AMC1 145.A.10 Scope

CAA ORS9 Decision No. 38

Line Maintenance and Base Maintenance

1. ‘Line maintenance’ refers to limited maintenance for the aircraft suitable to be carried out whilst the aircraft remains in the air operation environment.

   Line maintenance may include:

   — trouble shooting;

   — defect rectification;

   — component replacement with use of external test equipment if required. Component replacement may include components such as engines and propellers;

   — scheduled maintenance that will detect obvious unsatisfactory conditions / discrepancies / malfunctions, but does not require extensive in-depth inspection. It may also include internal structure, systems and powerplant items which are visible through quick opening access panels/doors/ports;

   — repairs, modifications and other maintenance tasks which do not require extensive disassembly and can be accomplished by simple means.

2. ‘Base maintenance’ refers to any maintenance for the aircraft other than line maintenance.

3. Organisations maintaining aircraft should have a MOE procedure to determine whether the tasks or groups of tasks to be carried out fall under the line maintenance or base maintenance scope of the organisation, with due regard to the expected duration of the maintenance, number and type of tasks, shifts and disciplines involved, work environment, etc.

   For temporary or occasional cases, the organisation may also have a MOE procedure which allows, subject to a task assessment (including all relevant aspects and conditions), to conduct a base maintenance task under line maintenance environment.

4. In particular, maintenance tasks of aircraft subject to ‘progressive’ or ‘equalised’ maintenance programmes should be individually assessed in respect of such procedure to ensure that all the tasks within the particular check can be carried out safely and to the required standards at the designated line maintenance station.