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Another "smart pilot's trick"

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  • Another "smart pilot's trick"

    A pilot of a CRJ-200 is cleared to descend and slow down.

    To speed-up the process, he intentionally unlocks two red triggers, that are there to prevent that the thrust levers are inadvertently moved below the IDLE setting and towards the SHUT OFF setting, and intentionally moves the thrust levers below the IDLE setting.

    The result? Simultaneous double engine shut down. Brief loss of all electric power (until the RAT kicked in).

    The captain is then "surprised" that this had happened even when the thrust levers didn't reach as far as the SHUT OFF mark. It is not reported, but I can hear him saying (or thinking) "it had never happened the times I did this before".

    A good reason not to give this pilot a Darwin award is because there were a bunch of innocent passengers behind. Fortunately, he was able to restart both engines thus saving the passengers (and skipping the Darwin award).

    A nice outcome would have been a power-off off-airport landing (with no injuries, please). I'd have loved listening this captain's explanations.

    Aviation Herald - News, Incidents and Accidents in Aviation

    --- 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
    Good thing they were able to restart the engines before they started cooling down and locked the core.
    [SIGNATURE GOES HERE]

    Felipe Garcia

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    • #3
      Originally posted by Felipe Garcia View Post
      Good thing they were able to restart the engines before they started cooling down and locked the core.
      I am not sure, but I think that the opposite happened in the Pinnacle crash.

      They attempted a windmill restart to high and slow, well out of the windmill restart envelope. The engines were not windmilling fast enough and there was not enough air passing through the engine. When they tried to restart, the fuel burned too hot(*) and locked the core.

      (*) most of the air that goes through the engine core is used not to burn fuel, but to mix and cool the lesser part that is used to burn fuel until it reaches an acceptable temp for the turbine.

      --- 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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      • #4
        W +
        If it 'ain't broken........ Don't try to mend it !

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        • #5
          Double U plus anchor?

          --- 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


          • #6
            Originally posted by Gabriel View Post
            To speed-up the process, he intentionally unlocks two red triggers, that are there to prevent that the thrust levers are inadvertently moved below the IDLE setting and towards the SHUT OFF setting
            At some point, we are going to have to make it a requirement that pilots understand how their plane works before they are certified to fly it. Not yet though. More people have to die first. We don't want to seem overly cautious.

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            • #7
              Originally posted by Evan View Post
              At some point, we are going to have to make it a requirement that pilots understand how their plane works before they are certified to fly it. Not yet though. More people have to die first. We don't want to seem overly cautious.
              What do you mean? I have no doubt that this pilot knew that these red mechanical locks are there to prevent that the thrust levers are moved below the IDLE setting and that he was not supposed to intentionally release them and move the levers below that setting, and at minimum he should have imagined that there was a good reason for all that.

              I don't think this case was one of lack of knowledge about how the plane works, at least not directly. This was more a pilot doing a stupid trick and knowing it was a stupid trick.

              But to your point, a reader comment in AvHerlad says that this trick doesn't work anyway because the engines do not go below idle by moving the levers below idle. They just keep at idle until the levers reach the "shut off" zone. Another user mentioned that the descent rate and loose of speed implicit in the clearance wasn't much for this plane and it could have been easily achieved at idle thrust. An another mentioned that he could have very well used the spoilers instead of trying to get less thrust than the minimum allowed in flight.

              From this point of view, if the above is true then a better knowledge of the plane and procedures could have prevented this either because it wouldn't work anyway or because there were other means (and legal ones) to achieve the same result.

              But you would still have a pilot with the willingness of doing stupid tricks. Not this trick this time, but maybe another trick at another time. I'm not sure that any amount of training can fix that.

              --- 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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              • #8
                Originally posted by Gabriel View Post
                Double U plus anchor?
                wanchor

                else wize known as wanker

                british term for Fing Idiot.

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                • #9
                  Thanks for the, errr..., enlightenment?

                  --- 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


                  • #10
                    Originally posted by Gabriel View Post
                    I am not sure, but I think that the opposite happened in the Pinnacle crash.

                    They attempted a windmill restart to high and slow, well out of the windmill restart envelope. The engines were not windmilling fast enough and there was not enough air passing through the engine. When they tried to restart, the fuel burned too hot(*) and locked the core.

                    (*) most of the air that goes through the engine core is used not to burn fuel, but to mix and cool the lesser part that is used to burn fuel until it reaches an acceptable temp for the turbine.
                    What I don't know is if you let the engines cool down by themselves (no cooling airflow) if there would be a difference in the time it takes for all the turbine components to cool down and have short periods of core lock until everything has contracted down to normal levels. I guess I will have to wait a few more weeks to find out, now I'm really considering not dropping that High Temperature Turbine Materials course this coming semester.

                    Also, the fact that the Pinnacle pilots tried to restart the engines 4 or so times may have contributed significantly to the core lock.
                    [SIGNATURE GOES HERE]

                    Felipe Garcia

                    Comment


                    • #11
                      Originally posted by Gabriel View Post
                      What do you mean? I have no doubt that this pilot knew that these red mechanical locks are there to prevent that the thrust levers are moved below the IDLE setting and that he was not supposed to intentionally release them and move the levers below that setting, and at minimum he should have imagined that there was a good reason for all that.
                      What I mean is that he should have known what THAT REASON is.

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                      • #12
                        Originally posted by Evan View Post
                        What I mean is that he should have known what THAT REASON is.
                        Well, the rest of my post (the part that you didn't quote) adressed that, or at least my opinion on that.

                        --- 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


                        • #13
                          Originally posted by Felipe Garcia View Post
                          What I don't know is if you let the engines cool down by themselves (no cooling airflow) if there would be a difference in the time it takes for all the turbine components to cool down and have short periods of core lock until everything has contracted down to normal levels.
                          I hope and guess that the design takes that into consideration to prevent it. If you accidentally shut down an engine you should be able to attempt a restart as soon as you are within the required envelope.

                          That said, I think there is a "waiting" period between an unsuccessful restart and the next attempt.

                          --- 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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                          • #14
                            Originally posted by Gabriel View Post
                            Well, the rest of my post (the part that you didn't quote) adressed that, or at least my opinion on that.
                            So you would agree that the pilot clearly didn't understand how the throttle works in this position, as he was attempting a trick that wouldn't have worked anyway?

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                            • #15
                              Originally posted by Evan View Post
                              So you would agree that the pilot clearly didn't understand how the throttle works in this position, as he was attempting a trick that wouldn't have worked anyway?
                              I don't know. That's what the AvHerald reader said.

                              But the core of my opinion is that, in any event, the pilot was INTNTIONALLY doing something he KNEW he was NOT supposed to do. And no airplane knowledge can justify that, unless it's an emergency and the pilot judges that doing that will save lives.

                              Say that the AvHerald user is wrong, and that the pilot was right, that in fact if you move the levers below idle but above shut-off gives you a reduced thrust below idle. Are the pilot's actions any more acceptable?

                              --- 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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