More flights (350 - maximum number?)

I used to put more radars and each radar increased the total number of flights. Now only one radar of each type increases this number.

(ACEO 1.0-44)

350 is the limit. Actually not many players ever reach that number.
Otherwise you have to switch to Sandbox mode, there you can get to unlimited flights.

I understand, thanks. In general, my computer is already heavily processing the existing airport:

You can also use ACEO Tweaks if you like, which recently reworked this system.