(620 ILCS 5/21) (from Ch. 15 1/2, par. 22.21)
    Sec. 21. "Airport protection privileges" means easements through or other interests in air space over land or water, interests in airport hazards outside the boundaries of airports or restricted landing areas, and other protection privileges, the acquisition or control of which is necessary to insure safe approaches to the landing areas of airports and restricted landing areas and the safe and efficient operation thereof.
(Source: Laws 1945, p. 335.)