Making the choice to split sectors or not in a complex Air Traffic Control environment

Abstract: Air Traffic Controllers (ATCOs) are essential sharp-end workers in the increasingly complex Air Traffic Management (ATM) system that the European ATM network has become. This research is based on an event that occurs many times daily in the Copenhagen Area Control Center (ACC). ATCOs choose whether or not to split sectors. To cope with workload, which is constituted by variation in traffic volume and complexity, the controller must make the choice to split sectors or not. It is not an easy choice, often judged retrospectively. Most splits turn out well, however a positive outcome does not necessarily indicate a good decision and vice versa. This study uses a qualitative research strategy to investigate what competencies ATCOs possess to manage this task, and why controllers sometimes choose not to split sectors in the presence of high traffic volumes. Interviews with ATCOs from Copenhagen ACC, Supervisors and managers combined with storytelling, form the results that show how the professional identity of being an ATCO and belonging to a small group of professionals can relate to sector splits. Student controllers during their education, must show that they possess the ability to call a split of sectors at the right time, in order to show overall competence and thereby get included in the professional group of controllers. This is a difficult task to achieve considering how experienced controllers themselves struggle to make the choice to split sectors or not. In addition, the different views on sector splits and their effect on safety are discussed. The results indicate a strong dependence on what role you possess in the organisation: Controller - Supervisor or Manager. For the ATC system to work it needs to be resilient to the daily variations in traffic demands. The resilience depends upon flexibility from controllers to make the choice to split sectors or not. Sometimes the flexibility means and relies upon the controllers ability to work beyond the sector capacity. The extra capacity created by controllers is appreciated by supervisors and management because it gets the work done. Most controllers enjoy to work in busy traffic and are proud to contribute and create the extra adaptive capacity when needed - by extending the operational envelope buffers.