It would be good if I could check the weekly/daily income per each plane. Or if it is in the game, where can I find it?
There's no such a function, but why do you need it anyway? You have profit per flight...
Yes, it would be cool to have. Until then, as TWAAir suggested, you can just add up the profit per flight for each flight of the day. Cumbersome, but doable.
why do you need it anyway? You have profit per flight...
Cumbersome
(to the point of impracticability.
But IIUC the issue is that profitability is only computed on an ad hoc basis whenever a request is made by the user, so an aircraft's total profitability is simply not information that is available on the server.