RV-12 Wing Wobble

Hey guys, I just discovered that both wings on my RV-12 can be moved fore and aft in relation to the fuselage by a small amount. This is with both spar pins installed. Not sure that I was actually seeing movement, I had a friend grab a wing tip and wiggle it back and forth while I observed the gap between wing and fuselage. Sure enough, the gap contracted and expanded.

I don't have the wing/fuselage rubber seal installed yet and doing so will most likely eliminate this movement, but still it doesn't give me a warm fuzzy feeling. Anyone else noticed this phenomenon?

Walt Shipley

The fix...

I am pretty sure Van's makes replacement W-1207B Rear Spar Doubler Plates in at least 2 oversizes to correct this. You could call them and discuss options. It is probably impossible to design a mass produced thing like this with no tolerance at all. If no tolerance, the wings might not go on. So I suspect they all will have a bit of back and forth wobble. How much is acceptable is the question. Let us know what they say.

I think some builders have used shims in the receptacles, there have been earlier posts about this.

Replacing the W-1207B requires a number of rivets to drill off and replace including some of the pesky number 4 solids, however this would be a better fix than shims.

Tony

Walt, I had the same problem with my right wing. It would move 1/32 of an inch when wiggling wing fore and aft. Van's made me two new sub spars, W1207B-35 and W1207B-45 which are .035 and .045 larger than orginal ones. They cost $12.50 each and I used the -45 one and wing is now solid as a rock. Contact Joe Blank at Vans help desk and he should be able to help you out. The aft sub spar is very easy to replace.

good luck