Right Side Horizontal Stabilizer

With the left side done, I proceeded to complete the right side. This went a good bit faster now that I’ve had some practice.

I did run into an issue that I was almost sure was going to require replacement of all the pieces for the front spare, both sides. After having drilled the top hole through the front spare and into HS-00005 rib, I checked edge distance and discovered it was less than the recommended 2D (2x rivet diameter). A quick VAF search yielded many others running to problem around there with the rib and even more critically, the HS-00001 doubler. Mad at myself I just stopped for the night.

The next morning (Saturday) I sent an email to Van’s, basically just to have them tell me what I already knew, to order more parts. However, as they pointed out to me, there was a service bulletin (SB 14-01-31) issued in 2014 that required a doubler (HS-00001) to be installed to prevent cracks in the forward HS spar. In it, there is a “magic” note that allows for a reduced edge distance of 5/32″ (0.156″), rather than the typical 0.24″ (or 0.219″ if you’re looking at the absolute minimum in the military specs) for a #30 hole. While this note applies to the HS-00001 part, Van’s confirmed with me that if the top hole in the HS-00005 rib also meets that, it will be OK. Hooray! While I’d love more edge distance, if Van’s is comfortable with it, so I am. And my HS-00001 edge distance was OK as well.

More for my records, this is what Van’s wrote back to me initially:

The SB that was the cause for the HS-00001 doubler has additional minimum edge distance information allowing shorted than the typical 2D. If you meet the specs shown on page 21 you can build on, if not these effected components will all need to be replaced.

Since my question to them was specifically about HS-00005 rib, I asked them to verify that this was applicable to HS-00005 as well. Reply:

5/32 on the rib flange would be acceptable but this is not a critical component, the key item here is the HS-00001. If you are uncomfortable with the rib flange edge distance you can easily fabricate a new flange for the rib with a small piece of angle as shown in the SB.

I finished up drilling the remaining holes, all edge distances checked out OK.

With both sides of the HS now complete, I removed strips of blue plastic off the rivet lines. I was really torn between just removing all of it and taking the time to remove strips. In the end it’s going to get painted and scuffed up a lot during paint-prep. However, since between now and then I just know seeing marks all over it would bother me too much. Plus, it does provide some kind of resistance barrier, so there is that. Once I got my adjustable temperature soldering iron setup, it was a fairly quick and easy process. I’m also not in a huge hurry (will take time to level-up to the wings kit), I’m not loosing time.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.