All revenues derived by the authority from the operation of any revenue-producing facility which may not be required to operate, maintain, enlarge, and improve its airport facilities, or to create any necessary reserves for them, or to pay obligations incurred in the issuance of any revenue bonds sold pursuant to the resolution or resolutions adopted by it in connection with the issuance of the bonds may, in the discretion of the authority, either:
S.C. Code § 55-11-660