AME licensing, privileges and responsibilities under Part 66
What this domain tests
Part 66 is the licensing rule for aircraft maintenance engineers. The exam tests licence categories, how ratings are granted, what a licence holder may certify, and the personal responsibilities that come with certification.
Licence structure and privileges
- Part 66 provides for AME licence categories and ratings. The category defines the broad scope (for example, mechanical versus avionics), while type or group ratings define the aircraft or systems covered.
- A licence holder may certify maintenance only within the privileges of the category and the ratings held, using approved maintenance data and within the limitations of the licence.
- Certification is a personal act. The AME must be satisfied that the work has been completed, that required inspections and tests have been done, and that the aircraft or component is airworthy in respect of the work performed.
- Part 66 also sets knowledge, experience and examination requirements, and the conditions for keeping the licence valid. Part 145 organisations may add authorisations, but they cannot widen the underlying Part 66 privileges.
Worked example
A B1-licensed engineer is asked to sign off a repair to a radio communication system. The repair is avionics work. Unless the engineer also holds an appropriate B2 or avionics rating, or the task is expressly within the B1 privileges under the approved data and organisation authorisation, the engineer must decline and refer the task to appropriately rated staff. The reasoning is privilege-based: the question is not whether the engineer is competent in a general sense, but whether the licence category and rating authorise that certification.
Traps
The common failures are certifying outside category or type rating, assuming a company authorisation overrides Part 66, and forgetting that a licence is not a blanket permission for every aircraft. Also watch for questions that confuse the licence with the organisation approval: Part 66 authorises the person; Part 145 authorises the organisation.