Marcus Biella

Safety net for a sectorless air traffic management concept

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.

The influence of task load on situation awareness and control strategy in the ATC tower environment

The safe and efficient operation of air traffic is highly dependent on the performance of the Air Traffic Control Officer (ATCO). The ATCOs control the traffic within defined areas by monitoring the traffic and granting clearances. A key element in analyzing the ATCOs is their interaction with the environment through their workplace. Especially the influence of task load on their situation awareness (SA) and applied control strategy provides information on the quality of the workplace. As task load increases, controllers are able to maintain performance by using different management or compensation strategies. This article supports the evaluation of ATCO’s workplaces by focusing on whether probe techniques for assessing SA are applicable for tower control operation and for measuring the influences of increased task load on the control strategy. An experiment with nine ATCOs was conducted in a simulated real-time air traffic control environment. Different measurements for SA were applied and compared regarding their efficiency and validity. The manipulation of task load and visibility influenced the SA and control strategy at the same time. Performance metrics were selected in advance to evaluate the participant’s efficiency. SA was measured with a probe technique and an offline self-assessment method. Findings suggest that probe techniques increase the insight into the understanding of SA in comparison to self-assessment and that they are applicable to the air traffic control environment. Control strategies were derived from the information-gathering process via the eye-movement behavior and connected to task load. The results imply that SA is part of the individual performance and that increasing demand through task load is handled with an adaptation of the control strategy.

How can a future safety net successfully detect conflicting ATC clearances: yet remain inconspicuous to the tower runway controller? first results from a SESAR exercise at hamburg airport

To increase runway safety a new safety net for Tower Runway Controllers was developed which detects if controllers give a clearance to an aircraft or vehicle contradictory to another clearance already given to another mobile. In a shadow mode validation exercise with eleven controllers at the operational environment of the airport Hamburg (Germany) operational feasibility was tested in order to clarify if operational requirements in terms of usability are fulfilled. At the same time operational improvements regarding safety were studied e.g. if the new safety net detects all conflicts and if nuisance alerts are suppressed.

Color schemes for a sectorless ATM controller working position

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 situations 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 processing 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.

Operational landing credit with EVS head down display: crew procedure and human factors evaluation

Feasibility of an EVS head-down procedure is examined that may provide the same operational benefits under low visibility as the FAA rule on Enhanced Flight Visibility that requires the use of a head-up display (HUD). The main element of the described EVS head-down procedure is the crew procedure within cockpit for flying the approach. The task sharing between Pilot-Flying and Pilot-Not-Flying is arranged such that multiple head-up/head-down transitions can be avoided. The Pilot-Flying is using the head-down display for acquisition of the necessary visual cues in the EVS image. The pilot not flying is monitoring the instruments and looking for the outside visual cues. This paper reports about simulation activities that complete a series of simulation and validation activities carried out in the frame of the European project OPTIMAL. The results support the trend already observed after some preliminary investigations. They suggest that pilots can fly an EVS approach using the proposed EVS head-down display with the same kind of performance (accuracy) as they do with the HUD. There seems to be no loss of situation awareness. Further on, there is not significant trend that the use of the EVS head-down display leads to higher workload compared to the EVS HUD approach. In conclusion, EVS-Head-Down may be as well a feasible option for getting extra operational credit under low visibility conditions.

EVS: head up or head down

Feasibility of an EVS head-down procedure is examined that may provide the same operational benefits under low visibility as the FAA rule on enhanced flight visibility that requires the use of a head-up display (HUD). The main element of the described EVS head-down procedure is the crew procedure within cockpit for flying the approach. The task sharing between pilot-flying and pilot-not-flying is arranged such that multiple head-up/head-down transitions can be avoided. The pilot-flying is using the head-down display for acquisition of the necessary visual cues in the EVS image. The pilot flying is monitoring the instruments and looking for the outside visual cues. Results of simulation trials suggest that pilots can fly an EVS approach using the proposed EVS head-down display with the same kind of performance (accuracy) as they do with the HUD. There seems to be no loss of situation awareness. Further on, there is not significant trend that the use of the EVS head-down display leads to higher workload compared to the EVS HUD approach. In conclusion, EVS-head-down may be as well a feasible option for getting extra operational credit under low visibility conditions.