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MD-80 skidded off runway at LGA

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  • #46
    Originally posted by Evan View Post
    "What's it doing now?" being my favorite.
    A perfectly logical statement when a plane does something against the vast majority of knowledge on how planes work.
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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    • #47
      Originally posted by 3WE View Post
      A perfectly logical statement when a plane does something against the vast majority of knowledge on how planes work.
      True, if all you have is general knowledge of how planes work. If you know the machine you are flying however, the question should be, "What should I be doing now" and the answer should be found in your head.

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      • #48
        Originally posted by Evan View Post
        "What's it doing now?" being my favorite.
        I have to reply to this comment from 2 different POVs:

        1- Which, in many cases, would be solved with click click, clack clack, and flying it like a man (for which flying it similar to a C152 tends to be enough, even if barely enough), enforce the flight path and performance you want (within what's allowed by Physics), and only then asking "Why was it doing that"? (Note the use of "many cases", "similar" and "tends to", AKA why pilots ALSO need to know the specific airplane's systems and procedures)

        2- I was not talking of that. I was talking about assertions that are conceptually wrong. Example: The NTSB naming the downwind turn as a factor in a stall accident, for its effect in reducing the airspeed. "What is it doing now" at least is a sign of humbleness (not that this will save your life anyway).

        --- 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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        • #49
          Originally posted by Evan View Post
          As far as the spoilers are concerned, the fatal error was in not confirming them deployed once they touched down. Even when armed, spoilers do not always extend correctly. It is not enough just to arm them on the checklist.
          Case in point: Latest DL-1086 info on AvHerald:

          The automatic spoilers did not deploy but that the first officer quickly deployed them manually.
          If that failure to deploy is related to a hydraulic reservoir issue it could have gone something like this:



          Still no info on reverser setting.

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          • #50
            Originally posted by Gabriel View Post
            ...The NTSB naming the downwind turn as a factor in a stall accident, for its effect in reducing the airspeed...
            The "Aftermath" column in Flying seems to have evolved into choosing incidents where the NTSB report seems questionable and addressing those questions. And, indeed, the Flying typists often seem to make valid points.
            Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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            • #51
              Originally posted by Evan View Post
              True, if all you have is general knowledge of how planes work. If you know the machine you are flying however, the question should be, "What should I be doing now" and the answer should be found in your head.
              This dismisses that the machine you are flying and that you know very well, have trained intensively on, studied the FCOMPOHQRH, is now behaving in a manner inconsistent with what it has always done as well as what the 150 would do.
              Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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              • #52
                Originally posted by 3WE View Post
                This dismisses that the machine you are flying and that you know very well, have trained intensively on, studied the FCOMPOHQRH, is now behaving in a manner inconsistent with what it has always done as well as what the 150 would do.

                RIght. Remind me again of what the ADIRU fault procedure is for the 150?

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                • #53
                  Point taken, but the "steam gauges" in 150s and other old aircraft can and do have problems all the time.

                  Vacuum pumps fail, causing attitude indicators to go nuts (and pilots to go nuts as a result). Pitot tubes ice over, causing erroneous airspeed indications (sound familiar?) - that's of course if you fail to turn the heat on at the right time. Heading indicator drift isn't exactly a "failure" but imposes increased workload on the pilot to keep it in check, or can cause navigational errors if forgotten.

                  And I can see where the above could be related to some of the issues with newer planes.

                  In the old aircraft, pilots *expected* the instruments to have various issues, and to just plain break sometimes. In other words, they required frequent attention and were not 100% trustworthy.

                  Nowadays you have data displayed on a screen that comes from "a highly sophisticated and redundant computer system" and the implication is that the data will be 100% correct all the time, with no attention from the pilot required.

                  Since the data actually is 99.999% correct 99.999% of the time, you've got a recipe for complacency - and problems the other 0.001% of the time.
                  Be alert! America needs more lerts.

                  Eric Law

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                  • #54
                    Spoilers not auto-deploying

                    For the spoilers to deploy automatically certain criteria have to be met. I believe one of them is main gear spin up.

                    The report quotes the pilots as saying that the runway appeared white as they broke cloud cover. Pure conjecture here, but if the landing were "too smooth" maybe there was not enough friction for the gear to spin up quickly enough to trigger the auto-deploy?
                    Yet another AD.com convert!

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                    • #55
                      Originally posted by Evan View Post

                      RIght. Remind me again of what the ADIRU fault procedure is for the 150?
                      You know, I'm not good with acroynm's, I've saved those brain cells to remember to think carefully about pulling up the whole time, to not dick with the autopilot during a rip-roaring downdraft, and to glace at the airpseed indicator very regularly, but especially on short final...

                      But I think the procedure (which I've mentioned many times) is use super-familiar power settings and super familiar attitudes that have given you super familiar speeds for 80% of your hundreds or thousands of hours, as the case may be.

                      Not in the QRH, but Gabriel tells me it does indeed work.
                      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                      Comment


                      • #56
                        Originally posted by mawheatley View Post
                        For the spoilers to deploy automatically certain criteria have to be met. I believe one of them is main gear spin up.
                        The criteria are main wheel spin-up or nosegear groundshift. All the more reason to brief a nice positive touchdown and to lower the damn nose promptly in these conditions
                        Parlour Talker Extraordinaire

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                        • #57
                          Originally posted by 3WE View Post
                          You know, I'm not good with acroynm's, I've saved those brain cells to remember to think carefully about pulling up the whole time, to not dick with the autopilot during a rip-roaring downdraft, and to glace at the airpseed indicator very regularly, but especially on short final...

                          But I think the procedure (which I've mentioned many times) is use super-familiar power settings and super familiar attitudes that have given you super familiar speeds for 80% of your hundreds or thousands of hours, as the case may be.

                          Not in the QRH, but Gabriel tells me it does indeed work.
                          The (naturally trending off-topic) topic here was the perennial and pedantic "forum posters who are not actual professional pilots can't possibly know what they're talking about" argument to which Gabriel pointed out "professional pilots sometimes don't know the things that non-professional forum-junkie-aviation-geeks have learned". Including the things they really should know.

                          They all know basic airmanship, any of them could fly a 150, but how many know what to do when their A330 or B777 suddenly goes "haywire" and departs the flight path with a mind of its own? Well, it's happened on both aircraft and in neither case did the pilots take the correct steps to isolate the problem. For example, in the case of the B777, they left the A/T armed and the erroneous ADIRU data valid. In the case of the A330 they failed to shut down the ADIRU with both the pushbutton and the rotary switch, also leaving the erroneous data valid (prompting an AD to clarify the procedure).

                          Now how many B777 pilots still don't know what steps to take in a similar event? Would Capt Ho Lee Fuk know? I think not. How many A330 pilots know the procedure to properly ensure that the affected ADR is isolated? Would that chief pilot in Pakistan who flew his A321 into a mountain because he didn't know how to engage the AP in selected modes fare well in such a situation? I think not.

                          For the most part, we keyboard pilots would have a real time of it flying the real thing in real-world reality, but that doesn't mean we don't have access to real technical information provided by real investigations and our geek instincts tell us to delve deeper into it than some real life pilots. Really.

                          In a perfect world, all airline pilots would also be aviation safety forum junkies as well. Through the great catalog of lessons learned the hard way, some of them might even learn something new from a non-pilot .

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                          • #58
                            Originally posted by mawheatley View Post
                            For the spoilers to deploy automatically certain criteria have to be met. I believe one of them is main gear spin up.

                            The report quotes the pilots as saying that the runway appeared white as they broke cloud cover. Pure conjecture here, but if the landing were "too smooth" maybe there was not enough friction for the gear to spin up quickly enough to trigger the auto-deploy?
                            390 to 725rpm is needed for autospoiler actuation. On a 44.5" tire that equates to about 50-95mph ground speed. If a lack of traction could cause them to fail to reach those speeds before derotation, the nose gear strut compression will also do the trick (assuming the actuator is fuctioning). But main gear weight-on-wheels will still unlock the ground spoilers for manual deployment prior to nose gear touchdown, which might be what happened here.

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                            • #59
                              I find it a shame, almost criminal, that we find it necessary to compress our lives into such narrow parameters in the name of efficiency?
                              Live, from a grassy knoll somewhere near you.

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                              • #60
                                Originally posted by guamainiac View Post
                                I find it a shame, almost criminal, that we find it necessary to compress our lives into such narrow parameters in the name of efficiency?
                                WTF are you talking about?

                                --- 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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