(a) A certificate shall be valid under the terms set forth in the certificate for a period to be designated by the Administrator or his authorized representative. Application for renewal of any certificate shall be filed in the same manner as an original application under this part.

(b) No effective certificate shall expire until action on an application for renewal shall have been finally determined, provided that such application has been properly executed in accordance with the requirements, and filed not less than 15 nor more than 30 days prior to the expiration date. A final determination means either the granting of or initial denial of the application for renewal of a certificate, or withdrawal of the application. A “properly executed” application is one which contains the complete information required on the form.