Who Keeps Aircraft Airworthy? The Evolving Role of Continuing Airworthiness in European Aviation
By Florin Necula, PhD | Maintenance Manager & Licensed Aircraft Engineer
Jul 29th, 2025
INTRODUCTION
In the world of aviation, the journey to ensuring safety does not end at certification. While initial airworthiness is concerned with the design and manufacture of an aircraft, continuing airworthiness is the discipline that ensures that aircraft remain airworthy throughout their operational life. This ongoing vigilance is a cornerstone of aviation safety – a responsibility shared between regulatory bodies, design organizations, maintenance providers, operators and dedicated airworthiness management entities (EASA, 2014; ICAO, 2022).
This article explores the concept of continuing airworthiness, placing it in historical context and unpacking the key actors and regulatory interfaces defined within the European Union Aviation Safety Agency (EASA) framework.
A BRIEF HISTORY OF AIRWORTHINESS
Pre-JAA and JAR-OPS Era
Before the Joint Aviation Authorities (JAA) and the introduction of harmonized European aviation regulations, airworthiness responsibilities were largely decentralized. Each national aviation authority — such as the UK CAA or Germany’s LBA — operated under its own maintenance rules and oversight frameworks. In this fragmented regulatory landscape, maintenance organizations held both the operational and managerial responsibility for ensuring continuing airworthiness on behalf of the aircraft operator (JAA, 2000).
Maintenance organizations developed maintenance schedules, tracked compliance with airworthiness directives (ADs), and managed technical records. However, this model blurred the lines between execution and oversight, increasing the risk of organizational bias or oversight failure.
With the implementation of JAR-OPS 1 (JAA, 2000), some structural improvements were made. Operators were required to submit a Maintenance Management Exposition (MME), and maintenance was conducted in accordance with JAR-145-approved organizations. Nonetheless, responsibility for airworthiness remained largely with maintenance providers, with operators exercising limited direct control over the continuing airworthiness process.
From JAR-OPS to EASA Part M: A Paradigm Shift
The creation of EASA in 2002 and the subsequent adoption of Regulation (EU) No 1321/2014 introduced a clearer, risk-based, and role-separated framework. This regulation formalized the split between continuing airworthiness management (CAMO) and maintenance execution (Part 145), reinforcing the principle that while maintenance may be contracted, airworthiness responsibility is not delegable (EASA, 2014; EASA, 2023).
INITIAL AIRWORTHINESS VS CONTINUING AIRWORTHINESS
Initial airworthiness refers to the design, certification, and production of aircraft and components, primarily governed by Part 21 (EASA, 2020). It includes activities like Type Certification (TC), Supplemental Type Certification (STC), and production approvals.
By contrast, continuing airworthiness encompasses the processes required to maintain an aircraft’s airworthy condition post-delivery – including inspections, repairs, modifications, airworthiness reviews, and compliance with ADs and service bulletins (ICAO, 2022; EASA, 2014).
CAMO: THE AIRWORTHINESS BACKBONE
The Continuing Airworthiness Management Organization (CAMO) was introduced to manage tasks previously embedded within either the operator or maintenance organization. As defined under Part M Subpart G, a CAMO is responsible for:
- Developing and controlling the Aircraft Maintenance Programme (AMP)
- Monitoring compliance with ADs and manufacturer data
- Managing the planning and coordination of scheduled maintenance
- Maintaining airworthiness records and logbooks
- Performing Airworthiness Reviews and issuing or extending the ARC (EASA, 2014)
This clear segregation between “management” and “execution” marked a safety-driven evolution from the JAR-OPS framework, enhancing accountability and traceability.
PART 145 ORGANISATIONS: THE MAINTENANCE EXECUTORS
Part 145-approved organizations are responsible for physically performing maintenance, inspections, modifications, and repairs, and for releasing aircraft or components back to service. Their obligations include:
- Adhering to approved maintenance data and instructions (e.g., AMM, SRM, CMM)
- Certifying maintenance tasks via Certificate of Release to Service (CRS)
- Ensuring staff competence and proper facilities
- Reporting occurrences that affect airworthiness (EASA, 2014)
Under JAR-OPS, many of these organizations also managed continuing airworthiness — a practice that EASA explicitly restructured to prevent conflicts of interest and improve safety oversight (JAA, 2000; EASA, 2023).
CAMO AND PART 145: A SYNERGISTIC RELATIONSHIP
Today, the CAMO determines what needs to be done and when, while the Part 145 organization handles how the maintenance is performed. This separation of responsibilities improves operational integrity, as each party can focus on its area of expertise, while maintaining structured communication and documented coordination.
Interface control documents, contracted maintenance agreements, and shared access to aircraft records (e.g., task cards, AD status reports) are now standard practice to ensure alignment and regulatory compliance (EASA, 2023).
CAMO AND PART 21: DESIGN MEETS OPERATION
Continuing airworthiness also relies heavily on coordination with Part 21 Design Organizations (DOA). Whether addressing modifications, repairs, or configuration management, CAMOs must ensure that:
- Only approved design data is used
- Changes to the aircraft are correctly recorded and certified
- Operational documentation and maintenance programmes are updated accordingly (EASA, 2020)
This interface was far less structured during the JAR era, with many maintenance providers communicating directly with OEMs without formal approval flows.
AIRWORTHINESS REVIEW: CLOSING THE LOOP
A cornerstone of continuing airworthiness under EASA is the Airworthiness Review, mandated under Part M Subpart I. It includes:
- A full review of aircraft records for completeness and compliance
- A physical survey of the aircraft
- Assessment of conformity to the approved type design
- Verification of maintenance programme adherence
When successfully completed, the CAMO issues or extends an Airworthiness Review Certificate (ARC), validating the aircraft’s airworthiness for up to 12 months (EASA, 2014).
TRANSITION OF ARC PRIVILEGES FROM COMPETENT AUTHORITIES TO CAMOS
When the Airworthiness Review Certificate (ARC) process was first introduced under the EASA regulatory system, Competent Authorities (such as national aviation authorities) were initially responsible for performing airworthiness reviews and issuing ARCs, particularly for complex aircraft or those transitioning between regulatory systems. However, with the establishment and maturing of CAMOs, the privilege to conduct these reviews and issue or extend ARCs was progressively delegated to approved and appropriately authorized CAMOs under Part M Subpart I (EASA, 2014).
This shift was driven by several key objectives: reducing administrative burdens on authorities, improving efficiency, and enabling operators to maintain better oversight and scheduling flexibility through their internal or contracted CAMOs. Importantly, CAMOs granted this privilege must demonstrate robust systems, competent personnel (including appropriately qualified airworthiness review staff), and a track record of compliance. Competent Authorities continue to retain oversight responsibilities and may still perform reviews themselves, particularly for high-risk or non-commercial operations. However, the delegation of ARC privileges represents a strategic move towards a more decentralized, performance-based oversight model — allowing regulatory authorities to focus resources on risk-based surveillance, rather than routine compliance tasks (EASA, 2023).
ULTIMATE RESPONSIBILITY FOR AIRWORTHINESS
Despite the distributed responsibilities across various actors, the ultimate legal and operational responsibility for ensuring an aircraft’s airworthiness lies with the aircraft operator or owner (EASA, 2014, M.A.201; ICAO, 2022).
In the case of commercial air transport, the operator must ensure:
- The aircraft is maintained in an airworthy condition
- Required maintenance and inspections are performed on time
- The Airworthiness Certificate remains valid
- All applicable ADs and limitations are complied with (EASA, 2014)
Even when a CAMO is subcontracted to manage airworthiness or when maintenance is outsourced to a Part 145 organization, responsibility is not transferred. The operator remains accountable for ensuring those organizations are approved, competent, and effectively coordinated (EASA, 2023).
For privately operated aircraft, these obligations fall to the registered owner, who must ensure maintenance and airworthiness reviews are carried out in accordance with Part ML and other applicable rules (ICAO, 2022).
This principle – that delegation of tasks does not equal delegation of accountability – is central to the modern regulatory approach and reflects international standards defined in ICAO Annex 8.
CONCLUSION
The evolution from JAR-OPS to the EASA framework represents a major structural shift in how continuing airworthiness is managed in European aviation. By clearly defining the roles of CAMO, Part 145, and Part 21 organizations — and reinforcing the ultimate responsibility of the operator — the system enhances safety, traceability, and regulatory oversight.
As maintenance practices, aircraft systems, and operational models continue to evolve, so must our approach to managing airworthiness. The future lies in enhanced digital tracking, integrated airworthiness data environments, and ever-closer collaboration across stakeholders — all under the guiding principle that airworthiness is not just maintained but continuously assured.
REFERENCES
EASA (2014). Regulation (EU) No 1321/2014 on the Continuing Airworthiness of Aircraft and Aeronautical Products, Parts and Appliances, and on the Approval of Organizations and Personnel Involved in These Tasks. European Union Aviation Safety Agency.
EASA (2020). Part 21 – Certification of Aircraft and Related Products, Parts and Appliances, and of Design and Production Organizations. European Union Aviation Safety Agency.
EASA (2023). Acceptable Means of Compliance (AMC) and Guidance Material (GM) to Part M and Part CAMO. European Union Aviation Safety Agency.
EASA (2012). Regulation (EU) No 965/2012 on Air Operations. European Union Aviation Safety Agency.
ICAO (2022). Annex 8 to the Convention on International Civil Aviation – Airworthiness of Aircraft. 11th Edition. International Civil Aviation Organization.
JAA (2000). Joint Aviation Requirements – JAR-OPS 1 and JAR-145. Joint Aviation Authorities.
