I drilled the angle clip to the stiffener on the bench. You have to hold one side flush with the angle and stiffener. If you get the wrong side flush, it is a screw up. I screwed up TWICE so check twice before drilling. With the fuselage upside down and the drawing right side up, I'm make mental errors and it is costing me $6 bucks for a new F-719 R.
After the clip and stiffener are drilled you can put them in place and drill the side skin, just like we did for the auxillary longerons using a centerline on the angle to make it lined up right and to ensure good edge margins.
Then I marked the location for the hole through the angle and firewall stiffener. This is the hole you don't drill first. I used my angle drill and it came out fine.
