As a real newbie, I really appreciate and enjoy the free missions available for download and kudos to the kind folks who created them. However, some are beyond my navigation skill at this time without an included flight plan in the GPS. Thankfully, some authors would include a cheat sheet with waypoints in longitude and latitude coordinates in a separate document. The problem is a newbie like me have a hard time finding info on how to enter these into the mission without losing the reward (like clicking the Enable changes to the mission ...and creating a flight plan).
After much searching and experimenting over several days, I admit I am a slow learner, I gather the following way to change the mission files and hope this will help someone else.
Adding a Flight Plan to an Exiting Mission when you only have the GPS coordinates of waypoints Creating the Flight Plan file to get the necessary codes Go into Free Flight and specify the same aircraft as used in the mission you want to fix
Create Flight Plan by entering departure and destination airports, choosing VFR, Direct GPS Go into Edit tab to view map click on the red flight path line to add a way point choose the new way point in the right column and click to edit waypoint enter the proper longitude, latitude coordinates and altitude repeat until all way points have been entered save flight plan file, default to C:\Users\[user]\Documents\Flight Simulator X Files\[Flight Plan], substituting names where appropriate (extension .PLN) save the flight now (default to the same folder, extension .FLT) Using the obtained files to modify the Mission File goto your missions folder (C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\Missions)
open the mission you want to add the flight plan edit the [mission].FLT file with a text editor, make changes as follows: Find the [ATC_Aircraft.0] section and change: [ATC_Aircraft.0] ActiveFlightPlan=True RequestedFlightPlan=False
copy the [GPS_Engine] section from the flight file you saved above (extension .FLT; not the Flight Plan file) into the [mission file].FLT file after the [ATC_MessageSystem] section. Double check the path in the Filename item of the [GPS_Engine] section. It should point to the location of your saved Flight Plan (you only need to specify the filename of the Flight Plan file without the path if you put it in the same folder as the [mission].FLT file. This is more portable if you want to package the mission.) save the changes Call up the mission in FSX and the GPS should now show the flight path