En-route IFR Flights and ATFM Delays (FIR, Post Ops Adjusted)

Please note that software release 20.0 of the Network Manager on 04 April 2016 introduced a change to improve the accuracy of the ATFM delay calculation for operational purposes. For more information on the change in methodology click here .

The en-route ATFM delay provides an indication of ATFM delays on the ground due to constraints en-route.

In Europe, when traffic demand is anticipated to exceed the available capacity in en route centres or at airports, Air Traffic Control ( ATC ) units may request the local Flow Management Position ( FMP ) to instigate an Air Traffic Flow Management (ATFM) measure, or regulation . Aircraft expected to arrive during a period of congestion are given ATFM delay at their departure airport, under the authority of the Network Manager, in order to regulate the flow of traffic into the constrained downstream en route sector or airport, thus ensuring safety.

The calculation of En-route ATFM delay is based on a well established and commonly accepted algorithm and has been in use as a commonly agreed proxy for en-route capacity shortfalls since 1999.

The ATFM delays are calculated as the difference between the estimated take-off time calculated from the filed flight plan including updates and the calculated take-off time allocated by the central unit of ATFM.

The reason for the regulation is indicated by the responsible Flow Management Position (FMP).

The delay is attributed to the most constraining ATC unit.