47 CFR 78.30: Forfeiture and termination of station authorizations.

(a) A CARS license will be automatically forfeited in whole or in part without further notice to the licensee upon the voluntary removal or alteration of the facilities, so as to render the station not operational for a period of 30 days or more.

(b) If a station licensed under this part discontinues operation on a permanent basis, the licensee must cancel the license. For purposes of this section, any station which has not operated for one year or more is considered to have been permanently discontinued.