66.A.20(a) Licence privileges
(a) The following privileges shall apply:
1. A category A aircraft maintenance licence permits the holder to issue certificates of release to service following minor scheduled line maintenance and simple defect rectification within the limits of tasks specifically endorsed on the certification authorisation referred to in point 145.A.35 of Annex II (Part-145). The certification privileges shall be restricted to work that the licence holder has personally performed in the maintenance organisation that issued the certification authorisation.
2. A category B1 aircraft maintenance licence shall permit the holder to issue certificates of release to service and to act as B1 support staff following:
— maintenance performed on aircraft structure, powerplant and mechanical and electrical systems,
— work on avionic systems requiring only simple tests to prove their serviceability and not requiring troubleshooting.
Category B1 includes the corresponding A subcategory.
3. A category B2 aircraft maintenance licence shall permit the holder:
(i) to issue certificates of release to service and to act as B2 support staff for following:
— maintenance performed on avionic and electrical systems, and
— electrical and avionics tasks within powerplant and mechanical systems, requiring only simple tests to prove their serviceability; and
(ii) to issue certificates of release to service following minor scheduled line maintenance and simple defect rectification within the limits of tasks specifically endorsed on the certification authorisation referred to in point 145.A.35 of Annex II (Part-145). This certification privilege shall be restricted to work that the licence holder has personally performed in the maintenance organisation which issued the certification authorisation and limited to the ratings already endorsed in the B2 licence.
The category B2 licence does not include any A subcategory.
4. A category B2L aircraft maintenance licence shall permit the holder to issue certificates of release to service and to act as B2L support staff for the following:
— maintenance performed on electrical systems;
— maintenance performed on avionics systems within the limits of the system ratings specifically endorsed on the licence, and
— when holding the ‘airframe system’ rating, performance of electrical and avionics tasks within power plant and mechanical systems, requiring only simple tests to prove their serviceability.
AMC 66.A.20(a)(4) System rating limits
‘Within the limits of the system ratings specifically endorsed on the licence’ refers to the fact that the privileges of the licence holder are limited:
— to the group/subgroup of aircraft endorsed on the licence, but also
— to the system rating(s) endorsed.
When an applicant wishes to get the privilege to issue certificates of release to service and to act as support staff for electrical and avionics tasks within powerplant and mechanical systems, he/she should apply for the rating ‘airframe system’ on the B2L licence. The reason is that the ‘airframe systems’ rating is the only rating which covers completely the electrical and avionics tasks of the powerplant and mechanical systems of the aircraft.
5. A category B3 aircraft maintenance licence shall permit the holder to issue certificates of release to service and to act as B3 support staff for the following:
— maintenance performed on aeroplane structure, power plant and mechanical and electrical systems; and
— work on avionics systems requiring only simple tests to prove their serviceability and not requiring troubleshooting.
6. A category L aircraft maintenance licence shall permit the holder to issue certificates of release to service and to act as L support staff for the following:
— maintenance performed on aircraft structure, power plant and mechanical and electrical systems;
— work on radio, Emergency Locator Transmitters (ELT) and transponder systems; and
— work on other avionics systems requiring simple tests to prove their serviceability.
Subcategory L2 includes subcategory L1. Any limitation to subcategory L2 in accordance with point 66.A.45(h) becomes also applicable to subcategory L1.
Subcategory L2C includes subcategory L1C.
7. A category C aircraft maintenance licence shall permit the holder to issue certificates of release to service following base maintenance of the aircraft. The privileges apply to the aircraft in its entirety.
GM 66.A.20(a) Privileges- Definitions
1. The following definitions apply:
Electrical system means the aircraft electrical power supply source, plus the distribution system to the different components contained in the aircraft and relevant connectors. Lighting systems are also included in this definition. When working on cables and connectors which are part of these electrical systems, the following typical practices are included in the privileges:
— Continuity, insulation and bonding techniques and testing;
— Crimping and testing of crimped joints;
— Connector pin removal and insertion;
— Wiring protection techniques.
Avionics system means an aircraft system that transfers, processes, displays or stores analogue or digital data using data lines, data buses, coaxial cables, wireless or other data transmission medium, and includes the system’s components and connectors. Examples of avionics systems include the following:
— Communication, Radar and Navigation;
— Instruments (see NOTE below);
— In Flight Entertainment Systems;
— Integrated Modular Avionics (IMA);
— On-Board Maintenance Systems;
— Information Systems;
— Fly by Wire Systems (related to ATA27 ‘Flight Controls’);
— Fibre Optic Control Systems.
NOTE: Instruments are formally included within the privileges of the B2 and B2L with system rating ‘instruments’. However, maintenance on electromechanical and pitot-static components may also be released by a B1, B3 or L licence holder.
Simple test means a test described in approved maintenance data and meeting all the following criteria:
— The serviceability of the system can be verified using aircraft controls, switches, Built-in Test Equipment (BITE), Central Maintenance Computer (CMC) or external test equipment not involving special training.
— The outcome of the test is a unique go – no go indication or parameter, which can be a single value or a value within an interval tolerance. No interpretation of the test result or interdependence of different values is allowed.
— The test does not involve more than 10 actions as described in the approved maintenance data (not including those required to configure the aircraft prior to the test, i.e. jacking, flaps down, etc, or to return the aircraft to its initial configuration). Pushing a control, switch or button, and reading the corresponding outcome may be considered as a single step even if the maintenance data shows them separated.
Troubleshooting means the procedures and actions necessary, using approved maintenance data, in order to identify the root cause of a defect or malfunction. It may include the use of BITE or external test equipment.
Line maintenance means any maintenance that is carried out before flight to ensure that the aircraft is fit for the intended flight. It may include:
— trouble shooting;
— defect rectification;
— component replacement with use of external test equipment, if required.
Component replacement may include components such as engines and propellers;
— scheduled maintenance and/or checks including visual inspections that will detect obvious unsatisfactory conditions/discrepancies but do not require extensive in depth inspection. It may also include internal structure, systems and powerplant items which are visible through quick opening access panels/doors;
— minor repairs and modifications which do not require extensive disassembly and can be accomplished by simple means;
— for temporary or occasional cases (Airworthiness Directives, hereinafter AD; service bulletins, hereinafter SB) the quality manager may accept base maintenance tasks to be performed by a line maintenance organisation provided all requirements are fulfilled. The Member State will prescribe the conditions under which these tasks may be performed.
Base Maintenance means any task falling outside the criteria that are given above for Line Maintenance.
Aircraft maintained in accordance with ‘progressive’ type programmes need to be individually assessed in relation to this paragraph. In principle, the decision to allow some ‘progressive’ checks to be carried out is determined by the assessment that all tasks within the particular check can be carried out safely to the required standards at the designated line maintenance station.
2. The category B3 licence does not include any A subcategory. Nevertheless, this does not prevent the B3 licence holder from releasing maintenance tasks typical of the A1.2 subcategory for piston-engine non-pressurized aeroplanes of 2 000 kg MTOM and below, within the limitations contained in the B3 licence.
3. The B1.2 and B3 licences do not include any L subcategory. Nevertheless, the holder of a B1.2 or B3 licence with the appropriate ratings is entitled to receive, upon application, licences in the L1 and L2 subcategories under the conditions described in point 66.B.110(d).
4. The privileges of the B2 licence with given aircraft ratings include the privileges of the B2L licence for all the system ratings for the same aircraft ratings. Nevertheless, the holder of a B2 licence with given aircraft ratings may apply for a B2L licence in order to include a different aircraft rating if the applicant only wants to demonstrate compliance with the experience requirements for certain system ratings.
5. The category C licence permits certification of scheduled base maintenance by the issue of a single certificate of release to service for the complete aircraft after the completion of all such maintenance. The basis for this certification is that the maintenance has been carried out by competent mechanics, and category B1, B2, B2L, B3 and L support staff, as appropriate, have signed for the maintenance tasks under their respective specialisation. The principal function of the category C certifying staff is to ensure that all required maintenance has been called up and signed off by the category B1, B2, B2L, B3 and L support staff, as appropriate, before issue of the certificate of release to service. Only category C personnel who also hold category B1, B2, B2L, B3 or L qualifications may perform both roles in base maintenance.
66.A.20(b) Experience and competence
(b) The holder of an aircraft maintenance licence may not exercise its privileges unless:
1. in compliance with the applicable requirements of Annex I (Part-M) and Annex II (Part-145); and
2. in the preceding 2-year period he/she has, either had 6 months of maintenance experience in accordance with the privileges granted by the aircraft maintenance licence or, met the provision for the issue of the appropriate privileges; and
AMC 66.A.20(b)(2) Recent maintenance experience
The 6 months of maintenance experience in the preceding 2-year period should be understood as consisting of two elements, duration and nature of the experience. The minimum to meet the requirements for these elements may vary depending on the size and complexity of the aircraft and type of operation and maintenance.
Within an approved maintenance organisation:
— 6 months of continuous employment within the same organisation; or
— 6 months split up into different blocks, employed within the same or in different organisations.
The 6-month period can be replaced by 100 days of maintenance experience in accordance with the privileges, whether they have been performed within an approved organisation or as independent certifying staff according to M.A.801(b)1, or as a combination thereof.
When a licence holder maintains and releases aircraft in accordance with M.A.801(b)1, in certain circumstances this number of days may even be reduced by 50% when agreed in advance by the competent authority. These circumstances consider the cases where the licence holder happens to be the owner of an aircraft and carries out maintenance on his/her own aircraft, or where a licence holder maintains an aircraft operated for low utilisation, that does not allow the licence holder to accumulate the required experience. This reduction should not be combined with the 20% reduction permitted when carrying out technical support, or maintenance planning, continuing airworthiness management or engineering activities. To avoid a too long period without experience, the working days should be spread over the intended 6-month period.
2. Nature of the experience:
Depending on the category of the aircraft maintenance licence, the following activities are considered relevant for maintenance experience:
— Operational and functional testing;
— Changing component;
— Supervising these activities;
— Releasing aircraft to service.
For category A licence holders, the experience should include exercising the privileges, by means of performing tasks related to the authorization on at least one aircraft type for each licence subcategory. This means tasks as mentioned in AMC 145.A.30(g), including servicing, component changes and simple defect rectifications.
For category B1, B2, B2L, B3 and L, for every aircraft included in the authorisation the experience should be on that particular aircraft or on a similar aircraft within the same licence (sub)category. Two aircraft can be considered to be similar when they have similar technology, construction and comparable systems, which means equally equipped with the following (as applicable to the licence category):
— Propulsion systems (piston, turboprop, turbofan, turboshaft, jet-engine or push propellers); and
— Flight control systems (only mechanical controls, hydro-mechanically powered controls or electro-mechanically powered controls); and
— Avionic systems (analogue systems or digital systems); and
— Structure (manufactured of metal, composite or wood).
For licences endorsed with (sub)group ratings:
— In the case of a B1 licence endorsed with (sub)group ratings (either manufacturer sub-group or full (sub)group) as defined in 66.A.45, the holder should show experience on at least one aircraft type per (sub)group and per aircraft structure (metal, composite, wood).
— In the case of a B2 or B2L licence endorsed with (sub)group ratings (either manufacturer subgroup or full (sub)group) as defined in 66.A.45, the holder should show experience on at least one aircraft type per (sub)group.
— In the case of a B3 licence endorsed with the rating ‘piston-engine non-pressurised aeroplanes of 2000 kg MTOM and below’ as defined in 66.A.45, the holder should show experience on at least one aircraft type per aircraft structure (metal, metal-tubing with fabric, composite, wooden).
For category C, the experience should cover at least one of the aircraft types endorsed on the licence.
For a combination of categories, the experience should include some activities of the nature shown in paragraph 2 in each category.
A maximum of 20% of the experience duration required may be replaced by the following relevant activities on an aircraft type of similar technology, construction and with comparable systems:
— Aircraft maintenance related training as an instructor/assessor or as a student;
— Maintenance technical support/engineering;
— Maintenance management/planning.
The experience should be documented in an individual log book or in any other recording system (which may be an automated one) containing the following data:
— Aircraft type;
— Aircraft identification i.e. registration;
— ATA chapter (optional);
— Operation performed e.g. 100 FH check, MLG wheel change, engine oil check and complement, SB embodiment, trouble shooting, structural repair, STC embodiment, etc.;
— In the particular case of Part-145 organisations, the type of maintenance i.e. base, line;
— Type of activity i.e. perform, supervise, release;
— Subcategory used (A1, A2, A3, A4, B1.1, B1.2, B1.3, B1.4, B2, B2L, B3, C or L1, L1C, L2, L2C, L3G, L3H, L4G, L4H, L5);
— Duration in days or partial-days.
GM 66.A.20(b)2 Experience requirements
The sentence ‘met the provision for the issue of the appropriate privileges’ included in 66.A.20(b)2 means that during the previous 2 years the person has met all the requirements for the endorsement of the corresponding aircraft rating (for example, in the case of aircraft in Group 1, theoretical plus practical element plus, if applicable, on-the-job training). This supersedes the need for 6 months of experience for the first 2 years. However, the requirement of 6 months of experience in the preceding 2 years will need to be met after the second year.
3. he/she has the adequate competence to certify maintenance on the corresponding aircraft; and
AMC 66.A.20(b)3 Competence
The wording ‘has the adequate competence to certify maintenance on the corresponding aircraft’ means that the licence holder and, if applicable, the organisation where he/she is contracted/employed, should ensure that he/she has acquired the appropriate knowledge, skills, attitude and experience to release the aircraft being maintained. This is essential because some systems and technology present in the particular aircraft being maintained may not have been covered by the training/examination/experience required to obtain the licence and ratings.
This is typically the case, among others, in the following situations:
— Type ratings which have been endorsed on a licence in accordance with Appendix I to AMC to Part-66 ‘List of Type Ratings’ after attending type training/on-the-job training which did not cover all the models/variants included in such rating. For example, a licence endorsed with the rating Airbus A318/A319/A320/A321 (CFM56) after attending type training/on-the-job training covering only the Airbus 320 (CFM56).
— Type ratings which have been endorsed on a licence in accordance with Appendix I to AMC to Part-66 ‘List of Type Ratings’ after a new variant has been added to the rating in Appendix I, without performing difference training. For example, a licence endorsed with the rating Boeing 737-600/700/800/900 for a person who already had the rating Boeing 737-600/700/800, without performing any difference training for the 737-900.
— Work being carried out on a model/variant for which the technical design and maintenance techniques have significantly evolved from the original model used in the type training/on-the-job training.
— Specific technology and options selected by each customer which may not have been covered by the type training/on-the-job training.
— Changes in the basic knowledge requirements of Appendix I to Part-66 not requiring re-examination of existing licence holders (grandfathered privileges).
— The endorsement of group/subgroup ratings based on experience on a representative number of tasks/aircraft or based on type training/examination on a representative number of aircraft.
— Persons meeting the requirements of 6 months of experience every 2 years only on certain similar aircraft types as allowed by AMC 66.A.20(b)2.
— Persons holding a Part-66 licence with limitations, obtained through conversion of national qualifications (66.A.70), where such limitations are going to be lifted after performing the corresponding basic knowledge examinations. In this case, the type ratings endorsed in the licence may have been obtained in the national system without covering all the aircraft systems (because of the previous limitations) and there will be a need to assess and, if applicable, to train this person on the missing systems.
Additional information is provided in AMC 145.A.35(a).
4. he/she is able to read, write and communicate to an understandable level in the language(s) in which the technical documentation and procedures necessary to support the issue of the certificate of release to service are written.
GM 66.A.20(b)4 Language
1. Holders of a Part-66 aircraft maintenance licence may not exercise certification privileges unless they have a general knowledge of the language used within the maintenance environment including knowledge of common aeronautical terms in the language. The level of knowledge should be such that the licence holder is able to:
— read and understand the instructions and technical manuals used for the performance of maintenance;
— make written technical entries and any maintenance documentation entries, which can be understood by those with whom they are normally required to communicate;
— read and understand the maintenance organisation procedures;
— communicate at such a level as to prevent any misunderstanding when exercising certification privileges.
2. In all cases, the level of understanding should be compatible with the level of certification privileges exercised.