Attached fore and aft ribs 1-12 to the left Spar and riveted on the rear spar. The drawing calls out some precautions to take to make sure the ribs are located correctly in relation to the top of the spar, but since I'm building a kit, and everything is pre-drilled, I didn't make a ton of measurements. I simply lined up all the predrilled parts and everything seemed to come out just fine. I've really been impressed in how well everything aligns.
Still have to install the root rib, and then thoroughly check everything again before I can rivet the skins on,
