The right F-7101 and drilling the floor^3h

Since I got my replacement F-7101 parts, I started drilling them to the skins and to the longerons.

The first thing, however, was to drill the F-772 forward bottom skin to the F-704 bulkhead, which I did.

I looked at the holes in the F-776 center bottom skin and I don't like a couple of them. Mostly, it looks good, but two or three holes on one side are a bit elongated. Not too bad, but not too great either. I cannot take a good look at the F-704 flange, however, so my current decision is to wait until I take everything apart. If the F-704 is too elongated, I will consider upsizing to the -4 rivet. If the F-704 is fine, I will either leave it as-is or maybe use NAS1241AD3 rivets.

For the F-7101, I first drilled the aft holes that are shared with the auxiliary longeron. That longeron is not attached to the F-704 and can potentially bend. To drill these first few holes, I put the #31 drill bits through the skin and the auxiliary longeron (to align them), then marked the location of two holes by rotating the #31 drill bit by hand. This left enough of the mark to drill the hole with the #45 drill bit and upsize it to #31.

After that, I clecoed the part to the skin and to the longeron and drilled the remaining holes.

To finish the day, I switched to deburring the F-772 forward bottom skin as it is now fully drilled to other parts.