XPLM_API void       XPLMPlaceUserAtLocation(
                         double               latitudeDegrees,    
                         double               longitudeDegrees,    
                         float                elevationMetersMSL,    
                         float                headingDegreesTrue,    
                         float                speedMetersPerSecond);    

Places the user at a specific location after performing any necessary scenery loads.

As with in-air starts initiated from the X-Plane user interface, the aircraft will always start with its engines running, regardless of the user’s preferences (i.e., regardless of what the dataref sim/operation/prefs/startup_running says).