Procedure for Maintenance Organisations

MCAR-145 Approved Maintenance Organisations

Requirements for the maintenance of aircraft used for Commercial Air Transport (CAT), or aircraft classified as a “Large Aircraft” are specified in MCAR-145. Aircraft not classified as “Large Aircraft” and not used for CAT purposes can also be maintained by an approved MCAR-145 Maintenance Organisation.


Application for an MCAR-145 Maintenance Organisation Approval shall be made in accordance with Section A of MCAR-145 using the CAA Form 2. The application shall contain a copy of the draft MOE (refer below) and Form 4s. The application may be emailed to the CAA or sent via normal post. Details of the CAA regulations related to fees and charges can be found in MCAR-187.

Once the application package is complete and the fees paid, applicants will be issued a preliminary approval number with a suffix "P" indicating the pending status of the approval (for example MV.145.XXXXP). Airworthiness section of the CAA then starts the technical evaluation of the application according to MCAR-145.


The applicable charges are specified in MCAR-187. Details of the CAA Bank account may be downloaded from here. The organisation is also responsible for the audit costs in accordance with ASC 187-1

Time Frame

The normal time frame to process an MCAR-145 approval is 2 months from the application date, however the amount of time taken is largely dependent on the ability of the applicant to produce the documentation and rectify any non-conformances.

Technical Investigation


The applicant shall identify and analyse the maintenance processes intended to be included in the MCAR-145 approval and ensure compliance of such processes with MCAR-145. This analysis shall be used to develop the draft MOE (including any assoicated list(s) and procedure(s) as applicable.

EASA guidance document UG.CAO.00024 can be used to develop the MOE. Additional guidance material on specific technical requirements published by EASA may also be used in this process.

Form 4s

Refer to EASA guidance document WI.CAO-00115

Document Review

A CAA Inspector reviews the draft MOE to ensure full compliance with the applicable requirements and the relevant technical instructions. The inspector also verifies compliance of each management personnel (Form 4 post holders) and her/his deputies (where applicable) with the applicable requirements by using the relevant instructions as reference material.

Internal Audit

Once the draft of the MOE and the applicable CAA Forms 4 are confirmed as being acceptable by the assigned inspector, the Applicant’s Quality department shall audit the Organisation in full for compliance with the MOE and MCAR-145. All relevant CAA instructions dealing with specific technical matters (i.e. certifying staff, line maintenance, composite repairs, etc.) as applicable to the specific Organisation, shall be also used as reference.

A statement signed by the Organisation’s Quality Assurance Manager shall be provided to the assigned inspector before the CAA audit takes place confirming that processes, facilities, documentation, tools, equipment, material, components and personnel subject to the application have been reviewed and audited showing compliance with all applicable MCAR-145 and MCAR-M requirements. This means that all findings raised during this internal audit must have been closed with appropriate corrective actions before issuing this statement.

The relevant internal audit report(s) including the associated corrective actions shall be provided by the organisation along with the QM statement to the assigned inspector. The CAA compliance checklist may be used to demonstrate this.

CAA Audit

Once the draft MOE, CAA Form 4s, QM statement and internal quality audit report are deemed acceptable, the assigned inspector will initiate the on-site investigation. The inspector will liaise with the Organisation for scheduling the audit and to agree on the audit programme.

The CAA inspector(s) will audit the organisation against MCAR-145. They will also meet the Accountable Manager and all Form 4 post holders for an interview. The Inspector(s) will also present audit findings and conclusions to the organisation at the end of the audit. Organisations will be given the opportunity to discuss any non-compliances and timeframes. The final audit report will be produced with 20 working days from the end of the audit.

Should the initial investigation lead to significant and/or numerous discrepancies, this would show insufficient understanding / compliance of the applicant and a lack of effectiveness of the Q/A system. In that case the CAA may terminate/suspend the application, limit the requested scope of work or not accept the proposed post holders and/or nominated personnel.


Once the applicant’s compliance with MCAR-145 has been established and all findings are closed, the CAA will approve the MOE and issue the approval certificate.


Each approved organisation is audited at least once a year. This can be extended to two years for organisations that hold approvals from other CAAs or where the scope of work is extremely limited.

MCAR-M Subpart F Maintenance Organisations

The procedure for approval of MCAR-M Subpart F maintenance organisations is the same as that of an MCAR-145 organisation. Care must be taken when using the MOE guidance and other technical procedures applicable to MCAR-145.