70 ILCS 1865/4.12

For the prevention of accidents, for the furtherance and protection of public health, safety and convenience in respect to aeronautics, for the protection of property and persons within the District from any hazard or nuisance resulting from the flight of aircraft, for the prevention of interference between, or collision of, aircraft while in flight or upon the ground, for the prevention or abatement of nuisances in the air or upon the ground or for the extension of increase in the usefulness or safety of any public airport or public airport facility owned by the District, the District may regulate and restrict the flight of aircraft while within or above the incorporated territory of the District.