An important document for technicians working in aviation is an AML (Aircraft Maintenance License). To be able to apply for these, one must obtain all module certificates for the relevant Part-66 Basic training category (eg A, B1 or B2). A period of practical experience is also necessary.
If someone is in possession of an AML, one can expand the AML with a specific aircraft type by doing a Type Training. Now one can be authorized by the recognized aviation maintenance company (Part-145) to sign the performed maintenance and release the aircraft. This release of maintenance allows an aircraft to fly again. In some cases, maintenance may also be signed off by someone else.
An AML is valid in all countries of the EU and countries that are members of the EASA. Countries outside the EU can also recognize this document.