By the early 1980s, the increasing limitations of present communication, navigation and surveillance systems were becoming apparent. To address this, the ICAO council established the future air navigation system committee (FANS) to investigate new concepts and technologies and to recommend a system to overcome the present problems. The FANS committee concluded the existing systems were restricted to effective air traffic management and the problems could not be overcome on a global scale, except by new concepts and newer CNS systems which would fully support air traffic management. The FANS committee developed the CNS/ATM global concept. This text describes the world's vision for the future air navigation system and the concepts developed under the auspices of ICAO between 1983 and 1993, dedicated solely to the CNS/ATM concept. It covers the technical, institutional, economic, labour and human factors associated with the CNS/ATM concept.