70 ILCS 5/1
When used in this Act:
"Aeronautics" means the act or practice of the art and science of transportation by aircraft and instruction therein, and establishment, construction, extension, operation, improvement, repair or maintenance of airports and airport facilities and air navigation facilities, and the operation, construction, repair or maintenance of aircraft.
"Aircraft" means any contrivance now known or hereafter invented, used or designed for navigation of, or flight in, the air.
"Airport" means any locality, either land or water, which is used or designed for the landing and taking off of aircraft, or for the location of runways, landing fields, airdromes, hangars, buildings, structures, airport roadways and other facilities.
"Airport hazard" means any structure, or object of natural growth, located on or in the vicinity of an airport, or any use of land near an airport, which is hazardous to the use of such airport for the landing and take-off of aircraft.
"Approach" means any path, course or zone defined by an ordinance of an Authority, or by other lawful regulation, on the ground or in the air, or both, for the use of aircraft in landing and taking off from an airport located within an Authority.
"Facilities" means and includes real estate and any and all forms of tangible and intangible personal property and services used or useful as an aid, or constituting an advantage or convenience to, the safe landing, taking off and navigation of aircraft, or the safe and efficient operation or maintenance of a public airport. In addition, for all airport authorities, "facilities" means and includes real estate, tangible and intangible personal property, and services used or useful for commercial and recreational purposes.
"Board of Commissioners" and "Board" mean the board of commissioners of an established authority or an authority proposed to be established.
"Commercial aircraft" means any aircraft other than public aircraft engaged in the business of transporting persons or property.
"Airport Authority" means a municipal corporation created and established under Section 2 of this Act, and includes Metropolitan Airport Authorities. "Authority" and "Airport Authority" are synonymous, unless the context requires otherwise.
"Metropolitan Airport Authority" and "Metropolitan Authority" mean an airport authority established in the manner provided in Section 2.7 of this Act.
"Municipality" means any city, village or incorporated town of the State of Illinois.
"Public Agency" means any political subdivision, public corporation, quasi-municipal corporation or municipal corporation of the State of Illinois, excepting public corporations or agencies owning, operating or maintaining a college or university with funds of the State of Illinois.
"Private aircraft" means any aircraft other than public and commercial aircraft.
"Public aircraft" means an aircraft used exclusively in the governmental service of the United States, or of any state or of any public agency, including military and naval aircraft.
"Public airport" means an airport owned by an airport authority or other public agency which is used or is intended for use by public, commercial and private aircraft and by persons owning, managing, operating or desiring to use, inspect or repair any such aircraft or to use any such airport for aeronautical purposes.
"Public interest" means the protection, furtherance and advancement of the general welfare and of public health and safety and public necessity and convenience in respect to aeronautics.
"Rail Authority" means a Rail Authority established as provided in Section 22.1 of this Act.
"Rail facility" has the meaning set forth in Section 22.2 of this Act.
"Related facility" has the meaning set forth in Section 22.2 of this Act.
70 ILCS 5/1