The Civil Aviation Authority (CAA) is the statutory corporation which oversees and regulates all aspects of civil aviation in the United Kingdom. The CAA directly or indirectly regulates all aspects of aviation in the UK. In some aspects of aviation it is the primary regulator, in other areas, where the responsibility for regulation has passed to the European Aviation Safety Agency (EASA), the CAA acts as EASA's local office, implementing the regulations.
The CAA regulates licensing and approval of active professional such as pilots, licensed aircraft technicians & engineers, Air traffic controllers, Airlines, Licensed aerodromes, Organizations involved in the design, production and maintenance of aircraft and Aircraft registered in the UK.
Licensed technicians and engineers can certify their work that has been carried out on an aircraft and return it to service. Requirements to become licensed Aircraft Maintenance Technicians and Engineers are as follows;
You will be required to demonstrate by examination a level of knowledge in the appropriate subject modules in accordance with Commission Regulation (EU) No 1321/2014, Annex III, Appendix I. The examinations should be conducted either by an approved Part 147 training organization appropriately approved in accordance with Annex IV (Part-147) or by the competent authority. You must provide the following amount of practical maintenance experience gained within Part 145 Maintenance Organization in the form of logbooks / worksheets signed by the appropriate signatory.
You must provide the following amount of Aircraft Maintenance Work Experience gained within Part 145 Maintenance Organization in the form of logbooks / worksheets signed by the appropriate signatory.
The above experience requirement should be practical training on Aircraft maintenance tasks on operating aircraft specific to the category of License applied and practical experience must compliant with CAP741 under Section 3.1
If the experience has been gained in a Part 145 Maintenance Organization but an overseas company, original logbooks / worksheets and examination certificates will be required.
Aircraft Maintenance Work Experience Gained outside a Part 145 Approved Maintenance Organization, the applicant is required to submit with their application, a confirmation letter from the National Aviation Authority that has regulatory oversight of the approval under which the maintenance organization where the experience was gained is based.
Maintenance organisation and that the signatory in EASA Form 19 (Recommendation) is confirmed by the National Aviation Authority of holding the position stated in the maintenance organisation where Aircraft Maintenance Work Experience is gained. The recommendation document will need to be completed by a Quality Manager or the immediate senior person within the Quality Department of your current employer, or the organization where the experience is gained.
You must complete any categories of Part 66 Basic Modular Training Course and basic knowledge examinations within 10 years preceding the application for an Aircraft Maintenance License.
The above information taken from Civil Aviation Authority, United Kingdom website (http://www.caa.co.uk/Commercial-industry/Aircraft/Airworthiness/Engineer-licences/Part-6/Apply-for-an-EASA-Part-66-Aircraft-Maintenance-Licence)