Brief Description: Countersunk flanges for access plates
I researched some builder websites and reread Van's instructions before countersinking the spar flange for the inspection access plates. These platenuts are installed very close to the edge of the flange so care must be taken to get enough depth to seat the access plate dimple but not so much depth that the countersink cutter gets to the flange edge.
I began by match drilling the inspection plates to the flange with a #27 drill and then dimpling the plates with a #6 screw die. After making a nutplate drilling jig to accept a #30 countersink cutter, I adjusted the countersink cage using some scrap aluminum. Once sure of the depth, I clecoed the jig in place and began machine countersinking (my jig accomodates all four nutplates). The plates were test fitted with good results.
