When X-Plane has finished loading your airplane, press Enter for XPlaneNetworkData to begin receiving data from X-Plane.
Airspeed, heading, altitude, and vertical velocity show in the window, along with a small circle indicating the airplane's vertical vector.
Press any key on your computer keyboard to see an auxiliary menu to see what pressing computer keys 1 thru 9 or D, K, or M does.
You can select any choice in the auxiliary menu before you press Enter.
The XPlaneNetworkData window can disappear for several reasons, but can be put back by pressing Alt-Tab.

To see anything else in XPlaneNetworkData, you'll need to create this folder: C:\\Users\Public\X to put helper files in (create the X folder).
To see bearing and distance to a destination, create a file in Notepad named Destinations.txt and put it in that folder.
In that file, write a destination name followed by the latitude/longitude for it that was copied from AirNav.com (use Windows copy and paste).
Example:
Palo Alto 37.4611111,-122.1150556
Castle 37.3804844,-120.5681864
Mariposa 37.5108611,-120.0395278
Moffett 37.4161422,-122.049131
San Jose 37.3629947,-121.9286206
Reid Hillview 37.3328611,-121.8198056
XPlaneNetworkData can read the Destinations.txt file and then show a list to select the desired destination when you press the 1 key.
A small circle on the large circle indicates the bearing to the destination, and distance to it shows at the top right of the window.

If you want to fly an ILS, in Destinations.txt, first enter lat/lon (or replace the lat/lon you might have already entered)
in the exact format that shows in AirNav for a specific runway (copy and paste lat and lon).
Then, after <Latitude&Longitude> add the magnetic runway heading,
and then the runway elevation at the runway threshold (all from AirNav).
Example:
Oakland 37-42.089558N 122-12.855418W 296 9
XPlaneNetworkData will compute an ILS.
If you press the 3 key, you'll see horizontal and vertical bars.
Put the center x on the vertical bar, and put the vertical vector circle on the horizontal bar to fly an ILS.

To help with aircraft carrier landings, if you add "Carrier" to your Destinations.txt file, then select it as the destination,
this program will show horizontal and vertical ILS bars. They will take you to the #2 wire.

To see VOR or fix info, create a file in Notepad named Fixes.txt and put it in C:\\Users\Public\X.
In that file, using information from AirNav, write the name of the VOR or fix, followed by its latitude/longitude.
For example, SANFRANCISCO 37-37-10.147N / 122-22-26.017W. Note that no VOR names can have a space in them.
NOTE when you copy from AirNav, that VORs have a / between Latitude and Longitude, and fixes don't.
Press 4 to select a VOR or fix.

To fly an arrival or departure to or from an airport, first create a file named ArrivalsDepartures.txt in Notepad and save it to
C:\\Users\Public\X. Then find an arrival or departure in AirNav. Add that name to ArrivalsDepartures.txt,
for example: MIRAMAR 24R.txt (add the .txt to the arrival or departure name because it will refer to a file with that name).
Then create a file with the exact same name as the one you put in ArrivalsDepartures.txt, and enter the fix or VOR names
with the information that might be associated with them. An example that I put in MIRAMAR 24R.txt:
MIRAMAR 24R
MISSIONBAY OUT 360 RADIAL
HELSI BELOW 6000'
GERNE ABOVE 7000'
JULIAN IN 245 RADIAL
MIRAMAR 13NM ARC RIGHT
MIRAMAR 038 RADIAL 7000'
MIRAMAR 065 RADIAL
ILS
NOTE that ILS above is just to tell you to begin following the ILS heading and glideslope bars (it doesn't need to be in Fixes.txt).
THEN create a file named Fixes.txt in C:\\Users\Public\X (if you didn't already). Copy the fix/VOR names into this file.
THEN in AirNav, find those fixes/VORs, and copy the latitude/longitude from AirNav to Fixes.txt. For example:
MIRAMAR 32-52-11.099N / 117-09-17.513W
MISSIONBAY 32-46-55.951N / 117-13-31.530W
HELSI 32-54-40.460N 117-11-03.920W
GERNE 33-00-28.830N 117-09-12.960W
JULIAN 33-08-25.651N / 116-35-09.365W
NOTE when you copy from AirNav: VORs have a / between Latitude and Longitude, and fixes don't.
NOTE2 that if you use uppercase AT, ABOVE, and BELOW, the altitudes following them will be checked to possibly show altitude in red.
Add to these 3 files as desired: 1.ArrivalsDepartures.txt, 2.(example)LAX 25R.txt, and 3.Fixes.txt.
Press D to fly an arrival or departure that you created using AirNav.