Aircraft maintenance is one of the vital components of aviation safety. There is no such thing as a safe flight if the aircraft is lacking inspection and maintenance of its structure, systems, and components.
Line maintenance
The most relevant tasks involved in line maintenance according to EASA and the FAA include:
- Troubleshooting.
- Rectification of defects.
- Replacing components, up to and including engines and propellers, with the use of external test - equipment if required.
- Scheduled maintenance and/or checks including visual inspections that will detect failures that can be easily spotted but do not require extensive in-depth inspection, or special equipment. It may also include internal structure, systems, and powerplant items that are visible through quick opening access panels or doors.
- Minor repairs and modifications which do not require extensive disassembly and can be accomplished by simple means.
Base maintenance
Unlike line maintenance, base maintenance involves the removal of an aircraft from service, for a longer period usually more than one day and could be up to thirty (30) days. This occurs in a hangar, where the aircraft is separated from its operating environment; specialized tools and equipment are required. It is during this aspect of maintenance where scheduled checks are performed, along with any rectification activities, and defect investigations. In essence, base maintenance involves ‘heavier’ tasks than line maintenance, such as C and D checks. Base maintenance calls for more time-consuming tasks, included structural work, corrosion prevention, interior refurbishment and the replacement of major components.
These activities are usually performed by an organization specialized in MRO (Maintenance, Repair, and Overhaul) and are described as major repairs that can only be performed by properly certified organizations and personnel according to the FAA.
Component Maintenance
Avionics units, various mechanical and electrical aircraft and engine components, and even the entire engines are among some of the components that are inspected in detail in a specialist shop, after being removed. LRUs also face the same fate. In this type of maintenance, you will be working on specific detached parts, rather than on the aircraft itself. A Component Maintenance Manual (CMM) is used to identify the tasks that should be carried out on a particular component. It includes the procedures for restoring the component to a serviceable state.