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The EASA Part 66 licence is required for engineers to obtain ‘approvals’ to work on aircraft. These approvals are issued by companies who are themselves approved by the CAA (EASA Part 145) usually after ‘type training’. The approved engineer can sign off work on the aircraft within his/her licence authority. So for anyone who aspires to work on civil aircraft as a maintenance engineer the Part 66 is a must. This means passing all the modules that go to make up that particular licence. The licence is divided into four broad areas:

Category A Line mechanic (airframes and engines)
Category B1 Licensed engineer (airframes and engines)
Category B2 Licensed engineer (avionics)
Category C Licensed engineer (base/supervisor)

Aircraft mechanic

Category A

Issued after passing the appropriate modules and obtaining the appropriate experience. The person is allowed to sign for certain designated tasks only.

Not recommended as a ‘stepping stone’ to the B1 licence as all the module examinations will have to be taken again – to the higher level.

A1 Turbine Engined Aeroplanes
A2 Piston Engined Aeroplanes
A3 Turbine Engined Helicopters
A4 Piston Engined Helicopters

Experience requirements can vary but would be a maximum of 3 years maintenance experience on operating aircraft within the last seven (certified in a log book).

Category B

Issued after passing all the appropriate modules and obtaining the appropriate experience. Allows the engineer to sign the Certificate of Release to Service for the aircraft in the category for which he/she is licensed.

The category B1 licence is split further into:

B1.1 Turbine Engined Aeroplanes
B1.2 Piston Engined Aeroplanes
B1.3 Turbine Engined Helicopters
B1.4 Piston Engined Helicopters

Experience requirements can vary but would be a maximum of 5 years engineering maintenance on operating aircraft within the last seven. For UK service personnel 4 of those years can be obtained whilst in the service and the last year has to on civil aircraft (all recorded in the log book).

Category C

Requires a suitable degree plus experience and can also be a person who holds a B1 and a B2 licence.


There are no experience requirements to be allowed to sit the examinations, they apply only when licence application is made. As the individual module exam passes have a life of 5 years it is important that all the exams for a particular licence are passed within 5 years of passing the first module. If all the modules are passed within the 5 year period, for a particular licence, then there is no time limit, at the moment, as to their longevity. In other words, the whole group of passes can be kept and the licence applied for at some later date – after getting all the experience, for example. Keep an eye on this as it might change in the future.

All the above experience requirements must include one years recent experience and that experience must include equipment for which application is made. In other words if you are applying for the B1.1 licence mechanical jet engined aircraft the one year recent experience must be on this type of aircraft – not on helicopters for example.

The experience must include a representative cross section of tasks on operating aircraft* and should include, for the mechanical person, some experience on instrument, electrical and avionic systems. Experience in maintenance bays (engine bays, instruments bays, tyre bays etc) is not considered appropriate.

* The term ‘operating aircraft’ means that the aircraft must be a flying aircraft and the servicing could include ramp/first line servicing and/or hangar maintenance.

The term ‘operating aircraft’ does not include work on gliders and UAVs (Unmanned Aerial Vehicles).

For more details you are advised to read BCARs section L or EASA Part 66 as appropriate. These can be obtained from TSO at Norwich, UK or viewed on the net


The syllabus for these licence exams are published in the Part 66 which is issued by the CAA/EASA. The syllabus and its’ contains are more detailed in module 10. The document attached below is published by CAA UK and contains all information in detail about EASA part 66 licencing.


Part 66