What?
Replace static handling capacity expressed in discrete amounts of pax or cargo units with something more fluid and realistic. If this sound abstract, it’s because it is.
In reality, an airport would have a certain amount of aircraft stands. Some with air bridges, some without. There would also be a certain amount of gates, some larger, some smaller. The terminal housing those gates could be specious or cramped, might offer a vast array of shops and restaurants, or not. Baggage handling could be modern and fast, or old and slow. The amount of security lines, check-in counters and baggage belts might be appropriate for a day’s peak traffic…or not. You get the idea.
An airline scheduling a flight to an airport requires all of these “capacities”, both in the actual sense - there has to be a gate - but also temporally - there has to be a gate from when the passengers start arriving until the aircraft leaves.
The “fluid” aspect mentioned in the first paragraph captures all the other attributes: You might be able to process a B767 worth of pax at a gate intended for narrow-body-sized planes, but pax won’t like it and there’s a high chance of delays or “operational challenges”. At the same time, all other parts of the building need to handle those pax either way and, up to a point, will do so. Again, it might just be slower than intended and passengers will suffer, but things wouldn’t suddenly stop working.
All in all, there isn’t a hard limit to what a terminal can handle, but the more the actual usage deviates from the designed usage, the worse the experience will be, with negative impact on both customer ratings/image and operational reliability.
All of this might be temporary, with a terminal operating at or beyond its design limit at certain times of the day but not others. Again, all of this would be rather fluid, just in the real world.
Why?
The way terminals currently work is silly and far too simplified. The value they add to the game is minimal and the way they are built and used breaks immersion, imo (think “41 terminals at FRA”).
That said, this is more of a conceptional topic, but one worth exploring on its own (possibly without any actual code changes). It is supposed to serve as the foundation for other features in the realm of infrastructure and ground handling.
When?
Anytime.