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  • I though that I had seen that somewhere. It is there in the official interim report. Both Lion Air flights (the one previous to the crash and the crash one) had stickshaker shaking from rotation and throughout most of the flight.

    --- 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 ---

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    • Originally posted by Gabriel View Post
      I though that I had seen that somewhere. It is there in the official interim report. Both Lion Air flights (the one previous to the crash and the crash one) had stickshaker shaking from rotation and throughout most of the flight.
      Stickshaker was most definitely on for most of the Lion Air fligt. I know this because a guy named Gabriel posted this


      Direct link - see graphs
      Aviation Herald - News, Incidents and Accidents in Aviation


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      • Originally posted by Gabriel View Post
        I though that I had seen that somewhere. It is there in the official interim report. Both Lion Air flights (the one previous to the crash and the crash one) had stickshaker shaking from rotation and throughout most of the flight.
        Yes, and to make it just slightly more confusing, only on the one side.

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        • Regarding the Lion Air fligt data from my last post.

          One thing I would like views on/I don't fully understand in the Lion Air flight data is the 'CCFORCE_PITCHCWSLOCAL' and CCFORCE_PITCHCWSFOREIGN'.

          During most of the flight 'local' and 'foreign' follow each other but at the end 'foreign' goes way above anything seen earlier in the flight. It is followed by an even more aggressive 'local' until the end.

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          • Originally posted by Evan View Post
            I still suspect that the system was supposed to compare inputs, detect the AoA anomaly and rule it out, but didn't work as designed. (See: Turkish 1951, specifically the DSB report, appendix Q)
            I find that to be a very interesting conjecture. In other words, the so-called "software enhancement" proposed by Boeing might just be about making the software work the way it was supposed to work in the first place?

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            • This article has a nice visual of the two satellite plots that the US and Canadian authorities were using: https://www.theglobeandmail.com/opin...define-safety/

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              • Originally posted by flashcrash View Post
                I find that to be a very interesting conjecture. In other words, the so-called "software enhancement" proposed by Boeing might just be about making the software work the way it was supposed to work in the first place?
                Wouldn't be the first time.

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                • New York Times reporting that the pilot requested a return after three minutes in a panicked tone of voice. They are also reporting that it "accelerated to abnormal speed". It also apparently turned back while in a climb.

                  I get the impression it was never stabilized on autoflight. But why the speed?

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                  • If I understand this correctly, MCAS was introduced because the new 737 MAX with its bigger engines had a tendency to pitch up in certain circumstances. In fact, it's been reported that the plane would not have received certification without this software add-on. However, when MCAS goes on the blink we are led to believe that the solution is for the pilot to disable it, take over and fly the bloody thing. If the pilot can be relied on to do this in an emergency situation, why is MCAS there in the first place? At the same time, MCAS only kicks in when the 737 is being flown manually. Typically, this is most likely at a low altitude. So this "helpful software"when things go wrong can throw up distractions and potential confusion at the precise moment when only seconds are available to sort it out.
                    Crazy or what?

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                    • sensor error readings rendered autopilot unusable, while on switching to manual mode the MACAS starts to kick in which confuses the pilot. plus pilots used to drive 737 plane previous to the MAX model which requires different skills to recover the airplane might be the cause of the accidents imho.

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                      • Originally posted by pegasus View Post
                        However, when MCAS goes on the blink we are led to believe that the solution is for the pilot to disable it, take over and fly the bloody thing. If the pilot can be relied on to do this in an emergency situation, why is MCAS there in the first place?
                        Excellent point. MCAS is provided to compensate for pilot error, yet the ONLY redundancy provided for a single point sensor failure is flawless pilot response. Irony.

                        Crazy or what?
                        No, I think this is just a developmental flaw in a rushed process with insufficient testing. I think it was designed to be redundant but didn't work as designed. However, the initial response from Boeing, that the system is safe simply because pilots have a shutdown procedure, is nuts.

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                        • Originally posted by Gabriel View Post
                          [sarcasm: off]

                          Did the pilots know that the plane did not stall? I have been having second thoughts in the last few hours. With he AoA that was being indicated in the Lion Air crash, I would expect the sticksahker to be shaking. Picture a scenario where the airspeed crap, the stick shaker activated, and the plane is pitching down by itself. Is it stalling or what? I can picture a scenario where the avalanche of seemingly contradictory and apparently nonsensical information can overwhelm the pilots' brain.

                          Pretty sure stickshaker was mentioned as one of the things the Lion Air crew were dealing it - I remember it for at least one of the flights, but probably it was on all of them. There was a lot going on, and that's why I said I thought the crew that didn't crash almost got kinda lucky. Or they were just really good at CRM and had more experience. A combination of factors, probably.


                          EDIT: never mind, I see stickshaker has been confirmed.

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                          • Originally posted by pegasus View Post
                            If I understand this correctly, MCAS was introduced because the new 737 MAX with its bigger engines had a tendency to pitch up in certain circumstances. In fact, it's been reported that the plane would not have received certification without this software add-on. However, when MCAS goes on the blink we are led to believe that the solution is for the pilot to disable it, take over and fly the bloody thing. If the pilot can be relied on to do this in an emergency situation, why is MCAS there in the first place? At the same time, MCAS only kicks in when the 737 is being flown manually. Typically, this is most likely at a low altitude. So this "helpful software"when things go wrong can throw up distractions and potential confusion at the precise moment when only seconds are available to sort it out.
                            Crazy or what?

                            This story discusses the history of the 737 aircraft https://www.msn.com/en-us/travel/new...cid=spartanntp

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                            • Originally posted by Black Ram View Post
                              ***the crew that didn't crash almost got kinda lucky. Or they were just really good at CRM and had more experience. A combination of factors, probably.***
                              Exactly WHEN HAL goes Y2K probably has a big influence.

                              If you are crusing along fat, dumb and happy at mach point something and with 30K feet of altitude to burn- it may be easier to say, "the computer is [naughty word] let's keep flying at healthy attitude and power settings"

                              Conversely, you are taking off- with the nose pointed WAY in the sky and flying a little bit slow and airspeed goes away and a stall warning goes off and you have 2000 feet to play with...

                              Dare I say that you are behind on the comprehension curve with less buffer to work out of some really dire warnings...

                              (Not to say that another crew on another day might have persevered (should have?)...but also, we are hearing that this isn't something you "trained on" either.)

                              With several of my bicycle crashes the time between fat dumb and happy and too-late-to-do-anything is pretty quick.

                              Conversely- with Lion air, the question if tough- they seemed to be managing things OK for a few minutes and then "just" dove in...

                              IF this crash is related, these guys did have a shorter time to work through things.
                              Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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                              • Was hoping to get some further clarity today on the abnormal speed issue.

                                What would cause a speed 'runaway'? EEC? Not on both engines at the same time. Unless... something... else... got... left... out of... the... manual,,,

                                No idea, really. Boggling development.

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