145.A.90
145.A.90(a) Validity
(a) An approval shall be issued for an unlimited duration. It shall remain valid subject to:
1. the organisation remaining in compliance with Annex II (Part-145), in accordance with the provisions related to the handling of findings as specified under point 145.B.50; and
2. the competent authority being granted access to the organisation to determine continued compliance with this Part; and
3. the certificate not being surrendered or revoked.
145.A.90(b) Surrender or revocation
(b) Upon surrender or revocation, the approval shall be returned to the competent authority.