Surely any airline wouldn't adverties a schedule if they hadn't already secured the ATC slots for the flights.
Ho hum...
ATC slots are issued as
a function of airspace capacity.
Idiots guide to ATC slots.
Its very simple, if you have a room that holds ten idiots,
you can't put eleven idiots in the room. (much as you might like to)
Idiot number eleven has to wait until one or more idiots come out, or the room is made bigger, so the idiot (No11), gets a slot time. This is the time the idiot has to present itself to
commence their journey to the room. If there's only seven idiots in the room, then you can get three further idiots in there without restricting their progress at all, but the fourth idiot and any subsequent idiots will have to wait their turn. If that room is in fact a corridor joining two rooms, then you can only get so many idiots down that corridor at any one time, even if the room at either end has a limitless supply of idiot capacity. Therefore any idiot wishing to pass through the corridor may get a slot time for the corridor, depending on how many idiots wish to use the corridor at any given time. If there is another different corridor, joining the rooms you can send the idiots down those corridors, which may mean that the idiots will not be restricted at all.
So you can see using the above idiots guide, you should be able to see that
ATC SLOTS, do
not get secured by an airlines schedule, or their staffing levels, they are a tactical daily/hourly response to airspace capacity. But please don't let inconvenient substance like facts get in the way
