Wing rib 8 top skin mismatch

If the wing rib gussets WG-BKT-015 are clecoed to the reinforcing caps WG-CAP-301 and 302 place the holes in the front four flanges on the topside of rib 8 mismatch the top root skin 4 holes to an increasing degree, from 1mm at the 4th rib back from the front, up to 3mm at the front most rib 8 flange.

These ribs cannot be forced due to the stiffening effect of the wing rib gussets and the rib reinforcing channel. One option is to introduce a crease into rib 8 that runs from the front along a line running just above the top three rivets of the rib reinforcing channel. It is true that the frontmost flange is about 1mm too high, indicating a slightly incorrect bend location. Apart from that the chances of achieving a fix without having to open out existing bends and risking cracking is not felt to be too good. There is visual evidence of the rib 8 flanges having been hand-worked with a hammer, which has the result of the flange bends being somewhat tighter then what I would want if I were to open the bend slightly (which is inevitable if one is going to introduce a crease, to move the flange laterally, then to restore the flange to the plane of the skin.

The other approach is to cleco the top flanges to the skin, which is easily achieved if one does not cleco the gussets to the reinforcing cap. A mismatch of up to 3mm results, as does a need to introduce a shim between the rib and the spar attachment angle.

There are two ways to achieve this 1) re-manufacture the wing rib gussets with altered hole positions, or 2) re-manufacture the reinforcing caps with altered hole positions. The reinforcing caps are simpler, unlike the gussets they have not been rivetted. The reinforcing caps have also been anodized, which makes them slightly more brittle than fresh 6061-T6. Therefore the latter path is being taken, using 1.6mm 6061-T6. The bends are also easier to implement.

This option also allows the slightly "bad" top root skin 4 to be used, which would otherwise result in an even worse mismatch. However the mismatch with the connection to the tip skin 5 would persist.