In major hub airports, during peak hours, variation in aircraft arrival times exceeds the capacity of the destination airport to handle them without incurring airborne delay. These delays can be computed through Arrival Management systems (AMAN), that take into consideration runway capacities, aircraft characteristics and separation standards to compute an arrival sequence. However, in today’s operation, the arrival management strategy is decided and implemented at a late stage of the flight since most of AMANs have limited horizon, capability and accuracy. Because of this late implementation, the tendency is to absorb those delays at low levels in the TMA with holding and/or vectoring, generating high workload for Air Traffic Control Operators (ATCO), extra costs for airlines and poor environmental efficiency.
For those major airports, another area of interest is the optimisation of Air Traffic Flow and Capacity Management constraints (ATFCM), with the use of locally computed pre-departure Target Time of Arrival (TTA). Also, even without capacity constraints, arrival streaming can be efficient for airport curfew management, as for example to avoid holdings or vectoring before the opening of the airport. The integration of the Airspace Users into the loop is essential as a few minutes gained on a flight can be sufficient to ensure connection for dozens of passengers, or avoid diversion because of a curfew at the destination airport. Combined with pre-departure TTAs, the development of collaborative processes with Airspace Users, ANSPs and Network Manager brings efficiency gains and arrival flexibility to improve arrival management process performance.
To address these challenges, the xStream project has demonstrated, at a very large-scale, new extended arrival management tools and techniques that improve flight efficiency and flight predictability at airports, in TMA, Extended TMA, and in en-route UAC / ACC. This includes the following solutions:
- Extended AMAN between 200 to 350 NM: the main target of xStream is to provide a ready-for-implementation solution for PCP deployment, with an extended arrival management horizon up to at least 200 NM in order to enable delay absorption earlier in the flight and at higher altitude, which is more fuel-efficient. When dealing with high levels of arrival delay, or for pre-sequencing the aircrafts before a detected congestion at the entry of the Extended TMA, this horizon can be extended up to 350 NM for maximum efficiency. Also, the concept of target times for airborne long haul flights was applied with a horizon outside of the European Network involving the AU’s OCCs in the process.
- Handling of multiple inbound flows to multiple airports in the sectors of upstream ACCs: with the extension of AMAN horizon, the cumulative effect of E-AMAN requests in the same sector may lead to an increase of ATCO workload, because of the competition between the flows, and induced conflicts. To prevent this, a CDM process has to be implemented to better coordinate E-AMAN activities, and assess upstream ACCs ability to deliver the E-AMAN service.
- Improvement of Arrival Planning: by using locally computed Pre-departure Target Time of Arrival sent to Network Manager in addition with a collaborative process to integrate Airspace Users’ preferences/priorities, the impact and cost of ATFCM delays can be reduced. TTA allocation also contributes to the arrival management process by enhancing the short-haul adherence to the targeted sequence.
- Integration of Airspace Users Preferences in the arrival planning process, thus limiting the cost of delay for airlines. UDPP and A-FLEX provide an efficient solution to reallocate ATFCM delay in order to optimize arrivals according to Airspace User needs, reducing the impact on Airline operations.
The project involved the largest number of upstream ACCs (actually most of ACCs of the Core Area) around those platforms, and Airspace Users in order to implement collaborative processes for the management of arrival sequence (A-Flex).
As part of the SESAR 2020 programme, the demonstrations contribute to SESAR CONOPS definition and engineering standardization work concerning the benefits brought by Extended Arrival Management (E-AMAN).
