Basically, the requirements to extend a cat A licence towards a cat B1.1 are demonstration of :
- the basic knowledge required for the relevant subcategory B1.1; and
- the experience required by Appendix IV to Part-66.
Two years of practical maintenance experience on operating aircraft in the B1.1 category (not in the A category) is needed before applying for the extension in addition to the demonstration of basic knowledge required for the relevant subcategory B1.1.
The experience requirement will be reduced by 50% if the applicant has completed an approved Part-147 course relevant to the category extension according to Appendix IV of Part-66.