Autopilot will not follow GPS

[petejohno]

Sorry for the late reply. Been away working...
Some further testing.
Asobo C172 classic. Gps tracks fine in GPS mode.
Just flight arrow. Will not track in GPS mode. Tracks fine in heading mode.
Just flight arrow with Spad.next controls. Will not track in GPS mode. ( This makes me suspect it is not a flight simulator control error )
In the arrow, i am unable to change the aircraft mode selector into GPS. It appears to be locked in heading mode, although previously it would select GPS mode, but would not track.
I am aware that just flight made some changes to the autopilot behaviour in the latest update, and I suspect this is where the problem is, although it is strange that most other uses have no problem. The TDS GTN worked fine before the update. I have checked for control conflicts and there are none.
Same behaviour with both the GTN750 and 650. I use the Honeycomb Bravo and Alpha.

Meanwhile, I can use the GTN in heading mode to the FAF and just change to the ILS there and all works well with vertical guidance. Same with a RNAV approach, where I just use the charts for a decent profile.

[adminOwner2]

For the JF Piper, can you please try this:
NAV/GPS switch to GPS, the autopilot is engaged, heading switch ON and the autopilot rotary switch to NAV.

[McCloud9]

I noticed the same thing going on for me, my Turbo Arrow III not following fight plan so I'm following this thread.

[petejohno]

For the JF Piper, can you please try this:
NAV/GPS switch to GPS, the autopilot is engaged, heading switch ON and the autopilot rotary switch to NAV.

I have done this many times. I am familiar with the arrow autopilot. The rotary switch will not set to nav now, it is stuck on heading.
I will  just use the gtn in heading mode for now in the arrow, it works fine in other aircraft.

[adminOwner2]

Can you confirm that the TDS GTNXi works fine in NAV mode with other aircraft?If yes, which version of the JF Arrow do you have installed and from which source?

[petejohno]

Can you confirm that the TDS GTNXi works fine in NAV mode with other aircraft?If yes, which version of the JF Arrow do you have installed and from which source?

Yes. the GTN works fine in nav mode in other aircraft. i have the very latest update for the arrow/arrow111 from the justflight website.
I have just tried with the new simupdate. I can now use the rotary switch to nav mode, but it will not track the gps course. It appears that the gtn is stuck in heading mode. The heading light on my bravo remains on, even when I have nav selected on the rotary knob.  
Anyway, thanks for your help. I can still use the heading mode ( in the GTN750 settings) to navigate around, it more an annoyance than anything else, and probably not  a fault not related to the TDS GTN. I will try a re-install of the arrow and see how that goes.

[adminOwner2]

Hello Pete,
Something must be interfering with the Piper Arrow that does not permit NAV mode to engage, hence why HDG mode is still up. Are you loading form a saved flight or do you have some hardware/mappings that could interfere?

[petejohno]

Hello Pete,
Something must be interfering with the Piper Arrow that does not permit NAV mode to engage, hence why HDG mode is still up. Are you loading form a saved flight or do you have some hardware/mappings that could interfere?

I reinstalled both arrows and same problem. The rotary button wont move off heading.
I don't  use saved flights and I can't find any conflicts. I'm giving up on this for a while. Spent too much time not flying trying to find the problem. I'll revisit later.

[adminOwner2]

Thank you for the information Pete, it is totally understandable.

If anybody else has this problem, please let us know.

[ryanbatc]

I wonder if there is some sort of control binding that's making the switch not move? This seems more like a JF issue.