A new dimension to the game could be more in depth maintenance. It would be cool if you could schedule A,b,c,d checks. The % thing isn’t really great, and does not really make sense.
It will a be good addition to the game but will increase the costs for sure and will be some difficulties with scheduling I think.
Maintenance ratio. It does make sense IMO. It limits aircraft utilization which is realistic because aircraft don’t fly 24/7, they need to spend some time on the ground for maintenance.
However, I think we need more things like A, B, C, and D checks, etc…
Hm…
this would make the game more realistic. But… we are CEO of an airline and we have staff to plan and organise the maintenance 
What I mean is: changes that improve the fun of playing, or allow more different strategies to the players, are fine. This change would increase the technicality of the game. And what would only be an added task for seasoned players, will be yet another technical obstacle for new players. I think there is a reason why the game now automatically installs a standard cabin configuration and such when you start a new airline…
Jan
We had several times the idea of having the A,B,C,D-Checks at all - but there is a problem - you. Well not you directly, but you - all the players. That would mean you had to check all your aircraft and have to lease spare aircrafts and so on or have some spare aircraft in you fleet. And that’s still impossible for the most of the player.
But there are plans to increase the complexity of maintenance again (who played the old german red/grey or blue/grey versions still know that there was a bit more complexity which was eliminated by players wish). But that’s future plan and not part of the actual developments.
I do agree that it has to be a user friendly and simple process. I would suggest that a possible was to do this would be have a maintaince schedule page. You would schedule the A check in the normal weekly route schedule. then the b,c,d check would be done in the maintainence schedule. That way you have have to make one B check monthly, c check every year and d check every 7 years or what ever it is. And in the schedule you could nominate another aircraft to replace the one in maintenance. I know this was a simple example and some more thought would deffinately be needed, but i think this could make running the epic massive airlines too time consuming and thus start to limit the growth a bit. I take this example off another online airplane sim. just an idea.
I am inlcined to agree with Jan here. While it would be realistic it is a rather technical issue and would more complexity than fun (unless they are automatically done). I like the idea of creating new ideas and adding improvements that would make stratergies and overall airline management more competitive. I just feel there would be more important things to incorporate before this imo.