The Impact of Single Controller Operation Versus Dual-Operator Setups on Workload in Air Traffic Control

Kurzfassung

The air traffic control system is a complex network that relies on highly trained personnel to manage the movement of aircraft through airspace. Air traffic outside the vicinity of airports is organised into control sectors that define the vertical and lateral boundaries of a specific part of the airspace. In Europe, these sectors are typically controlled by a team of two air traffic controllers (ATCo), each with distinct tasks. The radar controller is instructing the pilots to prevent unauthorised proximity between aircraft or to the sector boundaries. The planner controller coordinates with other units to minimise congestion around sector interfaces as far as possible. By deploying two air traffic controllers, air navigation service providers are able to offer a higher flight throughput per sector than would be possible and allowed due to workload and safety with one air traffic controller alone. However, an increasingly high demand for air traffic services, stringent applicant skill requirements, and demographic changes have led to significant staff shortages across almost all European air navigation service providers in recent years. These conditions force air navigation service providers to impose capacity limits on accepted traffic, leading to increased delays, cancellations, and detouring of flights, which ultimately impact airlines and passengers. To address these challenges, DLR proposed the Single Controller Operation (SCO) concept, where only one air traffic controller is deployed per sector on a planned basis, taking over tasks from both air traffic controller roles and supported by additional automation. While this approach may seem like an obvious solution to staff shortages, it also poses significant risks if not implemented carefully. The workload experienced by a single air traffic controller can be substantially higher than that of an air traffic controller team, which could compromise safety if not managed properly. This paper presents the results of a validation exercise of the SCO concept using a system with additional support functionalities regarding the impact on ATCo workload. Subjective ratings of workload did not significantly differ between team and SCO. Furthermore, a 10% traffic increase within air traffic controller team setup results in a 14% (mean) increase in workload, whereas in SCO setup the same traffic increase results in 10% increase in workload. Thus, our findings suggest that SCO has substantial potential as a solution to staff shortages in air traffic control without impacting on air traffic controller workload critically. This would not only address the pressing issue of staff shortages but also enable more cost efficient and sustainable air traffic management