Ad Hoc Minimum Separation: A challenge for Air Traffic Control (ATC)

Abstract

The SESAR programme aims at developing the future European air traffic management system. It focuses on four keys areas: capacity, safety, efficiency and environment. In view of the expected growth in air traffic demand in the coming years, the current goal is to increase the airspace capacity, which is already close to saturation in many cases. Currently, the separation standards applied in a given volume of airspace are fixed, both horizontally and vertically, which means that in many cases this is one of the determining factors of capacity. Separation management is an area where improvement is sought, in particular through the application of new operational concepts (separation modes) which include the redefinition of aircraft separation minima. One of the solutions to be investigated is the variable (Ad Hoc) separation proposal put forward by SESAR. This future concept implies a change in the application of separation minima from the current fixed standards to a new variable approach. With this new concept, ATCo (Air Traffic Controller) would separate aircraft by applying different separation minima in the same volume of airspace. These separation values are tactically determined for each particular aircraft pair (Ad Hoc) depending on a number of factors: aircraft categories, encounter geometry, atmospheric conditions, etc. Applying different separation minima in the same volume of airspace implies a substantial change in some of the ATC activities. Also, new functionalities in ATC support tools are needed. This study presents the Ad Hoc separation operational concept and provides the basis for the development of the algorithm for calculating variable separation minima.