Service Bulletin 16-03-28 addresses the cracking of wing aft spar web at the inboard aileron hinge bracket attach rivets. In addition, for RV-10 aircraft, there is a potential for cracking of the flange bends of the inboard aileron hinge brackets.
I currently have the bottom skins off, but I am getting ready to close up the wings, so I needed to decide if I was going to complete this service bulletin or not. The service bulletin itself states that the brackets should be inspected for cracks, and ff no cracks are detected, re-inspect at every annual condition inspection or until the modifications required by this service bulletin have been completed. It is tempting though, with the wings in the stand and the bottom skins off to just go ahead and knock out this bulletin. The reason you would not do this, is that you do have to drill a bunch of rivets out of the spar. That has a potential to screw up the holes and ultimately make things worse.
In the end I decided to move forward with SB 16-03-28. I started by taping everything off and trying to grind one of the rivet heads flush with the bracket. The thought on this was that you cannot miss the #30 hole if you are never drilling into it. While this seemed like a good idea, it took some pretty good effort to knock out the rivet after the head was ground off (the nice part about this is that you end up trashing the previous brackets, so you can grind into them all you want as long as you don't hit the spar)
After the first rivet removal in that technique I decided to go back to the tried and true method of just drilling out the rivet heads, breaking them off, and then punching the rest of the rivet out of the hole. I did get a little over ambitious with the grinder and touched one of the rivets that did not need to come out. I later drilled that out and replaced it.
With the heads broken off all of the rivets and a #40 drilled about half way into the rivet, the whole bracket pops off.
While this makes it look like I jacked up all of the holes, the dark shaded region is just sharpie from the original fit up. I was able to get everything drilled out without the drill bit ever touching the spar.
I forgot to take a photo with the bottom doublers in place, but I would definitely recommend going for the service bulletin if you are still sitting in the wing stands with the bottom skins off. This was an easy one.
