Brief Description: Drill & cleco the stabilizer ribs to the front spa
I marked 10 mm edge lines on the ribs, all around. Then I aligned the ribs with the pilot holes in the front spar, drilled and clecoed.
I put the assembly (front spar down) on rails for cleco clearance, and clamped the the rear spar to the ribs. Then I set the assembly on its side for drilling and clecoing. I had to put a 2x4 under the bottom rails to provide sufficient clearance for the clamps.