Match-drilling and drilling HS-404 and HS-405 ribs to skin and rear spar. I made a mistake on HS-404 by drilling the holes out of the sequence from the manual. As a result, the rib wasn't pushed fully back against the front spar, and so there was a gap. Builder support said I could use a shim, but due to a subsequent, bigger error I made, I elected to replace the rib.
