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  • #31
    Originally posted by 3WE View Post
    Must be that old US English slang vs. Gabriel ISO-9001-236A Espanol language thing again.

    I actually went to a dictionary on www.internet.com and indeed, the definition which I knew, seemed to be lacking.

    Blank = Empty (like a blank on a form)...i.e. nothingness...and make a verb out of it..."blank out" or "cover over what used to be there" "negate", or the final (but logical extrapolation) cover the the good airflow that used to be there with a weak, non-existent, non-effective, turbulent, backwards, lacking airflow.

    The reverse thrust (i.e. air blowing backwards) blanks out the normal airflow over the tail reducing it's effectiveness.

    Put the engines in the right place and keep the nose off the ground and you can even "blank out" the horizontal stabilizer with reverse thrust and plant the nose wheel quite firmly (think Turboprop singles!!!!)

    A friend I know who is an ag pilot had just departed with a full load of herbicide, the gearbox failed, the prop went into a reverse pitch and he said that the dive was very scary as he was pulling up relentlessly, but not stalling.

    His words in describing the story was "the prop went into reverse and blanked out the elevators".

    Fortunately, there wasn't a lot of stored rotational energy to generate the reverse thrust for more than a couple of seconds, he regained some elevator authority and his landing was 'good' by all of those classic definitions...The dead spot from the spilled herbicide was visible on Google Earth images for a couple of years.

    Rudder blanking (not sure exactly how it was worded) was a factor in the AA1491 crash at Little Rock...As they slid sideways, they let off the reverse thrust hoping to improve rudder authority...but sadly, could have used the additional braking to make the off-road adventure more gentle.
    (Yes, failing to arm the spoilers was perhaps a bigger contributor as it would have added braking and steering authority to the landing gear).

    (Does the mind of a Spanish speaking person focus very strongly on the color white for "blank/blanco" ? To English speaking folks, "Blank" isn't really a color, but something that's not completed...I left the answer blank on my test.)
    All that just to say "Yes"???
    Have you been smoking the same than me or what? (here comes the cursing again in 3, 2, 1...)

    Yes, we use the word "blanco" for the color white, and also because a paper that you have not written anything on yet is fully white, it is a "papel en blanco", and a part of a paper that should be filled and is not is also "en blanco" (like the answer in your test, even if the support wasn't really a paper but a computer screen), and we can use it with the mind for a "mente en blanco" too. I knew this expression in English too. I had never heard it with "rudder", but I immediately visualized a "void rudder". So how the rudder can be made "void", I wondered. And there the silhouette of the Mad Dog came to my mind, and I made the guess that I made, and, I don't know if you noted it, but I did it correctly for God sake!!!!

    --- 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


    • #32
      Originally posted by Gabriel View Post
      All that just to say "Yes"???
      Have you been smoking the same than me or what? (here comes the cursing again in 3, 2, 1...)...and I made the guess that I made, and, I don't know if you noted it, but I did it correctly for God sake!!!!
      1) You said the bold font stuff above:

      2) You in fact asked the question. (Quote=Gabriel, "Care to explain this term?)

      3) I instantly knew* what rudder blanking was, and have heard it used several times before.

      (*knew...i.e. didn't have to guess)

      Bottom line:

      If you ask a question and you make a guess, you don't get to accuse me of smoking nor do you get to inferentially cuss me out for writing an answer and explanation that's half the length of one of your typical explanations.

      So there!
      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

      Comment


      • #33
        Originally posted by 3WE View Post
        1) You said the bold font stuff above:

        2) You in fact asked the question. (Quote=Gabriel, "Care to explain this term?)

        3) I instantly knew* what rudder blanking was, and have heard it used several times before.

        (*knew...i.e. didn't have to guess)

        Bottom line:

        If you ask a question and you make a guess, you don't get to accuse me of smoking nor do you get to inferentially cuss me out for writing an answer and explanation that's half the length of one of your typical explanations.

        So there!


        You kiddies are cute.

        An incident occurs in the most sophisticated mode of transportation, at one of the most congested airports in the world, in a driving snow storm and you let your panties get in a wad over sarcastic humor and semantics. Cant we chalk it up to " schitt happens"? At least until the data has been processed?

        This forum has so much potential to be educational and informative to the professional, and layperson but fails because, and I quote from another forum of this genre about jetphotos.net. " it is crowded with pimply faced high school wannabe pilots whose real world experience is limited to..." I'll ad lib here - whatever aviation xbox flight simulator was popular at the time this forum was discussed.

        These treads start out great but quickly degerate.

        tighten up. humor is good . disecting someone's everyword and attacking them is childish.

        Comment


        • #34
          Originally posted by T.O.G.A. View Post
          ...humor is good...
          Care to direct me to "the other forum of this genre"? A PM would be fine too. I'd like a place to lurk and listen to some professionals, because indeed, this place is dominated by outsiders looking in (I'm guilty as hell). We also have folks who are liberal with free advice on how planes should be flown...I've been guilty of that too...trying to get better. And, from what I see and hear, PPRUNE is worse.

          I genuinely did consult a dictionary for the work "blanking". When I did not see "render ineffective" as one of the meanings, I described it...

          ...and not so much for Gabriel but realizing that if HE asked (and he knows his schitt) someone else might not know the term...

          Gabe jumped my case a bit, I fired back and apologies that we actually have a long relationship of both razzing, serious discussions and respect.

          This incident...the final report...I bet it will probably be much as you and V-Nav describe. Thousands of planes landed in snowstorms this year...many in windier conditions...I'm doubtful there will be a gross failure of pilot technique, equipment, and I'm even reading preliminary information that the runway was freshly plowed...excrement transpires.

          I'm serious about the link, name, whatever- I want to read what folks who analyze this place as pimple-faced, wanna-be, flight simmers have to say about aviation stuff. I promise, I won't register if you ask me not to.
          Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

          Comment


          • #35
            Originally posted by Gabriel View Post
            Care to explain this term?

            Ok, let me guess...

            Something nasty that happens when you put reversers on those engines that are so close to the tail?

            Gabe,

            You basically have it. With the bucket type reversers on the -88's tail mounted engines, max use of reverse thrust can disturb the airflow over the rudder essentially making it useless. the book number is anything over 1.3 EPR. Useless rudder on a slippery runway with a 10-15 kt left crosswind makes the plane weathervane into the wind and end up on the seawall.

            Rudder blanking has been a factor in all the -88 excursions that I'm familiar with and I saw a good first hand example of it recently with a new hire F/O landing on a non-grooved runway in the Carribean with just a hint of water from a shower an hour or so before. At the first sign of blanking you have to go back to reverse idle. Unfortunately, when you start sliding on a sloppy runway, the natural reaction is to increase any inputs that you think might help braking, but increasing reverse thrust just makes it worse.

            The only real way to battle it is when landing in contaminated conditions on short runways prebrief limited/judicious use of reverse thrust. More importantly, firm touchdown, ensure spoiler deployment, prompt lowering of the nose, and MAX autobrakes. I'm hoping the cause was mechanical or poor RWY maintenance/reporting, but I have a feeling the result will be found in the previous sentence

            BTW. the -90s don't seem to have the same problem. Obviously the engines are still tail mounted but the reversers only affect the fan air, not the core so that may not disturb the flow as much (I'm kinda talking out my butt here). I do know that I landed a 90 on a snow covered runway in this past weekend's storm in the midwest and she stopped like a champ.
            Parlour Talker Extraordinaire

            Comment


            • #36
              Originally posted by T.O.G.A. View Post
              This forum has so much potential to be educational and informative to the professional, and layperson but fails because, and I quote from another forum of this genre about jetphotos.net. " it is crowded with pimply faced high school wannabe pilots whose real world experience is limited to..." I'll ad lib here - whatever aviation xbox flight simulator was popular at the time this forum was discussed.


              I hate when people judges what others say more just by the diploma behind them on the wall (or lack of such) than by the content of what they are actually saying.

              I'm not talking of my last post which I admit was highly off-topic and irrelevant, and no doubt that some (or perhaps many) amateurs are clueless.

              That said, in nearly 100% of the commercial aviation crashes, the persons behind the controls were professional pilots, in about 66% pilot error (or some times negligence) was a direct cause of the crash, in many of that 66% and also in many of the remaining 33% the pilot failed to recover (which was doable) after the sequence was initiated, in many of them the pilots involved were no rookies but highly experienced airmen, and in more cases than I would like the airmanship displayed by them was incredibly awful.

              I am sure most airline pilots know very well their stuff. But nobody (and that includes ITS or Bob Hoover) is right just because he is who he is. And nobody is wrong or not worth listening just because he is a "pimply faced high school wannabe pilots whose real world experience is limited to whatever aviation xbox flight simulator was popular at the time".

              What a person says must be judged by what he said. Of course, credentials are important because they impact the credibility of the person, but they are not determinant in either way, neither to accept what he says as the revealed truth nor to discard it as a-priori-nonsense. The content of the message can be self-supporting or self-discrediting.

              --- 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


              • #37
                Thanks VNav,

                Kind of ironic that when the traction is the least, the reversers become more critical to stopping the plane and at the same time more dangerous to cause loss of directional control. If you don't use them enough you risk and overrun, if you use them too much you risk a veer-off.

                --- 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


                • #38
                  Pity that there was no device coupled that when the rudder was in "dead air" the reversers would compensate.
                  Live, from a grassy knoll somewhere near you.

                  Comment


                  • #39
                    Originally posted by 3WE View Post
                    Rudder blanking (not sure exactly how it was worded) was a factor in the AA1491 crash at Little Rock...As they slid sideways, they let off the reverse thrust hoping to improve rudder authority...but sadly, could have used the additional braking to make the off-road adventure more gentle.
                    (Yes, failing to arm the spoilers was perhaps a bigger contributor as it would have added braking and steering authority to the landing gear).
                    AA 1420. Rudder blanking was cited as a contributing factor. At the core of it was a pressed, unstabilized approach.

                    Rudder blanking is a well-known phenomena to MD-80 pilots. McDonnell Douglas made the phenomena clear in their FCOM.

                    The issue isn't whether to use reversers or not, the issue is to use proper procedure: reduce reverse thrust from the normal 1.6 EPR to the 1.3 EPR that MD-80 pilots are supposed to be taught to use during slippery runway conditions. Reversers limited below 1.3 EPR do not cause the rudder blanking phenomena.

                    Pilots are supposed to be taught this procedure in training, but following AA1420, the NTSB discovered that the procedure was not being trained in the SIM's. I'm not even sure that the SIM will simulate the phenomena. However, it is a manufacturer specified procedure and needs to be taught as a memorized item.

                    I think a big factor here was that traffic ahead reported good runway traction. If the problem of rudder blanking occurs unexpectedly after touching down, it might not be reasonable to expect pilots to identify the problem and take action in the minute span of time available on the runway. I think it needs to be set-up in advance as part of a pre-landing briefing. Unless the runway length is dangerously limited, I would think a cautious crew would limit reversers if even the threat of weathervaning exists. They can always be brought up to full power further on the roll out if necessary.

                    But the real issue to solve on this one might be in making better and more frequent runway condition assessments during weather like this, especially for runways like this one where ice can form quite suddenly.

                    At least that's what my X-Box tells me...

                    Comment


                    • #40
                      Originally posted by Evan View Post
                      AA 1420. Rudder blanking was cited as a contributing factor. At the core of it was a pressed, unstabilized approach.
                      Ummm.....

                      The core was the failure of the memory checklist item and CRM to arm the spoilers...

                      ...and the broad, basic, fundamental question if it's wise to conduct an approach directly into a known-severe-thunderstorm-damaging-wind-squall line.

                      One might even argue that the airspeed, altitude and even lateral alignment were within spec for the approach...

                      This NTSB animation shows the last minute of flight for American Airlines Flight 1420, which crashed while landing at Little Rock, Arkansas on June 1, 1999. ...


                      Maybe even a failure of the fundamental stick and rudder skill that having a first class crab AND landing into a thunderstorm gust front might be a bad idea.
                      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                      Comment


                      • #41
                        Originally posted by 3WE View Post
                        Ummm.....

                        The core was the failure of the memory checklist item and CRM to arm the spoilers...
                        Nnnnno...

                        The failure to arm the spoilers was the result of continuing an approach that exceeded safe criteria. The main reason we have stabilized approach criteria is that MANY studies have shown that unstable approaches place a high level of workload upon the crew and this is fertile the environment for skipped checklists and pilot error. It has to do with human factors.

                        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. Same goes for autobrakes.

                        Studies have also shown that pilots routinely continue into active thunderstorms. Get-there-itis. Plan Continuation Bias. Call it what you will. The problem lies in the human vulnerability to poor judgment.

                        Comment


                        • #42
                          Originally posted by Gabriel View Post
                          What a person says must be judged by what he said. Of course, credentials are important because they impact the credibility of the person, but they are not determinant in either way, neither to accept what he says as the revealed truth nor to discard it as a-priori-nonsense. The content of the message can be self-supporting or self-discrediting.
                          I don't disagree with you premise here, but there seems to be something about aviation that attracts people who are utterly unqualified to talk about it to the extent they do. In this sort of atmosphere, the odds of something a person like that says being "a-priori nonsense" are pretty good.

                          I'm not real sure why that is, I doubt there are too many non-accountants on accounting sites telling actual accountants how to do their job...

                          Comment


                          • #43
                            Originally posted by ATLcrew View Post
                            I'm not real sure why that is, I doubt there are too many non-accountants on accounting sites telling actual accountants how to do their job...
                            I'm more sure why that is:

                            If an accountant and an Excel spreadsheet killed a few hundred people every year or so...

                            If operating an Excel spreadsheet and interpreting tax law were half as cool as zooming across the sky or guiding a plane down a gusty final approach...

                            If little boys (oh yeah, and little girls too) loved doing taxes on toy Excel spreadsheets as much as throwing a toy glider, or building a model plane...

                            The wanna-be, learn what you can (with omissions and errors) factors are a lot stronger with airplane flying than accounting...

                            I might try Google in a minute, but I'm thinking I won't get any hits if I search Accountingphotos.net...

                            I'm sure there could be quite a discussion on the Enron Crash thread, but I don't really like Price Waterhouse's new livery all that much.

                            AND, be glad you are not a professional sports coach. Plenty of free advice on forums for those types of folks.
                            Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                            Comment


                            • #44
                              Originally posted by ATLcrew View Post
                              I don't disagree with you premise here, but there seems to be something about aviation that attracts people who are utterly unqualified to talk about it to the extent they do. In this sort of atmosphere, the odds of something a person like that says being "a-priori nonsense" are pretty good.
                              Yes, I agree, but:

                              In one of those not-so-rare occasions, tell that person "what you said is stupid because X so it doesn't have merit" rather than "you are a stupid because Y so what you've said doesn't have merit".

                              And... the other side of the coin... I've heard some real stupid things said by some "pros" too.

                              --- 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


                              • #45
                                Originally posted by Gabriel View Post
                                And... the other side of the coin... I've heard some real stupid things said by some "pros" too.
                                "What's it doing now?" being my favorite.

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