1/22/2021 -- 1.6 hours
The internal structure of the horizontal stabilizer started coming together with the stringer web assembly. The first step was to rivet the stringer web to the 2 inboard in-spar ribs. The angle of the forward and aft flanges of those ribs were modified previously since they are not perpendicular to the forward and aft spars like the rest of the ribs. The rivet locations were easily accessible with the pneumatic squeezer. I decided to set the factory head of the rivets on the stringer web since that piece is thinner than the stringers. The stringers were cleco'd into the assembly after the web was riveted to the ribs, and they were also riveted into place. The four outboard rivets were a little tight with the pneumatic squeezer, but I managed to squeeze those rivets by carefully spreading the angle of the ribs open slightly. The trickiest part of this step is figuring out the orientation of the stringers. It is not instantly obvious in the drawing, but it is very clear when the stringers are inserted incorrectly in the assembly.
[Pneumatic Squeezer with 2 1/2" Longeron Yoke, 1/8” Cupped Squeezer Set, and 1/4" Flat Squeezer Set]