Module 10: Aviation Legislation

Module 10: Aviation Legislation

1. Overview of Module 10

Module 10 of the EASA Part-66 basic knowledge syllabus provides the regulatory framework within which aircraft maintenance certifying staff operate. This module is fundamental because it defines the legal basis for the entire maintenance system, the privileges and limitations of different licence categories, and the responsibilities of certifying staff. The module covers the structure of the European aviation regulatory framework, the role of the European Union Aviation Safety Agency (EASA), the content of Regulation (EU) No 1321/2014 (which contains Part-M, Part-145, Part-66, and Part-147), and the key operational regulations that govern air operations and airworthiness.

For a Category A licence holder working on piston-engine aeroplanes, this module establishes the boundaries of their certification privileges, the conditions under which they may issue a Certificate of Release to Service (CRS), and the procedures to follow when encountering defects or situations outside their authorised scope. The knowledge level required for this module is typically Level 2 (general knowledge) for Category A, meaning the candidate must understand the principles and be able to apply them in routine situations.

2. The Regulatory Framework

2.1 The European Aviation Safety System

The European aviation regulatory framework is built upon a hierarchy of legal instruments:

• Basic Regulation (EU) 2018/1139: This is the foundational regulation that establishes EASA and sets out the essential requirements for aviation safety in the European Union. It replaced the original Regulation (EC) No 216/2008.
• Implementing Rules: These are detailed regulations adopted by the European Commission that contain the technical requirements. The most relevant for maintenance is Regulation (EU) No 1321/2014, which contains:
• Part-M: Continuing airworthiness requirements for aircraft
• Part-145: Requirements for maintenance organisations
• Part-66: Requirements for certifying staff
• Part-147: Requirements for maintenance training organisations
• Acceptable Means of Compliance (AMC) and Guidance Material (GM): These are issued by EASA to provide standard methods of compliance with the Implementing Rules. They are not mandatory in themselves, but they offer a presumption of compliance if followed.
• Certification Specifications (CS): These are technical standards used for type certification of aircraft and products.

2.2 Regulation (EU) No 1321/2014 – Key Parts

Part-M governs the continuing airworthiness of aircraft. It applies to all aircraft used in commercial air transport (CAT) and to aircraft above a certain mass used in general aviation. Key subparts include:

• Subpart A (M.A.101 – M.A.201): General provisions and scope
• Subpart B (M.A.301 – M.A.402): Continuing airworthiness requirements, including the maintenance programme (M.A.302)
• Subpart C (M.A.501 – M.A.505): Continuing airworthiness management organisations (CAMO)
• Subpart D (M.A.601 – M.A.610): Maintenance standards
• Subpart E (M.A.701 – M.A.710): Maintenance organisations (Part-M Subpart F)
• Subpart F (M.A.801 – M.A.803): Airworthiness review

Part-145 governs maintenance organisations. It requires that any organisation performing maintenance on aircraft used in CAT or on aircraft above a certain mass must hold a Part-145 approval. Key requirements include:

• 145.A.30: Personnel requirements, including certifying staff
• 145.A.35: Certifying staff qualifications and authorisation
• 145.A.40: Maintenance data
• 145.A.45: Tools and equipment, including calibration
• 145.A.50: Certification of maintenance (CRS)

Part-66 governs the licensing of certifying staff. It defines the licence categories, the privileges of each category, the requirements for obtaining the licence (examinations and experience), and the conditions for maintaining its validity.

Part-147 governs maintenance training organisations approved to deliver the basic training and examinations required for the Part-66 licence.

2.3 The Part-66 Licence Categories

The Part-66 licence is divided into categories based on the type of aircraft and the nature of the maintenance tasks:

• Category A: Limited to simple line maintenance tasks and simple defect rectification. The holder may issue a CRS for tasks they have performed or verified, within the limits of the tasks endorsed on their company authorisation.
• Category B1: Covers line and base maintenance on aircraft structure, powerplant, and mechanical and electrical systems. The B1 holder may issue CRS for these tasks and may also certify work performed by others.
• Category B2: Covers line and base maintenance on avionics and electrical systems. The B2 holder has similar privileges to B1 but limited to their avionics scope.
• Category B3: Specifically for non-pressurised piston-engine aeroplanes with a maximum take-off mass (MTOM) of 2 000 kg or less. The B3 licence covers the whole aircraft.
• Category C: Covers base maintenance certification. The C holder is responsible for the overall release of the aircraft after base maintenance but does not personally perform the tasks.

For piston-engine aeroplanes, the relevant subcategories are:

• A1: Aeroplanes with turbine engines
• A2: Aeroplanes with piston engines
• A3: Helicopters with turbine engines
• A4: Helicopters with piston engines

3. Category A Privileges and Limitations

3.1 Scope of Privileges

According to Part-66.A.20(a)(1), a Category A licence permits the holder to:

• Issue a CRS for minor scheduled line maintenance and simple defect rectification.
• Perform these tasks within the limits of the tasks specifically endorsed on the authorisation issued by the Part-145 organisation.
• Certify work that they have personally performed or work performed by others under their direct and continuous supervision, provided they have verified the work.

The key limitations are:

• No base maintenance: Category A does not authorise certification of base maintenance tasks.
• No complex defect rectification: The defect rectification must be simple and within the scope of the licence.
• No airworthiness review: Category A staff cannot perform or certify airworthiness reviews. These require at least a Category B1 or B2 licence (Part-M.A.710).
• No certification of work performed by others without verification: The certifying staff member must take full responsibility for the work, which requires that they have either performed it themselves or have directly supervised and verified it.

3.2 The Role of the Part-145 Organisation Authorisation

The Part-145 organisation must issue a company authorisation to each certifying staff member, specifying the exact tasks they are permitted to certify. This authorisation is based on the individual's licence category and type ratings, and it must be in accordance with Part-145.A.35. The organisation cannot grant privileges beyond those allowed by the licence category.

3.3 Type Ratings and Endorsements

To exercise certification privileges on a specific aircraft type, the Category A holder must have the appropriate type rating endorsed on their licence. This is obtained by completing an approved type training course (typically at a Part-147 organisation) and passing the examination. The type rating is valid for life, but to exercise the privileges, the holder must meet the recent experience requirement: at least 6 months of relevant maintenance experience in the preceding 2 years (Part-66.A.45). If this requirement is not met, the holder may need to undergo refresher training or examination.

4. Certification of Maintenance – The CRS

4.1 The Purpose of the CRS

The Certificate of Release to Service (CRS) is the formal document by which certifying staff confirm that maintenance has been performed correctly and that the aircraft is safe for operation. According to Part-145.A.50, no aircraft may be released to service after maintenance unless a CRS has been issued.

4.2 Conditions for Issuing a CRS

The certifying staff member may only issue a CRS when:

1. All required maintenance has been performed in accordance with the approved maintenance data (e.g., AMM, SRM, CMM).
2. No known defects exist that would make the aircraft unsafe, unless such defects are deferred in accordance with approved procedures (e.g., MEL or CDL).
3. The certifying staff member has the appropriate licence category and type rating for the work performed.
4. The certifying staff member has been authorised by the Part-145 organisation to certify the specific task.
5. The maintenance records are complete and accurate.

4.3 Verification of Work Performed by Others

A Category A certifying staff member may certify work performed by an uncertified mechanic, provided that:

• The work was performed under the direct and continuous supervision of the certifying staff member.
• The certifying staff member has verified that the work was completed correctly and in accordance with approved data.
• The certifying staff member takes full responsibility for the airworthiness of the aircraft.

The certifying staff member must have the necessary knowledge and access to verify the work. This means they must be physically present during the work or have the ability to inspect the completed work thoroughly.

5. Defect Management and Deferral

5.1 The Minimum Equipment List (MEL)

The Minimum Equipment List (MEL) is a document approved by the competent authority that lists the equipment that may be inoperative for a limited period, provided specific conditions are met (e.g., operational restrictions, additional inspections, or placarding). The MEL is derived from the Master Minimum Equipment List (MMEL) issued by the type certificate holder.

Key principles:

• If a defect is listed in the MEL and the dispatch conditions are satisfied, the aircraft may be dispatched with the item inoperative.
• If a defect is not listed in the MEL, it cannot be deferred via the MEL. The defect must be rectified before dispatch, or the aircraft must be grounded.
• Deferral of unlisted defects may only be possible through an approved operator procedure (e.g., a specific exemption or a Configuration Deviation List (CDL) for missing non-essential parts).

5.2 Actions When a Defect is Found

When a certifying staff member discovers a defect during a line maintenance task:

1. Assess the defect: Determine whether it is within the scope of the task authorisation and the approved maintenance data.
2. If the defect is not covered by the task authorisation: Stop the task and report the defect to the organisation. The organisation will determine the appropriate action, which may involve a different certifying staff member with higher privileges or additional procedures.
3. If the defect is not covered by approved maintenance data: The defect may constitute a major repair or modification, which requires approval from a design organisation (Part-21.A.433) or the competent authority. The certifying staff member must not attempt to repair it without approved data.
4. If the defect cannot be rectified before departure: The aircraft must not be dispatched unless the defect can be deferred via the MEL or another approved procedure.

5.3 Structural Damage

Structural damage that is not covered by the approved maintenance data (e.g., SRM or AMM) is considered a major repair. Major repairs require:

• Approval from a design organisation (Part-21.A.433) or the competent authority.
• A detailed inspection and assessment by appropriately qualified personnel.
• A CRS issued by certifying staff with the appropriate privileges (typically B1 or C for base maintenance).

A Category A certifying staff member does not have the authority to approve such repairs. The correct action is to stop the task, report the damage, and follow the organisation's procedures for obtaining approved repair data.

6. Tools and Equipment Control

6.1 Calibration Requirements

According to Part-145.A.45, all tools and equipment used in maintenance must be:

• Controlled and calibrated at specified intervals.
• Traceable to a recognised standard.
• Stored and handled in a manner that preserves their accuracy.

6.2 Expired Calibration

If a tool has a calibration sticker showing that the calibration due date has passed:

• The tool must be taken out of service immediately.
• The tool must be recalibrated before further use.
• Using a tool with expired calibration is a violation of the approved maintenance data and the organisation's procedures.

6.3 Unit Conversion

Approved maintenance data may specify torque values in either SI units (Newton-metres, Nm) or imperial units (foot-pounds, ft-lb). The certifying staff member may use a tool calibrated in either unit, provided the conversion is accurate and the result is equivalent.

The standard conversion factor is:

1 ft-lb = 1.3558 Nm

When recording the applied torque, the certifying staff member should record the value in the unit of the tool used, ensuring that the maintenance record reflects the actual applied torque and is traceable.

7. The Maintenance Programme

7.1 Responsibility for the Maintenance Programme

According to Part-M.A.302, the operator or the Continuing Airworthiness Management Organisation (CAMO) is responsible for ensuring that a maintenance programme is developed and approved by the competent authority. The maintenance programme must:

• Be based on the manufacturer's maintenance planning data (MPD) or the maintenance review board (MRB) report.
• Include all tasks required to maintain the aircraft in an airworthy condition.
• Be reviewed and updated periodically.
• Be approved by the competent authority.

The CAMO is responsible for managing the continuing airworthiness of the aircraft, including the maintenance programme, and for ensuring that all maintenance is performed in accordance with the programme.

7.2 Scheduled Inspections

Scheduled inspections, such as the "100-hour" inspection, are defined in the approved maintenance programme. The certifying staff member may sign the CRS after such an inspection if:

• The inspection is a line maintenance task (e.g., a scheduled check).
• The task is within the scope of the Category A privileges.
• The organisation has authorised the certifying staff member for the specific task.

If the inspection includes complex tasks that are outside the Category A scope, those tasks must be certified by a higher-category certifying staff member (e.g., B1).

8. Licence Validity and Recent Experience

8.1 Validity Period

According to Part-66.A.10, the Part-66 aircraft maintenance licence is issued without a time limit. It remains valid indefinitely unless it is revoked or suspended by the competent authority.

8.2 Conditions for Exercising Privileges

Although the licence itself does not expire, the holder must meet certain conditions to exercise certification privileges:

• Recent experience: At least 6 months of relevant maintenance experience in the preceding 2 years (Part-66.A.45).
• Type ratings: The appropriate type ratings must be endorsed on the licence.
• Company authorisation: The Part-145 organisation must have issued a valid authorisation.

If the recent experience requirement is not met, the holder may need to undergo refresher training or examination before exercising privileges.

8.3 Minimum Age

According to Part-66.A.30(a), the applicant for an AML must be at least 18 years of age. This is a basic eligibility requirement for all licence categories, including Category A.

9. Airworthiness Review

9.1 The Airworthiness Review Process

The airworthiness review is a comprehensive inspection of the aircraft's airworthiness status, including:

• Review of the aircraft's documentation and records.
• Physical inspection of the aircraft.
• Verification that all maintenance has been performed in accordance with the approved maintenance programme.
• Verification that all ADs have been complied with.

The airworthiness review is performed by an airworthiness review staff member, who must hold at least a Category B1 or B2 licence (or equivalent) and have the appropriate type ratings.

9.2 Category A Limitations

A Category A certifying staff member cannot perform or certify an airworthiness review. This is not a simple line maintenance task and is outside the scope of Category A privileges. The airworthiness review requires a comprehensive understanding of the aircraft's continuing airworthiness status, which is beyond the scope of Category A training and experience.

10. Key Regulations and References

The following table summarises the key regulatory references relevant to Category A certifying staff:

11. Common Relationships Between Concepts

• Licence Category ↔ Task Scope: The licence category determines the maximum scope of tasks that can be certified. A Category A licence is limited to simple line maintenance; any task outside this scope requires a higher category.
• Type Rating ↔ Aircraft Type: The type rating endorsement on the licence is required to exercise privileges on a specific aircraft type. Without the type rating, the licence is valid but privileges cannot be exercised.
• Company Authorisation ↔ Licence Privileges: The Part-145 organisation's authorisation cannot grant privileges beyond those allowed by the licence category. The authorisation defines the specific tasks within the licence scope.
• CRS ↔ Airworthiness: The CRS is the formal declaration that the aircraft is airworthy after maintenance. Issuing a CRS without proper verification is a serious regulatory violation.
• MEL ↔ Dispatch: The MEL allows dispatch with inoperative equipment only if the specific conditions are met. Unlisted defects cannot be deferred via the MEL.
• Calibration ↔ Tool Accuracy: Calibration ensures that tools provide accurate measurements. Using an uncalibrated tool compromises the quality of maintenance and violates Part-145 requirements.

12. Typical Exam Focus Points

When preparing for the Module 10 examination, pay particular attention to the following areas:

1. Category A privileges and limitations: Understand exactly what a Category A licence holder can and cannot certify. This is the most frequently tested area.
2. The CRS process: Know the conditions for issuing a CRS, including the requirement for personal performance or direct supervision and verification.
3. Defect management: Understand the MEL process and the actions required when a defect is found that is not covered by the MEL or the task authorisation.
4. Tool control: Know the calibration requirements and the correct action when a tool's calibration has expired.
5. Licence validity: Understand that the licence is valid for life but that privileges depend on recent experience and type ratings.
6. Minimum age: Remember that the minimum age for an AML is 18 years.
7. Airworthiness review: Know that this is outside the scope of Category A privileges.
8. Maintenance programme responsibility: Understand that the operator or CAMO is responsible for the maintenance programme, not the certifying staff.
9. Unit conversion: Be able to convert between ft-lb and Nm (1 ft-lb = 1.3558 Nm).
10. Regulatory hierarchy: Understand the relationship between the Basic Regulation, Implementing Rules (Part-M, Part-145, Part-66, Part-147), and AMC/GM.

13. Summary

Module 10 provides the legal foundation for the work of certifying staff. For a Category A licence holder on piston-engine aeroplanes, the key takeaways are:

• The licence authorises simple line maintenance and simple defect rectification only.
• The certifying staff member must have the appropriate type rating and company authorisation.
• The CRS may only be issued after verification that the work was performed correctly.
• Defects outside the authorised scope must be reported and handled by appropriately qualified personnel.
• Tools must be calibrated and used correctly.
• The licence is valid for life, but recent experience is required to exercise privileges.

By understanding these principles, the certifying staff member can operate safely, legally, and effectively within the European aviation regulatory framework.