Contracted vs Subcontracted CAMO Activities Under Part-CAMO
Understanding contracted vs subcontracted CAMO activities is one of the most misunderstood areas of Part-CAMO compliance.
Under Regulation (EU) No 1321/2014, operators must clearly distinguish between:
- contracted maintenance performed by approved maintenance organisations such as Part-145 providers
- subcontracted continuing airworthiness management tasks performed under the CAMO’s own management system and oversight
Sometimes these terms are used interchangeably. From a regulatory perspective, this is incorrect—and it regularly creates findings during initial approval and authority surveillance audits.
The real regulatory question is not who performs the work.
It is:
Who remains in control of continuing airworthiness?
That is what the Competent Authority will assess.
If you are establishing the wider approval structure, our guide on how to build a CAMO from scratch explains how these responsibilities fit within the full Part-CAMO organisation.
If you are documenting these responsibilities inside your exposition, our guide on how to write a CAME explains how contracted and subcontracted activities should be controlled and described.
This article explains the regulatory framework, the correct use of Appendix II and Appendix IV, and what authorities expect to see in practice.
1. The Regulatory Framework Behind Contracting and Subcontracting
The strongest CAMO organisations build this distinction around the actual regulation—not internal terminology.
The key references are:
- CAMO.A.125 — Terms of approval and privileges
- CAMO.A.200 — Management system
- CAMO.A.300 — Continuing Airworthiness Management Exposition (CAME)
- CAMO.A.315(c) — Contracted maintenance arrangements
- Appendix II to AMC1 CAMO.A.125(d)(3) — Subcontracting of continuing airworthiness management tasks
- Appendix IV to AMC1 CAMO.A.315(c) — Contracted maintenance
These two appendices are not interchangeable.
They regulate two completely different relationships.
Appendix II applies to Subcontracted CAMO tasks. These are continuing airworthiness management functions performed under the CAMO approval structure.
Appendix IV applies to Contracted maintenance. These are maintenance services performed by approved maintenance organisations working under their own approvals.
Understanding this distinction is fundamental.
2. Contracted Maintenance Under Appendix IV to AMC1 CAMO.A.315(c)
Contracted maintenance refers to maintenance performed by external organisations such as Part-145 providers.
Typical examples include:
- base maintenance
- line maintenance
- engine shop visits
- component repairs
- structural repairs
- NDT services
- outstation maintenance support
These organisations operate under their own approval—not under the CAMO approval.
This is not CAMO subcontracting.
The maintenance contract should define:
- scope of work
- maintenance locations
- maintenance programme reference
- AD and SB handling
- deferred defect responsibilities
- CRS responsibilities
- technical records flow
- meetings and communication routines
- subcontracting by the maintenance organisation
- supplier monitoring and oversight
The purpose of the contract is to ensure that all the maintenance is carried out by the maintenance organisation in accordance with the CAMO’s maintenance data and requirements.
Appendix IV to AMC1 CAMO.A.315(c)
This means the CAMO retains control of continuing airworthiness decisions even when maintenance is performed externally.
The CAMO must still control:
- maintenance planning
- work scope definition
- AMP control
- aircraft status management
- AD compliance decisions
- deferred defect acceptance
- CRS acceptance
Outsourcing maintenance does not outsource airworthiness responsibility.
3. Line Maintenance Contracts and the IATA SGHA
For line maintenance arrangements, many operators use the IATA Standard Ground Handling Agreement (SGHA) as the commercial framework for the contract, particularly where maintenance support forms part of wider station handling arrangements.
This is specifically recognised by EASA.
For line maintenance… IATA Standard Ground Handling Agreement may be used as a basis.
Appendix IV to AMC1 CAMO.A.315(c)
This is especially common for:
- outstation support
- transit maintenance
- handling plus technical support packages
- line stations with integrated operational services
However, the SGHA does not replace regulatory compliance.
It supports the commercial agreement.
The CAMO must still ensure all Appendix IV requirements are covered, including:
- deferred defect control
- AD compliance
- technical records flow
- release to service responsibilities
- maintenance programme alignment
- continuing airworthiness accountability
The contract format may vary. The regulatory responsibility does not.
4. Subcontracted Continuing Airworthiness Tasks Under Appendix II to AMC1 CAMO.A.125(d)(3)
Subcontracted CAMO activities are different.
These are continuing airworthiness management tasks performed under the CAMO’s own system of control.
Typical examples include:
- maintenance planning support
- technical records administration
- reliability programme administration
- engineering support
- AD assessment support
- Service Bulletin evaluation support
- AMP development support
These tasks remain part of the CAMO approval structure. They are not external maintenance services.
The CAMO should have adequate competent personnel for the management and supervision of the subcontracted continuing airworthiness management tasks.
Appendix II to AMC1 CAMO.A.125(d)(3)
This is one of the most important regulatory principles.
The CAMO must retain competent internal personnel capable of determining:
- what maintenance is required
- when it must be performed
- by whom
- to what standard
That responsibility cannot be transferred.
Required Controls
Authorities expect:
- pre-subcontract audit
- formal contract definition
- competence assessment
- documented interfaces
- continuous performance monitoring
- override authority by the CAMO
- full CAME integration
This is where many operators underestimate regulatory expectations.
5. What Cannot Be Subcontracted
Not every CAMO function may be subcontracted.
The approved CAMO must retain direct control over:
- Accountable Manager responsibilities
- NPCA responsibilities
- management system oversight under CAMO.A.200
- compliance monitoring
- safety policy and occurrence reporting
- final airworthiness decisions
- authority accountability
- acceptance of aircraft technical status
- regulatory decision-making affecting airworthiness
Authorities will not accept a CAMO that exists only on paper while real control sits elsewhere.
The organisation must demonstrate competent internal decision-making—not contractual delegation.
This becomes even more important as operators integrate Part-IS requirements for CAMOs, where governance and organisational control are increasingly scrutinised.
6. How the CAME Must Describe Both
One of the most common audit findings is poor description of contracted and subcontracted activities inside the CAME.
The exposition must clearly define:
- which activities are contracted
- which tasks are subcontracted
- who retains authority for each decision
- supplier approval and monitoring methods
- escalation pathways
- postholder oversight responsibilities
- authority reporting interfaces
The CAME should not simply list suppliers. It must demonstrate governance.
If the authority cannot identify who controls the function, they will assume the system is weak.
Our full guide on how to write a CAME explains how to structure this section properly.
7. Common Authority Findings
Authorities repeatedly identify the same weaknesses:
- no pre-subcontract audit
- a weak management of change
- weak supplier oversight
- contracts with unclear accountability
- suppliers making decisions reserved for the CAMO
- poor competence assessment of subcontractors
- technical records managed externally with no CAMO control
- unclear reporting lines between postholders and suppliers
Most findings are not caused by outsourcing. They are caused by loss of control.
The regulator is not asking who performs the task. They are asking who makes the airworthiness decision.
8. Build Oversight, Not Just Contracts
Many operators believe a signed contract is enough.
It is not.
Strong CAMOs control suppliers through:
- KPI monitoring
- supplier audits
- performance reviews
- occurrence reporting integration
- escalation pathways
- management review
- authority visibility
- postholder accountability
This links directly to the wider CAMO management system, where compliance monitoring and organisational control support supplier oversight.
A contract proves assignment.
Oversight proves control.
Authorities care about the second one.
Conclusion
Understanding contracted vs subcontracted CAMO activities is not about terminology—it is about regulatory control.
Under Regulation (EU) No 1321/2014, the approved CAMO must remain visibly responsible for continuing airworthiness, regardless of how much work is performed externally.
The strongest organisations demonstrate three things:
- clear accountability
- competent internal decision-making
- continuous supplier oversight
When those three exist together, authority confidence increases and audit findings reduce.
The question is never who performs the task.
The question is always who controls the airworthiness decision.
FAQs
What is the difference between contracted and subcontracted CAMO activities?
Contracted activities are external services performed by approved organisations such as Part-145 maintenance providers, while subcontracted activities refer to specific continuing airworthiness management tasks performed under the CAMO’s own management system and oversight.
Can all CAMO activities be subcontracted?
What is the difference between contracted and subcontracted CAMO activities?
Contracted activities are external services performed by approved organisations such as Part-145 maintenance providers, while subcontracted activities refer to specific continuing airworthiness management tasks performed under the CAMO’s own management system and oversight.
Which regulation covers CAMO subcontracting?
Subcontracting is primarily addressed under CAMO.A.125 and Appendix II to AMC1 CAMO.A.125(d)(3), while contracted maintenance is addressed under CAMO.A.315(c) and Appendix IV to AMC1 CAMO.A.315(c).
Can Part-145 maintenance be considered CAMO subcontracting?
No. Part-145 maintenance organisations work under their own approval and are considered contracted maintenance providers, not subcontracted CAMO functions.
Can IATA SGHA be used for line maintenance contracts?
Yes. Appendix IV to AMC1 CAMO.A.315(c) specifically recognises that the IATA Standard Ground Handling Agreement may be used as a basis for line maintenance contracts, provided all regulatory responsibilities remain properly covered.
What is the most common finding in CAMO subcontracting audits?
The most common issue is unclear responsibility—where contracts exist, but the CAMO cannot demonstrate actual control over continuing airworthiness decisions.
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