CAMO or CAO? Choosing the Right Continuing Airworthiness Organization for Your Light Aircraft

The short answer: a CAMO (Part-CAMO, Annex Vc) is approved to *manage* continuing airworthiness, while a CAO (Part-CAO, Annex Vd) is a combined organization that can manage continuing airworthiness and perform maintenance, but only for aircraft that are not complex motor-powered aircraft and not listed on a licensed air carrier's air operator certificate. For a private owner of a Part-ML aircraft, using either one is usually optional; for some operators, it is mandatory.

This comparison is for Americans who own or operate a light aircraft on an EU Member State register, and for U.S. maintenance businesses wondering how the European approvals work. It relies only on Regulation (EU) No 1321/2014 as consolidated on 22 February 2026 and on EASA's continuing airworthiness FAQ. FAA repair station or inspection authorization rules are not covered by these sources.

Do you need an organization at all?

Part-ML starts from owner responsibility: under ML.A.201(a), the owner ensures no flight takes place unless the aircraft is airworthy, equipment is serviceable or marked unserviceable, the airworthiness certificate is valid and maintenance follows the aircraft maintenance program (AMP). Whether an organization is required depends on how the aircraft is used.

• Commercial training and certain other operations (ML.A.201(e)): for aircraft operated by commercial approved or declared training organizations (ATOs/DTOs), or not operated under Part-NCO, or operated under Part-BOP Subpart-ADD or Part-SAO Subpart-DEC, the operator must be approved as a CAMO or CAO, or contract one, and all maintenance must be done by approved maintenance organizations.
• Everyone else (ML.A.201(f)): the owner *may* contract the management tasks to a CAMO or CAO under a written contract following Appendix I. If not, the owner remains responsible for performing those tasks properly.
• Aircraft on an AOC used for non-commercial or specialized operations (ML.A.201(h)): the continuing airworthiness tasks are performed by the AOC holder's CAMO or CAO.

EASA's FAQ confirms the practical consequence for commercial ATOs and DTOs: their non-complex aircraft cannot be maintained by independent certifying staff, because a maintenance release by an approved organization (a CAO with maintenance privilege, a Part-M Subpart F organization or a Part-145) is required.

What a CAMO is approved to do

Under CAMO.A.125(d), a CAMO may manage the continuing airworthiness of aircraft listed on its certificate, including aircraft of licensed air carriers when they are also listed on the AOC; subcontract limited continuing airworthiness tasks to organizations working under its management system; extend an ARC under ML.A.901(c); and approve the AMP of Part-ML aircraft it manages. If its principal place of business is in a Member State, it may additionally be approved to carry out airworthiness reviews and issue ARCs (CAMO.A.125(e)) and, on top of that, to issue permits to fly (CAMO.A.125(f)).

A CAMO does not itself perform maintenance under that approval. Where it is not also approved as a maintenance organization, CAMO.A.315(c) requires it to manage written maintenance contracts so that all maintenance is ultimately carried out by an appropriately approved maintenance organization.

The organizational requirements are substantial: an accountable manager with corporate authority over funding, nominated persons for compliance, compliance monitoring and safety management (CAMO.A.305), a full management system with safety policy and hazard identification (CAMO.A.200), an information security management system under Implementing Regulation (EU) 2023/203 (CAMO.A.200A), an internal safety reporting scheme, and a continuing airworthiness management exposition (CAME) approved by the authority.

What a CAO is approved to do

CAO.A.010 limits the CAO to aircraft that are not complex motor-powered aircraft and not listed on a licensed air carrier's AOC. Within that scope, CAO.A.095 lists privileges that can be held singly or together:

1. Maintenance: maintain approved aircraft and components at approved locations, or anywhere when an aircraft is unserviceable or occasional support is needed, and issue certificates of release to service.
2. Continuing airworthiness management: manage the aircraft, approve AMPs for Part-ML aircraft, and extend ARCs.
3. Airworthiness review: for a CAO with its principal place of business in a Member State, issue ARCs (and recommendations where applicable) and extend them. A CAO with maintenance privileges may also be approved to perform Part-ML airworthiness reviews and issue the ARC.
4. Permit to fly: for CAOs holding the airworthiness review privilege, under the conditions of Part-21.

The CAO's structure is lighter. It needs an accountable manager, a person or group responsible for compliance, a combined airworthiness exposition (CAE) and a quality system with a quality manager (CAO.A.100). A small CAO (only Part-ML aircraft in scope, or no more than 10 full-time equivalent maintenance staff, or no more than 5 in continuing airworthiness management) may replace the quality system with regular organizational reviews, if the authority approves, provided it does not contract management tasks to others.

Side-by-side comparison

What the owner signs: the Appendix I contract

Appendix I to Part-ML fixes the contract for Part-ML aircraft, whether the organization is a CAMO or a CAO. It names the aircraft, the owner, the organization and the type of operation, and contains a mandatory statement entrusting the organization with continuing airworthiness management and AMP approval. If either party breaches it, the contract becomes null, full responsibility returns to the owner, and the owner informs the authority of the Member State of registry within 2 weeks.

• Organization's duties include: having the type on its approval, approving the AMP and giving the owner a copy with justifications for deviations, organizing a bridging inspection, arranging maintenance and AD compliance, archiving records, and sending any ARC issued or extended to the authority within 10 days.
• Owner's duties include: a general understanding of the AMP and Part-ML, presenting the aircraft as directed, not modifying it without consulting the organization, reporting defects through the logbook, reporting flight hours, and informing the organization within 30 days of any pilot-owner maintenance.

For U.S.-based maintenance businesses

Where an organization's principal place of business is outside the Member States, the competent authority is the Agency itself (CAO.1 and CAMO.A.105(b)); EASA's FAQ notes that lists of organizations it oversees are published on its website. Note that the airworthiness review privilege, for both CAMO and CAO, is reserved to organizations with their principal place of business in a Member State.

To weigh your own case, ask the EASA continuing airworthiness knowledge base something like “Is there a real difference between a CAO and a CAMO, or are they basically the same thing?” or “I own a small aeroplane under 1,200 kg: do I need to hire a management organisation?” Answers cite Part-CAMO, Part-CAO or Part-ML directly.

This article explains EU rules; it is not legal advice on structuring an organization or a contract. Sources: EUR-Lex and EASA's FAQ. EASA's AMC/GM are not part of the knowledge base.