The bilateral system is based on the Chicago Convention and related multilateral treaties. The Chicago Convention was signed in December 1944 and has governed international air services ever since. the convention also contains a number of annexes covering issues such as aviation safety, safety monitoring, seaworthiness, navigation, environmental protection and facilities (acceleration and departure at airports). A bilateral air services agreement is reached between two states parties, which liberalizes commercial civil aviation services between these countries. Bilateral air services agreements allow designated airlines in these countries to operate commercial flights covering passenger and cargo transport between the two countries. In addition, they generally regulate the frequency and capacity of air services between countries, pricing and other commercial aspects. The Scandinavian countries – Denmark, Norway and Sweden – have long-standing cooperation in aviation policy. Normally, Scandinavian countries negotiate in joint delegation with other countries. However, Denmark, Norway and Sweden conclude bilateral agreements with other countries, but with largely identical texts. Agreements – usually in the so-called “route appendix” regulate routes and points that can be used. An agreement would generally regulate, among other things, the conditions applicable to airlines and the number of airlines that each contracting state can designate. Limitations on the number of frequencies that can be exploited or other capacity limitations may also be part of the agreement.

In 1944, when World War II was in the final stages, 54 countries came to the conference in Chicago, USA, to talk about the future of international aviation. The conference resulted in the signing of the International Civil Aviation Convention, commonly known as the Chicago Convention. The Chicago Convention defined the rules governing international air travel activity. In addition, the International Civil Aviation Organization (ICAO), the United Nations organization responsible for the planning and development of international air traffic (ICAO, 2011)1. Air Services Agreements (ASAs) are formal contracts between countries, Memorandums of Understanding (Memorandum of Understanding) and official diplomatic notes.