Brief Description: Marking up the F681 for drilling.
This F681 joins the front spar of the vertical stabilizer to the front spar of the horizontal stabilizer. Not all builders build the empennage exactly to plans and therefore, there are subtle differences to how the two spars meet each other. In my case I had to trim the forward spar of the vertical stabilizer to bring it into plan dimensions for mounting. The instructions reflect this possibility and allow for adding a spacer to bring the joint into perfect alignment with the horizontal spar. I needed to add a 1/4 inch spacer forward of the F681, between the F681 and the forward spar of the stabilzer to get the correct fit. I also read there were cracking issues at this joint due to the torsion forces at play there. So, AntiSplat Aero offered a stainless steel reinforcement for this location and I show it below. It is the answer to stiffen this area with lightweight steel. You will see the attachment when I finish drilling and installing.
1/4 inch spacer at top. Steel reinforcement pieces below.
Bottom of steel reinforcements get match drilled to existing spar bolt holes.
Reinforcement has large holes that allow for AD4 rivets to nest inside of. Small holes for new bolts.
