70 ILCS 5/15.2
An Airport Authority may construct office, aircraft hangar and service buildings and appurtenant facilities upon a public airport owned and operated by the authority for the use and occupancy of the State Department of Transportation under a lease to the State of Illinois for such purpose. The rents and charges payable thereunder shall be not greater than the total costs to the authority of constructing and maintaining said airport improvements and of funding such costs under the provisions of Sections 8.03, 8.04, 8.08, 15 and 15.1, as amended, of this Act as hereinafter provided. The rentals payable to the authority under such lease, together with such non-tax revenues as are available to the authority, shall also be adequate in amount for the authority to establish and maintain a bond reserve account. Such lease shall not be effective for a longer term than is reasonably required to enable such funding to occur, and in no event shall the term thereof exceed thirty years. Such airport improvements shall be constructed upon plans and specifications approved by the Department of Transportation. The lease of said improvements and the site thereof to the State of Illinois shall be executed by the Department of Central Management Services for the use of the Department of Transportation. In the event the General Assembly does not appropriate the necessary funds for paying the rentals on the lease entered into by the authority under this Section, the authority may lease such facilities to another lessee.
The authority may secure the funds required for the construction of said improvements through the issuance and sale of revenue bonds as authorized by and subject to the conditions stated in said Sections 15 and 15.1 of this Act, which bonds shall bear interest at a rate not to exceed that permitted in "An Act to authorize public corporations to issue bonds, other evidences of indebtedness and tax anticipation warrants subject to interest rate limitations set forth therein", approved May 26, 1970, as now or hereafter amended. Such revenue bonds shall be primarily secured by the income receivable by the authority under said lease. Other available and unpledged airport operating income may be pledged by the authority to meet any deficiency in the income from the lease in meeting the principal and interest maturities of said revenue bonds and the maintenance and depreciation requirements of said Section 15.1. The principal amount of such revenue bonds shall be based upon the actual total costs of said improvements including costs of engineering and architects services, the costs incidental to the issuance of the bonds, including legal costs, the costs of selling and printing the bonds, and the interest on the bonds during the time of construction. Construction contracts for said improvements shall be awarded upon competitive bids and such bids and the making of awards shall be subject to approval by the Authority and the Department of Transportation.
70 ILCS 5/15.2