14 CFR § 65.83 - Recent experience requirements.
A certificated mechanic may not exercise the privileges of his certificate and rating unless, within the preceding 24 months -
(a) The Administrator has found that he is able to do that work; or
(b) He has, for at least 6 months -
(1) Served as a mechanic under his certificate and rating;
(2) Technically supervised other mechanics;
(4) Been engaged in any combination of paragraph (b) (1), (2), or (3) of this section.