Originally Posted by
domer
Have a unique (at least to me) situation I've run into. What happens if a flight that carries the same number as one that's enroute is ready for departure?
Depends where the two flights are. If they are within or near the same airspace, one of them will have the flight number changed for ATC reasons. If the two flights are no where near each other, there is no need to change. You could have two flights numbered QF10, one in European airspace, another in Australian airspace.