I have a number of older aircraft that I have been able to retrofit  a 3rd party AP/GPS unit into & have it work by tweaking the Aircraft.cfg & Panel.cfg. files.

When the AP/GPS is activated the aircraft will climb to the set height at the set VS, following the Flight Plan GPS track to the destination.

I do this as my eyes aren't the best & I can't watch a screen for the entirety of a 2 hour flight.

 

However, I have a few aircraft that accept the AP/GPS unit, light up the correct buttons when I push AP, Nav, GPS & Alt on the unit, but won't follow the GPS track.

I am trying to find where the programming for the AP/GPS is hidden so I can, if possible, tweak it & get AP/GPS working.

Any thoughts?

Thanks

 

I am having a similar problem with my GoFlight MCP Pro autopilot. Engaging LNAV with the CMD buttons armed does not result in the aircraft following the magenta flightplan course line in the FMC. I will be interested to see how others reply to your post.

Some ideas to try -

 

1) For the aircraft that doesn't follow the GPS try using the complete [autopilot] section in the aircraft.cfg from one that does work.

 

2) Following the GPS track uses the command " TOGGLE_GPS_DRIVES_NAV1" therefore the aircraft must have the NAV1 radio at least configured to be working. Not necessarily installed in the panel. Again in the aircraft.cfg check to see that they have at least these entries -

 

[Radios]

Nav.1         = 1, 1, 1

 

Of course, save a backup up the aircraft.cfg prior to any mods. 

 

If the AP/GPS units work in other aircraft it means they are correct. It's the aircraft that is not interfacing correctly.

Is there code for enabling LNAV capability in an aircraft.cfg file?

Other than having a working NAV1 radio - No.

It would probably make things much easier to understand if the specific aircraft were known... 

On 1/6/2017 at 10:47 AM, spokes2112 said:

Some ideas to try -

 

1) For the aircraft that doesn't follow the GPS try using the complete [autopilot] section in the aircraft.cfg from one that does work.

 

2) Following the GPS track uses the command " TOGGLE_GPS_DRIVES_NAV1" therefore the aircraft must have the NAV1 radio at least configured to be working. Not necessarily installed in the panel. Again in the aircraft.cfg check to see that they have at least these entries -

 

[Radios]

Nav.1         = 1, 1, 1

 

Of course, save a backup up the aircraft.cfg prior to any mods. 

 

If the AP/GPS units work in other aircraft it means they are correct. It's the aircraft that is not interfacing correctly.

This is very helpful.

I have just put a WeFly AP/GPS unit into a Milviz F-86F-30.

Everything works, (follows GPS Flight Track & climbs at set VS),  other than it won't flatten out at the preset altitude. Even though VS goes to zero when preset altitude is reached, F-86 keeps climbing.

Any thoughts on how I can fix that?

TT45