AN3 Bolts and nut plates

I am I the process of attaching the control horns to the spar of the HS. 4 bolts for each control horn. 2 of the bolts will not engage the nut plates. All they do is spin and make a snapping noise but do not screw it like it is engaging and then slips. The other six seem to be fine. Changing bolts did not seem to help.

If you have any ideas please let me know what you think.

Don

One possibility is that two of the holes have the incorrect size nutplate installed.
Compare the view looking through the holes, to one of the holes where the bolt does go in, and see if it looks the same.

Another possibility is that you have a bad nutplate. There are a few, not many, but they exist. Worth checking just because of the hassle factor.

Dave

I'm guessing you mistook a -4 nutplate for a -3. Easy to do. Highly unlikely you would have TWO bad nutplates.

Another possibility is the hole in the AL is not lined up with the nut plate threads.

Problem solved. I spoke with Van's and they reccommended drilling out nut plates and replace. Turns out that they were infact the wrong size. Van's suggested using a wire and tying a knot in it so the nut plate can rest against it as it is pulled up against the spar. The rivets were replaced with pulled CR rivets at Van's suggestion. After about two hours of work I got it and it is all put back together. Whew!!!

Thanks for all the advice. I will be sizing all my nut plates before installaton

dsm8 said:

. . . I will be sizing all my nut plates before installaton

Click to expand...

Me too. A lesson learned by all, sooner or later. Good you got it all worked out without too much pain.