If you are departing from an uncontrolled airport and cannot obtain clearance on a Clearance, Ground, or Tower frequency, tune FSS and press 0 to open your flight plan. The FSS frequency for your departure airport can be found by using the PF3 Display Utility (pf3_display.exe, located in your PF3_Displayer folder) once PF3 is connected to the sim, or if there is no designated FSS frequency for your departure airport, use 122.20. You can then taxi at your discretion and use a Multicom or Unicom frequency (if your departure airport has one) to announce you are taking the runway. Once airborne, tune Departure frequency and press 0 to make contact (you can find the Departure frequency using the Display Utility). When landing at an uncontrolled airport, you can use Multicom or Unicom frequencies to announce when you are turning base, final, etc. Once on the ground, if your flight plan was not canceled in the air, you should ask FSS to close your flight plan. The Display Utility provides a list of key commands, or you can use Notepad to open and print the pf3_disp.dat file (also found in your PF3_Displayer folder).