Hey,
As airports grow in size they attract more flights. More flights means more time moving available flights in the flightplanner. Sadly, this cannot be left to the automatic flight planner as it is not capable of following any plan. Have your flight times staggered to avoid congestion, your out of luck and bound to spend the time on the flightplaner that you want to spend on evaluating personell and developing improvements, or just watch the airfield work. The solution is simple, allow the player to drag and drop “empty slots” into the flight planner that are automatically repeated weekly. The automatic flight planner than fills these slots with the flights as available via the contracts.
This way the player can have a neat flight schedule without the tedious work of filling the flight schedule.