Flight activation monitoring

A function to improve network predictability.

Network predictability improvements changes applicable from autumn 2018 onwards.

From the flight evolution data it collects, the Enhanced Tactical Flow Management System (ETFMS) knows which flights are airborne. This makes it possible to identify flights which were planned to take off and those that are currently still on the ground.

The Flight activation monitoring (FAM) function enables us to:

  • shift flights in time that are not reported as airborne after their expected take-off time;
  • possibly suspend those flights which are still not reported as airborne after a certain time parameter;
  • inform the aircraft operator and the departure tower of this development, prompting their reaction.

This improves network predictability.

Suspension parameters

There are two-time parameters related to FAM that trigger suspension:

  1. The flight is not reported as airborne after 15 minutes after the expected take-off time. It is applicable to all flights, whether regulated or not, departing from, landing at or crossing areas where the Network Manager receives Correlated Position Reports (CPRs) and FAM is activated. A not reported airborne flight departing from, landing in or crossing a CPR/FAM enabled area with less than 3 hour flying time to the FAM enabled area will be shifted 3 times by 5-minute steps. If not reported as airborne, the flight will be suspended by a Flight Suspension Message (FLS) after another 2 minutes, i.e. after 17 minutes in total;
  2. The flight is not reported as airborne after 120 minutes after the expected take-off time. It is applicable to flights departing from non-FAM-enabled areas and estimated elapsed time (EET) of more than 3 hours with a destination in FAM-enabled areas.


The objective is to further improve network predictability and reinforce the compliance of flights with route and airspace availability through the integrated initial flight plan processing system (IFPS).

Linked to the latter, ICAO establishes that any changes to the estimated off-block time (EOBT) of more than 15 minutes for any IFR flight within the IFPZ shall be communicated to the IFPS. (ICAO Doc 7030,

Way forward

After a process of consultation with aircraft operators and ANSPs, the Operational Development Sub-Group (ODSG) #41 gave its approval to proceed with a gradual reduction of the FAM parameter with these conditions:

  • the reduction of the 30 minutes’ FAM parameter will be undertaken in three steps;
  • each step will reduce the FAM parameter by five minutes until the suspension has been triggered, i.e. a flight would be suspended after 25, 20, 15 minutes after the expected take-off time;
  • each step will be linked to the NM release cycles, every six months, starting with NM release 22.5 (Autumn 2018) with an initial reduction of five minutes;
  • the Network Manager will closely monitor the reduction and report on the benefit and possible impact on its stakeholders;
  • NM, in coordination with the stakeholders and groups concerned, may, after having assessed the impact, decide to stop or reverse the reduction of this time parameter.

How to avoid a flight suspension

  • Aircraft operators should continuously monitor and update their flight plans with accurate EOBTs and adhere to their EOBTs and CTOTs;
  • Flow management positions (FMP) and towers should ensure that the taxi time provided to NM is updated and accurate;
  • Towers should ensure that departing flights are sequenced in such a way to be able to respect their ETOTs and CTOTs.

In case a flight is suspended

  • If the flight will operate but a new EOBT is not yet known, no action is required until the new off-block time is available;
  • If the flight will operate and a new off-block time is known, the aircraft operator must send a 'delay (DLA) or change (CHG)' message with an updated EOBT;

Note: A flight confirmation message (FCM) sent as a response to an FLS due to FAM will be rejected by the ETFMS.

  • If the flight will not operate, the aircraft operator must send a 'cancel (CNL)' message;
  • The departure tower should not let the aircraft start-up or depart before a de-suspension (DES) or slot allocation message (SAM) has been received.

Find out more about ETFMS