Brief Description: Lower Fuselage Skin to Wing Skin Screws
The F-776 bottom fuselage skin is attached to the lower wing skin using AN509-8R8 screws. Earlier I had marked the lower wing skins with a reference line 3" outboard from the screw locations and and a longitude line from each hole location. I did this before the wings were installed. Now all I had to do was measure back 3" along each line and mark the location where I would have to drill through the bottom fuselage skin. Ten holes on each side was required and I started with a #40 drill. The lower wing skin had already been riveted with AN426AD3 rivets being a quick build. As I drilled each hole, I had to also drill through the AN426AD3 rivets. I clecoed each hole as I drilled. Next I enlarged each hole to #19 for the #8 screw. I repeated the process for the right wing. Later when I have the wings removed, I will debur all the holes, dimple the fuselage lower skin and install the K1100-08 platenuts.