AP not engaging heading with G3X Touch GNS430 Variant Super Decathlon MSFS 2024

[MSFS 2024] Bug Reports Aircraft
, ,
1

Version: * 1.39.0.0*

Frequency: Consistently

Severity: High
Critical but work arounds are available

Marketplace package name: bfg-super-decathlon

Context: Mounted from community or owned

Similar MSFS 2024 issue: N/A

Bug description:
AP Heading mode not responding after SU2 using the Super Decathlon GNS430 Variant(G3X Touch), Tested it with and without PMS50 MOD and the Auto Pilot will not engage or follow the heading bug in the GNS430 Variant. Works fine with all other variants including the GTN650 Variant with the PMS50 MOD

Repro steps:
During flight select a heading and engage heading toggle with either AP or in game panel on the G3X AP - neither will engage heading tracking mode GNS430 (G3Xtouch) Variant only

Attachments:
None

Private attachments: N/A

The work around is simply don’t use the GNS430 Variant if you plan on using heading mode. NAV mode was working upon my testing. Something has changed with SU2 release for 2024 - The Super Decathlon didn’t have this issue until then.

2

To add on to the issue after SU2 the GNS 430 in my Navion L-17B also is having an issue with the WT GNS430 where the Nearest and Comm are not displaying the data without the PMS50 Mod installed. With the mod it works as intended, I contacted PMS50 and they have stated that “They have nothing in common and we don’t override any system file.” so this bug only happens in 2024 after SU2. In 2020 it works as intended.

For reference - Without PMS50 Mod installed 2024

image
image1884Ă—1046 171 KB

With PMS50 Mod Installed 2024 it works as intended
image
image1799Ă—988 125 KB

Not sure if I should make this a new thread or not?

1 Like
3

I think that should be fixed in SU3 and SU16 for the v1 (FS2020) GNS, and was fixed for the v2 GNS at FS2024 launch. A new thread is a good idea if not.

4

Thanks — I am using the direct HTML inclusion for the WT GNS430 as shown. I’m still seeing missing data in the Nearest and Comm pages in MSFS 2024 without the PMS50 mod installed, but it works fine in 2020. SU16 should’ve fixed v1, and 2024 should be on v2 by default, so maybe it’s a deeper regression or something interfering only in 2024.
I’ll spin this off into a new thread just to track it clearly. Appreciate the clarification!

[VCockpit01]
size_mm = 350,190
pixel_size = 350,190
texture = $AS430_Screen
htmlgauge00=NavSystems/GPS/WT430/WT430.html, 0, 0, 350,190

5

That’s the v1 GNS. It has to be maintained at that VFS path for backwards compatibility with FS2020 content running in FS2024. The v2 GNS is NavSystems/WTGNSv2/WT430/WT430.html.
2024/v2 docs: Working Title GNS Overview | MSFS Avionics Frameworks and Instruments

6

You’re absolutely right — this is the v1 GNS using the legacy path (NavSystems/GPS/WT430/WT430.html), and my aircraft is native to MSFS 2020 but carried forward into 2024 for backwards compatibility.

According to the SDK doc (as shown), MSFS 2024 includes both v1 and v2 GNS systems specifically to support 2020 aircraft like mine. So yes — I’m intentionally using v1 as expected.

That said, this bug only occurs in 2024 without the PMS50 mod installed. Everything works perfectly in MSFS 2020, but in 2024, the “Nearest” and “Comm” pages fail to populate data unless that third-party mod is active.

So while the path and implementation are correct for backwards compatibility, something in the core 2024 behavior for the v1 GNS appears to be broken — and that’s what needs attention.

I have already made a new thread for this bug.

Thanks for confirming the versioning though. Definitely helpful to point others to that doc for clarity.

{7DB9D75D-1A34-4390-BB58-B54A1205DB81}
{7DB9D75D-1A34-4390-BB58-B54A1205DB81}999Ă—617 34.5 KB

7

Hello @B4Gunner

This appears to be an instrumentation configuration issue on your side?
The mode seems to be correctly engaged but both the GNS430 and G3X are trying to drive the AP and sending conflicting instructions.
When the HDG mode is engaged, GNS sends the correct bank angle reference while G3X sends 0 and the latter is prevailing.
I also checked your aircraft on MSFS 2020 and the same thing occurs, except in this case the GNS 430 prevailed.

I’m not sure there’s a way for both AP to coexist. Working Title will be more knowledgeable than me on this.
@MattNischan FYI

Regards,
Sylvain

8

Thanks for the insight. Maybe Matt will have some info as to how to go forward to fix this?

9

If you don’t need it, you can probably start by removing the <Autopilot> tag for the G3X in that GNS configuration, in panel.xml?

10

Hello @B4Gunner,

I don’t have access to this package, but just want to confirm that you have disabled the GNS430 autopilot in your panel.xml. There is also a large amount of configuration required for the GNS and G3X to speak with each other properly.

Please see this docs page for more information: GNS Interactions with the G3X Touch | MSFS Avionics Frameworks and Instruments

Thanks,
Matt

11

Thanks, Matt — this actually helped narrow it down.
I’m going through the config now and referencing the GNS-G3X integration doc you linked. Looks like I’m on the right track to get everything speaking correctly. I’ll update this as soon as I’m finished.

Appreciate the guidance!

— B4Gunner

1 Like
12

@MattNischan

G3X + GNS430 Integration: Summary of Issues Resolved

By B4Gunner

Just wanted to share a quick breakdown of the key hurdles I had to overcome to get a fully working G3X Touch + GNS430 + custom autopilot setup in MSFS 2020. Hopefully this helps anyone else dealing with similar conflicts between nav sources and autopilot logic.

Issues Encountered and Solutions

1. Invalid FMS XML formatting

  • Cause: Hyphen characters copied from SDK docs were not standard ASCII dashes.
  • Fix: Replaced all with proper hyphens (-) to ensure the simulator parsed the <Fms> block correctly.

2. GNS430 conflicting with G3X autopilot logic

  • Fix: Disabled autopilot on the GNS using <DisableAutopilot>True</DisableAutopilot> and routed all nav data through the G3X as the master AP.

3. Mismatched nav source indexes

  • Fix: Standardized lnav-index, vnav-index, and ap-guidance-index between the GNS and G3X to ensure NAV and APR modes could engage.

4. GTN750 block removal

  • Fix: Removed unused <GTN750> block from panel.xml to avoid possible hidden overrides that were affecting autopilot behavior.

5. Incomplete <Autopilot> block in the G3X section

  • Fix: Replaced <Autopilot/> with a full autopilot definition to enable pitch and bank limits, glide slope arming, and mode engagement.

6. Buttons not sending sim events

  • Cause: Custom autopilot buttons were not triggering any sim events after correcting the FMS block.
  • Fix: Added <APSource>AP</APSource> to all applicable <UseTemplate> blocks for each autopilot mode button (NAV, HDG, ALT, VS, APR, FD, etc.).

7. AS307 not needed

  • Fix: Removed all AS307 references from panel.xml and interior.xml, since the setup used custom AP logic and didn’t require it.

Final Result

Autopilot modes now engage and operate as expected:

  • NAV follows flight plans built in the GNS430
  • APR captures glidepath and ILS when CDI is set appropriately
  • All buttons function correctly with no reliance on AS307 components
  • G3X handles guidance using the external GNS430 as intended

Hopefully this helps others trying to implement a clean hybrid glass + legacy GPS setup. Let me know if you’d like a working reference configuration.

— B4Gunner

2 Likes