Today I was thinking of a module where you can check up on aircraft maintenance and line checks. So, for example, you have a list of your fleet in the Admin panel and column says 'Last Check' and then the name of the check and the date it was carried out, like this:
Registration | Last Check | Next Check
It could also link to your expenses so that each check costs you, and perhaps even make the aircraft inactive for a day or so so that no one can fly it.
Thoughts?