Module 10: Aviation Legislation

Module 10: Aviation Legislation — Category B1.1 (EASA Part-66)

1. Module Overview

Module 10 of the EASA Part-66 basic knowledge syllabus provides the legislative foundation for aircraft maintenance certifying staff. For the B1.1 category (aeroplane turbine), this module covers the regulatory framework governing the continuing airworthiness of aircraft, the privileges and limitations of the aircraft maintenance licence (AML), and the obligations of maintenance organisations and certifying personnel.

This module is not about the technical execution of maintenance tasks—that is covered in other modules. Instead, it focuses on the legal and administrative environment in which maintenance is performed. A B1.1 certifying engineer must understand not only how to perform maintenance but also under what authority, using which data, and with what documentation the work is certified.

The primary regulatory reference is Regulation (EU) No 1321/2014, which consolidates the following Annexes:

Knowledge levels for this module range from Level 1 (overview of the regulatory framework) to Level 3 (detailed understanding of specific obligations, privileges, and procedures).

---

2. Key Concepts Explained in Detail

2.1 The Regulatory Hierarchy

The European aviation regulatory framework operates as a hierarchy:

1. Regulation (EU) No 2018/1139 — the Basic Regulation establishing the European Union Aviation Safety Agency (EASA) and laying down common rules for civil aviation.
2. Regulation (EU) No 1321/2014 — the implementing regulation for continuing airworthiness, containing Parts-M, 145, 66, and 147.
3. Acceptable Means of Compliance (AMC) and Guidance Material (GM) — issued by EASA to provide practical guidance on how to comply with the regulations. AMC are not mandatory but offer a presumption of compliance; alternative means may be used if they demonstrate equivalent safety.
4. Certification Specifications (CS) — technical standards for airworthiness (e.g., CS-25 for large aeroplanes).

For the certifying engineer, the most directly applicable document is Regulation (EU) No 1321/2014, specifically Part-66 (licensing) and Part-145 (maintenance organisation approval).

2.2 The Part-66 Aircraft Maintenance Licence (AML)

2.2.1 Categories of Licence

Part-66 defines the following licence categories:

Important distinction for B1.1: The B1.1 licence covers aeroplane turbine engines and associated systems. This includes engine removal and installation, engine-driven accessories, and the mechanical and electrical systems of the airframe. It does not include avionics systems (which fall under B2).

2.2.2 Eligibility Requirements for Licence Issue

Part-66.A.30 specifies the mandatory requirements for the initial issue of an AML:

• Minimum age: The applicant must be at least 18 years of age (Part-66.A.30(a)).
• Basic knowledge: Completion of a Part-147 approved basic training course and passing the corresponding module examinations, OR an alternative accepted by the competent authority (e.g., prior military experience, or a recognised engineering degree supplemented by additional examinations).
• Experience: For B1.1, the applicant must have at least 5 years of practical maintenance experience on operating aircraft (reducible to 3 years if they have completed an approved Part-147 training course, or 2 years if the course includes approved practical training).
• Type ratings: Type ratings are not required for initial licence issue. They are added later through type training and examination.

2.2.3 Validity and Recency Requirements

The AML is issued without a fixed expiry date (Part-66.A.10). It remains valid indefinitely unless revoked, suspended, or limited by the competent authority. However, to exercise certification privileges, the holder must meet the following conditions (Part-66.A.20):

• Recent experience: At least 6 months of actual relevant maintenance experience in the preceding 2 years.
• Type rating currency: For each type rating held, the holder must have either:
• 6 months of actual maintenance experience on that type in the preceding 2 years, OR
• Completed a type refresher course within the preceding 2 years, OR
• Completed a type examination within the preceding 2 years.

If these conditions are not met, the licence itself remains valid, but the holder cannot certify maintenance until the recency requirements are re-established.

2.2.4 Limited Licences

Part-66.A.30(b) permits the competent authority to issue a limited licence to an applicant who does not fully meet the experience requirements, provided they have at least 50% of the required experience. The limited licence is valid for a maximum of 3 years, after which it must be converted to a full licence.

2.2.5 Privileges of the B1.1 Licence

Part-66.A.20(a)(1) defines the privileges of a B1.1 licence holder:

• Performing maintenance on aeroplane structure, powerplant, and mechanical and electrical systems.
• Issuing a Certificate of Release to Service (CRS) for such maintenance.
• Acting as support staff for category C certifying staff in base maintenance.

Critical limitation: The B1.1 licence does not authorise maintenance on avionics systems (e.g., radio, navigation, instrument systems). These require a B2 licence. A B1.1 holder who performs avionics tasks is in violation of Part-66 and Part-145 requirements.

---

2.3 Part-145 Maintenance Organisations

2.3.1 Scope of Approval

Part-145.A.20 defines the scope of approval of a maintenance organisation. This scope specifies:

• The types of aircraft and components covered.
• The types of maintenance (line, base, engine, component).
• Any limitations (e.g., line maintenance only).

Key principle: A certifying engineer can only certify maintenance within the scope of the organisation that employs them. The individual's Part-66 licence does not override the organisational approval. If a Part-145 organisation is approved only for line maintenance, it cannot perform an engine change, even if the certifying staff hold the appropriate type rating.

2.3.2 Certifying Staff Requirements (Part-145.A.35)

Each Part-145 organisation must:

• Appoint certifying staff who hold a Part-66 licence appropriate to the tasks.
• List all certifying staff in the Maintenance Organisation Exposition (MOE).
• Ensure that certifying staff have access to the necessary data and tools.
• Ensure that certifying staff meet the recency requirements.

When a certifying engineer moves from one Part-145 organisation to another, their Part-66 licence remains valid and does not need to be reissued. However, the new organisation must include them in their MOE and verify that their type ratings are current.

2.3.3 Certification of Maintenance (Part-145.A.50)

The Certificate of Release to Service (CRS) is the document issued by certifying staff confirming that maintenance has been performed correctly and the aircraft is safe for return to service.

Fundamental rule: A CRS may only be issued for work that the certifying staff member has personally performed or directly supervised. Signing for work performed by others without supervision is a serious violation that can lead to revocation of the licence.

For components, the equivalent document is the EASA Form 1 (maintenance release). The CRS is for the aircraft; the EASA Form 1 is for components. They are not interchangeable.

2.3.4 Tools and Equipment (Part-145.A.40)

All tools and equipment must be:

• Controlled and calibrated at specified intervals.
• Traceable to a recognised calibration standard.
• Used only within their calibration validity period.

Using an out-of-calibration torque wrench, for example, is a non-compliance that could lead to incorrect torque application and potential component failure. The maintenance would not be considered properly performed, and the CRS could be invalid.

2.3.5 Required Inspection Items (RII)

Part-145.A.40 and AMC 145.A.40 require that certain tasks be designated as Required Inspection Items (RII). These are tasks where a mistake could have significant safety consequences. RII must be:

• Performed by qualified personnel authorised by the organisation.
• Independently inspected by an RII-qualified person.
• Signed off by the RII holder before the aircraft is released.

The organisation's MOE defines which tasks are RII and the procedures for their control. A certifying staff member who is not an RII holder for a specific task cannot sign off an RII, even if they performed the work.

---

2.4 Part-M Continuing Airworthiness

2.4.1 The Approved Maintenance Programme (AMP)

Part-M.A.302 requires that all aircraft, including those in non-commercial operations (Part-NCO), are maintained in accordance with an approved maintenance programme. The AMP must:

• Include all mandatory requirements, including Airworthiness Directives (ADs).
• Be based on the manufacturer's maintenance planning data.
• Be approved by the competent authority or by the CAMO (Continuing Airworthiness Management Organisation) under a limited scope.

When a new AD is issued, the owner/operator must ensure that the AMP is updated to incorporate the AD's requirements.

2.4.2 The CAMO (Part-M Subpart G)

The Continuing Airworthiness Management Organisation (CAMO) is responsible for:

• Managing the continuing airworthiness of aircraft.
• Developing and controlling the maintenance programme.
• Arranging maintenance with Part-145 organisations.
• Ensuring that all ADs are accomplished within their compliance times.
• Issuing the Airworthiness Review Certificate (ARC).

Important distinction: The CAMO does not perform maintenance itself. That is a Part-145 function. The CAMO manages; the Part-145 organisation executes.

2.4.3 Airworthiness Directives (ADs)

An AD is a mandatory airworthiness requirement issued when an unsafe condition exists. Key principles:

• All applicable ADs must be accomplished within their specified compliance times.
• An aircraft cannot be released to service if an AD is overdue.
• If a logbook shows an AD as completed but it is found not embodied, the certifying staff must not certify the aircraft. The discrepancy must be recorded and reported through the organisation's procedures (Part-145.A.60).
• Deferring an AD is not permitted unless the AD itself allows it.

---

2.5 Approved Data (Part-145.A.45)

Maintenance must be performed using approved data. This includes:

• Manufacturer's documentation (AMM, CMM, SRM, IPC).
• Service bulletins that have been incorporated into the type certificate holder's instructions or the operator's maintenance programme.
• Data accepted by the competent authority.
• Repair designs approved under Part-21.

Critical principle: A vendor service bulletin becomes approved data only when it is incorporated into the type certificate holder's instructions or the operator's maintenance programme. Using unapproved data is a violation of Part-145.

If damage is found that is not covered by the SRM or AMM (e.g., a crack in a structural member not listed as repairable), it cannot be repaired using a 'standard patch' without design approval. The certifying staff must not release the aircraft unless:

• The damage is confirmed as allowable, OR
• A repair design is obtained from a Part-21 Subpart J design organisation.

---

2.6 Part-21 Design Approvals

Part-21 governs the design and production of aeronautical products. Key concepts for the certifying engineer:

• Minor modifications require design approval under Part-21 Subpart D (e.g., by the Agency or a Design Organisation Approval holder).
• Maintenance staff do not have the authority to approve design changes, even if minor.
• A modification not covered by an existing Supplemental Type Certificate (STC) or the manufacturer's Instructions for Continued Airworthiness requires a design approval before it can be embodied.

This is a key distinction between maintenance (restoring to an approved condition) and design (changing the approved condition).

---

2.7 Part-147 Training Organisations

Part-147 governs the approval of maintenance training organisations. Key points:

• Part-147 approved basic training courses are the standard route to meeting the knowledge requirements for a Part-66 licence.
• Examinations assess theoretical knowledge in the modules of the Part-66 syllabus.
• Practical skills are assessed separately through experience and, for category A, a practical assessment.
• English proficiency is not part of the Part-147 examination.

---

3. Important Regulations and Procedures

3.1 Key Part-66 References

3.2 Key Part-145 References

3.3 Key Part-M References

3.4 Key Part-21 References

---

4. Common Relationships Between Concepts

4.1 The Certification Chain

The relationship between the key actors can be summarised as:

Part-21 (Design/Production)
↓ provides approved data and airworthy parts
Part-M (Continuing Airworthiness Management)
↓ defines what maintenance is required (AMP, ADs)
Part-145 (Maintenance Organisation)
↓ performs maintenance using approved data
Part-66 (Certifying Staff)
↓ issue CRS confirming work correctly performed
Aircraft released to service

4.2 Licence vs. Organisation Scope

A common source of confusion is the relationship between the individual licence and the organisational approval:

• The Part-66 licence defines what the individual is qualified to certify.
• The Part-145 approval defines what the organisation is authorised to perform.
• The certifying engineer can only certify within the intersection of their licence privileges and the organisation's scope of approval.

4.3 AD Compliance and the CRS

The relationship between ADs and certification:

• The AMP must include all ADs.
• The CRS can only be issued if all ADs are accomplished within their compliance times.
• If an AD is found overdue or not embodied, the aircraft is not airworthy and must be grounded until compliance or an approved exemption.

4.4 Approved Data and Airworthiness

The relationship between data and airworthiness:

• Approved data defines what constitutes a serviceable condition.
• Maintenance performed without approved data is non-compliant.
• A CRS issued for non-compliant maintenance is invalid.
• Parts must be accompanied by an EASA Form 1 (or equivalent) to be considered airworthy.

---

5. Typical Exam Focus Points

Based on the source questions, the following areas are frequently examined:

5.1 Licence Eligibility and Validity

• Minimum age of 18 years for AML issue.
• The AML has no expiry date but requires recency to exercise privileges.
• Limited licences are valid for a maximum of 3 years.
• Type ratings must be revalidated within 3 years to remain current.

5.2 Licence Privileges and Limitations

• B1.1 covers aeroplane turbine engines and mechanical/electrical systems.
• Avionics tasks are excluded from B1.1 (require B2).
• Engine removal/installation is within B1.1 scope.
• The B1.1 licence does not authorise design approvals.

5.3 Certification Obligations

• CRS can only be issued for work personally performed or directly supervised.
• An overdue AD means the aircraft cannot be released.
• Finding an AD not embodied (despite logbook showing completion) requires the aircraft to be grounded and the discrepancy reported.
• RII sign-off is mandatory before release.

5.4 Organisational Requirements

• Certifying staff can only certify within the scope of the employing organisation.
• Out-of-calibration tools invalidate the maintenance and the CRS.
• Maintenance must be performed using approved data only.
• Work outside the organisation's scope must be subcontracted to an appropriately approved Part-145 organisation.

5.5 Design vs. Maintenance

• Minor modifications require design approval under Part-21.
• Damage not covered by approved data requires a repair design from a Part-21 Subpart J organisation.
• The IPC is a reference document, not an airworthiness approval.

5.6 Regulatory Structure

• Regulation (EU) No 1321/2014 contains Parts-M, 145, 66, and 147.
• Annex I = Part-M; Annex II = Part-145; Annex III = Part-66; Annex IV = Part-147.
• The CAMO manages continuing airworthiness but does not perform maintenance.

---

6. Summary of Key Principles for the B1.1 Certifying Engineer

1. Know your licence: Understand exactly what your B1.1 privileges cover and, equally importantly, what they do not cover.
2. Know your organisation: You can only certify within the scope of your employing Part-145 organisation, as defined in the MOE.
3. Know your data: Only use approved data. If it is not in the AMM, SRM, or an approved document, do not use it.
4. Know your ADs: An overdue AD grounds the aircraft. Never issue a CRS if any AD is not accomplished.
5. Know your tools: Out-of-calibration tools invalidate the work. Check calibration dates before use.
6. Know your supervision: Only certify work you have personally performed or directly supervised. Never sign for another's work without supervision.
7. Know your documentation: The CRS is for the aircraft; the EASA Form 1 is for components. Both are required for release to service.
8. Know your limits: Design changes require Part-21 approval. Maintenance staff cannot approve modifications, even minor ones.

---

7. Conclusion

Module 10 provides the legal framework within which all maintenance activities must operate. For the B1.1 certifying engineer, mastery of this module is not merely an examination requirement—it is essential for safe and lawful practice. The regulations are designed to ensure that every aircraft released to service is airworthy, that every maintenance task is properly documented, and that every certifying staff member acts within their authority.

The recurring themes are authority (who may do what), data (what may be used), documentation (what must be recorded), and compliance (what must be accomplished). Understanding these four themes and their interrelationships is the key to both passing the examination and practising safely as a certifying engineer.