Do I need to match drill these 4 holes on HS-00001 doubler on the front spar?
 

Hey guys,
I am about to rivet up the tail section soon, and I had a question about the HS-00001 doubler plates that go on the back of the HS-702 Horizontal stabilzer spar in the empennage.

See this photo:


I have the 4 holes that I am not sure about circled with black sharpie in that photo. These are the holes that existed on the plate when it came in the kit, but I wanted to be sure if I need to back drill them to the front spar, since it looks like they will be close to the other holes. These are the only 4 holes that I do not have matched drilled to the other parts of this section.

If I need to drill them, I am guessing its a #30 and using the same size rivets as their neighbors?

I'm really stretching my memory, but if I remember correctly NONE of the holes are supposed to line up.

I think the gap between the doublers its 3 3/4 inches. I missed that note in the plan and had to re order the doublers and the angle irons. Just make sure you have the proper gap between them and that should answer your question.

I just did a week ago...of curse I may be wrong.
 

Lynn, there is a good youtube video of the SB being performed on an existing HS. I will see if I have it (within my attention span). It does address the holes and mentions to check several times to ensure the all holes are staggered.

The other thing is to be sure it in not so far inboard as to interfere with the VS spar connector plate overlap.

Nicely done video too!


Ahh - https://www.youtube.com/watch?v=HgE0T8EMaZk

screen shot from the video...
 

BTW: is there a reason to have shop heads on one side vs the other? or just whatever is easier to get the rivet gun in?

I drilled them....
 

Hi ,

Here's mine. I did drill them.



You can take a look at my page, there's more pictures.
http://projetrv7.com/blog/index.php/...hs-front-spar/

Related question?
 

While we are on this topic. Is this a mistake in the plans? it says #40 drill. but it clearly says to use AN470D4 rivets on these spots. that would be a #30 drill?

It's probably just to make sure that the first hole is drilled with a #40.
The drawings should always be right and the holes must be opened to #30 afterwards.

Thanks!
 

Thank you. The plans don't mention it anywhere

Rivet orientation
 

Yes. Factory head always on the thinner material side. It's not written in stone. There are places where it can't be done but always try.