Tonight I returned to rivet the spar doublers and reinforcement angles to the front spar. Here are the parts after a quick priming and light paint job. I don’t normally paint interior parts like these, but I’m not a fan of the self-etching primer. It holds moisture too easily, so I figured a light layer of paint wouldn’t hurt.

Everything was clecoed together and then I used the pneumatic squeezer to the best of my ability to set as many rivets as possible.

I was able to get all the top rivets and center rivets. Unfortunately the bottom angle is too wide for my squeezer’s yoke, so I had to buck these rivets.

I had two minor smilies. Both in the same position on each side; three from the inside on the bottom. They are not worth drilling out.

Riveting the remaining rivets was going to be a challenge, so I played around with several different rivet sets with no luck. I was out of ideas, so I grabbed Mike who happened to be working on his annual.

Luckily he had a single offset rivet that was just the right length. Wrapped with electrical tape to prevent rotation and walking, I was able to get the majority of the remaining rivets.

A few of the rivets required a second set of hands, and Mike was nice enough to help out. We made super quick work of finishing it up. Here you can see the results. I’m extremely happy with how this entire project has turned out. A few blemishes here and there, but there is nothing in this service bulletin that I will lose sleep over. Moreover, I will be more comfortable knowing this SB has been complied with in its entirety.

Next it was time to work on the HS-0002 angles. The process described in the service bulletin instructions is rather convoluted. Essentially they have you clamp one side, then the other. Drill one side, clamp again, remove, and finish drilling. I can only surmise that all of that would be necessary without an angle drill or small clamps. I initially clamped the angle in place with the cleco clamps, but I found this to be insufficient. I wound up, and advice you, to use C-Clamps (unfortunately I didn’t take a picture with the c-clamps. I used the c-clamps to clamp the angle to both the rib AND the spar. Then I began drilling the section that mates to the spar and clecoing as I went. After that was completely drilled and clecoed, I repeated the process for the section mating to the HS-405 rib.
  

You can see here that both sides are clecoed, and flush.

End result. I completed one side, but not the other. in the next session, I should easily be able to wrap up this project!

Squire made his triumphant return to the hangar today! He had TPLO knee surgery in December as a result of a completely ruptured CCL (ACL). Its been 10 weeks, and he’s healing very well. No lameness and he’s able to start light jogging and other fun activities. He should be able to play fetch in another few weeks. He was super excited to return to the hangar!

Today I set about match drilling the doublers to the spar. The doublers are clamped in place. The position is adjusted by viewing the rivet lines drawn previously, and aligning the bend with the bend in the spar. Its also important to keep an eye on the rivet alignment. The pre-drilled holes in the doubler are offset from the holes in the spar. Additionally, you should ensure you have the proper amount of room between the doublers to allow the mounting of the vertical stabilizer.  For drilling, you begin with the 8 rivet locations in the center of the doubler. You can see those locations here after drilling are attached with clecoes.

After you drill the center, its time to drill the remaining holes that attach the reinforcement angles. An angle drill works nicely. Use the adjacent cleco to aid in alignment.

Here is the finished result. Note the offset rivet immediately above the “L” and the “R”, this denotes the top of the doubler. Additionally, you will note the offset rivet on the lower side second from the inside. This is normal and is a match drill location. I’m very happy with how this has turned out, and I will sleep comfortably knowing the spar is strengthened!

  

Next I fabricated the angles that will be used to attach the HS-405 ribs after they have been trimmed.

And finally, I primed all the parts before re-installing. In the next session, I should be able to rivet everything together and call this service bulletin complete!

Session time: 4 hours.