What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Front spar assembly question

dwollen89

Well Known Member
Well I'm off and running. Wishing I would've started at the vertical stab instead of the horizontal as others indicated. I have a question for the group of 7 builders.

On the front spar assembly when match drilling the holes for HS-702 and HS00001, there are two holes on each side that don't have a corresponding hole in the reinforcement angle HS-710 and HS-714. Should I drill these holes through the angle? Or are they just unused?

https://photos.app.goo.gl/ru3DW58ghTxZzdwT6
 
Last edited:
Check VIEW A-A on the plans, I believe they are visible on the plans from the HS-710 / HS-714 side (meaning you need to drill them).

This is what my part turned out to be: https://ivans-rv.idubrov.name/_app/...ted-de3a20b3.jpeg?nf_resize=fit&w=1008&h=1008.

Also, be careful when drilling holes from the SEC D-D (ones that you mark on the reinforcing / splice angle first and which go through HS-702 / HS-00001 and HS-00005). I got very close to the limits (which are reduced for the Service Bulletin these parts came from!) on one of the holes: https://ivans-rv.idubrov.name/blog/2022/05/13/horizontal-stabilizer-skeleton-finishing

P.S. Link to the service bulletin. It gives some context. Not that instructions are incorrect, but I found instructions a bit confusing in that area. Service bulletin could help explaining why it is done this way.
 
Thanks for the reply! I added a picture for clarity, but looking at your spar pic, you must've drilled it out. You're building a 7 correct?

I really really hope some of the directions and pictures are better after this horizontal spar. Some of the illustrations are confusing because they are not the exact part I have, so it's kinda frustrating. I also hate that you have to modify a spar for an 8 to fit the 7. On such a crucial piece, you'd think it would be worthwhile to make it model specific.

Oh well, I'll build on :)
 
Yes, I've just started building an empennage for the 7.

Looking at the service bulletin, page 14 shows exactly all the same rivets on HS-00001 doubler I have. So I hope I got it right :D

I had the same thoughts on the horizontal stabilizer. Some of the instructions seem to be a bit off. Even tiny little things like drawing showing SECTION F-F being 3/4 SCALE, but in fact looking more like an actual scale. I remember there was something in the text that also did not exactly align as well or did not make most sense to me.

Same thought about the horizontal spar. Bending it one way, then unbending it back cannot be good for the aluminum longevity, can it?

Vertical stabilizer is much simpler and I don't remember anything confusing about it.

Haven't gotten past that yet, though.
 
You were right. I ended up calling Vans and chatting with them about it, along with a couple other things. Very helpful gentleman I spoke with. He said to go ahead and drill the holes out. He said I can go ahead and drill the holes for the fuse attachment too, just don't enlarge them beyond the 30 right now. He also gave me a bunch of tips for a new builder, so I really appreciated that.

The doublers that got added were apparently a direct result to the SB that came out about the cracking of the HS forward spar. So that should really fortify that area if you're worried about it at all.
 
You were right. I ended up calling Vans and chatting with them about it, along with a couple other things. Very helpful gentleman I spoke with. He said to go ahead and drill the holes out. He said I can go ahead and drill the holes for the fuse attachment too, just don't enlarge them beyond the 30 right now. He also gave me a bunch of tips for a new builder, so I really appreciated that.

The doublers that got added were apparently a direct result to the SB that came out about the cracking of the HS forward spar. So that should really fortify that area if you're worried about it at all.

Fun and challenging process :) . A good idea/tip, which I’m glad I did before it was riveted is notch the rear spar flange for the elevator horns. You can figure the dimensions by looking at another drawing. If you want, when I get home I’ll go measure the distance I have so there is reduced head scratching for you. I may have documented it in my build log too, I can’t remember. Enjoy!
 
The H stab is one of the hardest things to build imo. I just finished up my wings so I can attest through that. I had to reorder a few parts when my holes didn’t line up in the area you are talking about.

Keep on keeping on.
 
That would be great! I saw that in the plans when I was looking ahead. Those are the things that I spend huge amounts of time pondering, measuring and remeasuring before I actually pull the trigger and cut or drill something. Hopefully, that will get better as I learn and gain confidence, haha.
 
The H stab is one of the hardest things to build imo. I just finished up my wings so I can attest through that. I had to reorder a few parts when my holes didn’t line up in the area you are talking about.

Keep on keeping on.

That's good to know. I'm surprised at how many things are conflicting in the plans vs. pictures. Or when they tell you to look at figure 6-6...which apparently doesn't exist :cool:
 
That would be great! I saw that in the plans when I was looking ahead. Those are the things that I spend huge amounts of time pondering, measuring and remeasuring before I actually pull the trigger and cut or drill something. Hopefully, that will get better as I learn and gain confidence, haha.

I notched it 1 1/8” each side of center, worked perfectly.
 
Back
Top