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AR-1 N923DJ Texas 15-12-18

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  • #91
    Kolibri, I don't understand what your problem is. You also have a way of misstating the facts as narrated.

    Did you know of the condition described by Birdy/Doug/Chuck before this thread? I did not. I also discussed this condition with a couple of other CFIs, and they did not know either. Go and take some training and become a gyro CFI is my recommendation to you.

    What I wrote is:
    "When I felt the impact, which was significant, I heard the engine go quiet and I instinctively knew that the prop had stopped. There was the sound that I heard, probably of the prop striking, and I knew then that I was toast. I actually closed my eyes and felt the rotors impact and when I opened them again, I was tipped over to the right side."

    You can see that I closed my eyes after the impact. What is it that you do not get in my statement?

    I have no desire to continue this with you. You requested me to narrate the details so that you could learn something. I do not wish to get dragged into your arguments.
    Antony Thomas
    “Learning without thought is labor lost; and thought without learning is perilous”
    ― Confucius

    Comment


    • #92
      Antony, you're right; you closed your eyes after the first impact, but before the rotors struck and you turned over.
      Your gyro hadn't yet come to rest. I only quoted Bob Hoover's dictum for us all: to never stop flying the aircraft whilst in motion.
      I wasn't trying to belittle or badger you.

      Sink from airflow reversal via helo-esque hovering to a gyro's auto-rotation: no, I hadn't heard it explained like that, either.
      Being neither helo pilot nor gyro CFI, I don't know what they generally know or not.
      But, I was surprised that such a phenomenon would be a revelation to anyone in that level of aviation.
      I meant no personal dig, but regrettably did not express myself clearly enough to prevent unintentional offense, so I apologize for that.

      Regards,
      Kolibri
      PP - ASEL complex (C172RG, Piper 180, C206, RV-7A), SP - Gyro (Calidus, RAF, Sport Copter II, M912), soloed in gliders

      "
      When an honest but mistaken man learns of his error, he either ceases to be mistaken -- or he ceases to be honest."

      Comment


      • #93
        Originally posted by Kolibri View Post
        WaspAir, regardless of what you advocate, vertical descent seemed exactly what you described
        Are you being intentionally obtuse?

        I described a continuous roundout and flare, with no period of level flight in between, on final approach (this was to draw contrast to a procedure you seemed to describe as three steps, with a roundout, followed by level flight at a steady low altitude while rotor rpm decreases, then followed by a flare).

        I cannot imagine how anybody could construe my procedure to be a vertical descent. Are we once again wrestling with non-standard usage by you of otherwise standard vocabulary?

        Vertical descent means your path is 90 degrees (perpendicular) to the ground. All motion is vertical. No motion is horizontal. That's basic geometry. The notion of roundout and cyclic flare is ridiculous in that context, because both require forward speed, and that makes your reading of my description pretty bizarre.

        Level flight means your path is 0 degrees (parallel) to the ground. All motion is horizontal. No motion is vertical. That is also basic geometry.

        I do not advocate either vertical descents or level flight on short final.

        Your suggested procedure involves rounding out after descending close to the ground, arresting the descent after roundout, briefly flying level at a low fixed altitude, and then performing a flare. You countenance a loss of rotor rpm between 6 and 0 feet.

        I find that, at best, an unproductive carry-over from bad fixed wing habits, and at worst, foolhardy.

        I applaud your concerns for safety, but find your procedural advice unwise and highly unhelpful.

        Comment


        • #94
          No, not intentionally obtuse, I'd not realized that you were still stuck on my mentioning in passing about brief level flight at 2 feet.

          From my post 71, the green line illustrates what I've been trying to describe. It's a very flat slope (i.e., more level than not):
          Click image for larger version  Name:	green line on HV diagram.png Views:	1 Size:	49.9 KB ID:	1141244




          However, even if one did not descend so slightly, but kept level for a short distance at 2 feet while bleeding off airspeed,
          how is that worse in turbulence than floating down at 14 degrees in a classic gyro descent?

          Simple (and yet unaswered) question: when turbulence is present, is it generally stronger at 0-10 feet or at 20-50 feet?
          That's been my central point in this entire thread.

          During turbulence, I want to negate as much of it as possible by getting lower ASAP.
          What turbulence remains will pose less risk because I've nearly no height left to drop from and my strong ground effect acts as cushion/spring against downdraft energy.


          Regards,
          Kolibri



          PP - ASEL complex (C172RG, Piper 180, C206, RV-7A), SP - Gyro (Calidus, RAF, Sport Copter II, M912), soloed in gliders

          "
          When an honest but mistaken man learns of his error, he either ceases to be mistaken -- or he ceases to be honest."

          Comment


          • #95
            Originally posted by Kolibri View Post
            Not really, Vance.
            Your truncated account here left out the most important thing: when the gust subsided you were at 20 feet, and you barely saved it with the prompt application of power.
            Here is your own description from another thread:



            (You'd already rounded out, thus above 20 feet.)
            Let's be honest: Had that happened a couple of feet lower, or had the gust subsided more, you'd have dropped in hard.
            What I summarized then I still believe: you were operating at that moment with very little margin for safety.
            My impression is that you do so more often than you realize.


            _____

            IIRC, my 30' rotors are not 10' high, but about 9'. Thus, a roundout/initial flare at 6 feet for me is within ground effect. It certainly feels like it.


            Real professional of you to implicitly call me a liar, Vance.
            a) I didn't claim to invent it, and b) I've used it many times.

            It is axiomatic that flight inertia which is more horizontal than vertical will better handle turbulence, as well as more quickly penetrate a dirty block of air.
            And the lower to the ground one does so, the less the turbulence and the less drama it can impress upon the aircraft.
            If, for example, I'm plopped down from 1 foot at 10mph, it's merely a hard landing of slightly involuntarily timing.
            However, get plopped down from 4 feet . . .

            But, hey, keep dropping in mostly vertically from your classic 20 foot roundout. You've already admitted to many close calls.




            I am confident that nobody flying with one-eyed vision has the required depth perception to confidently and consistently roundout/initial flare at 6 feet.
            For such a pilot, such would indeed probably be a bad idea, or even dangerous.

            Regarding Vance's calling B.S. on me, I've GoPro videos of my training days in a Calidus rounding out at or below 6 feet.
            I could do so then in my first several hours of gyro flying. (I was already a PP-ASEL, thus not an ab initio pilot.)
            Only one time did my CFI Chris Lord ever reach for the stick, and that was when I experimented with rounding out at probably 3 feet.
            I had already preceded his reaction with ample back stick, and he apologized for nearly adding to it as he thought we might have pancaked in.
            I apologized for not giving him a heads up that I was going for a bit lower that time.

            Just to make sure I wasn't misremembering things, I reviewed some of those landings. I was definitely rounding out in ground effect.
            In fact, I watched the stick dip forward a tiny bit to compensate for the initial cushioning and not balloon up.
            I.e., instead of using back stick to arrest descent in my roundout, I was using the gyro's ground effect to arrest my descent.
            The video is also clear enough to carefully see the altimeter at roundout vs. touchdown.

            So, anybody sufficiently confident that I do not have the skill set to land as I've described, should PM me to place a $$$$ wager on it.
            I'll install my GoPro and gather some witnesses to also film it from the ground.




            Wow, really? This assertion from a gyro CFI?
            It's not a
            "bad idea" because . . . gusts and wind shear are less severe at 5' than 50'.
            You've said so yourself many times: downdrafts don't reach the ground, they decrease in velocity the lower they go, etc.
            Ever seen a winds aloft table? Winds are almost always stronger with altitude.

            Doesn't anybody recall their earliest student pilot landings during gusty crosswinds?
            On short final at 100 feet being buffeted around, and having the CFI assuage your nervousness with "
            Don't worry, ride this out, things will settle down once you're lower to the runway."
            He was right, and I often say the same thing to any nervous passenger during a gusty short final.

            So, I've NO IDEA why getting quickly low and below much of the turbulence is so controversial here.
            My CFI can't understand it, either.



            ___________

            Fair enough, WaspAir, willco.


            Yes, I agree with all that.


            I disagree. He didn't even lose engine power, but merely experienced a subsided gust, and yet he still nearly crunched in.
            His own account corroborated what it's like to be right on the H:V line when something unexpected happens.



            I wrote "hardly any" settling.


            During such a vertical descent with no level flight, sure, I agree. In fact, I've already conceded that, as the rotor is consistently loaded.

            However, during turbulence I've been describing a much flatter descent, with less rotor loading between the roundout/initial flare and the full flare landing.
            There is very little [additional] rotor loading from 6 feet to 0 feet, but much more reduction in AS. Thus the slight RRPM decay within the lower 300s.
            Why this is so difficult to accept for some, I don't know. Perhaps I should film it as proof?



            ____________
            Antony, I've played around with high-G base-final turns and noticed the increased RRPM.
            However, I've found it to quickly dissipate and RRPM returns to normal values for the AS.
            I don't recall any base-final overspeeded RRPM lasting into the roundout.

            Since you didn't describe your flare as anything vigorus, nor mention any ballooning, it's hard for me to envision an oversped rotor from that flare.

            But, if, now, you've come to believe that when you were at 4 feet and 10mph that you still had some overspeeded RRPM from either your turn or your flare,
            which then began to decay causing an airflow reversal and sink, then I hope you're correct in your appraisal and have learned what you needed to learn.

            However, since you're a gyro CFI, I admit to some surprise that this was something you didn't already know.

            The other thing that surprised me was that you actually closed your eyes before impact.
            As Bob Hoover was famous for saying,
            "Fly the aircraft all the way into the crash."
            I've actually commanded myself to "Aviate! " during dicey moments, and it helps.

            _____
            Thanks for everyone's participation; it's been enlightening, and my particular thanks to Antony for sharing his experience here.

            Safe flying,
            Kolibri
            Wow! The trifecta, Kolibri has argued with and insulted three CFIs in a single post.

            People wonder why more CFIs don’t share what they know on the Rotary Wing Forum. This is a perfect example of exactly why.

            I doubt he has learned anything and he has wasted a lot of people’s valuable time.
            Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

            Comment


            • #96
              Originally posted by Kolibri View Post
              Not really, Vance.
              Your truncated account here left out the most important thing: when the gust subsided you were at 20 feet, and you barely saved it with the prompt application of power.
              Here is your own description from another thread:


              (You'd already rounded out, thus above 20 feet.)
              Let's be honest: Had that happened a couple of feet lower, or had the gust subsided more, you'd have dropped in hard.
              What I summarized then I still believe: you were operating at that moment with very little margin for safety.
              My impression is that you do so more often than you realize.


              Safe flying,
              Kolibri[/COLOR]
              You are misconstruing a nonevent and pretending it was something that was dangerous.

              I am not finished with my round out at 20 feet above the ground as you postulate.

              The mental picture you have created based on your ignorance about landing a gyroplane is totally unrelated to the reality of the event.

              Not everyone it trying to hide something.




              Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

              Comment


              • #97
                Originally posted by Kolibri View Post


                I am confident that nobody flying with one-eyed vision has the required depth perception to confidently and consistently roundout/initial flare at 6 feet.
                For such a pilot, such would indeed probably be a bad idea, or even dangerous.

                Regarding Vance's calling B.S. on me, I've GoPro videos of my training days in a Calidus rounding out at or below 6 feet.
                I could do so then in my first several hours of gyro flying. (I was already a PP-ASEL, thus not an ab initio pilot.)
                Only one time did my CFI Chris Lord ever reach for the stick, and that was when I experimented with rounding out at probably 3 feet.
                I had already preceded his reaction with ample back stick, and he apologized for nearly adding to it as he thought we might have pancaked in.
                I apologized for not giving him a heads up that I was going for a bit lower that time.

                Just to make sure I wasn't misremembering things, I reviewed some of those landings. I was definitely rounding out in ground effect.
                In fact, I watched the stick dip forward a tiny bit to compensate for the initial cushioning and not balloon up.
                I.e., instead of using back stick to arrest descent in my roundout, I was using the gyro's ground effect to arrest my descent.
                The video is also clear enough to carefully see the altimeter at roundout vs. touchdown.

                So, anybody sufficiently confident that I do not have the skill set to land as I've described, should PM me to place a $$$$ wager on it.
                I'll install my GoPro and gather some witnesses to also film it from the ground.


                ____
                Thanks for everyone's participation; it's been enlightening, and my particular thanks to Antony for sharing his experience here.

                Safe flying,
                Kolibri[/COLOR]
                This is typical of your "proof".

                I doubt if any flight instructor would have you landing in gusting 25kt to 35kt winds so your review of your training video has no purpose.

                I have already written that low time pilots tend to round out low because they have only flown in light winds and as soon as they fly in gusting winds above 25kts they quickly learn what a bad idea it is to round out low.

                I have no idea why you appear to misunderstand the most basic things about flying a gyroplane, the effect of the wind and aviation decision making. There is clearly no point in me explaining it to you further.

                Your continued snarky remarks about my monocular vision again reveal another of your misunderstandings.

                If you imagine judging the timing of the round out and flare is done with binocular depth perception you are looking in the wrong place during your landings.

                I fly with a statement of demonstrated ability and the FAA representative did not find anything deficient about my ability to execute simulated emergency landings.
                Regards, Vance Breese Gyroplane CFI http://www.breeseaircraft.com/

                Comment


                • #98
                  Originally posted by Kolibri View Post
                  From my post 71, the green line illustrates what I've been trying to describe. It's a very flat slope (i.e., more level than not):


                  However, even if one did not descend so slightly, but kept level for a short distance at 2 feet while bleeding off airspeed,
                  how is that worse in turbulence than floating down at 14 degrees in a classic gyro descent?

                  Simple (and yet unaswered) question: when turbulence is present, is it generally stronger at 0-10 feet or at 20-50 feet?
                  That's been my central point in this entire thread.

                  During turbulence, I want to negate as much of it as possible by getting lower ASAP.
                  What turbulence remains will pose less risk because I've nearly no height left to drop from and my strong ground effect acts as cushion/spring against downdraft energy.
                  Where to start . . .

                  Here are two things for you to think about:

                  1. Ground effect does not provide a "cushion" to a gyroplane. It provides a reduction in induced drag which enhances performance when close to the surface. It is not an upward force to overcome downdrafts, and in no way acts like a spring to resist descent. The benefit you seek from it isn't real. It will not absorb any kinetic energy from dropping. Those who talk about a "cushion" of air don't understand the physics; ignore any sources that put it in such terms. There will simply be no advantage in your procedure from this phenomenon.

                  2. Tracks like the green line on your H-V diagram are sometimes drawn to show a preferred take-off profile. I suppose you can also draw a proposed path for approach on an HV diagram if you wish (I don't recall seeing it done before, because the HV diagram is, as I said above, intended to show risks of sudden engine failure in continuous high power operation, not atmospheric action on approach to landing). However, you must keep in mind what it shows and what it doesn't. The "slope" there is in units of foot of altitude lost per mph of airspeed, which is a very unnatural way of thinking for most pilots. There is no horizontal distance or time information presented, and no distance or time units can be inferred. That means it does not show glideslope information (slope of your path in space over the ground), and does not show how quickly speed is lost or gained (no g load information). The green line you drew could be flown in 2.5 seconds at a steady 2g deceleration or in 2.5 years with a very small g load and the line would look the same. The slope over the ground in the first case will be much steeper than in the other, but the line would not change. The rotor rpm will go very much higher in the first case and sit very, very stable in the second (at least until the last few months when you are below minimum level flight speed and can no longer hold to the line as shown). The runway distance used could be 100 feet with a 6 degree slope in the first, and 600,000 miles at barely more than 0 degrees in the other.

                  Comment


                  • #99
                    Closing an eye, I'd not feel confident trying to roundout below 10 feet, no matter where I was looking.

                    I'm not trying to insult anyone, not even Vance. Buck up if you feel that way; trying to save lives here.


                    ___________
                    I realize that no time component is present in my diagram.
                    I kept the illustration simple for clarity.



                    It is not an upward force to overcome downdrafts, and in no way acts like a spring to resist descent.
                    A wing generates lift by deflecting the oncoming airmass (relative wind) downward. The deflected or "turned" flow of air creates a resultant force on the wing in the opposite direction (Newton's 3rd law). The resultant force is identified as lift. Flying close to a surface increases air pressure on the lower wing surface, nicknamed the "ram" or "cushion" effect, and thereby improves the aircraft lift-to-drag ratio. The lower/nearer the wing is with regards to the ground, the more pronounced the ground effect becomes.
                    https://en.wikipedia.org/wiki/Ground..._(aerodynamics)
                    Increasing air pressure on the lower wing surface sounds like an "upward force" to me.

                    Your description of the reduced drag is correct but incomplete (as are the FAA Handbooks), as you ignore the increased lift from actual ram pressure:


                    Lift: When you are in free space, the high pressure below your wing dissipates into the surrounding air.
                    When you're in ground effect, the high pressure below the wing encounters an incompressible solid, and therefore
                    cannot dissipate as quickly, causing higher pressure below the wing, and therefore more lift.

                    The "cushion-effect" explanation is actually quite correct. The pressure which lifts the airplane is not only created
                    by accelerating air downwards, but also by ram pressure. This effect disappears once the wing is far enough from the ground.
                    Here is the high pressure beneath a wing, in the air on the left, and in ground effect on the right.


                    Click image for larger version

Name:	ground effect on the right.png
Views:	2
Size:	32.1 KB
ID:	1141254


                    Even if this were untrue, nobody has yet purported that turbulence is worse (or even identical) at 0-10 feet than 20-50 feet, and thus why it's so dangerous "down there".

                    Also, try to explain why a low-wing Piper lands easier in turbulence than a high-wing Cessna.
                    Even that few feet lower matters.
                    PP - ASEL complex (C172RG, Piper 180, C206, RV-7A), SP - Gyro (Calidus, RAF, Sport Copter II, M912), soloed in gliders

                    "
                    When an honest but mistaken man learns of his error, he either ceases to be mistaken -- or he ceases to be honest."

                    Comment


                    • Drop a brick on your foot on a windy day and notice just how well the increased ram air pressure as it gets low to your toes cushions the impact and gives an upward spring effect to protect your foot (the air it has been displacing as it falls must have nowhere to go now, right?).

                      Well, I guess the FAA and I have had it wrong all these years, and we should trust simplified laymen's explanations and homespun vocabulary from Wikipedia instead. It's a shame I wasted all those years of education.

                      If I thought you were really asking questions with an open mind and willingness to learn, I'd keep at this, but that doesn't seem to be the case.

                      To the reader:

                      Don't use Kolibri's suggested landing approach method.

                      See you on some other thread soon, everybody, bye-bye.

                      Comment


                      • WaspAir, a dropped brick is not an airfoil flying in ground effect.

                        I suspected that you'd cop-out with some disparaging comment about my quoting Wikipedia.

                        So, here's a scientific paper for you.

                        Below is page 4 from "
                        Wing in Ground Effect Craft Review" found at
                        https://apps.dtic.mil/dtic/tr/fulltext/u2/a361836.pdf

                        Click image for larger version  Name:	Wing in Ground Effect Craft Review.png Views:	1 Size:	161.0 KB ID:	1141257



                        "The resulting altered pressure distribution causes a net increase in the lift . . . "

                        As I said, you correctly described the reduction in induced drag, but omitted everything about increased lift.
                        Sorry.


                        PP - ASEL complex (C172RG, Piper 180, C206, RV-7A), SP - Gyro (Calidus, RAF, Sport Copter II, M912), soloed in gliders

                        "
                        When an honest but mistaken man learns of his error, he either ceases to be mistaken -- or he ceases to be honest."

                        Comment


                        • Originally posted by Kolibri View Post
                          Stay safe? How could we do that?
                          You're Instrument Helo rated, as well as a Gyro CFI. You've some 3,400+ hours in rotorcraft.

                          I cordially ask that you make this an instructional example for us.
                          In retrospect, would you have done anything differently that day?
                          What can we learn from that day?

                          If nothing, then you leave us with the impression that sudden wind shear is an unrecoverable bane during gyro landings.
                          That your crash has nothing to teach us but that "sh*t happens".

                          Personally speaking, I cannot accept that.

                          Thank you,
                          Kolibri

                          I had the choice of just ignoring your request. At this point in the thread, it is doubtful if you are trying to "learn from that day". This in addition to your insults (which you do not seem to perceive) delivered in most of your posts.
                          Rather, it seems to me that you are trying to teach everyone else something. How much flight time do you really have?
                          As a healthcare professional, I perceive your constant nit-picking at the different CFIs on the minutest of details in your posts of something more troubling deep within you. A desire to be "Right" all the time.
                          I am not trying to insult you. What I have learned is that I will be very careful in future in responding to any requests from you.
                          Antony Thomas
                          “Learning without thought is labor lost; and thought without learning is perilous”
                          ― Confucius

                          Comment


                          • Antony, we're all pilots. None of us has the luxury of being wrong.
                            All of us have the desire to be "Right". It keeps us alive.
                            Now, how we do so on this forum is another matter, and worthy of discretion, courtesy, and respect.
                            I've not always comported myself well there, and neither have others.

                            Yes, you could have ignored my request, and this thread would have just died out without your input.
                            Only from there, however, did some very interesting things burble up, the airflow reversal theory of your incident, for example.

                            I am here to hear the truth, and speak the truth.
                            I've repeatedly asked a most relevant question throughout this thread, about the severity of turbulence related to altitude strata near the runway.
                            It still hasn't been answered, and I suspect that some readers are by now wondering why not.

                            I'm lower time than many here, but also higher time than many.
                            I own FW and gyro. As PIC I have within just several years landed at 121 airports across 26 states, for those who are curious. I fly every week.

                            I do not target gyro CFIs for any reason, much less for nit-picking. However, they are not perfect and complete in their knowledge.
                            One believed until recently that only rotor drag prevented HTL gyro PPOs, while another denies the increased lift/"cushion" of in-ground-effect flight.
                            No doubt it rankles them that it was Kolibri who pointed that out, but that is still no reason for conduct unbecoming a CFI, such as jeering at a lower-time pilot.

                            I am not trying to "spike the football" here, with you, or Vance, or WaspAir.
                            However, I won't kow-tow to any CFI ego if I have a viable disagreement with their opinion or technique.

                            Look, it's the first week of a brand new year, 2019. I actually do not revel in discord.
                            I apologize for any that I've created or kept energized.
                            Shall we all begin anew?
                            May I be the first to offer across the miles a handshake of friendship and solidarity to my fellow gyronauts?

                            I believe that we owe a respectfully growing knowledge base to those aviators yet to come, and a professionalism probably not yet seen in the gyro community.
                            I am keen to lean my shoulder into that common mission.

                            Safe flying and best wishes to you all,
                            Kolibri



                            PP - ASEL complex (C172RG, Piper 180, C206, RV-7A), SP - Gyro (Calidus, RAF, Sport Copter II, M912), soloed in gliders

                            "
                            When an honest but mistaken man learns of his error, he either ceases to be mistaken -- or he ceases to be honest."

                            Comment


                            • Meanwhile, this thorny olive branch showed up in my PM box:

                              Comment


                              • All bickering and theoretical arguments aside. I am not a CFI, I am a low time pilot with 250 hours in a gyro and about 250 in a FW. My only interest is to be able to be more knowledgeable and safe regarding my future flying experiences and approaches to land, and not to argue theoretical considerations. I tend to fly my approaches to land, even in the gyro at our busy airport (KDED) in a standard pattern, not as thomasant describes his approach in this incident, so I am not concerned here about reverse flow through the blade etc. I find my control inputs and glide slope on approach in an Aircam (High drag fixed wing) are not unlike the gyro except for increased rudder input in the Aircam.
                                From a pure practical perspective. Assume I am making an approach to land and winds are moderate to high, say 14, gusting to 22. This wind info is the only thing I can actually have clear information about. I cannot know with any real predictability about wind shear and downdrafts etc, but I can assume that these are more likely under these gusty conditions. My present approach for both gyro and FW is to increase power and airspeed by about half the gust factor. In both cases my ground speed will not generally increase, and will possibly be decreased compared to a low wind day. I am not questioning or asking about how long to fly over the runway, how high and when to round out etc.
                                It seems to me that in both the gyro and the FW I am building in an extra reserve of energy and lift to buffer any possible variations in wind speed close to the ground. (A gyro cannot stall, but still comes down pretty hard when behind the power curve). I understand that when in doubt on landing I will still apply full power and go around. Simple question to the CFI's, is there a flaw in this argument and am I doing something in a gyro which is likely to make my landing less safe?

                                Comment

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