The fuel tanks in Section 18 of the plans are not complete yet, but the tanks need to sit for a couple of weeks to let the sealant cure before starting the initial leak testing. It is also way too cold to work in the garage this week, so I'm skipping ahead slightly to this section while I wait for the sealant and a warm front!
I started this step by scanning the safety directives and alerts, service bulletins, notifications and letters, and revisions and changes on the Van's support page to ensure my plans and parts are up to date. There is a revision for this step on the Van's website, and that revision matches the printed plans that Van's delivered with the wing kit as well as the electronic plans on the computer. With the latest plans in hand, I dove in to see what is involved in this section of the build.
Wing systems for this step in the build include the lighting harness for both wings, the ADAHRS harness in the left wing, the autopilot servo harness in the right wing and the pitot and angle of attack lines for the pitot tube. I have not 100% committed to an avionics suite, but I'm leaning toward a Garmin G3X system. I studied the plans for this section with the Garmin sensors in mind to get a handle on how the ADAHRS and autopilot wire harnesses integrate with the Garmin systems.
A question that involves the installation of the wing wiring is the location and wiring for the Garmin GMU 11 magnetometer. The G3X/G3X Touch Installation Manual includes a “Recommended Distance from Magnetic Disturbances” table for the GMU 11, which is identical to the table for the GMU 22. The left wing has an ADAHRS bracket in the left wing just outboard of the wing walk area, and Van's provides a mounting system for the GMU 22 that mates to the ADAHRS bracket (Plans Section 62). Based on the “Recommended Distance from Magnetic Disturbances” tables, the GMU 22/ADAHRS location should be suitable for the GMU 11. My plan is to modify the bracket to mount the GMU 11. It looks like other builders have successfully done the same thing with no magnetic disturbance issues.
Another question is the location of the Garmin GTP 59 Temperature Probe. The probe is wired directly to the G3X ADAHRS, so wiring isn't an issue at the moment. The primary consideration right now is a “clean” location for accurate temperature measurements. Van's East-coast demonstrator has the temperature probe adjacent to the aft, inboard corner of the inboard access panel on the left wing. I wonder if that is too close to the downstream engine exhaust for accurate temperature readings, but it's as good a starting place as any for placement options.
Finally, I am going to install a mast-mounted Garmin GAP 26 Heated (unregulated) Pitot/AoA Probe. I will dive more deeply into installation of the GAP 26 and after-market mast when I get to the bottom wing skins section of the build. Installation of the mast requires cutting a hole in the bottom wing skin and riveting the mast, wing spar, and bottom skin together. I will run the AOA and pitot lines now, and I will also try to run the power and ground lines for the probe heat.