Sorry it’s very long.
Maybe the flight generation system needs to consider how much unused time I have on my stands.
Using my airport as an example:
I have medium and large stands (no small commercial stands)
I have very little unused time for my medium stands, but plenty for my large stands. So most of the new flight offers I get should be for my large stands.
As a theoretical possibility using all 3 stand sizes:
If 45% of my UNUSED stand time is for small stands, 10% of it is for medium stands and 45% is for large stands, then newly generated offers would be broken down so that 45% of new offers would be small, 10% would be medium and 45% would be large.
As a worked example:
12 stands (4 of each size):
Overall I have 168 hours of stand time for each stand each week (7 days with 24 hours = 168 hours)
Across 4 stands I have 672 hours of available time each week for each size.
Now assume:
The schedule contains
40 small flights at 3 hours each = 120 hours of small stand use
138 medium flights at 4 hours each = 552 hours of medium stand use
24 large flights at 5 hours each = 120 hours of large stand use
The unused time for each stand size is:
Small: 672-120 =552 hours
Medium: 672-552=120 hours
Large: 672-120=552 hours
My total unused time is: 552+120+552=1224 hours.
As a percentage (rounded to the nearest 1%) of the total unused time (not within each stand type):
Small: 552/1224=45%
Medium=120/1224= 10%
Large: 552/1224=45%
Based on the vacancies I have, my next 20 new (ignore the existing offers) flight offers should be:
9 small (45%), 2 medium (10%) and 9 large (45%).
I know that different sizes require different turnaround times but since the minimum separation time and which (if any) stands are remote affect the total time between arrival times, it would make it more challenging for the player to have to make best use of the available flights by not factor it into the generation rate.
However you do need to have flights offered in the relevant categories to make that happen (hence my suggestion)