No, the maintenance costs are calculated using the total aircraft value and the average aircraft age. There is no individual aircraft taken into consideration.
To lower your maintenance costs, you have to either lower the total value of your aircraft or the average age. The last option is the easiest.
If you click on the button 'Aircraft' on the top menu bar, you can see you daily maintenance costs and average aircraft age. Note both to watch your progress.
Go to 'View Aircraft' and sort them by age (Or ID, they are practically the same), and order replacement planes for the oldest planes you have. You can click on the little plus sign to the left to see the age of the specific aircraft. Anything above three years is to be replaced.
Wait for the new planes to arrive, already now the average aircraft age should be lower, but since you have many more aircraft, the maintenance won't be lower yet. Replace as many aircraft as possible, and get rid of them asap. (A little tip to when you are re-creating routes: Aircraft with the highest ID are the youngest aircraft. Use the youngest aircraft first, you want to get rid of the old ones!) You decide if you want to sell them or scrap them, but it is until you don't
own the planes any more that they don't cost you in maintenance.
Check you aircraft average age, and note it has fallen lower after getting rid of the aircraft. But the maintenance costs won't change until the month change, because it is calculated monthly.
Things that does
not affect aircraft value:
Cycles and hours of aircraft. Though it is planned that it will.
Fleet commonality (e.g. only fly Airbuses instead of a mix of Boeing, Airbus, Fokker and Tupolev)
Individual aircraft age - you can have one 15 year old aircraft, and it won't really impact your maintenance if you have a huge fleet (300+ a/c)
I hope this little guide helped, may you have fun playing AM!
Oh, btw, can I get a link to your airline? Thanks
