I riveted the left and right step supports to the ribs and then checked the tail cone assembly for straightness with a laser line level. I leveled the tail cone to the floor, but the floor isn't quite level either so estimated the bubble position on the laser line level and and shot a line centered on the bottom ribs. The top of ribs appeared to be canted toword the left side of the aircraft by a few millimeters. I may be able to take this out when I rivet the top skin in place.
