Started on conduit holes in left wing. Used the poster board template which I made earlier to mark and drill #40 pilot holes in the ribs. Then I opened them up to ¼” followed by a ¾” step drill. The 3 wing walk ribs and the 2 ribs next to them required a different process. After using a long #40 drill to go thru all of the wing walk ribs, I next used a step drill to open the first hole to ½”, followed by a ¾” step drill. I added a 12” extension and switched back to the ½” for the next hole, followed again by the ¾” step drill. Kept swapping step drills and adding extensions until I had all of the inboard ribs drilled to accept the conduit.
