Need help on RV-10 spar. "Question"

I have red 15 times and probably over thinking on this but. Would you explain underlined text please. If you have picture that is even better.

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Step 2: Machine Countersink the nutplate attach rivet holes in the flanges of the W-SPAR ASSY-L Spar Assembly-Left. Machine Countersink those rib to spar flange attach river holes that are in line with the nutplate attach rivet holes and are inboard of the most outboard fuel tank attach nutplate.

Thank you in advance.

On the part of the spar where the fuel tanks attach, there are extra holes that appear between the nutplates on the same lower row as the nutplates. This is what they're talking about. It's not countersunk yet in this photo but I've marked it in red. The ribs will attach here.



You can view the whole album here if that helps any: https://picasaweb.google.com/111259797666670045339/RV10WingKit#

Is it only one hole per side? and that is it? Does that hole also machine countersunk to accept the head of the rivet as well?


While i have your help I want to ask you one more question. On step 6 it asks you to rivet the nut plates for access plate. Even tough we did not match drill those holes for J-STIFFENERS I thought stiffeners would go first What am I missing.

And really thanks so much.

Aycan.

G34U said:

Is it only one hole per side? and that is it?

Click to expand...

No, there's about 7 per side.

G34U said:

Does that hole also machine countersunk to accept the head of the rivet as well?

Click to expand...

Yes - An AN426AD3 rivet will be placed in that hole.

G34U said:

While i have your help I want to ask you one more question. On step 6 it asks you to rivet the nut plates for access plate. Even tough we did not match drill those holes for J-STIFFENERS I thought stiffeners would go first What am I missing.

Click to expand...

The j-stiffeners never attach to the spar so its not necessary to match drill them to the access panels. You just use the spar as a guide to help create the j-stiffeners then you set them aside. The stiffeners end up going in the middle of the wing skin.

Brandi is correct. What is important to visualize here as that those rivets for the spar-to-rib will be underneath the fuel tank skin. So you countersink them to full depth for the rivet head, and they are just under where the fuel tank skin goes. The aftmost spar to rib holes there don't get the same treatment because they will be riveted all the way through to the skin; they actually get a deeper countersink to fit a skin dimple.

As for the stiffeners, the spar just serves as an incomplete drilling guide. The stiffeners will later be clecoed to the skins and the holes you couldn't drill due to the gaps for the inspection openings will now be match-drilled through the skin.

It is little more complicated than I thought. But I believe I understood. When I go home tonight I will check and countersink those holes for the rivet head.

I appreciate your responses.
Aycan.