Sofema Aviation Services (SAS) (www.sassofia.com) takes a look at how The Aircraft Maintenance Program comes together.
The Role of the MPD
The Primary Source of the Operators Aircraft Maintenance Program (AMP) is the Maintenance Planning Document (MPD).
The MPD is actually an “unapproved” document and is essentially a repository for multiple maintenance requirements coming from other documents (so-called “sources”) such as the Airworthiness Limitation Section (ALS) or the Maintenance Review Board Report (MRBR).
The MPD establishes the link between the requirements and the maintenance procedures listed in the Aircraft Maintenance Manual (AMM). The MPD also contains additional information to help operators in the organization of maintenance (e.g. access information, man-hours, elapsed time, required skills, etc.).
Optimization of maintenance programme intervals essentially relies on scheduled and unscheduled data collected by the manufacturer from different operator environments, aircraft utilisation, aircraft configuration, aircraft age, etc. (Without operators’ data, manufacturers do not have the means to optimize maintenance tasks.)
Note – there are different MPD concepts depending on the aircraft manufacturers.
- Airbus MPD identifies all repetitive scheduled maintenance requirements and consolidates within the source documentation whereas other aircraft manufacturers may consider the MRBR only, or the MRBR and the ALS.
- Special attention should thus be paid when comparing MPDs between aircraft from different manufacturers.
The MPD can be used as a source for all three groups but it must be ensured that requirements issued since its publication are not overlooked.
Note – It is essential to ensure that operators implement a thorough aircraft configuration management to only select tasks applicable to their fleet and, more importantly, not to miss any requirements that apply.
Example – A320 Family MPD lists about 3,000 maintenance requirements for all models. Customized at aircraft level in an operator’s AMP this number is reduced to approximately 1,000 tasks.
Manufacturer Maintenance Requirements for Revision / Evolution
ALS and MRBR are developed in the frame of the initial Type Certification (TC) & typically are kept up-to-date for the duration of the life of the programme.
There are three major triggers for a maintenance programme revision:
- Regulation changes
- Configuration changes (aircraft modifications)
- In-service experience feedback
Manufacturer Maintenance Requirement Summary
The manufacturer maintenance requirements are published in multiple documents (e.g. ALS parts, MRBR, etc.) and developed according to quantitative and qualitative analyses.
The Role of the Certification Process / MRB Process is to:
- Demonstrate compliance with instructions for continued airworthiness regulations according to industry standards (e.g. MSG-3)
- Approved by the certification authorities
- Envelope the entire fleet for a given programme and cover all possible configurations.
- Provide a list of maintenance requirements sorted by ATA chapter
The Operators AMP shall list all requirements:
- From the manufacturer’s regulatory compliance documentation (e.g. MRBR, ALS, Certification Maintenance Requirements (CMR’s) as well as specific procedures applicable to the operator’s fleet).
- From the manufacturer’s recommendations (e.g. SB, SIL and OIT) (As Applicable) – provided the operator’s engineering office considers them to be effective in the local operational environment.
- Coming from Airworthiness Directives (AD).
- Imposed by the operator’s NAA and national laws
- Coming from the operator’s in-service experience.
- Coming from any aircraft Supplemental Type Certificate (STC).
Note – Operators may not deviate from the ALS and AD requirements applicable to their fleet. However, regarding the MRBR, operators have the possibility to deviate from the published requirements according to procedures agreed with their NAA.
Next Steps
Please see www.sassofia.com & www.sofemaonline.com for multiple courses compliant with EASA Part CAMO objectives. Email Team@sassofia.com for any questions or further guidance.
Tags:
Aircraft Maintenance Manual, Aircraft Maintenance Program, ALI, AMP, aviation, CMR, Maintenance Planning Document, MPD, MRB, SAS blogs, Type Certification
