ATFM Slot Adherence

ATFM departure slots are allocated centrally by the European Network Manager upon the request of the local Flow Management Position ( FMP ), when an imbalance between demand and capacity is foreseen at airports and/or en-route. The purpose of such regulation is to hold aircraft on the ground.

An ATFM slot tolerance window is available to ATC to sequence departures. The standard slot tolerance window is [-5 minutes, +10 minutes]. ATC at the departure airport has a joint responsibility with aircraft operators to ensure that flights departure within the allocated ATFM slot tolerance window in order to optimise traffic flow. ATFM departure slot adherence, simply named ATFM slot adherence hereafter, measures the share of take-offs inside the slot tolerance window of [-5 minutes, +10 minutes].

ATFM slot adherence monitoring is a pre-requisite to fine tune traffic predictions at the departure, en-route airspace and at the destination airports. The higher the number of regulated departing aircraft inside the assigned ATFM standard window, the more accurate the predicted traffic and associated down-stream ATFM measures.