You can register and archive all aircraft defects by entering section Maintenance > Hold Item List. Leon keeps history of each aircraft discrepancies and limitations that result from defects.
Click on 'Add new HIL' and the new window will show up. Fill in all mandatory fields: HIL & MEL (Minimum Equipment List) item number, date, due date and discrepancy description. You can also add flight limitations and corrective actions.
If you have added an open HIL to one of your aircraft within a certain period of time, in section OPS > Table an aircraft reg number is highlighted in yellow (if HIL caution is marked in 3-dots filter) and if you hover the mouse over it, Leon will show HIL's information in a pop-up window.
In a section Calendar such aircraft registration is highlighted in red. Hover the mouse over to see details.
If you try to add a new flight for the period selected in new HIL section Leon will issue a warning in top-right corner of the screen:
MEL - Minimum Equipment List is a categorized list of systems, instruments and equipment on an aircraft that may be inoperative for flight. Specific procedures or conditions may be associated with operation with the relevant item in operative. It is considered by default that any equipment or system which is not included in the MEL must be operative for the aircraft to be allowed to flight. The MEL is defined on a per aircraft model basis.