Love the airplane series! Would you provide a complete list of all airplanes? Would love to see that before v1.2 release.
Regarding aircraft maintenance cost, I think irl if you set up the facility, the average maintenance cost would go down if you have more aircrafts. I feel it can be part of base maintenance, and don't see why you want to separate it out.
Also for special events, can Olympics happen at multiple airports at the same time?
Good work, thanks for everything!