Drilled upper and lower inboard and outboard skin stiffners. Had to pull the lower skins to get access to the upper stiffners and marked all the positions of the stiffners. I did not add the additional rivet holes in the inboard stiffners and I have to add the rivet line for the second rivet line on the outboard rib at station 69.0. Piched that up from DJ Merril's builders blog. That will be for next sesion or I will continue work on the pitot tube.