The Chicago Convention (also known as the Convention on International Civil Aviation), established the International Civil Aviation Organisation (ICAO), a specialized agency of the United Nations charged with coordinating and regulating international air travel. The Convention establishes rules of airspace, aircraft registration and safety, and details the rights of the signatories in relation to air travel; it also exempts air fuels from tax. The Convention was signed by 52 states on 7 December 1944 in Chicago, Illinois, U.S., and came into effect on 4 April 1947.
The Convention provided for the sovereignty of airspace above the territory of each state, together with five freedoms (later expanded to nine by the addition of four unofficial freedoms) which govern the freedom of states to operate air transport flights (including the carriage of passengers, cargo and mail) across, into and within the airspace of other states. Only the first two of these freedoms (see below) apply automatically to signatory states, the remainder being subject to national agreement.
Right to overfly a foreign country without landing
Right to refuel or carry out maintenance in a foreign country
Right to fly from one's own country to another
Right to fly from a foreign country to one's own
Right to fly between two foreign countries during flights which begin or end in one's own
Right to fly from one foreign country to another one while stopping in one's own country
Right to fly between two foreign countries while not offering flights to one's own country
Right to fly between two or more airports in a foreign country while continuing service to one's own country
Right to fly inside a foreign country without continuing service to one's own country