1. Nose Rib No. 1 (NR#1) cut down 11-mm at the base, per confirmation from Roger Dubbert of my inquiry to Zenair Tech support—Image 1.
2. Beveled to 12° ends 20-mm flange of ZU-1-4 for NR#1 to provide clearance to fit inside flanges of NR#1—Image 1.
3. Drilled 3/32" pilot holes down center of both flanges of ZU-1-4 for NR#1—Image 1.
4. Drilled #20 holes in ZU-1-3 for NR#2, through the existing holes in the spar web for the original 6-W-3-9 nose rib angle. Clecoed ZU-1-3 to spar—Image 2.
5. Trimmed 3-mm from base of NR#2. Before trimming, I checked that 3-mm was adequate by clamping NR#2 to ZU-1-3. The bend radius pushes NR#2 outward, so that the trim must be greater than the 0.040” thickness of ZU-1-3—Image 1.
