Short-term ATFCM measures: building on the local flow management process

Since the introduction of the Enhanced Tactical Flow Management System (ETFMS), traffic predictability has continuously improved. Likewise, occupancy counts more accurately reflect the traffic that will occupy a given ATC sector at a given time.

These occupancy counts are used by some FMPs (Flight Management Positions) to identify “hotspots” where action can be taken to reduce traffic complexity.

Matching this process with the SESAR dynamic DCB (Demand Capacity Balancing) concept identified gaps which will be resolved by introducing new tools defined in the context of SESAR Step 1.

In support of SESAR Release 1, a three day live trial kicked off on 8 November 2011 with the aim of validating the overall dynamic DCB process. FMPs from London, Reims and Maastricht are participating in the trial, as are Network Manager and 11 airlines.

The aim of the SESAR dynamic DCB concept is to improve Air Traffic Flow and Capacity Management (ATFCM) by 2013. Its main objectives are to reduce traffic complexity and to streamline air traffic controller workload, thus improving capacity and safety.

Currently, the systematic application of ground regulations limits the traffic entering a sector because of the allocation of departure slots to all flights, regardless of how they contribute to the expected overload. This process, although still useful where there is a major imbalance, is no longer acceptable when demand does not significantly exceed available capacity.

A new star is born

Short-term ATFCM measures (STAMs) such as minor ground delays, flight level capping and minor re-routings applied to a limited number of flights can reduce the complexity of traffic peaks. Some FMPs use occupancy counts to identify “hotspots” in traffic bunching. They analyse lists of flights to anticipate ATC workload and identify actions to be taken in order to reduce the traffic complexity generated by those flights. The collaborative decision-making (CDM) process underlying the dDCB concept is the key element in the generation of immediate benefits. And although the decisions applied in a given sector might not automatically be beneficial to the controller in that particular sector, they will be in the next sector or even the next ACC.

The dDCB process takes place on the day of operations and maintains the balance between demand from all airspace users and capacity.

dDCB is reconciled at network level, and is fully integrated with airports, en-route and airspace user planning and execution processes.

The process starts from a strategy defined at DCB level. The iterative dDCB process takes place between a few hours and a few minutes before sector entry time, and comprises the following:

  • Detection of demand and capacity imbalance: Continuous monitoring of traffic performed by FMPs in their area of responsibility based on the parallel use of entry counts and occupancy counts. Traffic monitoring values are adjusted to each sector to help them detect potential traffic peaks;
  • Network view: Network consolidation of the traffic situation, based on the advisory information sent by FMPs when confident enough about the predicted peaks. AOs may react accordingly while Network Management Operations may use network solutions if coordination is needed to cope with multiple overloads;
  • Complexity assessment and preparation of STAM: The impact of the forecast traffic peak on the workload is analysed using occupancy counts and indicators available from flight lists. A STAM solution is investigated seeking minimum impact on AOs:
    • either through dynamic capacity adjustments based on short-notice configuration changes or negotiations with military authorities;
    • or by cherry-picking actions based on the identification of the flights creating the complexity, using enhanced flight list attributes providing FMPs with an accurate flight status and aircraft attitude. Possible actions include, in order of priority: the allocation of minor ground delays to specific flights, flight level reassignments or route changes negotiated with AOs and, in the last resort, interventions on airborne flights coordinated with adjacent FMPs where needed;
  • Coordination of proposed STAM: The selected STAM is coordinated with the actors concerned (adjacent units, airspace users, etc.). The coordination workflow will be defined and monitored by the FMP initiating the coordination.
  • STAM implementation: Implementation of the measure is based on systematic flight data updates in the network systems. Feedback of the measure into the network is essential for stability and traffic prediction.

dDCB (dynamic Demand Capacity Balancing) is a project of SESAR Work Package 7 (P7.6.5). It is led by DFS, with the participation of Aena, DSNA, NATS and EUROCONTROL.

A 3-day validation exercise from 8 to 10 November

A 3-day live trial kicked off on 8 November with the aim of validating the overall dynamic DCB process. FMPs from London, Reims and Maastricht are participating in the trial, as are Network Manager and 11 airlines.

The validation will assess:

  • The definition of a uniform process in accordance with the ATFM implementing rules, connecting ATFCM planning activities with tactical ATFCM interventions up to the ATC working horizon.
  • The definition of clear procedures based on this process and enabled by transparent information sharing throughout the network, to ensure collaborative decision-making (CDM) involving all partners.
  • The definition of a new allocation of roles and responsibilities between regional, sub-regional and local actors involved in network operations, resulting in the evolution of a dynamic DCB process within a FAB context, from planning to the tactical phase.
  • The enhancement of the roles and responsibilities of the FMPs and airspace users.

The Network Manager Validation Platform (NMVP) is used for this exercise. This does not of course exclude at a later stage interoperability and cross-fertilisation with local tools or even deployment into local tools.