MSG-3 – A Process Overview

Maintenance Steering Group -3 (MSG-3) is a maintenance planning system for aircraft that has been in use since 1980. The original document has since undergone numerous revisions and the current version of MSG-3 is version 3 which has been in use since 2011.

These days MSG-3 methodology is now the minimum accepted standard for bringing new aircraft into service within the Civil Airline Sector, National Aviation Authorities and the Civil Aviation Authority which approves the outcome report before an aircraft can be launched into service. MSG-3 analysis is frequently carried out at the planning and manufacturing stage using historical data which may exist on each of the components and systems. This has the advantage of allowing changes and modifications to be made at an early stage, if required. MSG-3 is the source of all aircraft inspection schedules. Safety is improved as hidden functional failures are addressed by the process and maintenance efficiency is improved by the elimination of redundant and ineffective tasks.

The basic idea of MSG-3 is as a task-orientated, top-down service which will identify possible failures within an aircraft, analyse the effect of these failures and then calculate the minimum maintenance requirements necessary for safe operation of the aircraft. A focus on safety is uppermost in the process and often a part will need to be overhauled or redesigned if an unacceptable risk is identified. The overall aim of the MSG-3 analysis is to maintain safety whilst formulating a programme of the minimum number of maintenance tasks required to achieve this. Cutting out unnecessary maintenance tasks increases efficiency, in turn resulting in a cost reduction.

MSG-3 is famed for its logical and systematic analytical approach. A prescribed list of questions are followed in a logical order whereby each component and system is considered in turn using a variety of criteria. The reliability of each individual component is considered along with analysis to measure the outcome, particularly on safety and economics, if that component were to fail. Once the MSG-3 process is complete, a maintenance review board report is produced. This report outlines the minimum maintenance requirements for safety and typically contains sections on the system itself, aircraft structures, zonal inspections and performance in lightening/high-intensity radio-frequency. The maintenance review board report is then presented to the Industry Steering Committee (ISC) panel (or FAA in USA) which approves it and this schedule of maintenance is then adopted by the aircraft operator for that aircraft.


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