47 CFR § 1.955 - Termination of authorizations.
(a) Authorizations in general remain valid until terminated in accordance with this section, except that the Commission may revoke an authorization pursuant to section 312 of the Communications Act of 1934, as amended. See 47 U.S.C. 312.
(1) Expiration. Authorizations automatically terminate, without specific Commission action, on the expiration date specified therein, unless a timely application for renewal is filed. See § 1.949 of this part. No authorization granted under the provisions of this part shall be for a term longer than ten years, except to the extent a longer term is authorized under § 27.13 of part 27 of this chapter.
(2) Failure to meet construction or coverage requirements. Authorizations automatically terminate (in whole or in part as set forth in the service rules), without specific Commission action, if the licensee fails to meet applicable construction or coverage requirements. See § 1.946(c).
(3) Service discontinued. Authorizations automatically terminate, without specific Commission action, if service or operations are permanently discontinued. See § 1.953.
(b) Special temporary authority (STA) automatically terminates without specific Commission action upon failure to comply with the terms and conditions therein, or at the end of the period specified therein, unless a timely request for an extension of the STA term is filed in accordance with § 1.931 of this part. If a timely filed request for extension of the STA term is dismissed or denied, the STA automatically terminates, without specific Commission action, on the day after the applicant or the applicant's attorney is notified of the Commission's action dismissing or denying the request for extension.
(c) Authorizations submitted by licensees for cancellation terminate when the Commission gives Public Notice of such action.