(70 ILCS 5/15.1) (from Ch. 15 1/2, par. 68.15a)
    Sec. 15.1. Ordinance authorizing obligations payable from operating revenue; Disposition of revenue; Enforcement of contract against airport authority. The ordinance authorizing the issuance of any such bonds, notes, or certificates of indebtedness payable solely from operating revenue of an airport or airport facility or facilities shall describe such airport, airport facility or facilities, state the purpose or purposes for which the funds derived from the issuance of such bonds, notes, or certificates of indebtedness shall be used and specify the interest rate thereof, which may include a variable interest rate, and any other details in respect thereto as to the Board of Commissioners seem necessary or desirable. The ordinance shall set forth the operating revenues which are to be, and are thereby pledged and apportioned or allocated in whole or in part to the payment of such revenue bonds, notes, or certificates of indebtedness, and which the Board of Commissioners of the Authority determine to be sufficient to pay the cost to the Authority of maintaining such airport, airport facility or facilities, to provide an adequate depreciation fund therefor, adequate reserve funds for the security of the bonds, notes, or certificates of indebtedness, and to pay the principal of, and interest upon, such revenue bonds, notes, or certificates of indebtedness, if apportioned in the manner proposed. The Board of Commissioners shall establish a depreciation fund and may establish one or more reserve funds, to be maintained as a separate account of the Authority for the purpose of providing for the continued and efficient maintenance of such airport, airport facility or facilities during the period such bonds, notes, or certificates of indebtedness may be outstanding and shall make and adopt by appropriate action, all needful rules and regulations for the occupancy, use, maintenance and operation thereof. The charges, tolls, fees, rates or rentals from which the operating revenues so pledged and apportioned or allocated are derived shall be designated by the ordinance and shall be sufficient to pay the cost to the Authority of maintaining such airport, airport facility or facilities, to provide an adequate depreciation fund therefor and adequate reserve funds for the security of the bonds, notes, or certificates of indebtedness, and to pay the principal of, and interest upon, such revenue bonds, notes, or certificates of indebtedness. The Authority may provide by ordinance for the appointment of a trustee on behalf of the owners of any bonds, notes, or certificates of indebtedness of the Authority and may authorize a trust indenture to set forth the duties and obligations of such trustee, which may include the custody and investment of any or all funds of the Authority. While the bonds, notes, or certificates of indebtedness are outstanding, the accounts, books or records of the Authority shall at all times reflect the amount of revenue received from the occupancy or use of such airport, airport facility or facilities, the sums credited to and deposited in any such depreciation fund or reserve fund and the amount of such revenue bonds, notes, or certificates of indebtedness issued and outstanding. The Authority may provide by the ordinance authorizing the issuance of such bonds, notes, or certificates of indebtedness that they shall be registerable, and may be called or accelerated in retirement with or without the payment of a premium or charge therefor, and in such case the bonds, notes, or certificates of indebtedness shall so state. Until payment in full of the bonds, notes, or certificates of indebtedness and interest thereon, the portion of the revenues pledged and allocated to the payment of such bonds, notes, or certificates of indebtedness shall be set aside as a separate fund and used solely for such purpose. The ordinance of the Authority authorizing any revenue bonds, notes, or certificates of indebtedness and any trust indenture with respect thereto may provide that in the event of any failure to pay principal of, premiums on, if any, or interest on the revenue bonds, notes, or certificates of indebtedness, the entire principal of any such revenue bonds, notes, or certificates of indebtedness together with all interest thereon may be declared to be immediately due and payable. In the event the fund becomes sufficient for the payment in full of all outstanding bonds, notes, or certificates of indebtedness due within the current fiscal year for which it is established, and premium, if any, and interest thereon, the surplus above the amount required for such payment from time to time accumulated in such fund may be transferred to the general corporate fund of the Authority by appropriate action of the Board and used for other expenses of the Authority. The ordinance and the provisions of this Act authorizing the issuance of bonds, notes, or certificates of indebtedness shall constitute a contract with the holder of any such bond, note, or certificate of indebtedness, or any coupon evidencing interest thereon, and may be enforced as against such Airport Authority and its corporate officers, in a civil action. Mandamus, injunction or any other appropriate proceeding may be brought and maintained to secure such enforcement.
(Source: P.A. 87-854.)