I started the tail kit today, having picked it up at the factory when I went to do the rudder workshop this past weekend.

First, pieces were inventoried: everything is present in stated quantities.

I started by labeling the horizontal stab front spar with "top" and "fwd/aft," and then placed it on wood strips with the aft side up (this puts the lightening hole flange down).

Next, I found the centerline of the spar and marked it with a vertical line on the aft surface. The lightening hole is seen to be centered in the spar.

Next, I found and marked vertical lines at 160 mm on either side of the spar centerline and a third line 60 mm to the pax side of the spar.

Then I test fitted the upper and lower doubler, found and marked their centerlines, and confirmed that the doubler centerlines match the spar centerlines, as they should, since all three pieces are 1220 mm long.

Then I drew rivet lines on the lower flange of the upper doubler and the upper flange of the lower doubler, making sure that the line was in the center of the flange and at least 10 mm from the edge of the flange.

Then I laid out rivet positions on the flanges of the upper and lower doublers on the lines I just made, starting in the center of the flange and working my way towards the ends, pitch 40, keeping in mind that the two rivet holes at the ends of the doublers should be 30 mm from the edge and 50 mm from the edge, respectively.

I found that the hole which is supposed to be 50 mm from the edge turns out that way automatically if you simply pitch the rivets 40 mm starting at the center of the doubler. Another rivet would fit at pitch 40, but that would put it 10 mm away from the edge, and it's supposed to be 30 mm, not 10 mm.

Actually, I think later we're going to rivet an ell angle to the end of the spar, and a rivet will end up at 10 mm from the end of the doubler anyway, right exactly where a rivet would have gone if we just continued to pitch 40 all the way to the ends of the doubler. So no big deal either way--as long as we do have a rivet hole 30 mm from the end, which is a spot where one would not be if we just pitched 40 mm all the way from the centerline.

Then I clamped the lower doubler to the spar and started drilling. I used a #40 drill bit and the silver clecos, drilling and clecoing the centerline rivet first, then drilling and clecoing the far left and far right hole (that is, the one which is 30 mm from the ends of the doubler).

Then I drilled and clecoed holes about halfway between the centerline and far left (and far right) holes and clecoed those. This gave me five drilled and clecoed holes about equally spaced out along the 1220 mm length of the spar and doubler.

Then I drilled out all the holes in between for a total of 31 holes in the lower doubler that continue on through the spar.

That was all I had time for today. I took apart the pieces, cleaned up, swept up, and put away. Total time today: 45 minutes.

Check back soon for updates.