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Advanced prediction models for flexible trajectory-based operations

Periodic Reporting for period 2 - ADAPT (Advanced prediction models for flexible trajectory-based operations)

Reporting period: 2019-01-01 to 2019-12-31

The objective of the ADAPT project is to propose a set of methods and tools at the strategic and pre-tactical level of network management that is conducive to the trajectory-based operations, which clearly demonstrates the flexibility, information exchange responsibilities, and benefits for all the stakeholders.
The European ATM system offers a high level of flight planning flexibility, as only the final flight plans need to be submitted several hours before departure. This allows Airspace Users (AUs) the possibility to account for previously uncertain factors like weather forecasts, and thus create flight plans that are most convenient for the day of operations. Conversely, the capacity provision (e.g. staffing levels) is usually planned starting more than a year ahead and is updated as time progresses.
To address imbalance, a main objective of ADAPT is to develop a set of linked models that exploit the past and current information in the early planning stages, for mutual benefit of all stakeholders. The past and early-shared flight-route information can be used to find the best distribution of the proposed flights that respect the capacity of the proposed network configuration or configurations. Next, the trajectories obtained in this process are assigned a measure of flexibility, which is termed time windows (TWs). Time windows measure the flexibility of flights in terms of time slack available to a flight, within which no capacity problems are expected to be created along the agreed trajectory. Apart from TWs assigned to flights, the saturated elements of the planned network configuration (i.e. sectors or airports) are also identified. Thus, already at the strategic level, an indication of the flexibility of flights and critical network elements can be obtained and shared through the Network Operations Plan. This approach to strategic planning we term ADAPT solution.
The ADAPT solution is assessed (validated) within the project. In order to do so, the project further aims to:
• Define metrics in support of the development and assessment of the ADAPT solution.
• Provide a thorough assessment (validation) of the ADAPT solution in the tactical setting, from two points of view: network-wide and flight centric.
• Involve stakeholders into the development and refinement of the solution, metrics and assessment methodology.
• By working in close cooperation with stakeholders, develop requirements for the visualisation of the ADAPT solution results. The goal is to present the results in a way that is useful to the stakeholders.
The ADAPT project had three main activities: (1) Development of the ADAPT strategic solution, (2) Tactical assessment, and (3) Visualisation.
The development of the ADAPT strategic solution which included the formulation and implementation of a deterministic model (European Strategic Flight Planning (ESFP) model) to define flight trajectories, their time windows and critical network elements at the strategic level; computational experiments and results are described in D3.1. Further, the assessment of the expected economic loss in case unwanted events occurring (e.g. flight delays, bad weather); and the identification and application of mitigation actions to improve the situation identified by the ESFP results (see D3.2).
ADAPT’s strategic flight planning solution is acceptable as long as these efforts result in better tactical/actual operations. Therefore, the tactical impact of the strategic solution from a flight-centric and a network-wide point of view has been assessed using simulation and stochastic modelling.
A data visualisation tool ( fed by the results of the strategic solution models was developed (a) better understand the quality of computed solutions and (b) propose an initial working prototype of a tool based on innovative visualisation techniques to support strategic level decisions for network management.
The key results of the ADAPT project can be summarised as follows:
1. Definition of a methodology (see D3.1) for a quantitative determination of the flexibility in terms of TWs.
2. Using real air traffic data of the fifth busiest day in 2017 (1st September) for the entire ECAC area, computational experiments show that a very large share (55.3%) of flights enjoys the maximum allowed flexibility (TW duration = 15 minutes), whereas only a minor part (3.5%) is constrained to TWs’ duration lower than 5 minutes. About 12% of sector-hours are saturated.
3. As ADAPT solution allows for what-if scenario assessments, the introduction of mitigation measures was tested.
4. Tactical, flight-centric assessment shows that: when considering uncertainties related to weather conditions (wind)and departure delays the assessments show that strategic TWs are robust enough to cope with such sources of uncertainty (see D4.1). Overall, the fuel consumption additionally needed to enforce adherence to the TWs increases as the TW duration decreases (see D4.2).
5. Tactical, network-wide assessment shows that TWs might reduce the controller’s workload (measured in terms of number of re-routings, flight level changes and directs), see D5.2.
6. The development of an ad-hoc visualisation tool for the strategic flight planning facilitates the understanding of the results and ensures a more effective dissemination of the project results across operational and practitioner stakeholders (see D5.3).
The state-of-the-art in the operational ATM management in Europe is largely tactical. AUs are offered a high level of flexibility in the trajectory planning as the flight plans need to be submitted only tactically, thus allowing to consider the latest information available (e.g. weather) and plan the most convenient trajectories. In planning, AUs do not have the information on airspace nominal capacities and do not need to consider it. As a consequence, the detailed traffic demand on the airspace network is known only on the day of operations, while the capacity provision is typically planned a year in advance and updated a few days before. As such, this flexibility makes ATM system less predictable, resulting in costs due to flow measures, and under-utilisations from a mismatch between available ATM capacity and traffic demand, often resulting in delays and deviations, which are very costly to AUs (e.g. estimated by EUROCONTROL to be more than 1B euro in 2014.
The new capabilities the ADAPT project developed are: optimised strategic planning respecting the nominal airspace capacity, with information on trajectories, timing flexibility of trajectories and saturated portions of airspace (and airports). These can be technically implemented as the information used is the information that is currently shared (trajectories, entry times at different portions of network, network configurations and associated nominal capacities). However, moving the planning to strategic phase would require the change of way of working for airspace users and ANSPs. This should be further researched - both the impacts and costs and benefits of the strategic planning implementation.
Average criticality index and number of critical sectors/airports per hour
ADAPT visualisation tool - main features
ADAPT logo
Distribution of constrained flights across the day
ADAPT visualisation tool - hourly geographic trends