183.15 Duration of certificates.
(a) Unless sooner terminated under paragraph (b) of this section, a designation as an Aviation Medical Examiner or as a Flight Standards or Aircraft Certification Service Designated Representative as described in §183.21, 183.23, 183.25, 183.27, 183.29, 183.31, or 183.33 is effective until the expiration date shown on the document granting the authorization.
(b) A designation made under this subpart terminates:
(1) Upon the written request of the representative;
(2) Upon the written request of the employer in any case in which the recommendation of the employer is required for the designation;
(3) Upon the representative being separated from the employment of the employer who recommended him or her for certification;
(4) Upon a finding by the Administrator that the representative has not properly performed his or her duties under the designation;
(5) Upon the assistance of the representative being no longer needed by the Administrator; or
(6) For any reason the Administrator considers appropriate.