What don’t I know???

I’ve been reading different build forums and blogs over the last several years as I’ve “mentally prepped” for the journey. I’m fairly handy (doing my own vehicle and household upkeep and mods to both the 2 Jeeps and the RV).

One thing I’ve always wondered is like when it comes to wiring, how are people making decisions on whet/how to wire thing in the most efficient manner? The physical wiring doesn’t concern me, but knowing what to wire, and when, and where... Does the manual give pointers on when to mount A/P servos and pitot tubing?

I know it’s a huge question, but I’m not really sure what to expect once the kit arrives...

The first question you need answered is: How do you want your airplane equipped? I figured out that answer and bought it all with the help of the avionics supplier. I did that sometime after I started first working on the airframe and flight controls. When it came time to cover with fabric I thought of where all the stuff I had bought needed to be mounted. Its just minimal number of items like the ELT, com, transponder antenna, horizontal stab trim motor. Placement of these items had little to do with efficient routing of the wires but more to do with, the KF available space. I don't know how the next guys ELT is mounted but I figured out my own way and installed it. People here helped me get my antenna placement done. Wire route was an after thought. My wire harnesses reveal this Im afraid. I wish it were more professional appearing but hey, I have never done this before and my stuff works. There certainly may be a day when you will come into something you were unaware of and have to figure that out too. Mine was the power boost safety trim item that is needed to allow the Garmin G3X to adjust the trim for the Auto Pilot servos when using the AP. Since I knew from the start I wanted an AP, I installed my servos as well. Those servos have no published method for installing so that is where this forum comes in. Plenty of pictures were provided to assist me in getting mine installed. The forum will be your savior more than once or twice.

You brought up a good point about fabricating mounting brackets. Reading back over my post, it was a little narrower in scope than intended because I meant to include the things like the when/where to mount equipment bits.

There was a post on here I read recently that discussed limiting the number of wires ran through the firewall and bringing in 1 wire and making a buss on the inside. It was that post that got me thinking about the instructions and the fact that things like that are probably not written in...

Eddie's suggestion is right on. Place the devices first and run the wires where they need to go second.



I will suggest that placing the antennas does require some thought; and, you need to know what you you are installing and the separation requirements of each antenna device before drilling the first mounting hole. Some ADS-B units use a single monopole antenna in common with the transponder and others use a second separate monopole for the transponder and for the ADS-B unit. Com antennas and ELT antennas also require manufacturer defined separation for other antennas. You can end up with a surprising number of antennas on a light aircraft and most of them require spacing from other antennas.


The build manual will not have a lot of detail on wiring beyond the basic engine wiring because each builder can have a very different constellation of electrical equipment.

The build manual is very good and leaves little for you to figure out, until you get to your panel and the firewall forward. I installed a 914, which is far less popular than the 912 engines. The firewall forward manual is good, but definitely leaves a few things to figure out. For example, where to locate the fuel pumps for the 914. The manual basically says: "Find somewhere to put them, and plumb them." Also, the firewall penetrations aren't really clearly defined. They tell you to locate the TCU and servo behind the panel, but don't really talk about how to route things through the firewall. I suspect these details are probably covered better for the more popular engines.

As for the panel, the manuals cover just about zero because everyone wants something different. However, it's not too difficult to figure out, and you can find loads of pictures on theses forums. If you're unsure about something, call the factory. They have always been willing to send me pictures of how they do things, and you may find that they already have a kit available that you can buy to solve your problem. For example, they have anautopilot servo mounting kit that even comes with the adhesive needed for the install.

I bought a Quick Panel from Dynon/AFS. If you're a first-timer concerned about wiring, it's a good way to go. The downside is that like Eddie, many of the wiring harnesses aren't the perfect lengths, so my wiring behind the panel doesn't look as clean as it would if I'd made my own harnesses to length. Also, if you have anything that they didn't have in mind when they designed the Advanced Control Module (Airmaster Prop, for example), you'll need to wire that independently, and so the overall system architecture is a little awkward. The panel turned out great though, and was pretty easy to install. If I built a second plane, I'd probably use a Vertical Power and do it all myself.

Your smart in asking what to expect from the adventure your about to take. I've seen others quit a build because they expected something else. Details wont be given about avionics and wiring because there are so many choices. This is your opportunity to be creative. Get what you want and make it your own. I did not do much research before i ordered my kit. I also expected it to take 3 yrs and it took me 5. But i was never once deterred. Just dont go into it in a hurry. This forum was an invaluable help. And of course almost anything can be found on the internet. I commend those who built before the internet.
If i can do it anybody can. Good luck.

I have had the same feelings you have about things.

I am a fan of forums like this and have been on them for years for various hobbies. I have spent a ton of time on here and a couple of others. Mainly searching a topic at a time with a deep dive into it.

You can read an ELT thread, and mixed in the thread are comments about antennas, placement, etc. I make a note of that complexity (that I do not understand) and search on antenna placement. I will follow those leads and study the comments and solutions.

Over time I have pieced together what I want to do in different areas, and tried to get the decisions made on avionics, etc. I then revisit my notes and try to cement the plan.