Sometimes FSUIPC just quits without obvious reasons. John, this is just to let you know, it doesn't happen frequently. Here's what I did this time: - startup the sim (and automatically FSUIPC) - load Icon A5 and do some assignments and checks in FSUIPC - go back to Main Menu - load Carenado C182RG - do several starts and landings - go back to main menu - start another flight with the Carenado C182RG - did a "Restart"  when 5 minutes into the flight.