This paper describes the basic principles of a method developed to guide aircraft accurately down to the runway in a time-of-arrival constrained environment. The method is designed to be used in a ‘zone of convergence’ context or in any similar advanced air traffic control system characterized by the integration of control phases over an extended area on the one hand and true ‘computer assistance’ to the air traffic controller on the other; that is, assistance provided at the decision-making level through the automatic generation of guidance advisories.

The method includes two closely-coupled basic components; namely, a ‘predictor’, which computes a trajectory once initial conditions and plans are known, and a ‘profile manager’, which adapts the plans to meet the time constraints and generates the guidance directives on the basis of present position, actual surveillance information, aircraft operation and route constraints.

The mobile radio communications industry has recently witnessed a new demand for terminal equipment which can provide both communications and position reporting capabilities on a global scale–for example, the automatic monitoring of secure cargoes during international transportation. Thus, there is much interest in the development of land mobile satellite terminal equipment in the form of a single integrated unit which can economically provide both of these facilities. In this paper the development of such a unit is considered using the Inmarsat-c satellite communications service and the Navstar Global Positioning System (GPS), with extension to GLONASS possible in a receive-only version.

The situation today can be described as very frustrating for a variety of reasons. Air traffic flow-management (ATFM) has dominated the scene for many years since its conception in 1980. At that time, the principles of ATFM were directed at ensuring that temporary or isolated sector overloads could be handled by ATC and only when broad, prolonged overloads were expected was ATFM activated. Today, we have the reverse situation, where ATFM is active throughout 16 h or more during each day. The system as such was never intended or planned to cope with such a burden and the results are seen in a variety of forms, including departure delays as shown in Fig. 1.

The paper has defined the objectives of flow-management, the techniques it uses, its present organization and the existing problems. It has covered the plans which have been made to radically improve the service and has described the final goal as we can see it from this point, together with the interim development phases.