Brief Description: Drill / Bolt Rear Spar to Fuselage
The next step was to position and drill the rear spar to the vertical bars on the aft deck. The manual indicated that the rear spar should be 3/16" above the aft deck in order to provide a 0 degree incidence for the horizontal stabilizer. The best way to do this was to insert a 3/16" drill bit between the rear spar and the aft deck. I initially did this but then also came across a note that said the front and rear tooling holes in the inboard HS ribs should be the same height above the aft deck as a double-check. I inserted a steel rod in the tooling holes and then measured the distance between the rod and the deck. fore and aft. The measurements were not the same using the 3/16" drill bit spacer. I ended up getting matching measurements by using a 5/32" spacer bit. Once I was sure I had 0 incidence, I clamped the rear spar to the vertical bars and then used the pre-drilled holes in the spar to match drill the vertical bars.
Front tooling holes are the same distance to the deck as the aft
Aft tooling holes are the same distance to the deck as the front
