Current crises in the air traffic industry demonstrate that changes are required to present systems. The levels of delay and poor safety standards being experienced around the world dictate the need for improved Air Navigation Services (ANS). A multitude of reasons explain these problems. For instance, fragmentation of national systems prevents optimum use of the world's airspace. In addition, inherent limitations of present ANS technologies and procedures mean that it is usually not possible to separate numerous aircraft on random routings. Thus, aircraft must often plan their flights along routes and be channelled so that the necessary separation can be maintained. This results in fuel and time penalties, in addition to airspace capacity being consequently constrained. Accordingly, this paper provides an analysis of changes that should occur to ANS during this decade by evaluating current and planned technologies and procedures.

A research and development programme performed in Sweden over a period of 9 years has created a substantial know-how on the design of satellite navigation user systems. Thus, a basic user system, called the GP & c Total System has been developed and tested over 3 years. This system can serve as a basis for the tailoring of an almost endless number of applications. The system is currently using data from the GPS satellites, but can also be operated with combined GPS/GLONASS receivers. The Swedish GP & c System is an example of how the communication, navigation and surveillance (CNS) concept and the various elements (ADS, ATM, etc.) for a new global Air Navigation System published by the ICAO FANS Committee can be implemented and integrated into a user-friendly operational system. The ICAO 10th Air Navigation Conference (5–20 September 1991) endorsed the FANS concept in which the main elements are based on the implementation of satellite navigation technology.