Category: Horizontal Stabilizer

Elevator Trim Wiring

May 8, 2020 – I connected the elevator trim servo to its wire bundle.

To get a connector in the tailcone where it can be accessed, I cut about a foot of the wire bundle and spliced it to the servo wires. Those wires are so short, they stay buried inside the elevator, so they needed to be extended.

One big issue I ran into was that I didn’t have wire strippers small enough to handle 26 gauge wire. I have an Ideal stripper, and I guess I wasn’t aware that the blades could be changed. I found a set on Amazon that was a whole lot cheaper than buying a new stripper. This range of wire sizes will make more sense for the work I have coming up.

So here’s the wire I have running from the servo out of the elevator. I’m just running it in the open space of the elevator leading edge. I installed a 6-wire molex connector I got from Stein.

The disconnect will lie in the space under the vertical stabilizer. Here’s the connection with the elevator on:

Time: 8:30

Continued Tail Fairings

April 4, 2020 – I continued work on the fairings for the tail.

I decided to enclose the elevator tips and make the cap wrap around the lead weight in the front. So I taped off the weights to keep the resin from sticking, and I wrapped cloth around the front. I also taped along the edge and filled there to smooth the transition between the elevator skins and the fairings.

Well, when I went to sand the ends, it was too thin. I also couldn’t remove the fairings…  🙁

So I decided to install them in place, and just use filler to fair out around the weights. Haven’t gotten to sand them yet. Hopefully this will work.

I moved on to the top of the vertical. I had previously made a foam plug to close the open end that faces the rudder. I hung the rudder back in place, and had to remove some material from the small vertical fairing for clearance. There’s a nice gap there now. I just have to seal the foam where material was removed, then fill the front of the rudder where the weight and the rudder skin are mismatched.

Then I moved to the fairing that wraps around the vertical and the horizontal stabs. I looked at the lower fairings, just flat pieces of aluminum that close the space under the horizontals. This is screwed in place into the longeron. So I removed the appropriate rivets, drilled up to #36, and tapped the holes for 6-32 screws. I also trimmed the tops of the fairings to give space for the rubber seal that will go there.

The top fairing fits OK. I wanted to get the front parts of this fairing fairly tight against the leading edges of the horizontal stabs, so the fairing twists a little bit when forced into that position. I’m backing off and thinking about how best to deal with this.

Time: 12:40

Drilled horizontal stabilizer

April 6, 2016 – I drilled the stabilizer to mount to the fuselage.

I made the shims that go under the HS-714 where the stabilizer mounts.


I made sure that the stabilizer would be mounted square. I measured from the aft outboard corner on each side up to the top corner of the side skin at the firewall. Both sides were right at 170″. Perfect.

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The plans call for a 3/16″ gap between the aft deck and the bottom of the stab, so I inserted two #10 drill bits.


I marked the location for the outboard holes that go through the HS-714, the aft deck, the longerons, and the support angle underneath. I drilled the holes with a #40. You can see the open hole in the angle in this photo shot from inside:


I’m OK with the edge distance here. I drilled the two holes just inboard of these, then took these four holes up to fit -3 bolts.


Once that was done and clecoed, I drilled the four aft bolts. This was a lot easier to get to.

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Here’s the end product. I have to take it all apart to deburr.

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Next up: drilling the vertical.

Time: 2:45

Continued horizontal stabilizer

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.

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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

Continued horizontal stab spar replacement

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.

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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.

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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.

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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.

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

Time: 6:40

Started horizontal Stabilizer v3.0

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.

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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

Continued horizontal stabilizer SB (again…)

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.

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Time: 7:25

Continued stabilizer SB

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.

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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.

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Time: 2:30

Started horizontal stabilizer service bulletin

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.

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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

Amazing Day!!!

Jan 6, 2010 – I survived the exploding rivets! Actually I was trying to move some of the padding on my table, and the container of rivets I was using (tiny ones!) fell off the table and exploded on the floor.

Other than that, I got a lot done. I’m just an hour or so away from a completed horizontal stab. My friend Joe Santee came over this morning and helped me do some riveting, then after he left I continued on. Finished installing the left stab skin, then moved to the right and finished it.

I then applied sealant to the mating surfaces for the aft spar, and clecoed it in place. I’ll let the sealant set up, and probably won’t touch it for a few days anyway, because of work and the fact that we here in Texas will all probably freeze to death through the weekend. It’s on the news, it must be true!

Time: 5:45

HS aft spar sealed and clecoed in place Stab skins shot on and aft spar clecoed in place

On a side note, I went to an EAA Chapter meeting (168) last night for the first time. Had a good time meeting other RV types, had some inspiring words from a recent first flight of an RV-8 owner, and even got to talk to a guy who was just thinking about starting one.

Stab Progress

Jan 1, 2010 –Assembled the inboard ribs to the forward spar, then started installing the left stab skin. Note to self: install the pop rivets in HS-708 before you rivet the skin. Looking back, that’s what the book says to do. OK, I got a little excited…

My son Blake helped to shoot some rivets. I do a lot harder than this at work by myself, but this material is so thin, I really don’t trust myself yet. He did a great job.

Time: 2:45

HS inboard ribs Blake and I riveting Blake clecoing skin to spar

HS-707 installed in LH skin HS LH skin

Having a Riveting Time…

Dec 23, 2009 –Shot the lower spar strap on today. I am so used to shooting rivets at work, that I didn’t realize how noisy this was going to be in the garage at home. Thankfully, these aren’t -6 rivets. (For those of you who aren’t familiar with what I’m talking about, -6 rivets are 3/16?) The majority of the rivets in this whole airplane are -3 (3/32?) and -4 (1/8?). Tiny by Boeing standards.

I’m going to go around to the closest neighbors and let them know what I’m doing. Next door says they never heard anything today. That’s good. I hope they weren’t just being nice.

Anyway, I’ve also had to move things around, since we need my table for Christmas meals with family. So I can’t do anything else until after Christmas is over.

Time: :45

Horizontal, continued

Dec 21, 2009 –Finally, a nice day in December in Texas…

Scuffing and alodining the HS skinsGot quite a bit done on 3 hours of sleep. I scuffed the interior of the stab skins, and alodined and primed those and the rest of the stab parts. Applied sealant to the HS-609PP straps and clecoed them to the aft spars. Shot a rivet, too! My first on this project. I’ll wait on the rest of the rivets until I’ve had some sleep.

Time: 3:00

Painting the HS parts

Sealing the aft spar straps The first rivet...

Slow Day

Dec 14, 2009 –Just did some work in the shop, made my frame of chicken wire to hold parts during priming. Too bad I’m not ready to prime: today is nice; tomorrow, not great painting weather. Started to take apart the parts for the horizontal. Attaching labels with part numbers and positions; since they will be cleaned up and primed, I can’t write on them.

Time: :30