The Bottom Aft Skin was placed on the rib skeleton. The rear of the skin was aligned to the Rear spar and clamped in place. The rear spar was drilled and cleco'd. The holes were then drilled in the ribs working from the rear spar to the main spar. The holes were cleco'd as they were drilled. Last, the Main spar was pilot drilled with a #30 drill bit.
