Where (and how big) can I drill holes in structure?

[claycookiemonster]

I was traumatized by the diagram of the wing rib, and the admonition to ONLY DRILL HERE for a wiring conduit. I guess I'm still carrying that caution.

But now that it's wiring season, I need to run some conduit and bundles around the place, and sometimes (like to the rudder for the strobe) there's no way to get there unless I make a new hole. Running wiring forward sure seems like I'm going to have to drill into the gear towers (RV8) and they're very important structural places. Maybe even sacred and sacrosanct?

Is there any general guidance on this? Are there any "Thou Shall Not Drill Here!" zones? Is there some sort of edge distance consideration to be aware of? And, while I'm at it, any advice on how far between restraints on wiring bundles or conduit?

 

[Marc Bourget]

Clay,

Look into the term of "moment of intertia" and Neutral Bend line or axis for a start.

 

[wirejock]

Holes

Most places the standard edge distance rule applies. When in doubt, ask Vans first.
Around the critical zones like the spars and center section, Vans has some documentation avaliable showing where and what diameter. Check the website.

 

[PaulvS]

Restraining

AC43.13-1B Section 9 has good info on bundling and restraining. You do have a copy of this essential reference?

 

[Jonnyb]

Have a look at OP-11. It gives routes for wiring in the RV8 including where to drill and how big the hole can be.

 

[claycookiemonster]

Well, shame on me. I had copies of both the Acceptable Methods... as well as all the Optional Drawings, but never saw the specific parts mentioned here. Thanks.

 

[claycookiemonster]

Actually, I only have the Optional drawings in .pdf form. Are they available in full size? Should I have them somewhere?

 

[bhester]

Office Max

If you don't have a full size. Take the PDF to Office Max and just tell them what size you want it printed out on.

 

[rongawer]

Simplifying the AC 43.13-1b advice - which is plentiful, just stay away from bends or edges by at least two diameters of the hole you're making (measured from the center of the hole to the edge, or beginning of bend), and then only make it as big as is necessary for the job.

And don't make any new holes in the main spar...

 

[Jonnyb]

Actually, I only have the Optional drawings in .pdf form. Are they available in full size? Should I have them somewhere?

I don't have them in paper form, Only PDF. They don't come with the kit as standard I think. I get my local copy shop to print off the ones I want.