I started assembling the rear spar. I was hoping to use my pneumatic squeezer, but it couldn't generate enough force to start setting the rivets at this end even at full pressure. So I ended up using my Main Squeeze hand squeezer.

Here is the rear spar fully assembled. I put the manufactured heads on the spar side, not the doubler side.

I got the rear spar clecoed up to the aft end of the main ribs and noticed that the five holes for the outboard aileron attach bracket seem awfully close to the edge of the aft flange of the outboard most main rib.

Inserting rivets proves that this could create a problem with clearance for the rivet set.

So I took the rib out and made a series of five reliefs in the rib flange.