Air agreements (SAAs) are formal agreements between countries – accompanying memoranda of understanding (MoU) and diplomatic exchange notes. It is not mandatory to have an ASA for the operation of international services, but cases where there are services without a contract are rare. impose or permit such a service to pay fair and proportionate charges for the use of such airports and other facilities; Such charges shall not be higher than they would be paid for the use of such airports and installations by their national aircraft providing similar international services: provided that the charges levied for the use of airports and other facilities are subject to verification by the Council of the International Civil Aviation Organisation established under that Convention; To report therein and make recommendations for the consideration of the State or States concerned. One of the first ATAs after World War II was the Bermuda Agreement, signed in 1946 by Britain and the United States. The features of this agreement have become models for the thousands of such agreements that were to follow, although in recent decades some of the traditional clauses of these agreements have been modified (or “liberalized”) in accordance with the “open skies” policy of some governments, particularly the United States.  The bilateral system is based on the Chicago Convention and related multilateral treaties. The Chicago Convention was signed in December 1944 and has regulated international air transport ever since. The Convention also contains a number of annexes covering issues such as aviation security, security oversight, airworthiness, navigation, environmental protection and facilitation (acceleration and departure at airports). the route to be followed in its territory by an international air service and the airports that such a service may use; This Agreement shall remain in force for as long as the abovementioned Convention; However, to the extent that any State Party which is a party to this Agreement may denounce it by a period of one year which it has given to the Government of the United States of America, which shall immediately inform all other States Parties of this communication and of its withdrawal. . . .