From 1 to 15 October 2014, partners[1] in the SESAR Research and Innovation Programme conducted a live trial across a large part of Europe’s core airspace to validate the feasibility and benefits offered by a wider and more harmonised application of Short-Term Air Traffic Flow Control Management (ATFCM) Measures (STAMs).

The management of air traffic flows in Europe is centralised at Eurocontrol headquarters in Brussels, in coordination with Flow Management Positions (FMPs) at all air traffic control centres in Europe. Today, flight plans are processed before departure to manage the flow of traffic and avoid overload in air traffic control sectors through which the flight passes, as well as at destination airports. Overloading is typically resolved by delaying the departure of flights that may contribute to the burden, which is done through the Network Manager (NM) by issuing a Calculated Take-Off Time (CTOT)

CTOTs are typically allocated two hours before the flight is originally scheduled to take off, and, while these measures help to manage situations of overload, their forward planning regulation requirements means that effectiveness and efficiency can be limited. With STAMs, the system has more flexibility to handle overload, since the measures are applied at a later stage, leading to improved efficiency and effectiveness of the overload resolution .

STAMs can be applied to either selected flights or to full traffic flows (e.g. all traffic with a certain destination or to aircraft flying over a specific area or on a specific route). The most frequently used STAM is level capping, which is used to protect a high altitude sector that would otherwise be overloaded by temporarily constraining a flight or group of flights to fly at a lower altitude; this is done by either delaying its climb or advancing its descent. STAMs can also impose ground delay either by issuing a CTOT-like restriction at short notice on a specific flight, or by requiring minimum departure intervals for an airport at selected time windows. Finally, the STAM toolbox allows the regulation of traffic demand by requiring that a minimum miles-in-trail separation is maintained between a series of successive aircraft on specific routes.

STAMs are implemented by local Flow Management Positions (FMPs), but of course have an impact on the whole network, and therefore require that an overall Network Impact Assessment be made by FMPs in coordination with NM. The recent SESAR STAM live trial (VP-522) brought together FMPs[2] from area control centres (ACCs), the Network Manager and airlines[3] to validate a harmonised STAM process and FMP workflow. During the exercise, around 70 STAM measures were successfully initiated, coordinated and implemented, using a proposed workflow and a set of coordination tools. Daily de-briefings, questionnaire inputs and observations complemented with system data recordings resulted in a useful amount of input for the trial analysis phase, which has now begun.

The results of this work clearly show the feasibility and benefits of applying STAMs more widely. Although the STAM toolkit was adequate for the trial purposes, the toolkit will be further developed within SESAR before its operational implementation. A follow-up trial (VP-700) is planned at the end of 2015, which will focus on integrating the STAM concept with local flow management tools through B2B System Wide Information Management (SWIM) services.

[1] The trial (VP-522) was undertaken as part of the SESAR R&I Project 13.02.03

[2] FMPs from the following ACCs took part in the trial: Brest and Reims (DSNA); Zürich and Geneva (SkyGuide); Swanwick (NATS UK); Maastricht Upper Area Control Centre (MUAC); Karlsruhe, München, Langen, Bremen (DFS); Roma (ENAV).

[3] The following airlines also gave their support to the trial: KLM; Air France; Lufthansa; Regional-HOP!; EasyJet; Emirates; SAS; Alitalia.