Posted 5 Jul 2020 I have an Avid Speedwing. In order to keep the plane flying level, I have to use a lot of uptrim. This has apparently been a problem since day one, as the original builder had a length of PVC pipe with a big lead slug travelling inside it that could be moved front to back by means of a rope and pulley system.The weights and balances are where they should be. The ailerons don't help.My solution would be to lower the leading edge of the horiz stab, but to do so I would have to notch the leading edge to clear the diagonals in the fuselage rear. I have a spare horiz stab to play with, so I can do that. I can also make it adjustable within limits. I know I will also have to fabricate new "V" struts.If I were building, I would modify the fuselage rear to incorporate a jack screw mechanism to raise and lower the leading edge, but right now , I don't want to be cutting and welding on the fuselage. Such a mechanism is used on early Pipers, and my brother's kitfox has a similar arrangement.Any body have a better idea?Bob McCaa A Share this post Link to post Share on other sites
Posted 5 Jul 2020 I should look at my Avid before I comment, but maybe it's possible to raise the back of the horizontal stabilizer a little, and lower the front a little rather then just trying to do it all on the front of the stabilizer. I know the Kitfox has 3 or 4 bolt holes on the front of the stabilizer for adjustment, and they use a heim joint rod end on the V struts for adjustment. JImChuk Share this post Link to post Share on other sites
Posted 5 Jul 2020 Thanks JIm, but the clearances are much too close. Raising the trailing edge would put the elevator bellcrank against the tailpost, and besides there is a top crossmsmber in the way. The very best solution would be to redesign the mounts a la Kitfox, but that's a major undertaking, and I don't know that the Avid stabilizer is sturdy enough to operate with a single point support strut.My overall evaluation is that the leading edge of the speedwing should be about 1" to 1 1/2 higher than it is to compensate for the flat-bottom airfoil, but that WOULD be a major undertaking.I have seen the four hole arrangement in the KFs, and brother Tom's KF 4 and KF7 actually has a jackscrew on the leading edge. Share this post Link to post Share on other sites
