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G3X Touch and GTN - yellow “VFR” on HSI

iamtheari

Well Known Member
The G3X Touch pilot guide says that, if the external navigator fails and it automatically reverts to the internal GPS, it will display both “REV” and “VFR” in yellow on the HSI. Mine just shows the VFR annunciation, no REV. I can control the GTN frequencies from the G3X. The messages on the G3X about not getting ARINC 429 data to away when the GTN boots up. I can navigate on the HSI with magenta needles from the GTN, including a highway in the sky for a visual approach loaded on the GTN. I think it’s configured right. But I don’t know why the yellow VFR shows up. I do know that I can’t seem to show green needles or control the OBS course from the G3X.

Does anyone know a setting I might be missing, or another reason the yellow VFR can show up without a yellow REV to go with it?
 
VFR REV

Setting between units is probably correct.
When the GTN goes off line the G3X should revert to internal GPS.
Old flightplan from GTN is still there.
VFR implies no IFR navigation.
Have you checked the settings on the page where you select external/ internav NAV on the G3X after GTN fails?

Good luck
 
My GTN isn’t failed. I don’t see “REV” on the HSI. Only the yellow VFR indication. I am wondering what conditions would lead to the yellow VFR without the yellow REV showing up, since I can’t find that in the manual.
 
At all times when you are using the external navigator (e.g. GTN) for navigation, and the G3X/G3X Touch system is not receiving A429 data from the external navigator, the yellow "VFR" annunciation will be present on the HSI like shown here.

VFR Annunciation.png

To generate the yellow VFR annunciation in the above screenshot, I just turned off power to the GAD 29 so the system was no longer receiving ARINC 429 from the external navigator.

In this scenario, the G3X system is using RS-232 provided MapMX data only. MapMX data provides lateral navigation suitable for VFR flight, but lacks the additional information provided by A429 which is needed for IFR lateral/vertical guidance.

As soon as I turned the GAD 29 back on, the yellow VFR annunciation immediately cleared.

You have a problem with your GAD 29, wiring, or configuration causing the G3X system to not receive A429 data from the GTN.

Steve
 
Last edited:
Thank you. I’ll spend some time with the configuration mode to see if I can find what I’ve misconfigured.
 
I had got the G3X configuration correct but not the GTN. I spent a few minutes with the G3X installation manual’s list of configuration settings for this setup and made adjustments as needed. Now I get green needles and an OBS knob just fine, so presumably everything else will work fine as well. Can’t wait to fly with it. :)
 
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