I don't think it's an addon conflict. I've got only the Chancellor and the TDS 750 in the community folder when it occurs. 

I had this kind of behavior too with the C414. For the last four flights (above relief with turbulences) I have been using the onboard tablet to refuel instead of the MSFS fuel page, and it seems to have cured the problem (until further notice) as it could be a problem of difference of weight and balance of the plane between the FSW tablet and MSFS(...?). If anyone else tries it on more than one flight this hypothesis could be confirmed or eliminated.

1 hour ago, Bernard Ducret said:

I had this kind of behavior too with the C414. For the last four flights (above relief with turbulences) I have been using the onboard tablet to refuel instead of the MSFS fuel page, and it seems to have cured the problem (until further notice) as it could be a problem of difference of weight and balance of the plane between the FSW tablet and MSFS(...?). If anyone else tries it on more than one flight this hypothesis could be confirmed or eliminated.

I've always used the EFB for fuel and payload, so I don't think that's the cause either. Not in my case at least. 

Has there been a fix found for this? I've noticed odd autopilot behaviour over the last couple of weeks too. I'm guessing the last update has some kind of bug in it. I use the Logitech multi panel so there may be a correlation/conflict between that and the latest version of the 414, and I know of 3 or 4 others who have suddenly started having having this issue. Basically, as the OP says, it sometimes won't hold altitude. But there are a few other issues, such as descending or climbing past it's target altitude. I've also noticed that sometimes when I'm flying manually, my autopilot switches itself on.

I had autopilot issues with the 414 when using the pms750 along with the pms750 livery, after changing to pms750+WT everything was fine.

Hope this helps.

mmm interesting.

Does the autopilot code for the altitude links to the GPS code?

I personally never add issues with the autopilot with the free version of the GTN 750.

But I am considering buying the full release, so I wish I will not stumble on this since I tend to use the autopilot for long hours while crossing long distance while playing OnAir manager.

I had many issues with the autopilot over older beta release of the 414. But it is now extremely stable and efficient in the official release.

 

Just found this thread while doing a search for the 414 autopilot.  I had the autopilot set and the aircraft was following a gps route (Garmin 530 set to GPS mode).  I went to make a drink and when I returned the NAV button/light was off.  I could not select nav or hdg.  I turned the autopilot off/on, but it would not engage the hdg/nav mode.  I selected another waypoint in the 530 and selected direct to, but still nav would not engage.   

Anybody see this and have a solution?  I'm in the SU15 beta.

1 hour ago, MrBitstFlyer said:

Just found this thread while doing a search for the 414 autopilot.  I had the autopilot set and the aircraft was following a gps route (Garmin 530 set to GPS mode).  I went to make a drink and when I returned the NAV button/light was off.  I could not select nav or hdg.  I turned the autopilot off/on, but it would not engage the hdg/nav mode.  I selected another waypoint in the 530 and selected direct to, but still nav would not engage.   

Anybody see this and have a solution?  I'm in the SU15 beta.

I've had that before, in the 414 but also in the Blacksquare planes.  You press NAV on the AP (and the GNS is correctly set to GPS) but it just doesn't respond. 

I think from memory it was something to do with a conflict between the WT GNSs, and having PMS GTN750 installed (in your Community folder).

Can you confirm whether you indeed had the PMS in your Community folder, while flying the 414 with the GNS?

1 minute ago, JYW said:

Can you confirm whether you indeed had the PMS in your Community folder, while flying the 414 with the GNS?

Yes, I have the PMS and TDS units.  However, I don't really need the PMS because the last TDS update added some great new features.  I'll delete the Ms and see if that works.

Thanks for the suggestion.

1 minute ago, MrBitstFlyer said:

Yes, I have the PMS and TDS units.  However, I don't really need the PMS because the last TDS update added some great new features.  I'll delete the Ms and see if that works.

Thanks for the suggestion.

See how you get on with the PMS removed from your Community folder.   I have a good feeling that the AP will work fine with the GNS in the 414, once the PMS isn't in there. 👍