Installed elevator hinge, riveted top horizontal stabilizer skin.

After we riveted, we noticed two bumps in the skin where the Front Spar Attachment Bracket (C75T2-1) and Front Spar Attachment Doubler (C75T2-2) are on the top skin. I am now concerned about that creating a stress riser. I went back through the manual and did not find anywhere that stated the attachment should be trimmed or filed to avoid this. We will wait and talk to the factory on Monday before doing anything to correct that.

Thoughts I have had so far are anything from doing nothing, drilling out a small circle around the stress riser to relieve the stress, to replacing the entire skin.

I started an online discussion in the Zenith Aircraft Builders page on Facebook, Our First Problem?.