Vertical Stabalizer mounting, DWG 27A

This is for my 7a slider
I'm reading ahead and missing something.
The manual talks about drilling the four bottom holes in the Vertical Stabilizer rear spar #30. I looked at DWG 27A. There is no dimensions to locate these four holes.
They correspond to four holes in the F-712E tie down bar but the bar is not yet installed and it is on the forward side of the bulkhead.
The manual mentions prepping the tie down bar by drilling the four holes that attach it to the F-712 bulkhead.
So how do you locate the other four holes common to the tie down, bulkhead and vertical stabilizer rear spar?
If they are drilled in the tie down, then how do you match drill in an area almost inaccessible except for the two access holes?
If they get drilled from the aft side, where are the dimensions to locate the holes?
I must be missing something and probably will fell stupid when it's pointed out but better to know now.

Larry
Drawing 21 shows the dimensions for the holes into the tiedown and the layout for the tiedown relative to the 712 bulkhead. Hope this helps.

After re-reading your question Larry I now understand your request more clearly. Drawing 21 shows the lower part of the tie down 7/16" below the top of the mouse hole centerlined to the 712 bulkhead. Drawing 27 for the taildragger shows the lower portion of the vert stab sitting right at the top of the mouse hole...1/2 scale drawing. Also shows the angle part of the vert stab intersecting the two top rivet holes. I looked again for you and was not able to find a numerical dimension.

You could use drawing 27A, A-A detail and scale down from the hidden view of your tie down to the bottom of the vert stab since the tiedown is already established on the 712 bulkhead. That should be able to set your vertical location.

Stab

Thanks Arnie. At least I didn't miss something on the drawing.

On my project I manufactured the F-712E as per the plans page 21 including the eight 1/8" holes detailed.

My quickbuild fuselage came with a rivet installed in the rear bulkhead where the plans say not to install one. Consequently I had to remove it and I drilled the resulting hole to 1/8" to remove the dimple. I positioned the F-712E against the bulkhead per plans page 27A and marked the hole location on the centre groove on the rear face.

On my drill press I then drilled a 1/8" hole at this location through until it just exited in to the eye bolt hole. I was then able to cleco the F-712E to the rear bulkhead. A 90 degree drill (i.e. ATS Pro - P/N: 775A fro Aircraft Tool Supply - or similar) was then used to transfer drill the eight 1/8" holes in to the rear bulkhead and then rivet 4 places the F-712E to the rear bulkhead.

The same 90 degree drill was later used to transfer drill the remaining 4 holes from the F-712E/rear bulkhead to the vertical stabiliser during installation.

Whilst it is a bit tight it is requires the right tools and patience. I have used this drill in quite a few other locations where space or clearance is a bit tight.