Place the Wd-641 Roll Bar on the fuselage as shown on DWG 42 View C-C. The Roll Bar fit within 1/16" to specs in plans, therefore, no adjustment was necessary. Clamp the Roll Bar in position as per DWG 42 and using a #40 bit back drill the 4 holes up from the bottom using the per-drilled pilot holes in F-721B as guides.
