Thanks for the reply Mark...

I think VasFMC just takes command of the heading bug from what you have entered in the FMC.

In the 727 all I have to do is set up my flight in VasFMC (just like a normal FMC programming) and then hit a "AP Couple" button on the FMC. At that point VasFMC will couple with the FD (HDG) and then you select NAV on the A/P and your off and running.

One thing I haven't tried yet is switching the INS/Doppler switch to INS mode. I'm wondering, if, for any external (3rd party) guidance system to take control of the HDG bug, you need to have that INS switch down.

I have been using VasFMC (1.1) for years and it works great with aircraft that dont have an FMC on board (freeware A/C and older payware A/C such as the CS727). It's VERY simple to operate (as a matter of fact it used to be called SimpleFMC), but has undergone some nice improvements since.

I will keep the NAV1/GPS thing in mind as well and try both that and the INS/Doppler switch.

Thanks!
Robert