Category: Horizontal Stabilizer

April 6, 2016 – I finished the assembly of the horizontal with the SB mod installed.

Since this is all pretty much covered back when this project was new, I’ll just put some of the newer pictures here.

Now I’m ready to drill the stab to the fuselage…

Time: 6:40

March 29, 2016 – I continued back-drilling the skins to the structure.

After the skins were back-drilled, I removed them, and got ready to prep and paint everything.

I needed to drill the hole for the elevator trim. I’m using electric trim, but I wanted to have the hole available for wiring. I marked the location of the hole, and drilled it to 5/8″.

After everything was deburred, dimpled, prepped and primed, I started the assembly.

Now it’s ready for installation of the skins. I need to stop for a couple of days, though. Last week we had a pretty healthy hailstorm. I ended up buying a new car. The problem is we have more storms forecast for this week, so we wanted to try to see if we could fit the car in the garage with the wings and the fuselage. So we took down my work table and moved everything over. The car does fit with about 6″ to spare on each side. So I’m going to wait until later this week to keep going with the stab.

Time: 5:40

March 17, 2016 – I honestly don’t remember the sequence for the assembly of the stabilizer, so I called Van’s to get the manual pages for the stab. They emailed me the entire current manual. That was nice.

So now I have the sequence a new builder would follow. I started by positioning the new doublers on the spar channels and drilling them.

The upper and lower reinforcement angles needed to be tapered and bent to fit. I tapered the ends and filed them to size. I’ll poilsh them when everything is drilled. Each end is to be bent 6 degrees. I used my protractor and the vise.

I clecoed the angles in place on the spars and drilled them.

The inboard forward ribs need to be trimmed to fit to the spar. One left and one right.

To get ready to drill the ribs, I clecoed the spar in place with the old structure, then clecoed one side of the skin in place.

After drawing centerlines on all flanges of the ribs, I slid them in place and drilled them. I really don’t see that I need to flute these ribs to straighten them. They lie flat on the table already.

With that side done, I’ll cleco the other skin in place and do the same thing.

Time: 6:40

March 6, 2016 – Since I’m awaiting warmer weather to cut my canopy, I decided to start working on replacing my horizontal stabilizer forward spar.

I previously attempted to do the mod for the Service Bulletin on the spar, and it got to a point where I just could not live with it, so I ordered parts to totally replace the spar.

I started out by drilling the left and right skins.

That’s it for now. I’m going to review the instructions and the new drawing, because I don’t even remember how the stabilizer went together.

Time: 1:40

January 11, 2016 – I really don’t know where to begin. I’ve wasted a lot of time on this little project, and I have nothing good to report. After getting close to closing the stabilizer, I had some new issues crop up, and I decided that I didn’t want to live life worrying about the structural integrity of the tail of my airplane.

I decided to order all new parts for the front spar of the stabilizer, and start fresh. I called Van’s, got a new drawing 3 with the current revisions, and I ordered the parts.

Here are the last pictures from the work I did. It was just time to move on.

Time: 7:25

December 29, 2015 – I continued with the disassembly of the horizontal stabilizer in order to do the Service Bulletin (SB) mod.

I drilled out the rivets to remove the upper and lower angles that support the center of the stabilizer.

The webs of the stabilizer’s forward spar had to have relief notches in them. This helps to prevent the cracking issue that’s being addressed. Since my tail kit is relatively new, the notches were there.

I slightly enlarged them to the dimensions called for in the SB.

The next step was to cut off the corners of the flanges for the spar webs. This was kinda fun because of the limited access. I used a Dremel to do the cuts. You have to be careful to prevent damage to the spar webs. I used a spare piece of titanium and taped a putty knife to the vertical part of the spar to prevent damage. Then I did my best to clean up the edges and the corners. When everything is ready to install, I’ll clean it all up and re-prime.

Time: 2:30

December 23, 2015 – After the rudder pedals were in, I cleaned everything up and got out the horizontal stabilizer.

On January 31, 2014, Van’s issued a service bulletin for cracks in the horizontal stabilizer. Compliance with the SB involves a visual inspection in the problem area every year. The SB is terminated by installing a doubler mod on the forward spar of the stabilizer. It was obvious to me that since I was still building, I should do the mod and never have to worry about it. I decided to go ahead and do it before I got further involved with the build of the rest of the airplane.

The mod is started by removing the inboard ribs from the stab. I hate to remove perfectly good rivets, but it went OK.

I’ll have to continue later. Tonight is our family Christmas dinner, then there’s Christmas Day, and a little bit of work mixed in there, so I’ll be back…

Time: :55