EASA Module 13 common mistakes
EASA Module 13 · Understand the traps and how to avoid them.
Confusing Part-66 certifying staff privileges with those of personnel in a Part-145 approved maintenance organisation, e.g. assuming that holding a Part-66 licence alone authorises certification of work in a commercial operation without any organisation authorisation.
Candidates read the licence privileges in Part-66 in isolation and overlook that Part-145 (and Part-CAMO/Part-CAO) impose additional organisational certification authorisation, scope limits and company procedures; the two layers are studied separately and never reconciled.
What to do instead
Build a two-column comparison for each staff category: what Part-66 grants (basic licence categories, type ratings, privileges, limitations) versus what the organisation must add (certification authorisation, scope, work location, shift limits). Practise questions that ask 'who may certify this task' and always answer through the organisation authorisation layer, not the licence alone.
Misapplying the continuing airworthiness management responsibilities of the operator versus the CAMO, e.g. attributing airworthiness review, maintenance programme approval or defect control to the wrong party in a Part-CAMO arrangement.
Module 13 content on Part-CAMO overlaps with Part-M legacy text and with operator obligations under Part-ORO; candidates memorise lists of tasks without mapping each task to the responsible entity and the contractual arrangement (CAMO contract, airworthiness management contract).
What to do instead
Draw a responsibility matrix: task (maintenance programme, AD compliance, airworthiness review, defect deferral, mass and balance, MEL) against responsible entity (owner, operator, CAMO, Part-145). For each cell note the regulatory reference and whether a contract is required. Rehearse with scenario questions that change the operating context (CAT vs non-commercial) and re-derive the answer from the matrix.
Treating the airworthiness review as a purely documentary desk check and forgetting the physical survey requirement, or stating that any Part-66 licence holder can sign the airworthiness review certificate.
The airworthiness review certificate and its eligibility rules are dense and easily reduced to 'review the records'; candidates skip the sample physical survey and the qualification requirements for the person issuing the ARC.
What to do instead
Write out the ARC process step by step: records review, physical survey of a representative sample, resolution of findings, issuance and validity, plus who is eligible (appropriately qualified personnel meeting the experience and training conditions). Test yourself by describing a full ARC for a specific aircraft and checking each step against the regulation text.
Confusing Part-CAO with Part-CAMO and Part-145, for example assuming a Part-CAO organisation can perform base maintenance on large aeroplanes or that its privileges automatically mirror a Part-145 approval.
Part-CAO is a combined, lighter regime aimed at certain smaller or non-commercial aircraft; its privileges and limitations are narrower and are often studied superficially because candidates assume it is 'Part-145 plus CAMO'.
What to do instead
Produce a one-page privilege table for Part-CAO showing aircraft categories, maximum mass and type limits, permitted maintenance (line only, limited base), continuing airworthiness management scope and airworthiness review rights. Contrast each row with Part-145 and Part-CAMO so the boundary conditions become explicit.
Assuming a Part-145 approval covers every aircraft type and every maintenance level the organisation physically can perform, instead of the specific rating and scope listed on the approval certificate.
Candidates learn the structure of Part-145 (facilities, personnel, tools, data, quality) but not that the approval is scope-limited by ratings (A1, A2, A3, A4, B1, B2, B3, C, D) and by type, and that work outside the scope requires different arrangements.
What to do instead
Memorise the rating system and how scope is expressed, then practise questions that give a task (e.g. base maintenance on a specific type, NDT, component overhaul) and ask whether it is within the approval. Always check the rating letter, the type list and the capability list before answering.
Describing the quality system and the independent quality audit as optional or as the same thing as the maintenance procedures, and failing to state that the quality manager must have direct access to the accountable manager.
Quality system requirements are abstract and get compressed into a single sentence; candidates also merge the quality function with production and lose the independence and reporting-line points that exam questions target.
What to do instead
Summarise the quality system as a checklist: documented procedures, audit programme covering all approvals and contracted activities, qualified auditors independent of the audited area, records of audits and corrective actions, feedback to accountable manager, and the direct access reporting line. Learn the difference between the quality manager's role and the accountable manager's responsibility for the system.
Getting the defect and unserviceability control rules wrong, e.g. permitting deferral of a defect with no approved deferral procedure, or accepting an MEL entry that is not in the operator's approved MEL for that aircraft.
Defect deferral sits at the junction of Part-145, the CAMO and the operator's MEL; candidates mix the general principle ('defer only under an approved procedure') with the specific documents and approvals that make a deferral valid.
What to do instead
Learn the hierarchy: airworthiness limitations and ADs must be complied with, no deferral; other defects only under an approved deferral programme (MEL, CDL, approved maintenance data). Practise classifying sample defects into 'ground the aircraft', 'defer under MEL with conditions', 'defer under approved data'. State the document that authorises each deferral.
Confusing Part-147 approved maintenance training organisation requirements with the Part-66 licensing requirements, for example assuming a Part-147 course alone grants a licence or that a Part-147 certificate substitutes for the Part-66 examination.
The two regulations share subject matter (basic training, type training) and candidates blur the boundary between training provision, examination and licence issue.
What to do instead
Separate the chains: Part-147 approves the training organisation and its courses (basic, type, continuation); Part-66 sets the knowledge, experience and examination requirements for the licence; the competent authority issues the licence. Map each element to its regulation and practise questions that ask 'what does the Part-147 certificate prove and what does it not prove'.
Understating the Part-147 instructor and examiner qualification requirements and the requirement for documented assessment, treating instructors as interchangeable with any experienced engineer.
Candidates focus on course content and syllabi and skim the personnel, assessment and record-keeping requirements, which are precisely what the exam tests.
What to do instead
List the Part-147 personnel requirements: competence and experience of instructors and examiners, knowledge of the assessment methods, independence in examination, and records of trainee progress and examination results retained for the required period. Then check each against a sample organisation description and identify the non-compliance.
Misreading the occurrence-reporting and continuing airworthiness data flow, e.g. sending a report to the wrong body or assuming occurrence reporting is optional for maintenance organisations.
Reporting obligations appear in several places (Part-145, Part-CAMO, Part-ORO, plus the competent authority and the state of registry/design), and candidates memorise one route without understanding the mandatory nature and the different addressees.
What to do instead
Build a reporting map: what must be reported (serious incidents, defects with airworthiness impact, unapproved parts, maintenance errors), to whom (competent authority, organisation's quality system, design approval holder where relevant), and within what timeframe. Practise with short scenarios and state the addressee and the reason for each report.