Elevator complete

I finished buttoning up the elevator last night, it looks good!

With the exception of an anti-collision light on top of rudder, I think I’m complete with all the empennage tasks! Now, back to the wings.. which means returning to my cold, cold garage :-/

Perfectly lined up with the horizontal stabilizer
I had to remove the elevator from the HS so that I could finish the rivets where the top and bottom skin curve around to meet each other at the hinge joint

Swapping an Elevator Skin

After trying to adjust the skins to eliminate the “banana” curve at the end of the right skin, I discovered other builders had also run into this, and it was because the skin was bent incorrectly. Worse, you can’t really fix this either.

The end of the skin (left) should form a straight point, but instead it’s curving up

As it turns out, I had another right skin that came with my original kit that I rejected for missing a line of rivet holes for a stiffening channel (it looks like my kit had a Sling 2 skin instead of a Sling 4 skin, since the Sling 2 doesn’t have this stiffening channel). I decided to test fit this skin to see how the end lined up. As luck would have it, this one lines up much better than the replacement skin.

So, I decided to measure where the missing holes needed to be, and simply drilled the original right skin.

The red line is where 8 holes should be for the stiffening channel at the top of the photo

With that problem out of the way, I was able to finish clecoing and riveting up the skin. I finished one side and will complete the other side next.

At the moment, I have the elevator temporarily attached to the horizontal stabilizer with some 1/4″ bolts, and I’m using clamps on the ends to keep the elevator horns lined up perfectly while I rivet the skin.

Elevator skin alignment

One of my fellow builders (Thanks Pascal!) recommended temporarily attaching the elevator to the HS to make sure the “horns” (end part of the elevator) line up perfectly with the HS skins before nailing the elevator skins down. The correct hardware to attach these two parts is AN4 bolts, which I don’t have yet, but I used some common 1/4″ bolts I had on hand. I then used some clamps to line up the horns to the horizontal stab.

I found that I need to adjust the skin to make things fit right. One of the folded ends of the skin doesn’t look quite straight, it looks like the bottom-left diagram in the picture below. The manual says to remove the clecos, adjust skin and try again. I’m not quite sure how this will help though – the holes are drilled pretty tight, and don’t leave much room for adjustment. I’m thinking that I will use a reamer to open the holes up to #31 size and then try again.

Here’s an in-process photo. This thing starts to look much bigger when you put the parts together!

Skinned the Elevator

I’m continuing with closing out empennage tasks; like the rudder skin issue I described last week, I also had a problem with one of the elevator skins from the original kit I bought. The skin was missing a row of pre-drilled holes for a stiffening channel, and I couldn’t see an easy way to match-drill in the right place, so TAF sent me a replacement skin a few months ago. After prepping and priming the skin Tuesday night, I clecoed it together Wed night. So far, so good, but I have to pay attention to the alignment of the left and right ends to make sure they align perfectly – I’ve seen other builders use a laser level and/or a digital inclinometer to achieve this, and I’ll do the same.

These empennage parts go together so much faster than the fuel tank! With that being said, I’m anxious to get back to the wing. I’m ready to complete the close out of my left tank, after which it must be attached to the wing so that the sealant sets in place correctly. We’ve had a long stretch of cold weather in NH lately so it’s too cold to work in the garage right now. The data sheet for the Flamemaster CS3204 sealant doesn’t list an acceptable temperature range for curing, it just says that it cures at room temperature and will take longer at colder temperatures.

Skinned the Rudder

After a long period of working on the fuel tank, I’m at a step where it needs to be attached to the wing. Unfortunately it’s ridiculously cold in NH right now, which makes working in the garage unpleasant. So, I decided to take a break from the wing and finish up some empennage tasks.

I had to request a new rudder skin from TAF a while ago, as the original one that came with my kit was damaged. The replacement skin arrived after I had already started working on the wing, so I didn’t get back to finishing the rudder until now.

It felt nice to quickly finish something in a day! The only thing that slowed me down was having to modify some rivets to shorten them to fit on the aft edge of the skin. Below is the (almost) complete rudder – the only thing left to do is attach the fiberglass cap, which I’m purposely waiting to do until I decide on which recognition strobe I’m going to use. I guess I also have the task of filling the rivet heads at some point.

Next up is the elevator, which also had a skin problem, but I have the replacements in-hand.

Newest piece in my kit, manufactured in 2018. Most of the other parts I have were made in 2016.

Clecoed Up

Done! I may try attaching it to the vertical stab to see how it looks

Closing up VS Skins

I attached the VOR antenna using 20mm length M4 screws with nyloc nuts and then began closing up the skin.

Unfortunately the antenna is inaccessible once the skin is riveted on, so for now I think I’m leaving one side open just in case – will just use a few clecos to hold it closed.

VOR Antenna Provisions

In addition to the doubler plate, I also need to modify the skin to accommodate the antenna elements.  I notched the skin so that I can slide it up around grommets at the base of each arm.  Pictures are better than words in this case…

Antenna attached to rib 4. The arms on this antenna aren’t removable so I had to slide one element through the hole
Notches I cut into the skin. On one side, the notch is exactly centered using one of the existing rivet holes; on the other side, I had to make a new hole with a 1/8” pilot drill. I used a step drill to open up both holes to 9/32”, and then used shears to create the notch. The notch is slightly narrower than the 9/32” hole so that the grommet “snaps” into place and doesn’t slide around
Testing of grommet fit in the notch
Sliding the notch over the antenna and grommet
Perfect fit!
View from the top side
Both sides fit nicely. Notice that this antenna has elements that are offset from each other, hence why the notches on the skin had to be in different places

VS Structure Assembled

Vertical stab parts are put together, minus the skin. I’m putting in an optional antenna for VOR/Localizer/Glideslope reception, so I had to make a doubler plate for the top spar where the antenna will be mounted to. To make the plate, I used a sheet of 0.032″ 3003 aluminum that I bought from Amazon a while ago, and simply traced the pattern from the rib.

I added wires and grommets for the antenna and for a light that will go on the top of the rudder. Since I had to pass the wire through two of the lightening holes, I attached some nylon caterpillar grommet material to the edge and secured it with silicone sealant.

(Left) Standard rib 4 as supplied in the kit (Right) Custom doubler plate made per kit instructions
All riveted together
Probably not what’s typically used for glue in an airplane, but this GE silicone has a wide temperature range and remains flexible, so I think it will do the trick for holding the caterpillar grommet in place

Vertical Stabilizer Parts Prep

I decided to take a break from working on the wings as I await a few things I need for sealing the fuel tanks.

A few weeks ago I got in a shipment of goodies from Jean at TAF, including missing brackets for the VS, so now I can build that up as well as finish off the rudder and elevator.

Today I prepped the VS parts and primed them in just under 3 hours. I still have to prep the skin, but next steps are to start putting the structure together and figure out how to mount the combo glideslope/localizer antenna I bought back in the spring.

Cold, wet, rainy weather has returned to New Hampshire so it’s back to using my “paint booth” and respirator mask

Rudder frame done

I finished assembly of the rudder structure this weekend. All went together as expected.

Unfortunately I will have to wait to complete the rudder as I am awaiting a replacement skin from TAF (the one that came in my kit was damaged in shipment). It’s on its way from the factory, hopefully will receive it soon.

As of now I think the empennage will have to go on pause; I’m awaiting parts for the remaining assemblies:

  • Rudder: replacement skin
  • Elevator: replacement right skin (missing holes for stiffener channel)
  • Vertical stabilizer: missing 3 sets of hinge brackets that are needed for step 2

Good thing I also ordered the wing kit, guess that’s what I’ll be starting this week!