Transcript
Receiving a Part-145 approval does not mean that an organisation can automatically perform every type of aircraft maintenance. Each organisation is approved for a defined scope of work known as the Terms of Approval. These terms describe exactly what the organisation is permitted to maintain and under which conditions the work may be performed.
The approval scope is linked directly to the organisation’s available personnel, facilities, tooling, technical data, and management systems. This helps ensure that maintenance activities remain properly controlled and supported. Under 145.A.20, maintenance organisations receive ratings that define the categories of maintenance they may perform. Some organisations may specialise in aircraft line maintenance, while others perform heavy base maintenance, engine overhaul, component repair, or specialised services. The approval may also contain limitations restricting the organisation to certain aircraft types, engine models, workshop capabilities, or maintenance tasks.
For example, an organisation approved for Airbus A320 line maintenance would not automatically be authorised to perform heavy structural maintenance on a different aircraft type.
Personnel should therefore understand that maintenance activities must always remain within the organisation’s approved scope.
An approval rating alone is not enough to safely support maintenance activities.
The organisation must also maintain the practical capability to perform the work correctly.
This means having:
- competent personnel,
- appropriate facilities,
- approved tooling,
- current maintenance data,
- and effective organisational procedures.
Even if a task technically falls within the organisation’s approval rating, maintenance should not proceed if the necessary resources or expertise are unavailable. Operational capability and approval scope must always remain aligned.
AMC1 145.A.20 provides additional material regarding how organisations manage approval scope and capability control. In practice, this often involves internal capability assessments before maintenance begins. For example, before accepting a new aircraft type, maintenance task, or contracted activity, the organisation may review whether it has the necessary:
- personnel,
- tooling,
- technical data,
- and facilities
available to safely support the work.
This process helps prevent unsupported maintenance activities and reduces operational risk.
When organisations wish to expand their approval scope, changes normally require review by the competent authority. Examples may include adding a new aircraft type, opening a new line maintenance station, or introducing a specialised workshop capability. Before approval changes can be accepted, the organisation must demonstrate that the required systems and resources are already in place. This may involve updates to:
- procedures,
- facilities,
- training,
- tooling,
- and organisational oversight systems.
The authority then evaluates whether the organisation can safely support the expanded scope of work.
Terms of Approval and capability controls form an important part of aviation safety. They help ensure that maintenance activities are only performed when the organisation has the proper resources, competence, and operational support available. Performing maintenance outside approved capability may lead to:
- maintenance errors,
- certification problems,
- regulatory findings,
- or operational safety risks.
Personnel involved in planning, supervision, management, or certification activities should therefore become familiar with 145.A.20, AMC1 145.A.20, and associated organisational procedures governing approval scope and organisational capability.
Regulatory References
- 145.A.20
- AMC1 145.A.20
- GM1 145.A.20