The requirements to extend a Part-66 licence with a category A1 to B1.1 are:
- the knowledge demonstration of those basic modules, which are of higher level for B1.1 (see Part-66 Appendix I); and
- the demonstration of 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 A1 category) is needed before applying for the extension. This experience need to be accumulated within the 10 years preceding the application.
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.
See Part-66.A.15.10, 66.A.25, 66.A.30 and related AMC/GM.