Bettina Birkmeier’s research while affiliated with German Aerospace Center (DLR) and other places

Sectorless air traffic management is an en-route concept, which eliminates the need for control sectors. Instead of assigning a geographic area (sector), air traffic controllers are assigned certain aircraft. Controllers are responsible for their assigned aircraft all the way from entry to exit. In previous simulations, one controller was responsible for six aircraft at the same time. As these aircraft can be located anywhere in the sectorless airspace, controllers were provided with one traffic display for each assigned aircraft. This discussion paper suggests other possibili-ties for providing traffic information to sectorless air traffic controllers. Instead of having one traffic display for each aircraft under control (tiled display), controllers could work with a general map, a zoom display to magnify certain traffic situations, or a combination of such displays. We revisit the concept of controller teams and explore alternatives. In addition to working alone or in pairs of executive and controller, the sectorless air traffic management concept opens possibilities for innovative teamwork. For example, there could be a team of one coordinator and several executives, or even a control-room team. This paper gives examples of new display and team ideas and discusses their respective advantages and disadvantages. We argue that the way traffic information is displayed to controllers affects their mental models and working methods. In addition, we provide results on the tiled display from previous simulations and introduce ideas for future research.

In sectorless air traffic management (ATM) concept, air traffic controllers are no longer in charge of a certain sector. Instead, the sectorless airspace is considered as a single unit and controllers are assigned certain aircraft, which might be located anywhere in the sectorless airspace. The air traffic controllers are responsible for these geographically independent aircraft all the way from their entry into the airspace to the exit. In order to support the controllers with this task, they are provided with one radar display for each assigned aircraft. This means, only one aircraft on each of these radar displays is under their control as the surrounding traffic is under control of other controllers. Each air traffic controller has to keep track of several traffic situa-tions at the same time. In order to optimally support controllers with this task, a color-coding of the information is necessary. For example, the aircraft under control can be distinguished from the surrounding traffic by displaying them in a certain color. Furthermore, conflict detection and resolution information can be color-coded, such that it is straightforward which controller is in charge of solving a conflict. We conducted a human-in-the-loop simulation in order to compare different color schemes for a sectorless ATM controller working position. Three different color schemes were tested: a positive contrast polarity scheme that follows the current look of the P1/VAFORIT (P1/very advanced flight-data pro-cessing operational requirement implementation) display used by the German air navigation service provider DFS in the Karlsruhe upper airspace control center, a newly designed negative contrast polarity color scheme and a modified positive contrast polarity scheme. An analysis of the collected data showed no significant evidence for an impact of the color schemes on controller task performance. However, results suggest that a positive contrast polarity should be preferred and that the newly designed positive contrast polarity color scheme has advantages over the P1/VAFORIT color scheme when used for sectorless ATM.

Sectorless air traffic management (ATM) presents a radically different, but operationally feasible approach to en-route air traffic control, which directly addresses sector bottlenecks and thus permits a significant capacity increase. Instead of partitioning the airspace into sectors, sectorless ATM regards the airspace as a single unit. Controllers are assigned individual aircraft, for which they are responsible from their entry into the airspace until their exit. The contributions of this thesis are fourfold. First, it provides a comprehensive compilation of concept elements, solutions, and prior research concerning sectorless ATM and addresses both expected benefits and conceivable obstacles. Second, this thesis provides a feasibility validation of sectorless ATM based on human-in-the-loop simulations and expert interviews. The main result of the feasibility analysis is that sectorless ATM is, in fact, operationally feasible. With the support of medium-term conflict detection, an automation necessary to decrease controller workload, it is possible for one air traffic controller to safely guide at least six aircraft under normal conditions. This implicates a productivity increase of more than 100 % compared with the current sectored ATM concept. Third, the thesis discusses expected changes to controller tasks, the controller's mental model and situation awareness, the necessary controller skills, and the overall role of the controller in the sectorless ATM concept. The conclusions are that controller tasks will shift from planning toward more monitoring, that controllers can still build up a modified mental model and keep situation awareness, that controller skills will slightly change away from memorization toward fast information retrieval, and that controllers will identify more strongly with their assigned aircraft. Fourth, a safety assessment provides suggestions for a safety net, safety criteria, a barrier model, pre-existing hazards, safety objectives, a functional model, a safety and performance requirements (SPR)-level model, and safety requirements. In conclusion, sectorless ATM provides a fundamentally different but feasible approach to en-route air traffic control, which holds great potential. Strategies to introduce the concept into operation include element-wise, aircraft-wise, time-restricted, area-restricted, and top-down transitions, all of which are described and discussed in this thesis.

In contrast to the traditional approach to air traffic management (ATM), which divides the airspace into sectors, sectorless air traffic management regards the airspace as a single unit. Instead of sectors, air traffic controllers are assigned several aircraft, which might not be in the same geographic region. Controllers are responsible for the assigned aircraft during their entire flight through the airspace from entry to exit. In previous papers we have detailed the sectorless ATM concept and shown that it is operationally feasible. One remaining question, however, is how to introduce the concept into operation. It is highly unlikely that sectorless ATM will be introduced for the entire airspace over a country, let alone a continent, in one step; a gradual introduction of the new concept limits the safety risks connected with new systems. Therefore, the concept will have to coexist with other ATM concepts. This discussion paper presents five different strategies for the introduction of sectorless ATM, namely element-wise, aircraft-wise, time-restricted, area-restricted, and top-down transition strategies. For each of these strategies we discuss advantages and disadvantages. In addition, we investigate the possibility of combining several strategies. In conclusion, we suggest a top-down transition strategy combined with an element-wise transition. This combined strategy limits the number of simultaneous changes but still takes full advantage of long-term planning. Furthermore, the number of controllers who have to be trained for the sectorless concept can be estimated quite accurately from the flight plans.

In contrast to the traditional approach to air traffic management (ATM), which divides the airspace into sectors, sectorless air traffic management regards the airspace as a single unit. Instead of sectors, air traffic controllers are assigned several aircraft, which might not be in the same geographic region. Controllers are responsible for the assigned aircraft during their entire flight through the airspace from entry to exit. In previous papers we have detailed the sectorless ATM concept and shown that it is operationally feasible. One remaining question, however, is how to introduce the concept into operation. It is highly unlikely that sectorless ATM will be introduced for the entire airspace over a country, let alone a continent, in one step; a gradual introduction of the new concept limits the safety risks connected with new systems. Therefore, the concept will have to coexist with other ATM concepts. This discussion paper presents five different strategies for the introduction of sectorless ATM, namely element-wise, aircraft-wise, time-restricted, area-restricted, and top-down transition strategies. For each of these strategies we discuss advantages and disadvantages. In addition, we investigate the possibility of combining several strategies. In conclusion, we suggest a top-down transition strategy combined with an element-wise transition. This combined strategy limits the number of simultaneous changes but still takes full advantage of long-term planning. Furthermore, the number of controllers who have to be trained for the sectorless concept can be estimated quite accurately from the flight plans.

In a sectorless air traffic management concept the airspace is no longer divided into sectors but regarded as one piece. A number of aircraft, not necessarily in the same airspace region, are assigned to each air traffic controller who is then responsible for these aircraft from their entry into the airspace to their exit. These individually assigned flights can be anywhere in the airspace and therefore in different traffic situations. This means that air traffic controllers will manage flights which may not be geographically connected. Such a concept change will necessitate also a significant change in the controllers’ routines and the support tools. Naturally, the question of safety arises regarding new procedures and systems. This paper provides a preliminary safety assessment for a sectorless air traffic management concept. The assessment is based on the Single European Sky ATM Research (SESAR) Safety Reference Material which was originally developed for SESAR purposes. This success-based approach stresses the positive contribution of a new concept while traditional approaches mainly consider the negative effect of possible hazards and failures. Based on validation activities including real-time simulations we have developed safety acceptance criteria and safety objectives for a sectorless air traffic management (ATM) concept. Starting from these we have sketched the safety performance requirement model and deduce the first safety requirements for normal conditions, abnormal conditions and in the case of internal system failures.

Today air traffic management divides the airspace into smaller sectors. Controllers are responsible for one of these sectors and all the air traffic within. In a sectorless air traffic management concept the airspace is no longer divided into sectors but regarded as one piece. Controllers are then assigned individual aircraft which they are responsible for from then entry into the airspace to their exit. This means, the controllers have to manage flights which are not in the same geographic region but can be anywhere in the airspace and hence in different traffic situations. Such a change of concept influences the way controllers work and calls for different support tools. Naturally the question of safety arises with regard to standard operations as well as special situations. This discussion paper investigates the different safety aspects relevant in a sectorless concept. It highlights the differences between a conventional sectored and the proposed sectorless approach. We argue that most elements of the current safety net in air traffic management can also be applied to a sectorless air traffic management concept. Such a safety net is proposed and several examples for its use are given.

Today air traffic management divides the airspace into sectors. Controllers are responsible for one of these sectors and all the air traffic within. In a sectorless air traffic management concept the airspace is no longer divided into sectors but regarded as one piece. Controllers are assigned individual aircraft which they are responsible for from their entry into the airspace to their exit. This implies that the controllers have to manage flights which are not in the same geographic region but can be anywhere in the airspace and hence also in different traffic situations. Such a change of concept influences the way controllers work and calls for different support tools. Naturally, the question of safety arises with regard to standard operations as well as special situations. This discussion paper investigates the different safety aspects relevant in a sectorless concept. It highlights the differences between a conventional sectored and the proposed sectorless approach. We argue that most elements of the current safety net in air traffic management can also be applied to a sectorless air traffic management concept. Additional safety net elements are proposed together with examples of their application.

In a sectorless air traffic management concept the airspace is not divided into sectors but seen as one piece. An air traffic controller is no longer in charge of a sector but is responsible for individual flights which he or she controls from the entry into the airspace to the exit. This means that the controller has to keep track of several flights and traffic situations which might not be in the same geographic region. Naturally, such a considerable change of concept influences the tasks and way of working for the controller. This paper gives first results about how a sectorless concept might change controller tasks. It is debated which tools might best support such a concept and help the controller to maintain situational awareness. We review different models for task analysis and use them for a comparison of tasks in a sectored and a sectorless concept. Especially the role of a conflict detection tool and other automatic support systems is discussed. Real time simulations conducted at DLR provided first indications regarding changes in controller tasks, which are presented and analyzed. In a sectorless concept coordination with adjoining sectors is no longer necessary. The presented findings show that in addition the introduction of conflict detection tools could relieve the controller of planning tasks, thus shifting the main tasks more towards tactic control and monitoring. The discussion suggests a work environment and procedures which help the controller to exploit the benefits of sectorless control while retaining situational awareness and focus on the task of conflict avoidance.

In sectorless air traffic management the airspace is considered as one piece instead of partitioning it into sectors. The air traffic controllers are no longer in charge of sectors but are given responsibility for a certain number of aircraft during their entire flight. This entails that the controller has to keep track of several different traffic situations geographically spread out over a potentially large area. Of course, such a considerable change of concept has implications on the controllers' mental model and the way conflicts are solved. This paper describes the shift of the controller's mental model away from one geographically limited view with long-term planning to several global views with short-term planning. It is illustrated how this altered mental model also implies changes of the controller's tasks and conflict solving. Real-time simulations within DLR's LRM2020 project have shown that working with a sectorless concept is possible and feasible if the controller is supported by suitable conflict detection. The details and results of these simulations are given and the effects of the altered mental model are analyzed. It is furthermore explained how a sectorless concept could change controller work away from controller teams consisting of executive and planner to a one-person workplace supported by a conflict detection. At the same time the principle that two pairs of eyes are better than one is retained. The controller’s tasks are not reduced to monitoring jobs but the essential conflict avoidance task remains.