Empennage

The next section of the front spar involves putting the front spar pieces together (there's a left and right half, and a stiffener plate and reinforcement angles) and drilling them all together. You make some careful bends to match the shape of the HS. Unfortunately, I didn't get some pictures of some of this work. At the time, I had no idea I would be putting this website together, and I was so focused on the build that I neglected to take more pictures. However, you'll have plenty of opportunities to see the work and how it came out in the following pages. You make these bends using a simple cardboard template to check the bend angle.

Following the detailed instructions in the plans, I continued this work and finished the basic front spar. Next, you prepare the ribs. When you're finished with the deburring, some of the ribs need to be straightened. This is done with "fluting". Putting flutes in the flanges of the ribs is done with a fluting tool. It puts small crimps, or flutes, in the flanges of the ribs. This has the effect of straightening out a rib that otherwise might be warped or twisted. It's amazing how effective this is! But you can't put the flutes in until you know where the rivet holes will be. So the ribs are first clamped in place, and since the skin is pre-punched, you can use a sharpie to mark through the holes in the skin onto the rib to show where the holes will go. Then you take it apart for fluting and deburring.

Next, you choose which ribs will be on the left and which on the right (doesn't really matter, just mark them) and you can start putting the assembly together for the first time. From here, you just follow the plans. You'll be clecoing the ribs to the spars, and drilling out to full size. Then you dismantle it to deburr, put it back together again, then attach a skin, and before you know it, you have a beautiful structure clecoed together!

It's amazing to see this come together for the first time! Here's another shot from a lower angle, clearly showing the rear spar and those stiffeners:

At this point, none of the holes have been drilled out to full #40 size. It's so exciting to see a real airplane part coming together!

Here's a shot looking inside the HS. You can see the ends of the clecos sticking in, and the copper-colored #30 clecos that hold the rib to the spar down inside. Cool! Next, the inboard end ribs are attached and clamped in place. These aren't pre-punched, so you can't just cleco them on. They will involve more work.

Above: here's a shot showing the inboard end of the left side. You can see on top how the spar was bent to accomodate the final shape of the HS. The stiffeners on the forward spar are clecoed in place, but the inboard end ribs are just clamped for now. You take a sharpie or felt pen and mark through the holes in the skin to show where the holes will go on these ribs, then they are taken out so you can put the flutes in place in between the marks.

The nose rib on the HS has been clecoed in place, but not yet drilled. Slight final adjustments in position must be carefully made, so some of these holes aren't pre-punched. You can mark through the holes in the skin onto the rib showing where the hole will be drilled, then the rib can be fluted and deburred before drilling.

Here's a shot showing how the nose rib attaches to the forward spar. Can you see the problem with this rib? The full-width flange had to be trimmed so it will sit down between the stiffeners onto the spar web. I measured and cut the flange, then when I put it in place, it had obviously been cut too much. There's not enough edge distance for these two holes. There's at least 1/8" too much trimmed off each side of the flange. See the gaps (red arrows)? The flange should almost touch the stiffener on each side. It would have been better to put the part here in place first, then mark where to cut it. So this rib went into the scrap pile. I'll have to order another one from Vans.

I'm sorry these two pictures are blurry. Obviously, I'm not only learning how to build an airplane, but how to run a digital camera. Anyway, the edge distance on the ends of these rib flanges is also questionable. I'm afraid I'm going to have to scrap them, too.

I guess before I can go any further, I need to go down to Vans and pick up some replacements. I'm not off to a very good start. If I keep ruining parts at this rate, this will turn into a very expensive kit.

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