How to become an instructor for training instructors

FCL.905.FI FI – Privileges and conditions
Regulation (EU) 2020/359

The privileges of FIs are to conduct flight instruction for the issue, revalidation or renewal of:

(j) an FI, an IRI, a CRI, an STI or an MI certificate provided that they meet all of the following conditions:
(1) they have completed at least 500 hours of flight instruction in the appropriate aircraft category;
(2) they have passed an assessment of competence in accordance with point FCL.935 in the appropriate aircraft category to demonstrate to a flight instructor examiner (FIE) the ability to instruct for the relevant certificate;