Continued installing the root doubler today. After the upper aft skin I now needed to drill the forward skin and I thought about how to do this for a while but in the end the solution is fairly easy. There are two holes that goes through the aft and forward skin (and spar), which were drilled already when doing the aft part of the doubler with the upper aft skin as template. This was enough to allow me to remove the forwrd skin, cleco the doubler to the forward skin in those 2 holes, clamp the remainder of the doubler in place and continue drilling. With the lower aft skin I'll do the exact same thing as the forward skin and lower skin also share an overlapping hole.
