Part-145: The Approved Maintenance Organisation
EASA Part-145 explained: what an approved maintenance organisation is, its terms of approval and scope of work, the MOE, and the privileges it may exercise.
Dionysis Kefalas4 min readFor Part-145 and CAMO staff
Part 1 of 6 in EASA Part-145 Maintenance Organisation Show parts
Quotes checked on against EASA Easy Access Rules for Continuing Airworthiness (Regulation (EU) No 1321/2014) — 2 Sep 2025 revision.
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What a Part-145 organisation is
The approval certificate is for the maintenance of aircraft and components. Part-145 is the section that sets the requirements for issuing that certificate and for keeping it. It sits in the same regulation as the continuing airworthiness series.
This Section establishes the requirements to be met by an organisation to qualify for the issue
or continuation of an approval certificate for the maintenance of aircraft and components.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
A Part-145 organisation is the holder of that approval certificate. The line station, the base maintenance hangar, and the engine or component workshop are the places it covers. The rest of this series is what the approval is made of: the people, the data, the release, the exposition, and tool control.
Bounded by its approval
What the organisation maintains is fixed by the terms of approval attached to the organisation certificate, and by the scope of work in the maintenance organisation exposition (MOE).
(a)The organisation’s scope of work shall be specified in the maintenance organisation
exposition (MOE) in accordance with point 145.A.70.
(b)The organisation shall comply with the terms of approval attached to the organisation
certificate issued by the competent authority, and with the scope of work specified in the MOE.
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
The exposition has its own guide.
What a Part-145 organisation may do
In accordance with the MOE, the organisation shall be entitled to carry out the following tasks:
(a)maintain any aircraft or component for which it is approved at the locations identified in
the certificate and in the MOE;
(b)arrange for the maintenance of any aircraft or component for which it is approved at another
subcontracted organisation that works under the management system of the organisation. This is
limited to the work permitted under the procedures established in accordance with point 145.A.65
and it shall not include a base maintenance check of an aircraft, or a complete workshop
maintenance check or overhaul of an engine or an engine module;
(c)Maintain any aircraft or any component for which it is approved at any location subject to
the need for such maintenance arising either from the unserviceability of the aircraft or from
the necessity of supporting occasional line maintenance, subject to the conditions specified in
the exposition;
(d)Maintain any aircraft and/or component for which it is approved at a location identified as
a line maintenance location capable of supporting minor maintenance and only if the organisation
exposition both permits such activity and lists such locations;
(e)Issue certificates of release to service in respect of completion of maintenance in
accordance with point 145.A.50;
(f)if specifically approved to do so for aircraft covered by Annex Vb (Part-ML) and if it has
its principal place of business in one of the Member States, the organisation may perform
airworthiness reviews and issue the corresponding airworthiness review certificates under the
conditions specified in point ML.A.903 of Annex Vb (Part-ML).
Quoted word for word from Regulation (EU) No 1321/2014, Easy Access Rules for Continuing Airworthiness, 2 Sep 2025 revision.
The privileges are exercised in accordance with the MOE, for an aircraft or component for which the organisation is approved. Point (e) is the certificate of release to service under point 145.A.50, covered in its own guide. Point (b) shall not include a base maintenance check of an aircraft, or a complete workshop maintenance check or overhaul of an engine or an engine module. Point (f) applies where the organisation is specifically approved to do so for aircraft covered by Annex Vb (Part-ML), and has its principal place of business in one of the Member States. The airworthiness review itself is the subject of the airworthiness review guide.
How this series is organised
This guide is the map. Certifying Staff, Support Staff and Personnel covers the accountable manager, the nominated persons, and the certifying and support staff. Maintenance Data, Components and Performing the Work covers the data, the components, the tools, and the performance of maintenance. Certification of Maintenance and Records covers the certificate of release to service and the records. The Maintenance Organisation Exposition (MOE) covers the exposition that specifies the scope of work. Tool Control in Aviation Maintenance: 145.A.40 Calibration covers tool control and calibration in practice.
Where to read it yourself
Part-145 is Annex II to Regulation (EU) No 1321/2014, consolidated with the AMC and GM in the EASA Easy Access Rules for Continuing Airworthiness, a free download. Every citation in this guide was checked against the 2025-09-02 revision. The same book contains Part-M and Part-66.
Educational content, not regulatory compliance advice. Verify against the current regulation text before relying on it.
In this series
Related
- Certifying Staff, Support Staff and Personnel under Part-145Guide · 7 min
- Maintenance Data, Components and Performing the WorkGuide · 8 min
- Certification of Maintenance and Records under Part-145Guide · 6 min
- The Maintenance Organisation Exposition (MOE)Guide · 4 min
- Tool Control in Aviation Maintenance: 145.A.40 CalibrationGuide · 16 min
Written by Dionysis Kefalas. Retired Hellenic Air Force Captain and founder of Avioverse. About the author
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