I riveted the rear spar to the rear ribs. I discovered an issue with the plans. The plans called for ribs #2-12 to be riveted to the rear spar using CCP-42 rivets. This is OK for most of the ribs, but rib #9. At this rib attach location on the rear spar, there is a 1/8" doubler plate that goes over two of the rib attach holes. These two holes need to use CCP-44 rivets to grip through the added thickness of the doubler plate.
Doubler plate requiring CCP-44 rivets for two holes to attach rib #9.
