Controller tools and team organisation for the provision of separation in air traffic management

Providing air traffic controllers with more automated tools to allow them to concentrate on situations where human intervention is crucial.

The SESAR 2020 project PJ 10 covers a diverse set of solutions grouped loosely around the theme of assisting en-route and approach controllers in their task of separation management.


Improving the accuracy of trajectory prediction can significantly reduce controller workload, mainly by eliminating many low-probability conflicts which would otherwise normally require controller time for analysis and monitoring even if no action were eventually required to ensure separation.

Executive controller workload can be further reduced by allowing the planner controller to resolve more conflicts in advance using the controller-pilot datalink (CPDLC).

Overall, this project should reduce controller workload and increase predictability and safety.

Our role

EUROCONTROL is contributing to the development and deployment of three distinct solutions:

  • PJ 10-02a - Conflict detection and resolution tools;
  • PJ 10-02b - Flight-centric (sectorless) air traffic control (ATC);
  • PJ 10-05 - Integration of remotely piloted aircraft systems(RPAS).


Conflict detection and resolution tools

With ATC capacity increasingly cited as the cause of regulations and delay in the core area, the need for new tools to reduce the workload of the controller is ever more apparent. Medium-term conflict detection (MTCD) has been in operation in some ATC centres for a decade or more, but the benefits are limited, particularly in complex airspace, largely because of the uncertainties in trajectory prediction.

The main thrust of this activity is, therefore, to try to improve the performance of the tools using downlinked aircraft parameters. EUROCONTROL has conducted a fast-time study to quantify the potential benefits of improving the accuracy of trajectory prediction to various degrees.

This involved the development of an analysis tool integrating two key components:

  • a detailed conflict detection, monitoring and resolution controller workload model;
  • a probabilistic conflict detector and resolver.

Using the analysis tool with a recording of traffic data from Maastricht UAC, we were able to calculate the likelihood of aircraft interactions breeching some separation limits and the consequent impact on controller workload.

Following the fast-time study, EUROCONTROL is now preparing a real-time simulation with the Czech Air Navigation Service and Thales, the aim of which is to further validate the resolution of conflicts by the planner controller. The new resolution method under investigation is a “cleared to … via …” clearance, uplinked to the aircraft using the CPDLC, which would be used instead of the heading instructions to create a small deviation in the flight in order to achieve the required separation. Unlike the heading instruction, this re-routing instruction does not require further instruction to return to the planned route and is not subject to drift caused by changing winds.

As a longer-term activity, EUROCONTROL has held a series of workshops bringing together experts in the fields of avionics, cockpit automation, ground ATC systems, ATC operations and pilots to develop a concept based on the use of the downlinked trajectory (“Extended Projected Profile” - EPP) in conjunction with the use of the CPDLC to issue 3D clearances, with the aim of permitting more efficient flight profiles.

Flight-centric air traffic control

The flight-centric concept replaces the traditional organisation of ATC on the basis of geographic sectors, where a single controller normally has executive control of all the flights in his/her sector, by a system whereby a flight is allocated to a single controller for its complete duration within the sectorless airspace. Each controller will thus handle flights over a much larger area than is currently the case, but will be responsible only for a subset of the flights in that area.

This will reduce the workload of both the controller and the aircrew associated with transferring a flight from one sector to the next as it approaches the boundary, and might allow a better balancing of workload between controllers. Furthermore, in highly complex airspace, where traditional sectors cannot be split any further, it might allow additional controllers to be assigned. However, procedures and tools need to be developed to address the additional complexity in separating aircraft which arises from the fact that no single controller is responsible for all the flights in a conflict and that it is impossible for the controller to maintain situational awareness in the traditional sense.

EUROCONTROL has organised a number of expert group workshops and a fast-time study in collaboration with the Czech ANS and AgentFly Technologies to assess the suitability of the allocation strategy, complexity indicator, task allocation, conflict resolution and the impact on human performance. A further fast-time study is now being prepared to analyse in more detail the benefits in terms of controller workload, measuring the average workload per controller and the distribution of the workload amongst controllers.

Integration of remotely piloted aircraft systems

The rapidly increasing number of remotely piloted aircraft systems (RPAS), or drones, necessitates their better integration in ATM. This poses a number of problems, most notably because the performance of RPAS is often very different from that of commercial aircraft, and the time delay in talking to the pilot of an RPAS can be much longer than when communicating with a pilot using radio. The purpose of this activity is therefore to investigate ways in which RPAS may be able to use technical capabilities and procedural means to be safely integrated into ATM, including compliance with ATC instructions in order to execute operations in non-segregated airspace (en-route and TMA) under instrument flight rules (IFR).

EUROCONTROL, in collaboration with the Italian and Maltese ATC service providers, has simulated RPAS operations in a realistic en-route environment based on Italian and Maltese cross-border airspace, and has collected feedback on feasibility and acceptability. Particular consideration was given to the assessment of the impact of RPA-related aspects such as potential latency of communications and contingency procedures, and collection of needs (e.g. HMI, flight plan information) to keep ATCOs’ awareness of RPAS activities in their AoR at a safe level.

This gave indications that the integration of the RPAS, even in an en-route environment, cannot be achieved without taking into account the fact that it may come at the expense of additional workload for ATCOs. Difficulties in managing RPAS were often a direct consequence of latency in the communication (latency greater than 4-5 seconds was considered acceptable) and additional complexity due to particular missions flown by the RPAS and contingency procedures after failures. 

As far as possible, RPAS contingency procedures should be compatible with existing manned emergency and communications failure procedures. This would reduce the uncertainty for ATCOs over what procedure should be flown, or over what traffic management measures should be taken with each individual aircraft type experiencing an emergency/contingency (manned or unmanned).

A further exercise, comprising three incremental real-time simulations at the EUROCONTROL Experimental Centre in Brétigny, will further investigate the integration of RPAS operations in non-segregated en-route airspace (again based on the Italian Maltese cross-border airspace) and aims to review the working method, operational needs and problems identified in the first phase.

Particular emphasis will be given to the assessment of:

  • the impact of the latency in communication in a ‘voice plus CPDLC’ environment;
  • the interaction and consistency of RPAS contingency with manned operations emergency situations.


Main EUROCONTROL partners: ANS CR, Thales, AgentFly, Airbus, ENAV, MATS.

Project contributors: DFS (lead), Airbus, DSNA, ENAIRE, ENAV, Leonardo, Skyguide, SAAB (NATMIG), NATS, Dassault, Thales Air Systems, Indra, EUROCONTROL, ANS CR, FRQ, DLR, COOPANS (Naviair, ACG, CCL, IAA, LFV), PANSA.