Brief Description: Drill & cleco rear ribs to spar
1. After carefully adjusting rear ribs so that they are perpendicular to the spar, drill & cleco 3/32". I found that the vise-grip C-clamp worked very well for holding the rib flange up close to the spar while drilling. See Fig. 1.
2. I laid a 4' straight-edge across the tops of the ribs before drilling to make sure that they were aligned vertically.
3. As noted earlier, all of the rear ribs required additional joggle so that they would not bulge the spar cap angles up or down when pushed up to the spar.