A schedule of tasks to be carried out within certain intervals to one or a group of aircraft (fleets) during their operational lifetime with the purpose of maintaining their airworthiness. It is a document that must be approved by the local aviation authority.
While customizing an AMP or aircraft maintenance program, the first 3 main sources that are to consider are the MPD or maintenance program document, the local CAA requirements and the engine maintenance practices (EMM).
MPD is the document containing information from all sources related to maintenance tasks assigned to certain aircraft type/family/model, tasks that where considered as highly recommendable and mandatory after testing, experience, studies while designing, manufacturing and monitoring feedback during the aircraft’s operational life (Reliability).
This is the guide from the manufacturer that contains all tasks that cover every single study made to structures, systems, wiring, computers, etc. It is constantly being improved and revisions are published depending on the manufacturer. Every time a new revision is released, the operators have the responsibility to revise/update their AMP in accordance with the latest MPD revision. A maintenance program document can contain from hundreds to thousands of tasks depending on the number of systems, structures (size), parts that an aircraft has.
Please note that the MPD comes from the manufacturer of the aircraft, not from the engine manufacturer, when building or customizing the aircraft maintenance program the engineer/s in charge must consider the engine maintenance practices that are required regularly for example:
– Oil levels checks,
– Walk around (GVIs),
– Oil filter change, etc.
The local CAA (civil aviation authorities) regulate intervals regarding weight and balance, ATC transponder, ELT, CVR and FDR, these must be considered and prioritized over the MPD intervals in case the same task is mentioned by both manufacturer and the authorities.
Reliability data has a huge role when you are operating with the same aircraft model during a long time, it’s mission is to count the parts that have failed over periods of time, re-adjust or assign a periodicity to prevent them from failing before being replaced or overhauled enhancing safety and reducing or sometimes adding maintenance costs. External factors such as airports near to: desserts, volcanoes, water, harsh environment directly affects the aircraft’s systems and parts, reliability engineers consider these factors while analyzing the data that is being accumulated.
Continuing analysis and surveillance system CASS and Safety management system SMS are also direct sources and mostly take decisions based on the current operation of each aircraft and are in continuous monitoring mode.
All changes should be mentioned in a chapter called Summary of Changes where it is visible what were the main changes made on each task or paragraph that describes how the AMP is handled.
The AMP is used in parallel with the MPD and other sources while doing a Last Done Next Due Review (LDND) which is a must at an End-of-lease or Aircraft transition.
Normally, technical records that have been digitized without any problem undergo this review. In other cases, when the aircraft’s technical records have not been properly reviewed the consultant or airworthiness engineer is in charge of this task on-site where he can see at first hand which documents are available and which are lacking.
The economical impact of not having this job done correctly is serious considering the fact that each maintenance task demands as minimum:
– Manpower (A&P or Aircraft Licensed Engineers),
– Tools,
– Hangar space
The list can get even worse:
– Non destructive tests,
– Floor panel removals,
– Modification mandatory upgrades,
– Unaccomplished airworthiness directives,
– Aircraft on ground.
We invite leasing companies, aviation organizations and businessmen that have an upcoming aircraft transition project to consider our prices, we provide only the best consultancy services on the globe.
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