The International Air Services Transit Agreement guarantees (1) the freedom of civil aircraft to fly over foreign countries and territories as long as they do not land, and (2) the freedom of civil aircraft to make nontraffic landings, for refueling or overhaul only, in foreign territory. The agreement thus established for the first time the principle of automatic right of transit and of emergency landing.
The International Air Transport Agreement, also known as the Five Freedoms Agreement, affirms, in addition to the two freedoms covered by the transit agreement, three other freedoms of the air: (3) freedom to transport passengers and cargo from an aircraft's homeland to other countries, (4) freedom to transport passengers and cargo from other countries to an aircraft's homeland, and (5) freedom to carry air traffic between countries other than the aircraft's homeland.
Because the Chicago Convention was adopted in December 1944, ICAO possesses a constitution older than the UN Charter. Countries were much slower in ratifying the Chicago Convention, however, than they were in ratifying the UN Charter. For this reason, ICAO did not come into being until 4 April 1947, 30 days after the convention had been ratified by the required 26 states.