Brief Description: Countersink the Left Spar Flange
Set up the #30 countersink and tested on scrap. Followed directions in plans to start slowly and was able to get good countersinks on the holes for the mounting screws. Cut down a #8 screw to check the countersinks. Used a magnet to hep get the resulting very small screw in and out of the countersinks. Made the depth approximately .007 past flush as per the updated Section 5 in the manual. The nutplates acted as a guide to center the countersink in the hole. This resulted in the nose of the countersink slightly distorting the first couple of threads in the nutplate. I tested several with a #8 screw and the screw started with no problem in each test.
