ROOT REAR RIB, ROOT NOSE RIB, REAR UPPER STRUT FITTING,

I/B & O/B REAR CHANNEL, REAR CHANNEL DOUBLER ASSEMBLY

A center line was drawn on the rear flange of the Root Nose Rib.

With a #20 drill bits, a hole was drilled on the rear flange of the Root Nose Rib.

The Root Nose Rib was drilled and cleco.

The holes in the Rear Upper Strut Fitting and the single hole in the Rear Channel Doubler

and I/B Rear Channel was expanded with a #20 drill bit and cleco.