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  • Kurt, I'm having a few minor points I don't understand about your post:

    Since the memory items had only two items: pitch 5deg and thrust to CLB (it absolutely did not mention "hold altitude"), and they folowed none of them, what's the memory item you say they were trying to follow?

    Do you imply that the AF pilots have the same ability to learn and apply emergency procedures that a comodo dragon?

    Do you mean that they were in a zone with a very narrow speed margin and they still managed to pull up 1.4 Gs and climb 3000 ft at vertical speeds exceeding 7000fpm and loose more than 100 kts before stalling? (I actually know the answer to this one: No. The reason why they were at their ceiling was not that they were in the coffin corner because they were not, it's because they were running out of engine, in the sense that max engine power gets lower with altitude)

    --- 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 KurtMc View Post
      Engineer: "Walk the plank, there, matie, hold tight, HAL's taking a nap, but it will be alright."

      Pilot: Eject, Eject, Eject
      Thank you. This is definitely food for thought.

      Peace.

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      • Kurt,

        Since you haven't seen the third preliminary report that includes the FDR plots and CVR transcript, let me give you an executive summary of the sequence.

        The AP disconnected. The plane went into alternate law. The speeds were unreliable. The three things were correctly identified by the pilots within a few seconds.

        At this point, the pilot had only two things to do: pitch 5° and CLB thrust. Those are only the memory items for the correctly identified unreliable airspeed situation.

        One of the pilots grabbed the sidestick and immediately rolled the wings back to level (sice the plane has rolled due to turbulence) and simultaneously pulled up, for no apparent reason.

        The fisrt pull up could have been done inadvertely during the first intervention, however the pilot kept pulling up during several seconds and then some.

        They reached 1.4Gs, 11° nose up of attitude, more than 7000fpm of climb rate, and 37500 ft (from an initial 35000). That was COMMANDED, as the FDR show. Not the result of a 100MPH updraft. Additionally, they didn't add an ounce of thrust.

        Of course you notice that a 7000 fpm climb is not sustainable even with TOGA after take-off with a plane in the light side, let alone very heavy near its ceiling with a reduced thrust. The only reason why they reached such a climb when the plane lacks the performance to sustain it is because they traded speed for altitude. Of course you have only so much speed to trade.

        More than 30 seconds had gone since the start of the event. More than 30 seconds of the pilots doing the wrong things. At 37500ft the stall warning sounded. The pilot, following the procedure that you've cited, added full thrust. However, contrary to the very same procedure and to the most basic ultralight pilot knowledge, pulled up hard, and kept pulling up hard for a lot of seconds. THE STALL WARNING KEPT SOUNDING UNINTERRUPTEDLY FOR NEARLY ONE MINUTE, with the pilot mostly pulling up.

        More than a full one minute and a half had gone since the start of the event, more than one minute and a half of the pilots doing not only wrong things, but mostly exactly the contrary to what they should have been doing. Then, ONLY THEN, the stall warning stopped. ONLY THEN we can start taliking about the effects of this.

        Please explain the first one minute and a half and then we can go to this phase.

        --- 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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        • I hope we're not all forgetting about the ball lightning that may have struck the plane.

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          • Peace

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            • --- 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 guamainiac View Post
                Who advocated an extreme dive?...
                Gabriel does it all the time.

                He keeps citing all these crashes where he believes that if the pilots had sharply nosed over, a stall (and subsequent crash) would be averted.

                This is opposed to following the prescribed stall avoidance procedure.
                Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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                • Peace

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                  • Kurt,
                    Are you sure your comments are based on the video you've posted?
                    Please look at that purple line called "Flight Path Angle" in the second segment ("Alt vs Elevator vs Stall").

                    Suggestion: make a "elevator vs vertical speed vs flight path angle vs pitch" and you'll note that the 7000 fpm climb was commanded, that the nose down elevator after several seconds of nose up elevator resulted in a reduction of pitch, flight path angle and vertical climb (also commanded) but it was too late already to avoid a stall unless altitude was traded for speed (they had climbed too much and lost too much speed), and the stall was commanded too and the response to it, WITH THE STALL WARNING SOUNDING UNITERRUPTEDLY, was mostly to apply nose-up stick, including applying and holding full nose-up stick BEFORE the stall warning stopped after sounding uninterruptedly for nearly one full minute. I'm not really very interested in what happened after that, after more than one minute and a half of doing wrong things, all hopes were lost (not because the plane was unrecoverable at that point, but because the pilot were).

                    --- 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 3WE View Post
                      Gabriel does it all the time.

                      He keeps citing all these crashes where he believes that if the pilots had sharply nosed over, a stall (and subsequent crash) would be averted.

                      This is opposed to following the prescribed stall avoidance procedure.
                      Show me the post where Gabriel advocates "sharp nose over" please. I've only seen him advocate managing pitch to reduce AoA. Forward stick input does not necessarily mean nose down attitude.

                      Originally posted by KurtMc
                      A. There is a possible known bug in the AB software which might give pilots an indication that the AP/AT can be re-engaged even after UAS events cause the AP to drop offline. I'm aware that it's not supposed to re-activate but am asking you to assume it did (does/they're working on it, see posts a few above).
                      AP/AT can always be reengaged in alternate law, once the required redundancy returns, i.e. the ADIRU's are back in agreement on airspeed. This is by design, not a"bug". If the pilot had followed procedure, the autoflight could have been restored in a matter of minutes. Normal law cannot be restored until the aircraft is on the ground, but flight control is not affected, only certain manual flight protections (hence the term 'law').

                      B. When HAL handed controls over to the pilots, the aircraft's attitude required immediate course corrections from the pilots.
                      Yes. This is commonly referred to as manual flight.

                      C. The pilots initially recovered from the out-of-attitude condition and, thereafter, during the first portion of the 'climbout', when the Mach #'s became active again, the AP/AT buttons did too. They engaged OTTO at that point, and the aircraft went into an un-commanded climb of 7000 ft per minute, during which time the pilots applied marked, repeated, efforts at down elevator (as can be seen in the video).
                      The FDR is of the opinion that this is not at all what happened. The FDR plots clearly show that both the AT and AP remained disengaged after the initial loss of reliable airspeed data. But, you know, it's the FDR's opinion against yours... and it is probably biased, so this is a completely subjective issue...

                      E. There is no angle of attack sensor plot on an AB of this design, and the pilots had no practice at searching for one in the visual field.
                      There is an AoA plot on the FDR. What are you even talking about? The pilots had no practice "searching for one in the visual field" because there is no AoA instrumentation on the A330, nor is there on any large commercial airliner I am aware of.

                      Comment


                      • Originally posted by KurtMc
                        C. The pilots initially recovered from the out-of-attitude condition and, thereafter, during the first portion of the 'climbout', when the Mach #'s became active again, the AP/AT buttons did too. They engaged OTTO at that point, and the aircraft went into an un-commanded climb of 7000 ft per minute, during which time the pilots applied marked, repeated, efforts at down elevator (as can be seen in the video)
                        Kurt, you just never get tired, do you? For you it just has to be something uncommanded - bugs, updrafts, a flat spin...just get over the fact that pilots can do messed up things with the controls sometimes. Otherwise you can keep throwing more and more theories, each attempting to allow for you to run away from the truth and the facts.
                        As far as I know, the AP/AT never re-engaged on AF447. So why are we debating it? You really think the crew would not have reacted to an uncommanded computer input and would have said nothing on the CVR? When you have a crew that can't figure out if they are going up or down, it doesn't take uncommanded computer inputs to cause a crash, at least in alternate law.

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                        • Peace

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                          • Peace

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                            • Originally posted by Evan View Post
                              Show me the post where Gabriel advocates "sharp nose over" please.
                              I'm still waiting for a reference that would suggest that a crash is likely if a pilot used a power setting, attitude and VS that he was familiar with for normal operations- but didn't have airspeed indications...Please.
                              Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                              Comment


                              • EASA states that it has been determined that, when there are significant differences between all airspeed sources, the flight controls of an Airbus A330 or A340 aeroplane will revert to alternate law, the autopilot (AP) and the auto-thrust (A/THR) automatically disconnect, and the Flight Directors (FD) bars are automatically removed.
                                Further analyses have shown that, after such an event, if two airspeed sources become similar while still erroneous, the flight guidance computers will display the FD bars again, and enable the re-engagement of AP and A/THR. However, in some cases, the AP orders may be inappropriate, such as possible abrupt pitch command.
                                This is why established procedure calls for the manual DISENGAGEMENT OF FLIGHT DIRECTORS (SEE ATTACHMENT). This was not done. Pilot error. Not design error. And, while the AP may become intermittently available, it will not reengage on its own. There's no HAL.

                                Add to that, ADIRU's popping in and out saying "dead, no wait, I'm up, no wait, I'm dead" (mach part of vid) and giving the pilots the bait of being able to go back on AP (given the first quote above) is likely exactly why they decided to give HAL another try (..."the AP orders may be inappropriate, such as possible abrupt pitch command.")
                                Again, they have the FDR (they recovered it, remember?), and here is something we know as a FACT: this didn't happen. IT DIDN'T HAPPEN. The FDR plots include a binary plot for both AP and AT engagement. They clearly show that neither reengaged. The AT was neither active nor engaged. Both AP's were disengaged throughout the sequence. Nor is there anything on the CVR to indicate any attempt by the crew to reengage them. Now that you and I and everybody involved in the investigation knows this to be A FACT, where does that leave your theory?

                                And please explain to me what you keep referring to as HAL? The autopilots? The FMGC's? The flight control computers?

                                KurtMc, you can go on forever with your fanciful theories but they mean nothing to any of us who have read the FCOM and the reports. You simply do not understand how the A330 works, so you are making it up as you go along. If you spent more time learning the aircraft and studying the reports, and less time memorizing The Matrix, you would begin to understand. Free your mind. Read the factual material.

                                Seriously. If you base your theories upon what you learned by watching The Matrix and 2001: A Space Odyssey, how is that of any value here? Assume that we are knowledgeable and intelligent. That's all I ask.

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