Machine countersunk the following fuselage components:
Lower longerons Auxiliary longerons Landing gear box plates Seat back support plates Center section side plates Cockpit rail spacers
The pre-punched #19 holes in the cockpit rail spacers were slightly misaligned relative to the seat back support, so we Cleco’d it in position and used the holes in the seatback to guide the countersink pilot.
Machine countersunk parts
Countersinking cockpit rail spacers using seatback as a guide