I worked on the R-903 Top Rib and R-912 Counterbalance Rib. Both ribs were clecoed to the rudder spar and the attach holes were final drilled #30.
The counterbalance rib also has a counterweight that will get bolted on later in the rudder assembly. I final drilled #12 the forward attach hole for the counterweight. I clecoed the counterwight to the counterbalance rib and match drilled #12 the aft hole.
