--- title: "Appendix VII Basic knowledge requirements for category L aircraft maintenance licence — Part-66 · Avioverse" description: "The definitions of the different levels of knowledge required in this Appendix are the same as those set out in point 1 of Appendix I." url: "https://avioverse.aero/regulations/easa/continuing-airworthiness/part-66/appendices-to-annex-iii-part-66/appendix-vii" --- # Appendix VII Basic knowledge requirements for category L aircraft maintenance licence Annex III (Part-66) · Regulation (EU) No 1321/2014 · EAR revision 2 Sep 2025 Official sources: [EASA Easy Access Rules (opens in a new tab)](https://www.easa.europa.eu/en/document-library/easy-access-rules/easy-access-rules-continuing-airworthiness) · [EUR-Lex 2014/1321 (opens in a new tab)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32014R1321) Appendix Appendix ## Appendix VII Basic knowledge requirements for category L aircraft maintenance licence The definitions of the different levels of knowledge required in this Appendix are the same as those set out in point 1 of Appendix I. 1\. Modularisation The modules required for each [aircraft](https://avioverse.aero/glossary/easa/aircraft) licence subcategory/category shall be in accordance with the following matrix. Where applicable, the subject modules are indicated by an ‘X’, while ‘n/a’ means that the subject module is not applicable nor required. The basic knowledge requirement for L5 shall be the same as for any B1 subcategory (as indicated in Appendix I) plus other modules as shown in the matrix. | | Licence subcategories | | | | | | | | | | ----------------------------------------------------------- | --------------------- | ---------- | ---------------------------------------------------------- | -------------------------------------- | ---------------- | ------------ | ---------------- | ----------------- | ----------------------- | | | Composite sailplanes | Sailplanes | Composite powered sailplanes and composite ELA1 aeroplanes | Powered sailplanes and ELA1 aeroplanes | Hot-air balloons | Gas balloons | Hot-air airships | ELA2 gas airships | Gas airships above ELA2 | | Subject modules | L1C | L1 | L2C | L2 | L3H | L3G | L4H | L4G | L5 | | 1L ‘Basic knowledge’ | X | X | X | X | X | X | X | X | n/a | | 2L ‘Human factors’ | X | X | X | X | X | X | X | X | n/a | | 3L ‘Aviation legislation’ | X | X | X | X | X | X | X | X | n/a | | 4L ‘Wooden and/or metal-tube structure covered with fabric’ | n/a | X | n/a | X | n/a | n/a | n/a | n/a | n/a | | 5L ‘Composite structure’ | X | X | X | X | n/a | n/a | n/a | n/a | n/a | | 6L ‘Metallic structure’ | n/a | X | n/a | X | n/a | n/a | n/a | n/a | n/a | | 7L ‘Airframe – general, mechanical and electrical systems’ | X | X | X | X | n/a | n/a | n/a | n/a | n/a | | 8L ‘Power plant’ | n/a | n/a | X | X | n/a | n/a | X | X | X (¹) | | 9L ‘Balloons – hot-air balloons’ | n/a | n/a | n/a | n/a | X | n/a | X | n/a | n/a | | 10L ‘Balloons – gas (free/tethered) balloons’ | n/a | n/a | n/a | n/a | n/a | X | n/a | X | X | | 11L ‘Airships – hot-air/gas AIRSHIPS’ | n/a | n/a | n/a | n/a | n/a | n/a | X | X | X | | 12L ‘Radio Com/ELT/Transponder/ Instruments’ | X | X | X | X | n/a | n/a | X | X | X | MODULE 1L – BASIC KNOWLEDGE | MODULE 1L – BASIC KNOWLEDGE | Level | | -------------------------------------------------- | ----- | | 1L.1 Mathematics — Arithmetic — Algebra — Geometry | 1 | | 1L.2 Physics — Matter — Mechanics — Temperature | 1 | | 1L.3 Electrics — AC and DC circuits | 1 | | 1L.4 Aerodynamics/aerostatics | 1 | | 1L.5 Workplace safety and environmental protection | 2 | MODULE 2L – HUMAN FACTORS | MODULE 2L – HUMAN FACTORS | Level | | ------------------------------------------ | ----- | | 2L.1 General | 1 | | 2L.2 Human performance and limitations | 1 | | 2L.3 Social psychology | 1 | | 2L.4 Factors that affect performance | 1 | | 2L.5 Physical environment | 1 | | 2L.6 The ‘Dirty Dozen’ and risk mitigation | 2 | MODULE 3L – AVIATION LEGISLATION | MODULE 3L – AVIATION LEGISLATION | Level | | ---------------------------------------------------------------------------------------------------------- | ----- | | 3L.1 Regulatory framework | 1 | | 3L.2 [Continuing airworthiness](https://avioverse.aero/glossary/easa/continuing-airworthiness) regulations | 1 | | 3L.3 Repairs and modifications (Part-ML) | 2 | | 3L.4 [Maintenance](https://avioverse.aero/glossary/easa/maintenance) data (Part-ML) | 2 | | 3L.5 Licence privileges and how to exercise them properly (Part-66, Part-ML) | 2 | MODULE 4L – WOODEN AND/OR METAL-TUBE STRUCTURE COVERED WITH FABRIC | MODULE 4L – WOODEN AND/OR METAL-TUBE STRUCTURE COVERED WITH FABRIC | Level | | ------------------------------------------------------------------ | ----- | | 4L.1 Airframe wooden/combination of metal tube and fabric | 2 | | 4L.2 Materials | 2 | | 4L.3 Identifying damages and defects | 3 | | 4L.4 Standard repair and maintenance procedures | 3 | MODULE 5L – COMPOSITE STRUCTURE | MODULE 5L – COMPOSITE STRUCTURE | Level | | ----------------------------------------------- | ----- | | 5L.1 Airframe fibre-reinforced plastic (FRP) | 2 | | 5L.2 Materials | 2 | | 5L.3 Identifying damages and defects | 3 | | 5L.4 Standard repair and maintenance procedures | 3 | MODULE 6L – METALLIC STRUCTURE | MODULE 6L – METALLIC STRUCTURE | Level | | ----------------------------------------------- | ----- | | 6L.1 Metallic airframe | 2 | | 6L.2 Materials | 2 | | 6L.3 Identifying damages and defects | 3 | | 6L.4 Standard repair and maintenance procedures | 3 | MODULE 7L – AIRFRAME – GENERAL, MECHANICAL AND ELECTRICAL SYSTEMS | MODULE 7L – AIRFRAME – GENERAL, MECHANICAL AND ELECTRICAL SYSTEMS | Level | | ----------------------------------------------------------------- | ----- | | 7L.1 Theory of flight – gliders and aeroplanes | 1 | | 7L.2 Airframe structure – gliders and aeroplanes | 1 | | 7L.3 Air conditioning (ATA 21) | 1 | | 7L.4 Electrical power, cables and connectors (ATA 24) | 2 | | 7L.5 Equipment and furnishing (ATA 25) | 2 | | 7L.6 Fire protection and other safety systems (ATA 26) | 2 | | 7L.7 Flight controls (ATA 27) | 3 | | 7L.8 Fuel system (ATA 28) | 2 | | 7L.9 Hydraulic power (ATA 29) | 2 | | 7L.10 Ice and rain protection (ATA 30) | 1 | | 7L.11 Landing gear (ATA 32) | 2 | | 7L.12 Lights (ATA 33) | 2 | | 7L.13 Oxygen (ATA 35) | 2 | | 7L.14 Pneumatic/vacuum (ATA 36) | 2 | | 7L.15 Water ballast (ATA 41) | 2 | | 7L.16 Fasteners | 2 | | 7L.17 Pipes, hoses and connectors | 2 | | 7L.18 Springs | 2 | | 7L.19 Bearings | 2 | | 7L.20 Transmissions | 2 | | 7L.21 Control cables | 2 | | 7L.22 Fits and clearances | 2 | | 7L.23 Aircraft weight and balance | 2 | | 7L.24 Workshop practices and tools | 2 | | 7L.25 Disassembly, inspection, repair and assembly techniques | 2 | | 7L.26 Abnormal events | 2 | | 7L.27 Maintenance procedures | 2 | MODULE 8L – POWER PLANT | MODULE 8L – POWER PLANT | Piston | Turbine | Electrical | Level | | ------------------------------------------------------ | ------ | ------- | ---------- | ----- | | 8L.1 General engine fundamentals | X | X | X | 2 | | 8L.2 Piston engine fundamentals and performance | X | | | 2 | | 8L.3 Piston engine construction | X | | | 2 | | 8L.4 Piston engine fuel system (non-electronic) | X | | | 2 | | 8L.5 Starting and ignition system | X | | | 2 | | 8L.6 Air intake, exhaust and cooling system | X | | | 2 | | 8L.7 Supercharging/turbocharging | X | | | 2 | | 8L.8 Lubrication systems of piston engines | X | | | 2 | | 8L.9 Engine indication systems | X | X | X | 2 | | 8L.10 Electric aircraft engines | | | X | 2 | | 8L.11 Turbine engine fundamentals and performance | | X | | 2 | | 8L.12 Inlet and compressor | | X | | 2 | | 8L.13 Combustion chamber, starting and ignition system | | X | | 2 | | 8L.14 Turbine section and exhaust | | X | | 2 | | 8L.15 Other turbine engine components and systems | | X | | 2 | | 8L.16 Turbine engine inspections and ground operation | | X | | 2 | | 8L.17 Propeller | X | X | X | 2 | | 8L.18 Full authority digital engine control (FADEC) | X | X | X | 2 | | 8L.19 Lubricants and fuels | X | X | X | 2 | | 8L.20 Engine and propeller installation | X | X | X | 2 | | 8L.21 Engine monitoring and ground operation | X | X | X | 2 | | 8L.22 Engine/propeller storage and preservation | X | X | X | 2 | MODULE 9L – BALLOONS – HOT-AIR BALLOONS | MODULE 9L – BALLOONS – HOT-AIR BALLOONS | Level | | ----------------------------------------------------------------- | ----- | | 9L.1 Theory of flight – hot-air balloons | 1 | | 9L.2 General airframe of hot-air balloons | 2 | | 9L.3 Envelope | 3 | | 9L.4 Heater system/burner | 3 | | 9L.5 Basket and basket suspension (including alternative devices) | 3 | | 9L.6 Instruments | 2 | | 9L.7 Equipment | 2 | | 9L.8 Hot-air balloon handling and storage | 2 | | 9L.9 Disassembly, inspection, repair and assembly techniques | 3 | MODULES 10L – BALLOONS – GAS (FREE/TETHERED) BALLOONS | MODULES 10L – BALLOONS – GAS (FREE/TETHERED) BALLOONS | Level | | -------------------------------------------------------------- | ----- | | 10L.1 Theory of flight – gas balloons | 1 | | 10L.2 General airframe of gas balloons | 2 | | 10L.3 Envelope | 3 | | 10L.4 Netting | 3 | | 10L.5 Valves, parachutes and other related systems | 3 | | 10L.6 Load ring | 3 | | 10L.7 Basket (including alternative devices) | 3 | | 10L.8 Ropes and lines | 3 | | 10L.9 Instruments | 2 | | 10L.10 Tethered gas balloon (TGB) systems | 3 | | 10L.11 Equipment | 2 | | 10L.12 Gas balloon handling and storage | 2 | | 10L.13 Disassembly, inspection, repair and assembly techniques | 3 | MODULES 11L – AIRSHIPS – HOT-AIR/GAS AIRSHIPS | MODULES 11L – AIRSHIPS – HOT-AIR/GAS AIRSHIPS | Level | | -------------------------------------------------------------- | ----- | | 11L.1 Theory of flight and control of airships | 2 | | 11L.2 Airship airframe structure – general concepts | 2 | | 11L.3 Airship envelope | 2 | | 11L.4 Gondola | 3 | | 11L.5 Airship flight control (ATA 27/55) | 3 | | 11L.6 Electrical power (ATA 24) | 3 | | 11L.7 Lights (ATA 33) | 2 | | 11L.8 Ice and rain protection | 3 | | 11L.9 Fuel systems (ATA 28) | 2 | | 11L.10 Engine and propellers in airships | 2 | | 11L.11 Airship handling and storage | 2 | | 11L.12 Disassembly, inspection, repair and assembly techniques | 2 | MODULE 12L – RADIO COM/ELT/TRANSPONDER/INSTRUMENTS | MODULE 12L – RADIO COM/ELT/TRANSPONDER/INSTRUMENTS | Level | | -------------------------------------------------- | ----- | | 12L.1 Radio Com/ELT | 2 | | 12L.2 Transponder and FLARM | 2 | | 12L.3 Instruments | 2 | | 12L.4 Avionics general test equipment | 1 | ¹ Only applicable propulsion subjects of Module 8L are required; these depend on the B1 subcategory the applicant comes from. APPENDIX · Appendix VII — Regulation (EU) No 1321/2014 · Regulation (EU) 2023/989 · Continuing Airworthiness Easy Access Rules · EAR revision 2 Sep 2025 [All rules in APPENDICES TO ANNEX III (Part-66)](https://avioverse.aero/regulations/easa/continuing-airworthiness/part-66/appendices-to-annex-iii-part-66) Consolidated from the EASA Easy Access Rules (revision 2 Sep 2025, extracted 2 Nov 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.