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Air France 447 - On topic only!

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  • ok so obviously, it's been posited if not proven, that high altitude stall recovery should be a fairly basic and easy memory item for pilots to handle. however, as this instance and maybe some others (not sure) has proven, no everyone gets it.

    given the direction of more automation the industry is headed in, why not create a "staples easy button" for stall recovery that will work no matter what the computers are saying, that would operate/do exactly what the human pilot is expected to do--stop the stall: wings level, full power, what was it? 2 degrees nose up?

    Comment


    • Originally posted by UncleFire View Post
      My "speculation" is that the PF didn't realize he was in Alt Law and figured the protections where still in place (among other things). Hence the near constant pulling back on the stick.
      It is certainly possible, as the left seat pilot (PF) was clearly not properly trained on type. But after pulling up initially and getting the stall warning the right seat pilot (PM) seemed to clue in a bit and told him to 'go down'. He did reduce pitch enough to avoid stall and silence the warning. At that point they could have still flown out it out. Now, about 10 seconds after losing autoflight, the PM finally has a look at the ECAM and announces that they are in Alternate Law. He also notices the thrust lock condition and resets the thrust levers to full climb. Now everything is going to be ok... but then PF inexplicably pulls up again and stalls the airplane.

      There are two clues telling him that they are in Alternate Law and have lost the stall protections. First, the PM has announced it; second, the master caution message: FLT CTL / ALTN LAW (PROT LOST) remains at the top of the ECAM window for at least the first 10 secs.

      There are two things working against these warnings. First, the crew has not followed a proper CRM process to quickly assess the situation, therefore they are not listening to each other clearly and seem to be cross-talking at that moment. It's possible that the PF did not hear him. Second, the PM never announces the 'protections lost' part of the message, so if this incredibly under-trained PF does not instinctively realize this fact from the announcement of Alternate Law, he might still think he has envelope protections. If so, it is consistent with the cause of the crash being grossly inadequate pilot training.

      Comment


      • One other interesting thing I just noticed...

        Immediately before the loss of autoflight, almost simultaneously with the calvary charge, the clearly concerned PF asks the more senior pilot...

        2 h10 min 04,6
        Do you us [sic] to put it on
        ignition start?



        He is asking if he should switch the ignition to 'continuous' IGN START (a provision against ice-ingestion flameout). Then, just after the AP is lost, after stating that he has manual control, the PF says...

        2 h 10 min 09,3
        Ignition start

        Is he answering his own question either because FADEC has automatically switched it to 'continuous' (due to the ENG ANTI ICE selection), or is he restating the request? In any case, he says nothing else until the first stall warning.

        I'm thinking he might have been focused on this task more than his hand-flying in the first few moments without eyes on the artificial horizon. Though hard to imagine, that might explain the initial upset.

        EDIT: See post below...

        Comment


        • Originally posted by Gabriel View Post
          Could you provide a source please?
          Not that I don't believe you, but I want to investigate more.
          Gabe, I've attached two screen grabs from the FCOM because i'm too lazy to type them out.

          Comment


          • Originally posted by TeeVee View Post
            ...why not create a "staples easy button" for stall recovery that will work no matter what the computers are saying...
            PLEASE DO NOT SAY THESE SORTS OF THINGS WHERE GABRIEL MIGHT SEE THEM...THE POOR DUDE WILL GO OFF THE DEEP END!

            And in an attempt to help him- here's the short answer:

            1) Such procedures do exist.
            2) The FAA has recently changed procedures (likely in response to this and some other crashes), strongly towards these sorts of procedures.
            3) Don't tell Evan but the procedure works essentially the same for Piper Cubs and Boeing 777s.
            -The discussion for Airbii may be slightly more complicated- but the frightening truth is that the principles and procedures are the same.
            4) To further emphasize point #1, this general over-riding procedure has existed for a long long time.

            Indeed, a simple button!

            Gabriel: Count to 10, and please fill in the details I've glossed over.
            Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

            Comment


            • EDIT TO ABOVE: The engine anti-ice switches were selected ON at 2 h 10 min 03. The #1 engine anti-ice ON was recorded on at 2 h 10 min 05—exactly the moment of the auto-pilot failure. The switches are located on the overhead panel. Because there was no verbal callout for this, it is unclear as to which pilot makes the selection (it could be the exchange at 2 h 10 min 02 - PM: "Go on?", PF: "Go ahead".) But If the PF has made this selection instead of the PM, his eyes would have been on the overhead at that critical moment. FURTHERMORE, the PF does not confirm that continuous ignition start is active until almost 5 seconds after taking manual control. FADEC switches ignition to the continuous mode (ENG START) automatically after the ENGINE ANTI-ICE is selected ON and this would be confirmed by an IGNITION indication on the memo section of the E/WD**. Since the PM never acknowledges his request for continuous ignition, this suggests that the PF's eyes were focused on the E/WD at that moment and perhaps for the entire first five seconds!

              I think, as they began to encounter significant ice crystals (recorded on the CVR as increased cabin noise), the PF was primarily concerned with the engines flaming out and not focused on the task of manual flight.

              Here's the sequence again:

              -
              2 h10 min 04,6
              Do you us [sic] to put it on
              ignition start?

              -
              (no answer from the PM)

              -
              Either pilot could have selected this using the rotary switch but this is not recorded on the FDR, leading me to believe the switch was not used.

              -
              2 h10 min 05 - the engine anti-ice switches are selected ON on the overhead panel. In the same moment the autoflight is lost (calvary charge)

              -
              Simultaneously, the engine anti-ice is recorded on. This would cause FADEC to automatically engage the 'engine start' in continuous ignition mode.

              -
              2 h 10 min 09,3 - almost five seconds after taking manual control, the PF says "engine start" (meaning: continuous ignition). If he means this as a confirmation of his own request and the rotary switch has not been selected (according to the FDR), his eyes must be on the E/WD IGNITION memo indication**. If so, he is possibly not focused on the instruments and the task of hand-flying.

              I think there might be something to this.

              **AFIAK The FADEC automatic continuous ignition mode is indicated on the memo section of the E/WD where the ENG A. ICE message is seen (see attachment, ignoring the fire indication of course).

              Comment


              • Originally posted by Evan View Post
                Thjis link shows everything at a glance:

                http://www.airbusdriver.net/airbus_fltlaws.htm
                Thanks.
                Any idea what this means (under Alternate Law, NOT abnormal alternate)?
                "Certain failures cause the system to revert to Alternate Law without speed stability."

                --- 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


                • Originally posted by Gabriel View Post
                  Thanks.
                  Any idea what this means (under Alternate Law, NOT abnormal alternate)?
                  "Certain failures cause the system to revert to Alternate Law without speed stability."
                  No, but I'd bet loss of airspeed data would be one of them...

                  Comment


                  • Originally posted by Evan View Post
                    No, but I'd bet loss of airspeed data would be one of them...
                    Exactly my thought...

                    --- 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

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