A Study of Air Traffic Control System Capacity

Abstract : The long-range objective of the program is to develop tools and techniques to define, measure, and predict the quantitative capacity of an air traffic control system, which can then be used in analytical studies in support of long-range plans, management decisions, and system performance evaluations. A first approximation to a functional description of the present air traffic control system, largely free of descriptions of equipment or methods now used to implement the functions, was prepared. Several approaches to the quantitative use of measures of safety as system variables were formulated. The mathematical theory of time-dependent queues was found to be applicable to air traffic control system capacity problems. Some elementary applications, chiefly illustrative of methods, were made. It was concluded that: (1) A functional description of air traffic control which is applicable to a wide range of system concepts, including the present system and many suggested variations and alternatives, is feasible; (2) The mathematical theory of time-varying queues is an important, useful tool; (3) The quantitative study of safety is highly relevant to ATC capacity, but must be studied indirectly rather than through accident statics; and (4) Simple, straightforward definitions of concepts, such as capacity, demand, delay, and safety, are unlikely, but the need for them can be satisfied by families of less comprehensive terms.