Air Traffic Flow Management (ATFM)

Air Traffic Flow Management (ATFM) Air Traffic Flow Management (ATFM) is the function established to provide a safe, orderly and efficient flow of air traffic with maximum ATC capacities used, and to ensure compatibility between the quantity of air traffic, i.e. traffic demand (TD) and the declared capacity of relevant ATC units.

The declared capacity is usually referred to as the number of aircraft entering the defined airspace in a specified time period, taking into account all factors that may affect the workload of air traffic controllers responsible for that airspace. The air traffic flow management in the European region is provided by the Eurocontrol's Network Manager Operations Centre (NMOC), formerly the Central Flow Management Unit (CFMU).

This function is performed by the consolidation of planned demand (filed flight plans) and capacity plans of relevant ATC units and airports, taking into account the occurrences that might have a significant impact on air traffic flow (e.g. sport competitions, traffic increase during summer and winter holidays and similar events).

The ATFM function is organised at the strategic, pre-tactical and tactical levels. As a part of this function, in the Zagreb ACC a flow managemet position (Zagreb FMP) has been established. Our flow management controllers closely cooperate with the NMOC at the tactical level to ensure aircraft operators, when required, with a relevant alternative, such as adjustment of departure time, change of routes and flight profile, aiming to minimise traffic delays.

We also cooperate with Eurocontrol at the strategic level (up to 6 days before the operations), together with other air navigation service providers, and at the pre-tactical level of air traffic flow management (from 6 days to 1 day before the operations). At the strategic level the capacities are determined and a route network as well as other airspace structures improved; at the pre-tactical level daily plans are defined, while aircraft operators and relevant ATC units are briefed on the measures to be taken to ensure the optimisation of current capacities as well as the minimisation of delays and costs.