Snap Bushings in Wing Ribs

There are prior threads on this, but they all seem to resolve without a final answer.

I am on 14-04 at the stage where I have to start drilling for the snap bushings in the wing ribs.

Clearly if you follow the text of what they are asking you to do you end up drilling lots of holes which apparently are not used later on at all, and lack snap bushing callouts. Examples of this are the left wing, 4,5,6 ribs counting from the outboard side.

I have seen the master list of errors. Ken at Vans told me most likely they have this written this way so all the ribs are the same even if you don't use the holes you drilled. So my question for everyone who has done this already, is:

Did you end up looking ahead to Chapter 19 and just drilling the holes which were used, or did you follow the instructions here and drill out extra holes including using the sizes that they are calling for in the plans so that you can use the snap bushings provided?

Thanks.

Even if the plans for the prefab wiring don't show them being used, it's a huge prep item to do in the event you run wiring in the future. Who knows, you may opt to put antennas, cameras, different lights, etc out there. Doing them now will be a million times easier than later on down the road.

I made a spreadsheet with all the ribs listed for each wing and which wires went in each position. For example pitot lines start at about rib 10 so there is no point in drilling those holes on farther out ribs.

I think you mean 12-04 not 14-04?

I drilled the ribs exactly how the illustrations in 12-04 and 12-05 showed them, not the text.

Hopefully that is enough because I haven't got to the part yet where I'm running any wires or tubes so I'll be curious to hear what others say.

Tom,

I actually do mean 14-04, but you may have the older plans in which case it I believe would be 12-04. It is the Wing Rib chapter.

I am thinking of just drilling the holes as shown in the later diagrams for the systems. I may run extra wires as some have suggested though just in case I want to put another device (camera, etc) out there.

Still curious to hear from others as to what they did at this stage as it is clear the written instructions in this area differ from the diagram.

The other thing you can do instead of snap bushings is run wiring conduit instead. It's like a corrugated plastic tube that not only makes running wires a breeze but you don't have to worry about keeping them taught so they don't flop around in the wing. Installing it while the wings are still open will pay huge dividends later down the road.

The corrugated wiring conduit will work and the price is right.

However, I've always used lightweight PVC pipe because I wanted the rigidity and smooth bore. Saw a few rings from a scrap fitting and it's a snap to glue the pipe in place. You can see it in the lower left in this photo. Look closely, you can see the pipe, with a small ring around it. The ring is the sawed off scrap of an ordinary pipe fitting.



It's easy to run wires through the smooth bore. If you need a string to pull wires through, just tie a cottonball, or wad or paper towels, to a string and use your air compressor to blow the ball through the pipe. Easy.

The PVC pipes drills easily and cleanly too.

And I don't think the weight is much different than the corrugated conduit, if you use light weight PVC pipe.

YMMV! Have fun!