If you’ve done it before you might just dread it again – pulling Vans black corrugated conduit through the wings. Plans specify that the holes be 3/4″. The conduit is .81 OD. You might not think .06″ is a lot but trying to pull it through 4 ribs simultaneously at the base of the wing (under the wing-walk) is tough. I elected to enlarge those holes from 6/8″ to 7/8″ before pulling the conduit.
You will need a drill extension for this and will probably have to grind down the shank of the uni bit to get it to fit the extension. You will also need a right-angle drill. I made a drill template for where the hole should be and used it on every rib for hole positioning. If you are building your wings you should drill these holes before you assemble the wing.
