QB wing mistake

[xblueh2o]

Posting in the general area to get widest distribution/ideas.
I have an email in to Van's as well.

RV8, QB wings.
I was doing the initial metal work of dressing edges, rounding corners and de-burring etc. on the outboard bottom wing skin today when I found a mistake made during the construction on one of my QB wings.
In a nutshell they countersunk for, and installed a plate nut in the wrong place. Look at the furthest left holes in the spar web for the access panel



Here is another picture with the skin still correctly aligned side to side but pulled back slightly to allow a better visual understanding of the problem.



The only thing I can come up with is to remove the incorrectly placed plate nut.
Use hole #1 as is since it is correct
Use the now open hole #2 to attach the skin per its design.
Abandon and/or fill hole #3. Suggestions on rivet size would be appreciated.
Enlarge hole #4 to accept the access plate dimple and screw.
Use hole #5 for the K2000 one lug plate nut.
Drill and countersink a new hole at position #6 for the other hole in the K2000 plate nut.

I am interested to hear what Van's has to say about one more hole in the spar and the proximity of two holes that are countersunk deeply to accept access plate dimples.

Does anybody else have suggestions on other courses of action?

[KRviator]

What I'd do...

Hole 1 & 2, use to attach the wing skin per plans.
Matchdrill LHS plate nut to hole 3 and use appropriate size 426AD3/4 rivet.
Drill out hole 4 & machine countersink per plans.
Use existing hole 5 for RHS nutplate rivet.

It isn't the spar per se' only the flange so I reckon Vans will suggest something similar.

Either way, not the end of the world and a fast fix when they get back to you.

[Sid Lambert]

Your course of action sounds great. I'd probably just leave 3 empty.

[WenEng]

Drill out #2 so you can use it for the matching skin
After you drill out #4 and remove the nutplate,
Just put a short flush 8/32 (or 6/32..whatever you can fit best) screw in #3 with a locknut for a permanent fill.
Install your one lug nutplate in 4,5, and new hole 6.
I would be tempted to leave #3 open too, but a short screw/locknut would keep my eyes from always looking at an empty hole

[Bob Kuykendall]

What I'd do:

* Drill out #2 and #4 to remove the anchor nut.

* Make sure #2 is properly countersunk for a dimpled skin

* Drill #4 up to clearance size for the screw that is supposed to go into the anchor nut.

* Rivet the anchor nut in to #3 and #5 using appropriate lengths of countersunk 3/32" pop rivets such as MSC-3x.

The result would preserve the exterior locations of key rivets, and only use non-standard practice where it is just to attach an anchor nut.

Thanks, Bob K.

[xblueh2o]

Originally Posted by KRviator

Hole 1 & 2, use to attach the wing skin per plans.
Matchdrill LHS plate nut to hole 3 and use appropriate size 426AD3/4 rivet.
Drill out hole 4 & machine countersink per plans.
Use existing hole 5 for RHS nutplate rivet.

Heard back from Van's. This is pretty much what they suggested.
The next thing to look at is to confirm the K1000 plate nut will work with the existing holes. I am busy with work for the next couple weeks so it will have to wait until I get back.

[xblueh2o]

OK, back from an extended trip. Went to the hangar yesterday just to reacquaint myself with where I left off. Thinking about how to proceed and hoping the VAF brain trust can come up with some ideas.

As noted earlier, KRviator had the same solution as Van's
Hole 1 & 2, use to attach the wing skin per plans.
Matchdrill LHS plate nut to hole 3 and use appropriate size 426AD3/4 rivet.
Drill out hole 4 & machine countersink per plans.
Use existing hole 5 for RHS nutplate rivet.

My question is, how to set the rivet in hole #3? Obviously the manufactured head will be way down in the well of the incorrectly countersunk hole so a normal flush set won't work. I was thinking about it last night and thought perhaps I could use the male portion of a larger dimple die to reach down into the countersink. I'll take a look at that plan on my way home from work but wondered if anybody else had a thought on how to set this one rivet.

[bill@fusion4.net]

Fill the deep countersink with JB Weld, then re-countersink to the correct depth. The JB Weld will take the pressure of a rivet being compressed on it.

The rivet is not structural, just there to hold the nutplate in-place.

[Marc Bourget]

"It isn't the spar per se' only the flange so I reckon Vans will suggest something similar. "

For perspective only, as VANs has "ruled" on the repair. In a spar assembly using the cap-web-cap approach, the "only the flange" is a major load carrying member. The web (aided by ribs/stiffeners if present) maintains separation of the spar caps. (Yes, not relevant to this "problem" but builders benefit if the concept is understood).

Why not "fill the hole" with a "soft" rivet and shave the part remaining above the flange? I suspect a soft rivet would be superior to JB weld