The first work on the wings! I prepared both main spars to start with the nutplates installation. I final drilled the #40 holes and attached all the nutplates to the spar. Quite easy but repetitive work. Then I used the microstop machine countersinking tool with the #30 countersinker to let it center in the nutplate and countersinked the first part of the main spar holes. I messed up the first hole, because I used a wrong dimple guide – for a #10 screw instead of a #8 screw! I will insert a dimpled aluminum “homemade” washer and glue it in with scotch weld. According to my advisor, this will work out.