Riveted the E-1008A ribs to the lower left and upper right skin. This part was a bit confusing because I was having trouble visualizing the rib orientation on each side. Turns out the larger E-1008B ribs is supposed to be riveted to the top left skin and the bottom right skin. It took a while for me to realize that I had riveted the E-1008B ribs to the right rear spar incorrectly. I finally partially assembled the left and right elevators side by side (without clekos) to figure that out. Once I correctly identified the error it took me only 10 minutes to drill out the rivets holding the ribs to the rear spar and re-rivet them together in the proper orientation.
I took some time to drill out the proud rivets on the tip rib counterbalance skin and reinstalled them properly. No more proud rivets. I gained a lot of confidence drilling out the C/S rivets and I'm going to document my technique on a separate lessons learned entry.
E-1008A ribs and trim reinforcement doubler back riveted onto the LH lower skin.
Oops! Larger E-1008B ribs oriented wrong. The should be attached to the lower surface.
