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Yaw string

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  • Yaw string

    I'm curious, do all production gyro's come with a yaw string ?
    Jay Gunderson

    "Wise men talk because they have something to say;
    fools talk because they have to say something."


  • #2
    TitaniumExplorers do! ....I like it as I am very visual & it is right out there in center-vision on the radio antenna ... reminding me when I get out of co-rdinated flight! ... reacting to "wind-on-my shoulder" ... or wind noise in the passengers mic ... is slower than the sight pic!
    Chris T.
    3Rs - Rotors rock & rule!

    "Blessed are the flexible for they shall not be bent out of shape." Buck B.

    Time flies if you can but only the slowest.

    PRA# 4212
    EAA# 1126845


    • #3
      Well if they don't they should have,its probably the best instrument you can have on a Gyro.
      Best Regards,
      Eddie Sigman,Polvadera,nm
      (575) 835-4921


      • #4
        Back in my tech-rep days, I noticed that nearly all F-86s (Sabrejets) had a yaw string attached to the nose hatch with a black stripe painted underneath. Pilots said they could squeeze out a few more knots of airspeed using the yaw string for coordination rather than needle and ball.


        • #5
          Since John has not seen this post....Yaw Mon!, I think they do.
          "at 55 I did'nt GO over the hill, I FLEW over it"

          Sport Pilot Powered Parachute
          Sport Pilot Gyro

          Lifelong Member of the Dominator Fanclub.

          Currently building an Aviomania GS2 powered by a Honda 130 HP Engine. Expected completion about two weeks. Wait a minute....I finished it!


          • #6
            Yes, most gyros have a Yaw-String.
            I am going to guess that you are Not asking the question because you are doing a poll as marketing research because you plan to fund your retirement selling Yaw-Strings.

            What is the Real Question?


            • #7
              that cracked me up ....... uncle


              • #8
                Please define "production gyro". My kit didn't come with a yaw string... all it took was a piece of yarn, though.


                • #9
                  IDK, but after x hundred hours in sailplanes, I'm not a huge fan of them, depending on the aircraft. Why? Suppose one is making a fairly high-rate turn that would result in a 300' diameter circle, meaning the CG (or center of lift which isn't much different for a FW). If the turn is perfectly coordinated and the yaw string is taped above the CG, it remains perfectly aligned with the fuselage and makes a tangent to that 300' circle. But the string is stuck out front of CG and on a circle of larger diameter. Air motion is drawn from inside to outside during the turn, causing the string to tilt toward the outside of the turn. The only way it could be straight would be if the fuselage itself curved to form an arc matching the arc of the turn!

                  I know, it's a hard pill to swallow. Take a yardstick, tape a piece of wrapping ribbon to the end. Spin around with it - the ribbon trails straight back. Now make a T of two yardsticks, taping ribbon to the front and back of one, which forms now a "fuselage". Now spin it around. The ribbons trail to the outside.

                  Does it matter? Not when the turn radius is large, like on an F-86 mentioned above. It matters less when the string is not stuck out front a goodly distance too. On things that "turn on a dime", that is sailplanes (and presumably gyroplanes) it can matter. On the ASK-21 tandem two-seater I used to fly, oh yes. At thermalling speeds ~50 mph, banked steeply, it insisted that you apply ever more bottom rudder. Bad news and it almost killed me once in the Salto when years of "training" in keeping the yaw string straight kicked in at the wrong time.

                  Turning left fairly steeply on base to final @ ~250' AGL (normal for high-perfomance sailplanes), I glanced at the string pointed at my right shoulder. Without thinking, I straightened it with a little bottom rudder. The left wing went down, I applied opposite aileron, then it went bye-bye. I had airspeed, the yaw string was centered - my brain took a couple of seconds to figure it out. SPIN! The Salto is fully aerobatic and I'd spun it intentionally many many times. It is a rotten spinner, or better said, a rotten spin recoverer. The Citabria pops right out of a spin with opposite rudder and a relaxation of back pressure. Three turns into my first one turn spin with the Salto, I discovered, probably due to the V-tail, the Salto takes full opposite rudder and full forward stick, upon which for a full 3/8 - 1/2 of a turn, it continues spinning merrily down. Anyway a half turn into a spin, now < 200' AGL, I closed the spoilers, slammed in rudder and full forward stick and waited the longest 3 or 4 seconds of my life. I thought I was going to die. Rotation hadn't completely stopped but airspeed was increasing. Pull too hard and it stalls, not hard enough and I stick it into the ground. By the time I was level, I could clearly see the silks of tassels on the corn, maybe 20-30 feet below. Magically, the runway was directly ahead and with ground effect, L/D of 30:1 and 85 kts, after a brief climb over wires, I made an otherwise normal landing. I was shaking so badly afterwards, I couldn't walk for several minutes.

                  No, I don't care much for yaw strings. Though at least a gyro can't spin!


                  • #10
                    The yaw string indicates how well the longitudinal axis of a flying machine is aligned with the relative wind; nothing more, nothing less.

                    A gyro can make a zero radius turn at zero translational airspeed; -prop blast over a deflected rudder- but who worries about the yaw string in that situation?


                    • #11
                      Jeff your talking fixedwing,as Chuck has said, Gyros are a different breed of cat,no comparison at all except they both fly in the air!
                      Best Regards,
                      Eddie Sigman,Polvadera,nm
                      (575) 835-4921