Writing your own System of Maintenance (or Maintenance Schedule) this is not as difficult as it first looks. Writing your own System of Maintenance can have several advantages. Some of these are: 1. the registered operator can gain some flexibility, whereas the current schedule 5, for instance, only allows maintenance to be carried out annually or every 100 hours time in service. the operator may decide to develop a system where small amounts of maintenance from the schedule are performed at regular intervals rather than once a year. 2. the aircraft’s general airworthiness would be improved. 3. Certain concessions concerning maintenance intervals can be granted (for example a small over-run) . 4. the system of maintenance can be tailored to the operator’s specific requirements. the system must meet the requirements of CAR 42l and CAR 42M regardless. In addition certain parts of the manufacturer’s system can be included along with applicable parts of the current schedule 5. these two systems are the basis on which your system would be assessed for approval, along with the regulations previously mentioned.