FSX keeps an up-to-date history of the number of hours an aircraft flew, although not all aircrafts display such information.
Centurion T210 and the default Cessna C172 are both equipped with this type of display. Should someone wants to change it for any reasons:
- Open C:\Users\<User Name>\AppData\Roaming\Microsoft\FSX\SimObjects folder;
- Select the aircraft you want to change, then
- Edit the accumulated_time value in the aircraft’s state.CFG file will do.
Not recommended to push it too far; otherwise, you may soon need a new aircraft —- Just kidding.