Earlier with the wings mounted to the fusalage, I had drilled the screw holes in the bottom fusalage skin that is screwed to the bottom of the wing. My next task was to install the 10 K1100-08 platenuts on each wing fuel tank lower rib flange. First I deburred the holes on the fusalge lower skin and then the holes on each wing. The AN509 screw is tappered so I need to countersink both the holes in the fusalage and the holes in the wing. I did this using my pneumatic squeezer. The platenuts are held in place with AN426AD3-3.5 rivets. I shortened one #8 screw and used the dimpled hole to center and the screw to hold the platenut in place while I drilled the #40 holes. Once I had all the rivet holes drilled in both wings, I deburred the holes. I setup my pneumatic squeezer and used the shortened screw to hold the platenuts in place and set all the rivets.
