I had difficulty with the spoilers about 18 years ago. My recollection is that I identified the interference points and dressed the trailing edge of the spoilers with a file after trying some paraffin.They were binding and it took a hard yank to pop them open. Both are apparently warped or distorted. The trailing edge of both is now flush with the wing skin outboard and a few mm below grade at the inboard ends. I wonder if air loads--positive flex or deflection of the wings in flight--might contribute to the binding.
Michael Stockhill Polson, MT On Wed, May 17, 2023, 8:25 PM Kristin Nowell <kristinnow...@gmail.com> wrote: > thanks ian, that is quite generous. I'll keep trying, let you know where I > end up. > I hear you Rob, and because you shared the fear. I check airbrake function > as per your instructions after every assembly, and do a slightly less > complete check ( Kristin at controls, I hold brake shut, call and respond. > Kristin then pulls full brake, I feel around the perimeter, then grab the > brake and hold tight while Kristin moves lever and calls "resistance". I > release, she closes, and I verify full closure) before each flight. > I went to fuel up one frosty morning and the airbrakes had frozen shut - > very disturbing sensation to pull the handle and get no movement at all !!! > Any opinion Nigel ? Thickness of airbrake ? Adjust turnbuckle for more > closure tension on cable ? If I recall correctly, the adjustment turnbuckle > is right there behind the keel inspection panel at the copilot left hip. > Any specs for the airbrake/box closure spring ? > > Cheers > > On Sun, May 14, 2023 at 6:17 PM Rob Thompson <amessageto...@gmail.com> > wrote: > >> *Question:* When you push the raised section down, does it go correctly >> into position? I once fixed a similar problem but it was caused by an >> improper fit underneath the spoiler stopping it going all the way down. >> >> *WARNING!!! *The spoilers can jam *VERY* easily after an adjustment and >> you will only find out about it when the air is flowing over them, most >> likely when you are on finals which happened to me and I got some >> sideslipping practice. >> To test them, get one, preferably two people to spread their fingertips >> along the top of each spoiler and use friction to push the spoiler >> backwards and lightly downwards. Effectively simulating the airflow. If the >> fit is incorrect they will jam! The reason for this is that in the very >> first bit of normal movement of the spoiler is backwards not just upwards. >> It is a good idea to check this at least at every annual inspection. >> >> Rob >> >> Rob Thompson >> 0429 493 828 >> >> >> >> On Mon, May 15, 2023 at 3:33 AM Tom Preisser <t...@ecoflight.com> wrote: >> >>> I have a slightly warped airbrake which sits properly throughout 85% of >>> its span, but then proud of the surface for the outboard 15%. >>> Only five mm high at the very end, but it bothers me. Three fixes come >>> to mind - >>> I could grind it thinner, bringing it down to the surface of the wing. >>> I could mount another closure spring at that end. Even a little closure >>> force is sufficient. >>> I could weight it into form as it sits in the hot sun this summer, maybe >>> even paint a black topcoat, and see what it gets (?). >>> >>> Two questions; >>> Does anyone have a better idea ? >>> Has anyone replaced their closure springs ? I did on both wings, and it >>> isn't perfect - the common springs from the hardware store are close to >>> yield when airbrake is fully open, and don't provide much closure force >>> when airbrake is shut, i.e. if I flip a wing upper surface down the >>> airbrake will hang open just a little. Perhaps >>> the much more powerful airbrake closure spring isn't adjusted properly >>> to compensate for wear at the junction of the ball and pin drive on the >>> wings and the torque drive tube slots in the airbrake drive tube in the >>> wing root. >>> Any and all thoughts would be much appreciated. >>> >>> >>> >>>
