@rubio....
Sorry, that should be the direct answer on your "But the costs for maintenance will go up. Maintenance for an A380 ist much more expensive than for ATRs."
You are right that both aircrafts A380 and ATR do have different maintenace costs.
I tried to point out, that in case you do have A380 and ATR in your fleet only, you do not have to pay something on top of the basic maintenance fees for 3 categories.
Freehand english - without Madame Google :)
That’s correct. But I guess with your previous response you misunderstood my earlier response to the original poster, who was asking why his maintenance costs had gone up 41% when he added two more fleet types. To which I replied that the maintenance cost is not absolute, that it depends by aircraft type, so if his two new fleet additions were aircraft that have expensive maintenance cost, his total maintenance cost would likely increase by more % than a simple additional category penalty, and I used ATR and 380 example. In that meaning, “adding” A380 was not meant as just simple leasing, but adding as in “operating”.
@rubio....
That's correct. I based my observationa on the number of maintenance categories operated only and not on the use of extremly expensive additional aircrafts too.