Aircraft engineer licence (Part 66)

Part 66 of the Civil Aviation Safety Regulations 1998 (CASR) and its Manual of Standards (MOS) prescribes our licensing system for aircraft engineers. The legislation sets out the licensing types, categories and requirements.

Categories of a Part 66 licence

CASR Part 66 contains four aircraft engineer licence (AEL) categories:

Category A: Line maintenance certifying mechanic

The A Category licence includes minor scheduled line maintenance and simple defect rectification, and is further divided into the following subcategories:

  • A1 turbine-engined fixed wing aeroplane
  • A2 piston-engined fixed wing aeroplane
  • A3 turbine-engined helicopter
  • A4 piston-engined helicopter.

Category B1: Maintenance certifying engineer (mechanical)

The B1 Category licence includes maintenance of aircraft structures (airframe), powerplant and mechanical and electrical systems, and is further divided into the following subcategories:

  • B1.1 turbine-engined fixed wing aeroplane
  • B1.2 piston-engined fixed wing aeroplane
  • B1.3 turbine-engined helicopter
  • B1.4 piston-engined helicopter.

Category B2: Maintenance certifying engineer (avionics)

The B2 Category licence includes maintenance of avionics and electrical systems, and applies to all aircraft.

Category C: Base maintenance certifying engineer

The C Category licence applies to large aeroplanes in a base maintenance environment.

Last updated:
11 Feb 2022
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