I posted awhile back about the installation of my GTN650. We’ve been using it as a GPS source for some time now, but as I get ready to start my IFR training in earnest I need to be able to use the VOR/LOC/ILS features. Well, I hadn’t check those, and hadn’t spent much time learning about the 650, so I thought I’d share some of my new insights with those that follow.

First off, the GRT has an ARINC status page under general where you can verify the communications are working appropriately, which is nice. This is described in a 650 supplement that came out last summer.

Another interesting point, that I didn’t see anywhere, and did their online training and thumbed through the Pilot’s guide (I’m not saying it isn’t there, but it wasn’t easy to find). Unlike the very good performing, cheap, and easy SL30, the GTN650 doesn’t show VOR defections on the CDI on it’s face, EVEN IF YOU’RE IN VLOC mode. I find that rather odd, and more than a little confusing. I mean, why in heaven’s name not?

Also, I find that that the reception on my 650 is inferior to the SL30 which made me believe it was not working. To the point that I asked my local shop to check it while it was in for a software upgrade. Finally, the OBS doesn’t become active until it does lock onto a station, which I should’ve known because even the SL30 does that, so that’s on me – but that made me question if the GRT was really talking to the NAV head properly. I had been testing the Cincinnati VOR, and was having trouble getting close enough to hear it without entering their airspace, but I was able to verify and track inbound to the Midwest (Airborne Express/DHL) VOR at Wilmington.

All of this is to say that it is working now, and I very much like the GPS, transponder, and COM functions of the unit. I may like the NAV side as I start flying instrument approaches, but as a simple VFR tool for VOR use it’s been a bit tedious.

UPDATE: I have the NAV side working, and tracking VOR and ILS signals fine. For some reason the CVG VOR would never ID, but the 650 tracks it’s signal just fine. Here I’m tracking MXQ, at the old Airborne Airpark, what the output looks like on the Hx, and what the default NAV screen on the 650 looks like. Also note that the same station is tuned on the SL30, which is sensibly displaying the CDI on it’s face.

UPDATE 2: I’ve also just learned that there is a dedicated ARINC for the VOR/ILS, and that 2 ARINC connections are required to the Hx for it to be fully functioning. If the GPS is working properly (and a flight plan is entered) you see these indications (GPS messages under Display Maintenance, ARINC Status) and be able to select GNAV mode for the AutoPilot.

VOR tracking from GTN650 on GRT Hx

VOR Tracking on GTN650… note if the GPS Waypoint were not MXQ, the CDI deflections and next waypoint would say whatever was in the GPS flightplan, even though it’s giving a VLOC indication.

ARINC Status – 2 inputs, both incrementing, and note the NAV Mode and GPSV and GNAV status


Posted By: Brett Ferrell
Friday May 22nd, 2015 at 10:18 PM

Categories: Avionics
Tags: Avionics Building Electrical Garmin GPS GTN650

One response to “GTN-650 Installation Notes”

  1. Document says:

    […] might be of interest to folks building their own planes, one about what I consider quirks of the GTN650, and one on what I have hooked to my GRT Hx EFIS system, and how it’s configured. The Hx […]

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