620 ILCS 40/10
The county board of every county, for the purpose of acquiring land for an airport or landing field or airport facility, or constructing an airport, landing field or airport facility, or to exercise any of the powers enumerated in Section 1, may borrow money and may issue bonds, payable solely from the revenue derived from the operation or leasing of the airport, landing field, and facilities or appurtenances thereof. These bonds may be issued in such amounts as may be necessary to provide sufficient funds to pay all costs of acquiring the land for an airport or landing field or constructing an airport or landing field, or to pay the costs of exercising the powers enumerated in Section 1, including engineering, legal, and other expenses, together with interest on these bonds, to a date 2 years after the estimated date of completion of the airport or landing field, or to a date as determined by the bond sale contract.
Whenever the county board determines to acquire land for an airport or landing field or to construct an airport or landing field or to pay the costs of exercising the powers enumerated in Section 1, and to issue bonds under this Section for the payment of the cost thereof, the county board shall adopt a resolution describing in a general way the contemplated project and refer to the plans and specifications therefor.
This resolution shall set out the estimated cost of the project, fix the amount of revenue bonds to be issued, the maturity or maturities thereof, the interest rate, which shall not exceed 6 1/2% annually, payable annually or semi-annually, and all details in connection with the bonds. The resolution shall also declare that a statutory mortgage lien shall exist upon the property of the airport or landing field, and shall pledge the revenue derived from the operation or leasing of the airport, landing field, and the facilities and appurtenances thereof for the payment of maintenance and operating costs, providing an adequate depreciation fund, and paying the principal and interest of the revenue bonds issued thereunder.
Bonds issued under this Section are negotiable instruments.
620 ILCS 40/10