For those of us who tie down our aircraft outdoors and in the wind (whether continuously or just during an occasional cross country trip), it's important to lock the control surfaces so they don't "flap" unnecessarily in the wind. At the Sebring Expo earlier this year, Juan's Zodiac was fitted with these effective control stops:

Above, two tennis balls are joined by a bungee rope, and keep the ailerons from flapping.

Since this was a show, a tennis ball with a slice in it served as a visible yet soft guard for the wing tips, to prevent folks walking into them:

Two small pieces of plywood (painted bright red) and tied together with more bungee rope keep the elevator secure at each end of the elevator.

These control locks are easy and inexpensive to make, and easy to install and remove between flights.

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Comment by Tim Garrett on May 18, 2009 at 5:44pm
Excellent design! KISS in action! I've got to make a trip to Bass Pro to pick up the stuff...
Comment by Bob Simmons on May 17, 2009 at 6:17pm
Then maybe you can help Jay with his problem since they don't work for him.
Comment by Juan Vega on May 17, 2009 at 5:16pm
Check out that SEXY PLANE!! 427JV is lookin HOT!! The balls and the elevator plywood stops work just fine after one year and many storms. DOnt over engineer that damned things.

Juan Vega
Comment by Bob Simmons on May 13, 2009 at 12:07pm
Oh, and just personally, I wouldn't trust any of these as a long term solution. They could easily loosen over time. I'd probably want something that wrapped completely around the front of the wing for long term tiedown. Not all of that wrapped material would need to be bungee. You could just use rope or a strap with just enough bungee tied on to create the desired tension. But again, that's just me.
Comment by Bob Simmons on May 13, 2009 at 11:59am
Jay, how about a small piece of plywood (long enough to be over the rib) with a scrap piece of carpet attached? You could glue the carpet to the plywood or wrap it around the top and staple it. If you get the bungee length right, you could slide it up or down the aileron to get the amount of tension you desire. Just a thought.

The only problem I can imagine is if the plywood manages to twist around so that it is no longer over the rib. A circular piece? I don't know. How far is the rib from the edge of the aileron?
Comment by Jay Maynard on May 13, 2009 at 8:47am
I tried the tennis ball aileron locks, and found that they tended to be either ineffective (if the bungee wasn't tightened enough) or bent the aileron and flap skins at the edge (since the ribs aren't at the edges of the structure). How do you avoid these problems?
Comment by Jim Smith on May 13, 2009 at 6:51am
Note the actually tie down stakes. I found these at Bass Pro Shop in the camping department. They are heavy duty tent tie downs that auger into the ground. They are about a foot long and are very light weight. They come six to a box so two pilots can split a box. Cost was about $20. Great idea on the control locks.

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