620 ILCS 45/20
The Board of Directors may apply for and receive a grant or loan or other financial aid from the State or Federal government or from any State or Federal agency, department, bureau or board, necessary or useful for the undertaking, performance or execution of any of its objects or purposes, and any such Board of Directors may undertake the acquisition, establishment, construction or development or improvement of an airport or airports in co-operation with or as a joint enterprise with the State or Federal governments or with both the State and Federal governments acting or represented by any State or Federal agency, department, bureau or board.
In every case where Federal or State aid or financial assistance is to be secured, or where the Federal or State governments, or both the Federal and State governments, have joined with any such Board of Directors for the acquisition, establishment, construction, development or improvement of an airport, such Board of Directors may secure necessary funds to finance its portion of the cost of such project through the issuance of bonds in the manner provided by this Act, or by the issuance of obligations payable from operating revenue.
620 ILCS 45/20