REAR FUSELAGE SKIN  ( LEFT AND RIGHT SIDE )

With a #20 drill bit, the Skin was drilled through the Torque Tube.

The First L angle was drilled with a #20 drill bit from front until forward bottom fuselage skin.

The Skin was debured. Then, the Longeron was arranged on top of the left side skin

With a #40 drill bit, the Longeron was drilled through the Side Skin.