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  • Toe original AF447 thread is closed so...

    I'll post it here. This is an absolutely fantastic video. Although I think that Peter is being a bit too kind both with all the parties involved (pilots, AF, Airbus, EASA...)

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    Original thread here


    --- 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 ---

  • #2
    Originally posted by Gabriel View Post
    I'll post it here. This is an absolutely fantastic video. Although I think that Peter is being a bit too kind both with all the parties involved (pilots, AF, Airbus, EASA...)

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    100% on the money about pilots having a deep understanding for the type they are flying. Otherwise, he is confirming some factors I have previously brought up here, specifically the initial altimeter error indicating a loss of altitude (which might have prompted the intial climb from level flight) and the role played by the erroneous flight directors to encourage sustained pitch-up input (and thus the supreme importance of learning and following memory procedures like gospel). There are also a few new insights here, such as the role of the yaw damper in mitigating roll during the stall (and thus making the stall less obvious, though still quite obvious).

    One very crucial recommendation I didn't see in the final report is a software fix to keep the AoA valid even at 'impossible' values. Making this change would have kept the stall warning active and prevented any confusion from that source. It's better to have an occasional erroneous stall warning than a deactivated one that reactivates when the AoA is reduced. A simple software fix. Has it been done?

    Comment


    • #3
      Not that I know.
      What about the ECAM telling the pilots that the airspeed is unreliable?
      Or, since the plane is not going to protect itself against stall, enforce manual trim when in Alternate law to avoid that it autotrims all the way nose-up?
      And did you notice he saying (I am paraphrasing here) that the most important thing is to fly the pane and keep it stable by holding a healthy pitch and power?
      It was just me or he was implicitly putting that on top of doing so with the exact memory items parameters?
      And of course he also mentioned the effect that having 2 independently-movable sidesticks may have contributed to the more senior FO (PM) not really being aware of what the other FO (PF) was doing?
      Surprising that he did not mention what the memory items were and, that to set thrust to climb (one of the memory items), they have to move the thrust levers out of the climb detent. (he did mention the thrust lock function).

      --- 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 ---

      Comment


      • #4
        Originally posted by Gabriel View Post
        Not that I know.
        What about the ECAM telling the pilots that the airspeed is unreliable?
        Or, since the plane is not going to protect itself against stall, enforce manual trim when in Alternate law to avoid that it autotrims all the way nose-up?
        And did you notice he saying (I am paraphrasing here) that the most important thing is to fly the pane and keep it stable by holding a healthy pitch and power?
        It was just me or he was implicitly putting that on top of doing so with the exact memory items parameters?
        And of course he also mentioned the effect that having 2 independently-movable sidesticks may have contributed to the more senior FO (PM) not really being aware of what the other FO (PF) was doing?
        Surprising that he did not mention what the memory items were and, that to set thrust to climb (one of the memory items), they have to move the thrust levers out of the climb detent. (he did mention the thrust lock function).
        But of course the PF was flying the plane, just not flying it the way the memory procedure requires. The mystery remains: why did he leave level flight and this video shows a number of potential reasons. It also shows why he might have been concentrating on roll to the detriment of pitch and over controlling in the less dampened environment of cruise. As Mentor Pilot points out, his situational awareness was scrambled, in which case flying the plane can be very dangerous indeed.

        The Airbus cockpit is designed around CRM. Pilots are trained (if they are pilots) to follow the instructions on ECAM, one of which was to move the thrust levers. Pilots are trained to clearly state takeover and stay in their roles of PF or PM. And trim is designed to behave in a consistent manner in Alternate Law, which is only the first level of FBW degradation, to assist the pilot by relieving workload. The plane responded normally to pitch orders.

        There was nothing here but pilot error due to a number of factors, most importantly a lack of deep familiarity with the type and with CRM procedure. This led to a loss of situational awareness whereby three veteran pilots had no idea of what was happening. The only design change I would make is in the stall warning system. The rest is piloting.

        Comment


        • #5
          Originally posted by Gabriel View Post
          And did you notice he saying (I am paraphrasing here) that the most important thing is to fly the pane and keep it stable by holding a healthy pitch and power?
          It was just me or he was implicitly putting that on top of doing so with the exact memory items parameters?
          No.

          Follow the type specific procedures.

          Power and attitude values must come from recommended value tables in the FCOM, and used in the correct sequential order of QRH and memory checklists.

          Nothing else, including brief fundamental improvisation that would work and be considered intelligent, can be done.

          Nothing.

          Please return to rote memorization of procedures, by number. Make no effort to link said procedures to fundamentals.





          For what it’s worth, pulling up relentlessly is not in the type specific FCOMQRHPOH
          Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

          Comment


          • #6
            Originally posted by Evan View Post

            *** most importantly a lack of ***basic*** familiarity with the the ***most rudimentary fundamentals of airmanship and aerodynamics.***
            Fixed, again.
            Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

            Comment


            • #7
              Originally posted by 3WE View Post

              Fixed, again.
              The most fundamental aspect of airmanship is situational awareness. Without it, we have seen seasoned airman use their airmanship to fly straight into the ground. But you'll never get past the idea that airmanship is some sort of inherent superpower than is impossible to thwart with human factors and misleading instrumentation in IMC. So carry on.

              Comment


              • #8
                Originally posted by Evan View Post
                But of course the PF was flying the plane, just not flying it the way the memory procedure requires.
                Or in a way compatible with the most basic common aviation sense beyond the memory procedure.

                The mystery remains: why did he leave level flight
                For me the mystery is not why he left level flight, but he did so with a stall-warning triggering, 1.5G, 15 degrees nose-up pitch, 7000+ FPM, 2500ft climb. Certainly needing to recover 300 ft is not a good reason.

                "He did not follow the procedure" is, in my opinion, as useful as saying that a car rear-ended another because the driver didn't keep the distance, or that somebody died because his hart stopped beating. That is, not useful. If the pilot was in a state of mind that didn't let him avoid that crazy almost aerobatic climb, he was not in a mental state to follow any procedure. He was not really flying, he was just moving the stick about.

                Look, I intended to post this video in the original thread just because it is VERY good. With very complete and accurate information, very well explained, and presented in a very appealing fashion.

                I don't think that we are learning much new with this video, and even less than our opinions already discussed ad-nauseum in the original thread and many others are going to change because of this video or with further discussion.

                --- 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 ---

                Comment


                • #9
                  When I was in the Navy, I was a morse code radio operator. I was in a training squadron teaching crews to find submarines in P2V Neptune a/c. I remember several times while flying at night under and overcast, 200 miles out to sea, the training captain yelling "watch your altitude, watch your altitude". This was really IFR, no outside references, similar to what this crew faced. You must be comfortable when you have to convert to the basics, Pitch and Power and if the a/c was trimmed up to begin with you could almost let go and it would return but once you start changing things?????

                  Comment


                  • #10
                    Originally posted by Gabriel View Post
                    Or in a way compatible with the most basic common aviation sense beyond the memory procedure.


                    For me the mystery is not why he left level flight, but he did so with a stall-warning triggering, 1.5G, 15 degrees nose-up pitch, 7000+ FPM, 2500ft climb. Certainly needing to recover 300 ft is not a good reason.

                    "He did not follow the procedure" is, in my opinion, as useful as saying that a car rear-ended another because the driver didn't keep the distance, or that somebody died because his hart stopped beating. That is, not useful. If the pilot was in a state of mind that didn't let him avoid that crazy almost aerobatic climb, he was not in a mental state to follow any procedure. He was not really flying, he was just moving the stick about.

                    Look, I intended to post this video in the original thread just because it is VERY good. With very complete and accurate information, very well explained, and presented in a very appealing fashion.

                    I don't think that we are learning much new with this video, and even less than our opinions already discussed ad-nauseum in the original thread and many others are going to change because of this video or with further discussion.
                    We are learning a few things though, or rather putting them more into focus. Hörnfeldt goes into some detail about how static air data is influenced by erroneous airspeed and the resulting erroneous cockpit indications of negative vertical speed and loss of altitude. He also explains the more challenging aspects of manual flight at low density altitudes, the lack of natural damping requiring more precise inputs with roll now in unassisted direct law. He then suggests that the PF might have initially input pitch to regain flight level and then, overwhelmed and distracted by controlling roll occillations, might have unintentionally added a great deal more pitch. It IS a valid theory, more valid than the one about him being completely incompetent or insane, right?

                    Comment


                    • #11
                      Originally posted by Evan View Post
                      It IS a valid theory, more valid than the one about him being completely incompetent or insane, right?
                      “But I’ve been pulling up the whole time”
                      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                      Comment


                      • #12
                        Originally posted by kent olsen View Post
                        ***200 ft*** if the a/c was trimmed up to begin with you could almost let go and it would return but once you start changing things?????
                        But at 37,000 feet, if you were a tad off and climbed or descended (or phugoided) a bit…you might have some buffer.

                        Gabriel always has to remind me about the details of the climb…but for some reason I see this crash basically the same…maybe it was the stall warning…that, or 5 minutes of full aft stick and a steady, wallowing descent. I’ve been told that 172s don’t wallow quite as much, but, still, there’s something in the POH about ailerons and stalls and spins and stuff…
                        Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                        Comment


                        • #13
                          Originally posted by Evan View Post

                          The only design change I would make is in the stall warning system.
                          The BEA did make this recommendation in the final report:
                          When airspeeds are below 60 kt, the stall warning is no longer available, even though it may be beneficial for it to be available at all times. Consequently, the BEA recommends that: EASA require a review of the conditions for the functioning of the stall warning in flight when speed measurements are very low. [Recommendation FRAN-2012-051]

                          Comment


                          • #14
                            I remember. I also remember thinking (and saying) that the AoA envelope protection should not be eliminated in Alternate law where you are getting consistent AoAs from all 3 vanes. Degraded may be, but not eliminated. If you can still trigger a "STALL STALL" aural warning, you can keep the plane from exceeding the stall AoA by 40 degrees. Yes, stall AoA varies with Mach number, but you can at least provide protection against exceeding the max stall AoA (minimum Mach number) and if you stall at a high Mach (which is NOT what happened here) you would still be exceeding the real stall AoA by just a few degrees, and the recovery would be much easier and quicker if you have to reduce 5 degrees at 180 kts than if you have to reduce 40 degrees at 100 kts.

                            Alternate law where you have no AoA max protection, no low energy protection, no low speed stability (replaces the low energy protection in ALT1 but is lost in ALT2), and no pitch envelope protection, but you keep the normal law's autotrim and stick-to-load-factor or to-pitch-rate control law, looks very inadequate to me. If you are going to let me do do anything with the pitch, at least give me AoA feedback. That feedback doesn't require any logic, just make the deflection of the elevator proportional to the deflection of the stick and exclude the stabilizer unless commanded. Not that it would have made any difference in this specific case because "I have been pulling up the whole time" (or maybe it would because the plane would have not achieved these crazy AoAs without the stabilizer going fully nose-up.

                            --- 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 ---

                            Comment


                            • #15
                              Originally posted by Gabriel View Post
                              Surprising that he did not mention what the memory items were and, that to set thrust to climb (one of the memory items), they have to move the thrust levers out of the climb detent. (he did mention the thrust lock function).
                              He mentions that one of them presses the instinctive disconnect switch (which does the same thing in terms of releasing thrust lock and setting thrust to the current (CL) lever position). He mentions that, at this point, N1 increases from 84% to full climb thrust.

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