EASA Part CAMO, Part CAO and EASA Part-M

Maintenance Management – EASA Part CAMO, Part CAO and EASA Part-M

Maintenance management serves the purpose of ensuring continued airworthiness during the life cycle of an aircraft. To this end, basic maintenance measures must be defined before initial operation and their contiuous execution must be monitored. At the same time, the early identification of facts that could endanger airworthiness must be ensured as part of maintenance management.

To ensure continuing airworthiness in a structured and systematic manner, an organizational unit is required as the interface between the operator of an aircraft (e.g., an airline) and the maintenance organisation (Part 145). In the EASA area, this needs managed under an independend organisational structure. The legal requirements for this are described in EASA Part-M and Part CAMO or Part CAO. While Part CAMO formulates requirements for all aircraft operators, Part CAO is for “small CAMOs” specifically for non-complex, non-commercial aircraft operators. So these can apply for easing with a change to the Part CAO.


CAMO stands for Continuing Airworthiness Management Organization.

CAO stands for Combined Airworthiness Organization.

Requirements for Maintenance Management have been published in the Implementing Rule (1321/2014) for Continuing Airworthiness. However, the legal situation has changed 2021. The requirements of CAMO and CAO, which outsourced from Part-M Subpart F and G, and seperated to an independend Part CAMO and Part CAO. The end of the transition period ends in March 2022. The rest of the Part-M (besides Subpart F and G) remains valid.

Further legal requirements for Part-M, CAMO and Part CAO are supplemented by EASAs Acceptable Means of Compliance (AMC). Guidance material was not published yet. The necessary documentation can be found via google inputs “easa easy access part camo”.

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Differences between Part CAMO and Part CAO and Part-M

Part CAMO contains requirements for the quality system of organizations operating aircraft to ensure their continuing airworthiness. Part CAMO is primarily aimed at operators of commercial and complex aircraft. With the exception of Safety Management (SMS), the requirements of the previous Part-M have not changed significantly compared to new Part CAMO.

In contrast, the Part CAO represents a simplification for operators of non-complex, non-commercial aircraft. Thus, certifying staff qualification requirements and operational procedures are slightly reduced from Part CAMO. Also, no distinction is made between line and base maintenance for CAO’s.

Part-M will continue to exist in the future, just without Subpart G and F, which have been spun off into Part CAMO and Part CAO. While Part CAMO and Part CAO impose requirements on the organization and its structure, Part-M makes more technical specifications, e.g. with regard to maintenance standards in execution and documentation, in component classification as well as for release to service (CRS) and airworthiness review certificate.

Differences between Part CAMO and Part CAO and Part-M

The main tasks of EASA Part CAMO organizations essentially include:

  • Ensuring all maintenance is based on an officially approved maintenance program,
  • Correcting deficiencies and damage that affect safe operation and performing modifications and repairs, based on approved maintenance data and repair approvals,
  • a system for evaluating the effectiveness of the maintenance program (reliability monitoring),
  • compliance with airworthiness directives and all other measures issued by the authorities.

The multitude and complexity of these tasks can only be managed if continuing airworthiness is planned, controlled and monitored in a structured manner. What is needed is comprehensive management of maintenance activities. This is all the more true when economic aspects have to be taken into account in addition to the legal requirements. Thus, the focus of maintenance management is increasingly on aligning maintenance planning and optimizing technical reliability from an economic point of view. Nowadays, the goal is no longer just to prevent system or component failures, but rather to minimize operating costs and by optimizing maintenance-related downtime.

Maintenance management tasks can be performed by aircraft operators (respectivly its CAMO organizations) themselves or subcontracted in whole or in part to qualified companies. CAMO operations that perform third-party maintenance management services are referred to as CAMO+ (pronounced CAMO Plus) organizations.

The following describes the major maintenance management activities that aircraft operators are required to ensure.

Maintenance programs

Many components of an aircraft are limited in their lifetime, so they must then either be replaced or maintained. Typical parameters that influence the operational capability of aircraft, engines and propellers, as well as components and equipment, include flight hours, the number of takeoffs and landings (flight cycles), and the area of operation.

Since wear and tear do not stop at aircraft, comprehensive maintenance activities are required to ensure sustained airworthiness. In particular, this is intended to detect or prevent fatigue damage, environmental deterioration and accidental damage in good time. CAMO organizations are responsible for planning the related maintenance activities.

Due to the high technical complexity of aircraft, these measures must be structured and defined for the entire operational cycle of the aircraft or its components in an aircraft maintenance program. This details, through the CAMO organizations, the scope and frequency of maintenance events on aircraft structure, systems, engines, components and parts. At the same time, maintenance programs thus also include the scope description and periodicity of checks. Maintenance programs are predetermined by the manufacturer and adapted by the operator (e.g. an airline / its CAMO) to its individual needs.

Reliability Management

Each aircraft owner or CAMO organization must ensure, through a reliability management system, that it has an analysis system in place to assess the reliability of its maintenance programs. At the same time, operational and maintenance-related threats to airworthiness are to be identified and minimized at an early stage. Furthermore, reliability management monitors the reliability of those systems that, due to their architecture, do not need to be controlled by the maintenance program. The related activities are defined and monitored via a Reliability Program. The core elements of a Reliability Program are components (e.g. systems, components, engines), parameters (e.g. consumptions, temperatures, error messages, findings, failures), frequencies (e.g. permanent, recurring), evaluation requirements.

From the data obtained, engineering (CAMO organizations) must derive the technical reliability and identify the needs for adjustment in the maintenance program or determine other measures. In addition to the Aircraft Reliability Program itself, other reliability subsystems are usually set up, such as for:

  • Aircraft Components (Component Reliability Monitoring),
  • engines (Engine Condition Monitoring),
  • Auxiliary gas turbines (APU Health Monitoring) or
  • Structural components (sampling programs)

Airworthiness Directives (ADs) and Service Bulletins (SBs)

Another task of CAMO operations is to evaluate and incorporate ADs and manufacturer announcements into maintenance planning. An Airworthiness Directive is an officially ordered action to restore adequate safety to an aircraft. ADs are aimed at aircraft owners and operators. Their implementation is mandatory.

The aviation authority then decides in favor of the publication of an AD if:

  • there is a defect in an aircraft, an engine or propeller, or a part or appliance that endangers its airworthiness, and
  • this condition also exists or could occur on other aircraft.

In addition to mandatory Airworthiness Directives published by the aviation authorities, the manufacturers or TC holders of aircraft and engines regularly issue non-binding Service Bulletins (SBs) to their customers. The execution of SBs is voluntary, since their content normally has little or no relevance to safety.

Service Bulletins do not necessarily represent a quality defect, so the publication of a SB is also not comparable to a recall. Thus, the manufacturer is neither obliged to publish SBs, nor to perform SBs for the customer, nor to bear the costs for their execution.

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