ICAO and Future Air Navigation Systems

During flight, the crew of an aircraft frequently communicates with stations on the ground. They may seek authorization for flight maneuvers, obtain information necessary to avoid collision, receive an update of weather conditions ahead, or question the operational status of navigation aids en route or at destination There is a continuous invisible link between the aircraft and the ground stations, and among the ground stations themselves. Many ground facilities and supporting services are needed for the safe and efficient operation of aircraft. To achieve harmonious functioning of all these ground facilities and services, international standardization is necessary.