Part-66 License Privileges: The 6-Month, 2-Year Recency Rule You Can't Ignore

Under point 66.A.20(b)(2) of Part-66, you may only exercise the privileges of your EASA aircraft maintenance license if, in the preceding 2 years, you have had 6 months of maintenance experience in line with those privileges, or have met the provisions for the issue of the relevant privileges. Missing it does not cancel the license, which stays valid for 5 years from its last issue or change, but it stops you from certifying or acting as support staff until you are current again.

This article is for U.S.-based engineers who hold or are working toward a Part-66 license, and for American owners and organizations who rely on EU certifying staff. It is based on Annex III (Part-66) to Regulation (EU) No 1321/2014, consolidated on 22 February 2026, and EASA's continuing airworthiness FAQ. FAA mechanic certification rules are not in these sources. One point the FAQ makes explicitly: none of the EU's bilateral agreements with third countries, the U.S. included, cover maintenance licenses.

The four conditions for using your privileges

Holding a Part-66 license is necessary, not sufficient. Point 66.A.20(b) lists four conditions, all of which must be met before you exercise privileges:

1. You act in compliance with the applicable requirements of Part-M, Part-145, Part-ML and Part-CAO.
2. Recency: in the preceding 2-year period you have had 6 months of maintenance experience in accordance with the privileges of the license, or met the provision for the issue of the appropriate privileges.
3. You have adequate competence to certify maintenance on the corresponding aircraft.
4. You can read, write and communicate to an understandable level in the language(s) of the technical documentation and procedures supporting the certificate of release to service.

Organizations have to check this, too. A CAO may only let its certifying staff release maintenance once it has ensured they meet 66.A.20(b), or the national rules where Article 5(6) applies (CAO.A.040(a)(1)).

License validity versus the right to certify

These are two separate clocks, and EASA's FAQ is clear on it: the validity of the Part-66 license “is not affected” by 66.A.20(b)(2). The license itself remains valid 5 years from its last renewal.

For renewal, 66.A.40(b) has the holder complete EASA Form 19 and send it with the license copy to the authority that issued the original license, unless the holder works for a Part-145 or Part-CAO organization whose exposition lets it submit on the holder's behalf.

Getting current again after a gap

Suppose you have been out of maintenance for a while. A purely illustrative date calculation shows how the rolling window works: you stopped hands-on work on March 1, 2025 and want to certify on October 5, 2026. The 2-year window runs from October 5, 2024; your experience inside it covers October 5, 2024 to March 1, 2025, roughly 4 months and 24 days, which is less than 6 months. How experience is counted in detail, and any reductions, is set out in AMC and GM that are not part of this base, so treat the example as a picture of the window, not an assessment.

If you fall short, the second branch of the rule applies: you can regain privileges by meeting “the provision for the issue of the appropriate privileges.” EASA's FAQ interprets this, by reference to 66.A.45, as:

• Taking type training again, with any need for on-the-job training assessed case by case;
• for aircraft whose endorsement does not require type training (Groups 2, 3 or 4): passing a type evaluation, including a practical assessment;
• where no type evaluation is required, for example a B2 or B2L license with a full Group 3 or 4 rating, or L-category licenses other than L5: demonstrating practical experience in the last 2 years covering a representative cross section of maintenance activities for the subcategory.

First type rating: type training plus on-the-job training

Recency matters most when it meets the type-rating rules. Under 66.A.45(b), endorsing a type rating requires the relevant B1, B2 or C type training under Appendix III. Under 66.A.45(c), for licenses other than category C, the first type rating in a given category or subcategory also requires on-the-job training (OJT) complying with Appendix III (gas airships aside, which need direct authority approval).

Section 6 of Appendix III sets the OJT rules:

1. The OJT task list and program must be accepted by the authority that issued your license before you start.
2. It takes place at one or more maintenance organizations approved for that aircraft type, one of which controls it.
3. You need a category A, B or L5 license first, or must have finished the theoretical type training and accumulated at least 50% of the basic experience requirement.
4. OJT is started and completed within 3 years before applying for the first type rating, with at least 50% of the tasks done after the theoretical type training.
5. Mentors supervise one-to-one and countersign each task, which refers to an actual job card or work sheet.
6. A final assessment by designated assessors lasts at least one working day.

Type training has its own clock: theoretical and practical elements must be started and completed within the 3 years preceding the application for endorsement (Appendix III, point 1). EASA's FAQ also says the OJT is performed on the type you are seeking, though a limited number of very similar tasks may be done on other types if justified to the authority. For Group 2 and 3 aircraft, 66.A.45(d) offers an alternative: a type evaluation plus demonstrated practical experience on the type.

Before you sign a release: a quick self-check

1. Is my license within its 5-year validity, signed and issued or changed by the competent authority (66.A.40(d))?
2. Is the aircraft type or group rating endorsed, and are there limitations on the license that exclude this aircraft (66.A.45, 66.A.50)?
3. Do I have 6 months of experience in line with these privileges inside the last 2 years, with records to show it?
4. Is the task within my category: B1 for structure, power plant and mechanical and electrical systems; B2 for avionics and electrical work, noting that B2 does not include any A subcategory?
5. Can I read and communicate in the language of the maintenance data and procedures I am using?

Related time limits worth knowing

• Basic license: basic knowledge exams must have been passed within 10 years before applying (66.A.25(c)), and experience acquired within the 10 years preceding the application (66.A.30(f)).
• Electric aeroplanes: until February 13, 2028, an aeroplane with electric power plant and MTOM below 5,700 kg may be endorsed on a B1.1 or B1.2 license if, among other conditions, the holder has at least 6 months of maintenance experience on aircraft of that (sub)category within the last 24 months (Article 5(8)).
• Evidence on request: certifying and support staff must produce their license within 24 hours when an authorized person asks (66.A.55).

Practical questions, such as whether a B1.2 holder can release work on piston-engine non-pressurized aeroplanes of 2,000 kg MTOM and below, are answered in the EASA Part-66 knowledge base with the point of Part-66 or the FAQ it comes from. (The FAQ's answer: yes, B3 is included in B1.2 by default, subject to 66.A.20(b).)

This article explains the regulation and is not an assessment of anyone's license status; that belongs to the issuing competent authority. Sources: EUR-Lex and EASA's FAQ. The AMC/GM to Part-66 are not in the knowledge base.