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  • Min Speed?

    One of the most appealing features of a gyroplane to me is the ability to fly very slowly, but I cannot seem to find exactly how slowly that is on any manufacturer's sites. Could someone tell me what the min speed for level flight is on either your model or some popular ones?

  • #2
    It depends on the weight at the time Jeremy.

    The Predator solo with half a tank of fuel will fly level down to about 17kts and two up down to around 21kts at sea level.

    In ground effect she will fly level down to about 13kts solo although I question the accuracy of the air speed indicator at low speeds.

    The Cavalon I flew was even less consistent with level flight possible down to around 23kts for five minutes solo and 27kt near maximum takeoff weight.

    The minimum speed is increased as the density altitude increases.

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

    Comment


    • #3
      Jeremy:

      Vance's numbers are true pretty much across the spectrum of small gyros.

      It's important to keep in mind the limitations of a gyro flying at those speeds, though. A typical small sport gyro has a rather draggy airframe. Such a gyro requires the LEAST power to fly level at an airspeed typically between 35 mph and 50 mph. "Dragginess" and rotor design determine where a given gyro's least-power-required speed will fall within this range.

      Below this least-power speed, the gyro requires MORE power to fly level. This leaves less reserve power to climb. At extremely slow speeds, the gyro will need wide-open throttle just to stay level, leaving zero reserve for climbing.

      Flying at speeds below the least-power speed is popularly called "flying behind the power curve." It's not especially safe at low altitudes. Even at higher altitudes, behind-the-power-curve flight can, in some cases, overheat the engine after awhile.

      Bottom line: we have an extended low-speed range available to us, as compared to a fixed-wing craft. We must use this capacity cautiously, though.

      Comment


      • #4
        At 1800 pounds all-up, free of ground effect, the A&S18A will maintain level flight down to about 26kts IAS if you advance the prop to high rpm and apply ample throttle, nose high. That's about the heaviest gyro you can see flying these days. The handling is a bit sluggish in that condition, as you might expect.

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        • #5
          One of the coolest experiences I had in the gyro was at night when the wind was about 8kt down the runway but 40kt about 1000ft AGL. Not bumpy at all, incidentally.

          Anyway, solo, cool evening, I could easily maintain 20mph into the wind - which meant I was moving 20+kt backwards! Lined up w the runway, it was surreal to see the lights recede.

          /Ed

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          • #6
            On my Hirth powered Dominator, I can maintain S&L at between 5-10 mph at about 65-75% power. That is about 720# all up and a 27' Dragonwings rotor.
            At Bensen Days, I will slow her to about 15mph IAS and trim her out and just enjoy the view from 1000' agl, and just hang around for a while. there are those that have tried to hang with me, and can't fly that slow.
            David McCutchen
            615-390-2228
            Bensen B7m, 90 hp Mac
            Dominator Tandem, 100 hp Hirth
            Kolb Mark III Classic, 80 hp Verner
            Certified - Advanced Master Beef Producer
            EAA Member #0511805
            PRA Member #28866
            PRA Chapter 16 Member
            Secretary & Treasure - PRA Chapter 16
            President / Sylvia - Yellow Creek Volunteer Fire Dept.
            Chairmen - Dickson County Veteran's Day Committee
            Volunteer - Dickson County Airport Aviation Day Committee
            2 busy 2 No!

            Comment


            • #7
              It's possible to set up a gyro so that it will fly, and even climb a bit, at under 20. Extremely flat prop pitch will do it. The engine will over-rev at about 30 mph, though, and in general it will be a nearly useless aircraft I flew a friend's Dominator once with a grossly mis-adjusted prop of this sort. The way it levitated at 10 mph was -- er -- interesting. And I was very happy to get around the pattern once and get back on the ground in one piece.

              Comment


              • #8
                The prop is not under-pitched. Actually, it is pitched so at full throttle in high speed flight the engine turns up to about 6250 rpm. redline is 6500 rpm.
                In static or climb, engine rpm only comes up to about 6000 rpm.
                I have not measured my thrust, but it should be healthy with the 74" three blade Warp drive that I am pushing.
                David McCutchen
                615-390-2228
                Bensen B7m, 90 hp Mac
                Dominator Tandem, 100 hp Hirth
                Kolb Mark III Classic, 80 hp Verner
                Certified - Advanced Master Beef Producer
                EAA Member #0511805
                PRA Member #28866
                PRA Chapter 16 Member
                Secretary & Treasure - PRA Chapter 16
                President / Sylvia - Yellow Creek Volunteer Fire Dept.
                Chairmen - Dickson County Veteran's Day Committee
                Volunteer - Dickson County Airport Aviation Day Committee
                2 busy 2 No!

                Comment

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