Part-66 licence and category extensions

What the Part-66 licence is

The Part-66 aircraft maintenance licence is defined in Annex III (Part-66) to Regulation (EU) No 1321/2014. It is issued by the competent authority of the Member State.

It evidences the holder's basic knowledge and experience. On its own it does not give the right to sign a release to service: a certification authorisation issued by a Part-145 (or Part-CAO, where applicable) organisation is also required.

The categories

The regulation defines several categories, divided into subcategories by aircraft and engine type:

• A — simple line maintenance tasks and simple defect rectification, within the limits set by the organisation.
• B1 — mechanical: structure, powerplant, mechanical and electrical systems, plus some simple avionics tasks.
• B2 — avionics and electrical.
• B2L, B3 and L — categories for light or unpressurised aircraft, with a scope defined by the regulation.
• C — base maintenance certification following a complete aircraft check.

Obtaining and extending a category

Obtaining a category rests on two pillars: passing the basic knowledge examination modules (Appendix I) applicable to the category, and a period of practical maintenance experience on operating aircraft set by point 66.A.30. That period is reduced when training was completed at a Part-147 approved training organisation.

For an extension (for example from B1 to B2, or from one subcategory to another), the holder passes the missing modules and completes the additional experience required by the regulation. Exact durations are in the text: always check the current consolidated version.

Practical steps

The general approach is the same for a first issue or an extension:

• Identify the target category and subcategory.
• Review which modules are already passed and which remain.
• Document practical experience (logbook, employer statements).
• Submit the application to the competent authority using the prescribed form.

Frequently asked questions