System.cfg Question

Regarding the [autopilot] section, there are two required entries I have questions about, namely [autopilot_available] and [flight_director_available]. Do these variables simply indicate that the plane in question does or does not have one installed in the aircraft? Or, does it mean that an external one, for example, one I design, will not work with that aircraft?
Thanks in advance.


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Interested to know.

I was thinking of Borrowing the lines out of cessna 172 file and inserting into the harvard and see if i can get one working with my saitek autopilot panel.


these variables simply indicate that the plane in question might have one installed in the aircraft. If it does then a 1 would turn it on and a 0 would turn it off.

But, if I want my autopilot to work, must I change these entries in the system.cfg or do I just turn my instrument on? The reason I ask is because I am leary of mucking around with those files and ending up having to re-install the sim!
Thanks for getting back to me. To Spoonsnz: I’ll report back my findings!


Regarding how to safely make changes to systems.cfg:

  • The safest method is to make a copy of the original file and keep it in a location other than the MSFS file structure. If things go awry, simply copy the original file back into the aircraft folder.

  • Another way to save original settings is to make a duplicate line and put a semi-colon in front of it. MSFS ignores anything that is preceded by a semi-colon.
    ; autopilot_available = 0 (this line will be ignored)
    autopilot_available = 1 (this line will be used)

Regarding whether MSFS will provide autopilot capability if you change autopilot_available from 0 > 1, the answer is: it depends. There are a lot of factors that determine what happens.

I use the try-it-and-see approach. I enable auto_pilot available, then use the AI pilot to see what happens. The AI pilot mostly follows what the autopilot would do, with added functionality such as altitude control and automatic approach patterns at major airports.

Yes, there are issues with AI flying into mountains and landing next to runways, but overall it does a pretty good job. I set a controller button to toggle AI, so it is very easy to momentarily jump in and help AI avoid problems.

Interestingly, AI often works as an autopilot in aircraft that don’t have a systems.cfg file.

Observations regarding using AI as an autopilot:

  • If I use AI for takeoff, it sometimes appears to veer way off course. If I’m patient, it usually loops back around to the general location of takeoff and then follows the flight plan.

  • In the World Map, if I indicate a departure runway that points in the direction of the first waypoint, AI does a much better job of not getting lost.

  • In instances where AI veers off course after takeoff, and fails to loop around to the flight plan, I find that manually flying past the first waypoint before engaging AI is often successful. Likewise, if it loses its way mid-flight, I disengage AI, fly past the next waypoint and re-engage.

  • When creating flight plans, set the cruising altitude higher than nearby obstacles. For example, if your plan travels through valleys, set your cruising altitude above the adjacent mountains. Sometimes AI takes a shortcut between waypoints and goes through mountains instead of around them.

You can always add the AP background code, but you may run into issues getting it to work in a vintage airplane. I ran into this exact issue back in FS9 when I modernized the Ford Trimotor. I had to change the way some of the gyro instruments worked in the background as well, but it’s been way to long for me to remember the specifics.