I was using FSNav, but not to fly by until i switched to the lear before that i was flying the Wilco fleet Legacy and it has its own FMC. if i needed to input a waypoint in my FMC and it would say it was invalid I would go to my FSnav and find a waypoint that was close to the one i didnt have that way I could stay on a somewhat same flight path as everyone else. honestly I have had many problems with using the AP and Fly Flight Plan within FSNav so i do not use it for that I love the fact that it is basicly a moving map with lots of excellent functions. Sometimes i will make the window small enough to fit on the cockpit and use it as a moving map (kinda like GPS). Anyway hope this helps I beelive there are some free flight planning software out there and In SimRoutes there is an option to save the flight as a FS9 flight plan