I am using Flightgear 2018.2.2 on Windows 10 and cant seem to figure out a way to automatically load the Flight Plan XML and run it as soon as the Flightgear starts.
The command I am using is:
fgfs --aircraft=737-300 --lon=151.177222 --lat=-33.946111 --altitude=10000 --heading=220 --vc=280 --airport=YSSY --fdm=jsb --flight-plan=plan.xml --prop:/controls/gear/gear-down=0 --prop:/autopilot/settings/target-speed-kt=280 --prop:/autopilot/locks/speed=speed-with-throttle --prop:/autopilot/settings/target-altitude-ft=10000 --prop:/autopilot/locks/altitude=altitude-hold --prop:/autopilot/locks/heading=true-heading-hold --prop:/autopilot/route-manager/destination/airport=YSCB --prop:/autopilot/route-manager/destination/runway=34 --prop:/autopilot/route-manager/departure/runway=34L --prop:/autopilot/route-manager/input=@INSERT-1:YSCB --prop:/autopilot/route-manager/airborne=true --prop:/autopilot/route-manager/active=true