if" branches, and are NOT intuitive. It's very complicated for a human to learn one in depth to the point of knowing what state the system is in among all the Logics tree, especially in times of stress where an action needs to be takes immediately.
    ok... where do I begin...

    How about here: automation is a tool for pilots. It isn't there to function without them. It isn't there to replace them. Under automation, the job of a pilot is to fly the plane via the automation. If, for any reason, a certain tool detects an error, it's thrown out. If the redundant tool cannot be proven reliable (a rare situation) that entire toolbox is thrown out and the pilot, who is always the last line of defense, takes over. This is called fail passive and it is the keystone philosophy of flight control avionics. Without the pilot there, it would not be fail-passive. And the second pilot makes the first pilot fail-passive. This makes aviation very very safe.

    So can we stop talking about automation as some sort of adversary to human pilots? The only time it becomes adversarial is when the pilots don't know how to use it, and don't understand what it is—and is not—doing for them. And that problem can be fixed.

    There's a lot of room for improvement as technology becomes more sophisticated and AI enters the picture. But it will still be a tool for pilots (and a safety measure for everyone concerned) for a long time to come.

    Also, I don't consider pilots under automation 'systems managers'. They're just using an alternate means of control.

    A few notes:

    - Most systems are designed to degrade gracefully. For example, the A320 FMGC degrades from Dual Mode to Independent Mode to Single Mode to Back-Up Mode (using the MCDU memory). Each degradation limits functionality but it doesn't just give up at the first sign of trouble. It puzzles me why the autopilot cannot be designed to degrade a bit mode gracefully as well in a loss of air data scenario. I agree that is has the means to first stabilize the aircraft at the checklist prescribed pitch and power settings and issue a warning a few seconds before it disconnects. This might be enough to avoid the startle factor and preserve situational awareness, allowing the crew to comprehend the situation before they have to take over.

    - The Airbus solution is not to merely increase thrust in a low energy scenario. Before it does this, it changes the sidestick translation into AoA, so it limits pitch to a safe angle below stall. If the pilot is near the edge of stall, a full aft, relentless pull will not result in any pitch increase (a very abrupt one might briefly exceed alpha max however). Under alternate law, Low Speed Stability actually introduces a pitch-down command if speed decays to that point.

    - it's interesting what you wrote about entering FLARE mode with a single RA. From the onset, it always seemed absurd to me that the 737NG would allow this, and years later, after some considerable research, I came to the facts (which I posted in another thread long ago). The NG autothrust was not designed to operate on a single RA but had a flaw which would occasionally prevent the comparator logic from detecting the disagree and taking the unit offline when either RA failed. There had been (if memory serves me) some 12 or so documented instances of this error resulting in erroneous AT behavior prior to the Turkish 1951 crash. Boeing knew about the problem but deemed it a minor issue and didn't do much to inform the operators. Meanwhile Boeing was working on a replacement unit, which (if memory serves me) was introduced in 2003. After that time, the unit was offered as a retrofit on earlier NG builds but the FAA did not make this a fleetwide mandatory refit. So there was this lurking threat in the pre-2003 builds, just waiting for the right layers of cheese to line up. No mission-critical autoflight system can be allowed to continue functioning without redundant sensory input and it requires three inputs to rule if one of them is invalid and thus provide fail-operational reliability. The 737NG autothrust was designed to be fail-passive, not fail-operational. With a MEL'd RA, it should have been impossible to use at that phase of flight.

    - You should read up on CWS mode on the 737NG. Essentially, it allows a pilot to make attitude adjustments under autopilot. When the pilot makes an input and then releases the yoke, the airplane self trims and the new attitude is held. So, essentially, the pilot tells the plane what he wants it to do via a traducer (because under CWS, the yoke/column is one big sidestick) and that intention is interpreted by the flight control computers and sent to the control surface servo via wire. Pitch control without trim-feedback. This is allowed because the autopilot is guarding the speed (either with pitch or power depending upon the current speed mode). What does this remind you of? (I'm told pilots rarely use CWS but it is part of the Boeing design philosophy and de facto autotrim FBW).

  18. #98
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    Quote Originally Posted by BoeingBobby View Post
    And I will tell you what Gabe, You get your butt up here to Miami, and I will get you in the 400 sim. I will put you on a 20 mile final, lined up and configured, and I will bet you with no automation, and no magenta line,no glide slope and no localizer,a handful of yoke and thrust levers, you won't make the field. A visual approach in a 600,000 pound airplane is not your Tomahawk.
    I take the challenge. I hope that your offer is not perishable because it may take a while for me to get the chance to get my butt up there to Miami.

    (I know that a 600,000 pound airplane is not my (rented) Tomahawk. Neither is the 150,000 lb 737, which I did hand-fly to a successful landing, in the sim of course).

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  19. #99
    Senior Member Gabriel's Avatar
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    Quote Originally Posted by Evan View Post
    - You should read up on CWS mode on the 737NG. Essentially, it allows a pilot to make attitude adjustments under autopilot. When the pilot makes an input and then releases the yoke, the airplane self trims and the new attitude is held. So, essentially, the pilot tells the plane what he wants it to do via a traducer (because under CWS, the yoke/column is one big sidestick) and that intention is interpreted by the flight control computers and sent to the control surface servo via wire. Pitch control without trim-feedback. This is allowed because the autopilot is guarding the speed (either with pitch or power depending upon the current speed mode). What does this remind you of? (I'm told pilots rarely use CWS but it is part of the Boeing design philosophy and de facto autotrim FBW).
    I am aware of CWS in the 737. I believe that it is the only type that has it. I don't like it, pilots mostly don't like it (and mostly don't use it) and it has caused* some fatal accidents when pilots thought that they were actually flying the plane "as usual" with the yokes.

    I would be ok to have a separate control for a sort of "attitude hold" mode, let's say something like the Sperry autopilot in the DC-3, except with some built-in protections.

    Note that, after some accidents and incidents, Boeing eliminated the possibility of entering CWS mode just by manipulating the control wheel while in AP. Now you have only one method to enter CWS, which is by selecting that mode. If you manipulate the controls while in AP (but not in CWS), do it smoothly enough and nothing will happen, do it hard enough and the AP will disconnect and you have full manual control. That's a start.

    * The CWS itself didn't cause the accidents, of course. As always, we had someone screwing up in the middle.

    http://avherald.com/h?article=49f13f56&opt=0
    http://avherald.com/h?article=4419c56e/0002&opt=0

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  20. #100
    Senior Member 3WE's Avatar
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    Quote Originally Posted by BoeingBobby View Post
    And I will tell you what Gabe, You get your butt up here to Miami, and I will get you in the 400 sim. I will put you on a 20 mile final, lined up and configured, and I will bet you with no automation, and no magenta line,no glide slope and no localizer,a handful of yoke and thrust levers, you won't make the field. A visual approach in a 600,000 pound airplane is not your Tomahawk.
    I may not have the same invitation, but I'll bet you a steak dinner I can do it.

    Gabriellian comments:

    I've been impressed with small town FBO pilots who right seat a 172 in the morning, left seat a Bonaza to take a lawyer to a trial, then left seat a hot-shot pressurized piston twin for the president of the local trucking company to New York the next day. Knowledge of lots of different airplanes with different performance and different feel.

    Bring in Flight simulator games...no not quite real, but they fly close to real numbers...

    Wow, this 172 feels very different, but hey, practice a bit and dang, I can land it.

    Wow, this 737 feels very different...no 1 mile final here....gimme 5! I really need to stay ahead of this thing and keep it stable...cool hands, good eyes...pretty soon, successful landings.

    Next up...a 747...WOW this thing IS big...WOW...you know, I really DO need a 15 mile (Ok, 20 mile) final (Just like Bobby says I do)....I really really need to stay ahead of this thing and have really really cool hands and really really good eye work to keep it stable.

    Watch the airspeed....watch the vertical speed...watch everything...stay ahead of the damn thing...and guess what...it lands.

    Now jump to Gabriel who did indeed land a 737 'real simulator' on his first try (still jealous of the SOB).

    It's important to note that some of the actual, real world feelings are missing from simulators (even the 'real ones')...conversely, I think experienced pilots have some fairly hard eye to arm wiring, where the buttocks contribution may be secondary.

    Special skill you got Bobby, but not sure how special. (Actually, the whole package is indeed special...Still...airspeed, attitude, yoke, power levers, yada yada...the fundamentals are the same...172tommycub or 74xyz.)

    I will offer disclaimers- you could get a steak dinner out of the deal. Years ago, there was another thread on another forum- someone with not-so-good English, asked if a dummy could land an airliner...Back then, I kind of thought I could do it.

    BUT, lo and behold, in Flying Magazine was an accident where a high-hour airline pilot rented a 182...crossed the threshold at 100 knots...floated...floated...bounced....floated....ran off the end and flipped it.

    Fascinating lesson: It is indeed bad practice to hop in an aircraft for which you are not familiar nor "current"...doesn't matter if you are a hot-shot, zillion hour ATP...and maybe the MSFS jock in row 23 won't be able to save the day after fish poisoning either...maybe Gabe and I will crash your simulator...

    Nevertheless, what are the rules here?...do we get some practice runs? Any hints on good power settings, to have the right speed on final? Easy weather or nasty gusty? CAVU or restricted visibility. Is the runway 200 by 12,000 ft? or 100 by 7000 ft?

    And, to repeat from above, I (and Gabe) have no hope of legally navigating your 747 to a New York airport unless we DO get a ton of type-specific rehearsal with the FMS and autoplot....without that, we would have a lot of people pissed at us.

    I'm not as confident as Gabe, but damn, he did land that 737 simulator cold, so it's worth it to try.
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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