Inspection of drilling. The inspection revealed 3 questionable holes in the rear spar 75T1-3 of the Horizontal Stabilizer assembly. These holes were misdrilled because the pilot holes of the rear spar 75T1-2 and the skin 75T4-1 were misaligned on assembly producing a hole in the rear spar with a irregular, oval shape. I emailed Zenith Aircraft Engineering for their assistance. The direction that came back from Caleb Gephart of Zenith Aircraft was to compare the hole width with the Construction Standards, then open the A4 Rivet holes that don't comply with the Construction Standards to a rivet size A5.
