Chicago Convention on International Civil Aviation
The Convention on International Civil Aviation, also known as the Chicago Convention, established the International Civil Aviation Organization (ICAO), a specialized agency of the UN charged with coordinating international air travel. The Convention establishes rules of airspace, aircraft registration and safety, security, and sustainability, and details the rights of the signatories in relation to air travel. The Convention also contains provisions pertaining to taxation. The document was signed on December 7, 1944, in Chicago by 52 signatory states. It received the requisite 26th ratification on March 5, 1947, and went into effect on April  4, 1947, the same date that ICAO came into being. In October of the same year, ICAO became a specialized agency of the United Nations Economic and Social Council (ECOSOC). The Convention has since been revised eight times (in 1959, 1963, 1969, 1975, 1980, 1997, 2000 and 2006). As of March 2019, the Chicago Convention had 193 state parties, which includes all member states of the United Nations except Liechtenstein. The Cook Islands is a party to the Convention although it is not a member of the UN. The convention has been extended to cover Liechtenstein by the ratification of  Switzerland. Main articles. Some important articles are: "Article 1": Every state has complete and exclusive sovereignty over airspace above its territory. "Article 3 bis": Every other state must refrain from resorting to the use of weapons against civil aircraft in flight. "Article 5": The aircraft of states, other than scheduled international air services, have the right to make flights across state's territories and to make stops without obtaining prior permission. However, the state may require the aircraft to make a landing. "Article 6": (Scheduled air services) No scheduled international air service may be operated over or into the territory  of a contracting State, except with the special permission or other authorization of that State. "Article 10": (Landing at customs airports): The state can require that landing to be at a designated customs airport and similarly departure from the territory can be required to be from a designated customs airport. "Article 12": Each state shall keep its own rules of the air as uniform as possible with those established under the convention, the duty to ensure compliance with these rules rests with the contracting state. "Article 13": (Entry and Clearance Regulations) A state's laws and regulations regarding the admission  and departure of passengers, crew or cargo from aircraft shall be complied with on arrival, upon departure and whilst within the territory of that state. "Article 16": The authorities of each state shall have the right to search the aircraft of other states on landing or departure, without unreasonable delay. "Article 24": Aircraft flying to, from or across, the territory of a state shall be admitted temporarily free of duty. Fuel, oil, spare parts, regular equipment and aircraft stores retained on board are also exempted from customs duty, inspection fees or similar charges. "Article 29": Before an international flight, the  pilot in command must ensure that the aircraft is airworthy, duly registered and that the relevant certificates are on board the aircraft. The required documents are: "Article 30": The aircraft of a state flying in or over the territory of another state shall only carry radios licensed and used in accordance with the regulations of the state in which the aircraft is registered. The radios may only be used by members of the flight crew suitably licensed by the state in which the aircraft is registered. "Article 32": The pilot and crew of every aircraft engaged in international aviation must  have certificates of competency and licensees issued or validated by the state in which the aircraft is registered. "Article 33": (Recognition of Certificates and Licences) Certificates of airworthiness, certificates of competency and licensees issued or validated by the state in which the aircraft is registered, shall be recognized as valid by other states. The requirements for the issuing of those certificates or airworthiness, certificates of competency or licensees must be equal to or above the minimum standards established by the Convention. "Article 40": No aircraft or personnel with endorsed licenses or certificate will engage in international navigation except with the  permission of the state or states whose territory is entered. Any license holder who does not satisfy international standard relating to that license or certificate shall have attached to or endorsed on that license information regarding the particulars in which he does not satisfy those standards. Annexes. The Convention is supported by nineteen annexes containing standards and recommended practices (SARPs). The annexes are amended regularly by ICAO and are as follows: Annex 5, "Units of Measurement to be Used in Air and Ground Operations", named in its Table 3-3 three "non-SI alternative units permitted for temporary use with  the SI": the foot (for vertical distance = altitude), the knot (for speed), and the nautical mile (for long distance). Bibliography. Paul Michael Krämer, Chicago Convention, 50th Anniversary Conference, Chicago, October 31 – November 1, 1994. Zeitschrift für Luft und Weltraumrecht 1995, S. 57.