Replace or not?

Hi,

While riveting the HS-905 nose rib in the horizontal stabilator, two clecos failed (probably due to improper attachment) and ripped out the first rivet of the nose rib. I decided to replace the skin. When the replacement skin arrived and while drilling out the nose rib, I noticed that the rivet hole of the nose rib was really ugly. In an attempt the correct it I drilled it to size #30 for an oops rivet. But it still looks bad to me. Hard to get it on picture, but I gave it a try. Continue building or replace the rib?

I would continue on with the oops rivet even if you end up with a less than desirable tail. After all, that one rivet won't compromise the whole plane. That's just my opinion. I'm sure others with more experience will chime in.

If the skin hasn't been drilled to #30 yet, how about a small internal dimpled square scrap of alum. on the inside to simply sandwich the oversize rib hole?

az_gila said:

If the skin hasn't been drilled to #30 yet, how about a small internal dimpled square scrap of alum. on the inside to simply sandwich the oversize rib hole?

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And if it has been drilled, dimple to #30.

Tip

If you do use the same hole with same size rivet, go with a longer rivet to "fill" hole. Like Vans says, one rivet here or there is ok.

Keep trucking on.

Avoid Opps rivets all costs, they can pull out later on as there is not much edge distance.

If you are worried, put one strip of aluminum (drilled, deburred, and dimpled) over the two holes and use longer rivets.

I have reordered the piece because I needed pro-seal and adding this rib was not changing the shipping costs.

The comment about the oops rivet made me thinking. Do you mean the distance that the skin has in the dimple which holds it in place?
I avoid them, but never thought about that. I had to use them on one place until now and that was where the bracket of the electronic trim is attached on the skin. The bend in the bracket was not well made which resulted in a really bad attachment to the skin surface. I had to drill 3 of the rivets out. This enlarged the holes because of the really thin skin used for the trim. Using oops rivets was the only option because I didn't want to go through all the trouble with the trim tab again.

WVM said:

...Using oops rivets was the only option because I didn't want to go through all the trouble with the trim tab again.

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Could you have gone to larger rivets?

I got that advice from a guy who restores planes for a living. My -9 doesn't have on opps rivet and no JBWeld in it.

The challenge is in how you solve your problem, not that you have a problem.

Hi,

I contacted VANS about the oops rivets that attach the horn to the trim tab skin. They suggested to drill them all out and replace them with AN426AD4-x rivets because the trim tab is somewhat critical during flight.

When I took a closer look at the holes with the oops rivets I noticed that the edge of all those dimples all had a crack. After I drilled them out this became even more visible.



I probably need to drill out the complete horn because the dimple will not work for the AN426AD4-x rivet.



How would you suggest to solve this to save the trim tab? Add a doubler plate behind the skin that covers the surface of the horn attachment? But how to solve the cracks in the dimple then?

Other suggestions? I really hope to save the trim tab after all the trouble I have had with it.