Brief Description: Countersink Coupler for Nutplates, etc.
When I took the leading edge off and examined the inboard rib to see how the holes came out I was a little bummed. This rib was not prepunched. As it turned out, the holes were drilled very close to the web, making it virtually impossible to dimple. I was worried about this but it didn't really turn out to be a problem. Since there are 3 pieces involved here - the skin, the coupler plate, and finally the rib, I ended up dimpling the skin, countersinking the coupler plate, and not doing anything with the rib. It may be a little difficult to buck these rivets but shouldn't be too bad since I will be able to fit the bucking bar right up against the web of the rib. I was a little amazed at how much work went into the coupler plate. There were many holes to countersink (rivet holes) and dimple (screw holes) for the nutplates on the fuel tank side and many more holes to countersink on the leading edge side so I wouldn't have to attempt to dimple the rib that had the holes drilled too close to the web. It all turned out fine in the end.
Inboard leading edge rib - Holes on flange a little close to web
Countersinking the leading edge/tank coupler plate
