Aircraft Maintenance Skills Matrix: How to Assess Competence Beyond a Licence

A Part-66 licence is an essential regulatory baseline, but it is not a complete measure of workplace competence. It confirms that an individual has met defined knowledge, experience and examination requirements. It does not, by itself, demonstrate that the person can safely perform a particular task, on a particular aircraft type, in a particular organisation, using the organisation's approved procedures.

For UK and European maintenance organisations, a skills matrix provides the controlled link between licensing, practical capability and organisational authorisation. Used correctly, it helps an organisation answer a more important question than, “Does this person hold a licence?”

Can this person safely and consistently perform, supervise, inspect or certify this specific work within our approved system?

What a skills matrix should measure

A useful aircraft maintenance skills matrix should record competence across several separate dimensions:

• Regulatory qualification: UK CAA or EASA Part-66 category, validity and limitations.
• Aircraft and component knowledge: aircraft type training, differences training and component-specific knowledge.
• Practical task capability: the ability to perform tasks using approved maintenance data.
• Certification capability: the scope of tasks the individual may certify or support.
• Organisational procedures: familiarity with the MOE, safety reporting, occurrence reporting and work-card processes.
• Human factors: understanding of fatigue, communication, error management, pressure and procedural compliance.
• Equipment and tooling: correct selection and use, calibration controls and defect reporting.
• Specialised activities: NDT, welding, borescope inspection and other specialist work.
• Recent experience: evidence that competence remains current rather than historical.
• Supervision and leadership: the ability to control work, brief teams and identify unsafe conditions.

These categories should not be reduced to a single competent or not competent field. A person may be fully capable of carrying out a removal and installation task while not yet being authorised to inspect the work or certify its release.

Licence status is only the starting point

Under the European Part-145 framework, 145.A.30 sets out personnel requirements and is more specific than many basic HR or training systems suggest. Organisations should refer to the current EASA Part-145 requirements when defining their competence and authorisation processes.

Certifying staff must normally hold a valid EASA Part-66 licence in the appropriate category, A, B1, B2, B3 or C. Where the organisation uses a relevant Appendix IV derogation, the individual may instead hold an equivalent qualification that has been assessed and authorised directly by the organisation in accordance with the applicable requirements.

For UK organisations, the equivalent baseline is governed through the UK CAA regulatory framework. The UK CAA Part-145 guidance should be used alongside the organisation's approved procedures. A matrix should identify clearly whether an individual is operating under a UK CAA Part-66 licence, an EASA Part-66 licence or another specifically recognised route. Recording only “licensed engineer” is insufficient.

It should show:

• the issuing authority;
• licence category and limitations;
• aircraft type or task-specific approvals;
• licence validity;
• organisational authorisation status;
• the date of the latest competence assessment; and
• any restrictions, supervision requirements or identified gaps.

A licence does not automatically confer an organisation's certification authorisation. The organisation must assess the individual against its own procedures, aircraft scope, facilities and intended duties.

Build the matrix around actual job functions

The matrix should be structured around the work the person is expected to perform, not merely their job title.

For example, a line maintenance mechanic may need separate competence entries for:

• aircraft servicing;
• panel removal and installation;
• wheel and brake replacement;
• defect rectification;
• independent inspection, where applicable;
• use of electronic technical publications;
• work-card completion;
• shift handover; and
• escalation of unexpected findings.

For more detail on inspection independence, see who can perform an independent inspection in aircraft maintenance.

A B1 or B2 engineer may require additional assessment for:

• troubleshooting;
• interpretation of wiring diagrams or system schematics;
• fault isolation;
• functional checks;
• duplicate inspections;
• technical decision-making; and
• certification within the privileges and limitations of the applicable authorisation.

A Category C certifying staff member requires a different competence profile. Category C certifying staff sign the final release to service on base maintenance after reviewing the work performed and certified by the B1 and B2 staff responsible for the underlying tasks. Their matrix must therefore assess:

• work-package control;
• review of task certification;
• management of incomplete or deferred work;
• coordination between maintenance trades;
• verification of required inspections; and
• final release decision-making.

The matrix should not treat Category C as simply a senior version of a task-performing role. The competence is partly technical and partly supervisory, review-based and organisational.

Use multiple forms of evidence

A robust assessment normally combines several methods rather than relying on course attendance or a manager's informal opinion.

1. Document review

Check the person's:

• Part-66 licence;
• type training and examination records;
• practical training;
• previous authorisations;
• recent experience;
• task records;
• specialist qualifications; and
• relevant military or civil maintenance history.

CAP 741 logbooks can provide useful evidence of practical maintenance experience and task exposure, but a logbook is not proof of current competence or organisational authorisation. See the guidance on how to fill out a CAP 741 logbook and common CAP 741 logbook mistakes.

2. Knowledge assessment

Written or oral examination may be appropriate for:

• aircraft systems;
• maintenance data;
• company procedures;
• human factors;
• safety management;
• technical records;
• defect reporting; and
• certification responsibilities.

The assessment should be relevant to the intended role. A generic multiple-choice test may confirm basic knowledge, but may not reveal whether an engineer can interpret a complex fault, challenge an unsafe instruction or manage conflicting technical information.

3. On-the-job evaluation

AMC material associated with 145.A.30(e) expects planners, mechanics, specialised services staff, supervisors and certifying staff to be assessed for competence through methods such as on-the-job evaluation and examination, as defined in the organisation's MOE.

An on-the-job evaluation should be planned and recorded. The assessor should observe whether the individual can:

1. locate and use current approved maintenance data;
2. identify the correct tooling and equipment;
3. follow the work-card or task instruction;
4. apply contamination, foreign object debris and tool-control procedures;
5. recognise unexpected conditions;
6. seek appropriate technical support;
7. complete the technical record accurately;
8. communicate effectively during handover; and
9. stop or escalate the task when the approved data or available resources are inadequate.

The assessor should record the task, aircraft or component, conditions, evidence observed and any limitations. “Observed satisfactory” is less useful than a short, evidence-based statement explaining what was demonstrated.

4. Simulation or scenario assessment

Some competencies are difficult to observe during routine work. Scenario-based assessment can test:

• an ambiguous defect;
• pressure to return an aircraft to service;
• a discrepancy between the work card and the maintenance data;
• an incomplete shift handover;
• fatigue-related error risk;
• a tooling or calibration problem; or
• a disagreement between production and quality personnel.

These scenarios are particularly valuable for supervisors, certifying staff and technical managers because competence includes judgement, communication and control of risk, not just manual task execution.

Human factors must be visible in the matrix

Part-145 competence requirements include an understanding of human factors and human performance issues appropriate to the person's function. This should not be recorded as a single tick box for human factors training completed. The SKYbrary human factors guidance provides useful aviation context for assessing how people interact with procedures, equipment and organisational pressures.

The matrix should test whether the individual can apply human factors principles in practice, including:

• recognising fatigue and reduced alertness;
• managing interruptions;
• using effective shift handovers;
• challenging unclear instructions;
• reporting errors and near misses;
• resisting production pressure;
• identifying communication failures; and
• maintaining procedural discipline in unfamiliar or abnormal conditions.

The organisation must establish and control the competence of personnel involved in maintenance, airworthiness review management and quality audits in accordance with a procedure and standard agreed with the competent authority. The same principle applies to the assessment system itself. The organisation must define who assesses, against what standard, using which evidence, and how disagreements or failed assessments are controlled.

Include specialist competence separately

Specialist capability should not be inferred from a broad maintenance licence.

For example, personnel carrying out or controlling continued-airworthiness non-destructive testing on aircraft structures or components must be appropriately qualified for the particular NDT method in accordance with the applicable European or equivalent standard recognised by the Agency.

The matrix should therefore identify:

• the NDT method;
• the qualification level;
• the applicable standard;
• currency and renewal requirements;
• equipment-specific competence; and
• whether the person performs, supervises or accepts the work.

The same approach can be applied to specialised services, composite repairs, welding, borescope inspection and other activities where competence depends on the method, equipment or material.

Control competence after the initial assessment

Competence cannot be treated as permanent simply because a licence or company authorisation remains valid. Recurrent training, including human factors training, must be conducted on a defined cycle, and competence must be reassessed rather than assumed to persist.

The matrix should trigger a review when:

• the person has not performed a task for a defined period;
• an aircraft type or component changes;
• maintenance data or tooling changes significantly;
• a serious error, finding or occurrence takes place;
• an audit identifies a weakness;
• the individual returns from extended absence;
• a new role or higher authorisation is requested; or
• recurrent training reveals a knowledge or performance gap.

A failed assessment should result in a controlled action, such as supervision, retraining, restricted authorisation, reassessment or removal of the relevant privilege. It should not be hidden by leaving an old competent status unchanged.

Align the matrix with the MOE

The matrix must reflect the organisation's approved procedures. Under 145.A.70, the Maintenance Organisation Exposition describes how the organisation performs and controls its activities. 145.A.65 also connects maintenance procedures with the organisation's safety and quality management arrangements.

This creates a practical systems risk. If the MOE requires one competence assessment process but the software uses another, or requires manual workarounds to reproduce the approved process, the organisation may create a gap between documented control and actual control.

That gap matters during audits. Auditors may compare:

• the competence procedure in the MOE;
• the software workflow;
• assessment records;
• authorisation records;
• training files; and
• evidence from actual maintenance activity.

A matrix should therefore be configured around the approved procedure, not designed independently by an HR or software team. It should preserve version history, assessor identity, evidence, expiry or review dates, restrictions and approval decisions.

Resource planning is part of competence control

Competence cannot be assessed effectively if the organisation has no realistic time or staffing plan. Part-145 expectations include adequate resources for compliance functions and the review of maintenance man-hour plans. Significant deviations should be defined and reported to the quality and accountable management functions for review.

For the matrix, this means monitoring whether:

• assessments are being completed on time;
• supervisors have sufficient time to observe staff;
• recurrent training is being deferred because of production demand;
• excessive overtime is affecting competence or human performance; and
• the planned hangar or maintenance visit programme is creating assessment bottlenecks.

A matrix that shows every employee as current while assessments are repeatedly postponed is not evidence of competence control. It is evidence that the process is not being operated as designed.

Recognising military maintenance experience

Military engineers and technicians may bring substantial practical capability, but military experience should be mapped to the civil role rather than accepted as a blanket equivalence.

UK Ministry of Defence service records, trade qualifications, task records and technical training may support applications through the relevant UK CAA recognition or licensing pathways. The organisation should still assess:

• the aircraft and systems involved;
• the maintenance environment;
• the standards and procedures used;
• the person's recent civil or comparable experience;
• knowledge of Part-145 requirements;
• human factors and safety reporting expectations; and
• competence with the organisation's current maintenance data and records.

The same principle applies internationally. An FAA A&P certificate, for example, is a US certification and should not be treated as an automatic substitute for a UK CAA or EASA Part-66 licence. It may be valuable evidence of training and experience, but the applicable authority, licensing route and organisation's authorisation procedure must be established separately.

What a mature matrix looks like

A mature aircraft maintenance skills matrix does not simply display green, amber and red cells. It provides an auditable chain between:

1. the legal or regulatory qualification;
2. the job function;
3. the specific task or aircraft scope;
4. the assessment method;
5. the evidence of performance;
6. the assessor's decision;
7. the authorisation granted; and
8. the review or reassessment date.

That is how an organisation assesses competence beyond a licence.

The licence establishes an important professional foundation. The skills matrix demonstrates whether the individual can apply that foundation safely, currently and within the organisation's approved system.

Need clearer evidence of Part-66 experience? Analyse Your Logbook Today! Our Part 66 Logbook Analysis tool helps aviation professionals review logbook records and organise evidence against Part-66 requirements.

For practical maintenance teams, a well-controlled matrix should also connect with accurate records, effective handovers and current procedures. Explore the aircraft maintenance shift handover checklist for another important part of competence control.