Airport ATFM Delay


Contact organisation EUROCONTROL: The European organisation for the safety of air navigation
Contact organisation unit Directorate European Civil-Military Aviation - Performance Review Unit (DECMA/PRU)
Contact name Performance Review Unit - EUROCONTROL
Contact mail address 96 Rue de la Fusée
1130 Brussels
Contact e-mail address [email protected]

Metadata update

Metadata last certified not applicable
Metadata last update 16 August 2021

Statistical presentation

Data description

Please note that software release 20.0 of the Network Manager on 04 April 2016 introduced a change in the computation of ATFM delay for operational purposes. ATFM delays on this web page are based on this new computation from 04 April 2016 onwards. See the Source data section below for more information on the changes in NM release 20.0.

The measure provides an indication of ATFM delays on the ground due to constraints at airports.

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 Air Traffic Flow Management 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 resulting 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.

As an output of the ATMAP Group, Airport ATFM delay has been in use as a commonly agreed proxy for airport capacity shortfalls since 2009. The calculation of Airport ATFM delay is based on a well established and commonly accepted algorithm and is compliant with the KPI definition in the EU legislation.

Classification system

Airport ATFM delay is classified per Member State, with a breakdown by airport.

Sector coverage

The measures pertain to the Air Transport and Air Traffic Management Sector of the economy.

Statistical concepts and definitions

ATFM delay
ATFM delay is defined as the duration between the last Estimated Take-Off Time (ETOT) and the Calculated Take-Off Time (CTOT) allocated by the Network Manager. ATFM delay comprises both Airport ATFM delay and En route ATFM delay. This indicator is solely concerned with Airport ATFM delay.
The delay is truncated to minutes.
All the IFR flights which have filed a flight plan and have landed at the relevant airport are taken into account.

Attribution of Delay

ATFM delay to which a flight is subjected is defined to have as cause the most penalizing ATFM regulation which affects it. Depending of the type and the entity responsible for the reference location protected by the ATFM regulation the ATFM delay is classified as either an airport or an en route ATFM delay and attributed to airport or en route facilities. Airport ATFM delays generated by arrival or global regulations are attributed to the arrival airport as stated in the flight plan. If the regulation is protecting a group of airports, the delay is attributed to the destination airport of the affected flight.

Each ATFM regulation also comprises a designator referring to the cause of delay which can be used in further analysis.

Statistical unit

The statistical unit is the airport. Airport level data is also aggregated to States.

Statistical population

The statistical population is the set of airports subject to performance monitoring within the Single European Sky Performance Scheme.

Reference area

The reference area is the Single European Sky Area.

Time coverage

2009 is the first year for which data is presented.

Base period

Not applicable.

Unit of Measure

Airport ATFM delay is measured in minutes per IFR arrival.

Reference period

  • The first reference period (RP1) covers the calendar years 2012 to 2014 inclusive.
  • The second reference period (RP2) covers the calendar years 2015 to 2019 inclusive.
  • The third reference period (RP3) covers the calendar years 2020 to 2024 inclusive.

Unless decided otherwise, the following reference periods shall be of five calendar years.


Release policy

Release calendar

Airport ATFM delay data is released monthly with yearly aggregates.

Release calendar access

Not applicable.

User access

Information is disseminated to the general public via the SES Data Portal.

Frequency of dissemination

Airport ATFM data is published monthly with the annual performance aggregate being available in January of the following year.

Dissemination format

Information is disseminated to the general public via the SES Data Portal.

Accessibility of documentation

Documentation on methodology

As per the pertaining regulations (see Institutional Mandate).
For technical questions not addressed in Statistical processing please contact: [email protected].
Additional definitions of the terms used in the frame of the this KPI are available in the Metadata page.

Quality documentation

Documentation on procedures applied for quality management and quality assessment is under development.

Quality Management

Quality assurance

The data is provided by the Network Manager and as such it is their responsibility to perform any quality assurance activities.

Quality assessment

Data is validated by random quality checks, e.g. missing data for given a day, adherent data, etc. Any issues are reported to the Network manager who works with the EUROCONTROL Performance Review Unit to resolve them.


The information is published for performance monitoring purposes in accordance with the relevant EU legislation.


The data is collected for the entire Single European Sky Area.

Accuracy and reliability

Overall accuracy

The Airport ATFM delay is the delay calculated as defined in SES legislation. This calculation is based on a well established methodology, which has been in place since 2009.

Timeliness and punctuality


The full set of Airport ATFM delay per IFR arrival at airports included in the performance scheme is published each month - in general between 14 and 16 days after the end of the month in question.


The internal databases are updated daily. The statistical processing is performed once per month.


Comparability — geographical

The data is collected centrally by the Network Manager and computed consistently throughout the entire Single European Sky Area which allows comparisons across different airports.

Comparability over time

Comparisons over time are valid.


Coherence — cross domain

ATFM delay is calculated relative to the flight plan.

Although not fully cohered, the delay reported by aircraft operators to the Central Office for Delay Analysis (CODA) under the corresponding IATA delay categories shows a high correlation with the ATFM delay calculated by the Network Manager. It should be noted that the delay reported by aircraft operators relates to airline schedules rather than flight plan.

Coherence — internal

Data is fully coherent from an internal perspective.

Cost and burden

Not available.

Data revision

The data revision policy has not yet been defined.

Statistical processing

Source data

The data for the calculation of this indicator is provided by the Network Manager.

Please note that the delays caused by READY to Depart (REA) messages and ATFM slot extensions were excluded from the ATFM delay computation with NM release 20 (4 April 2016) which reduces the overall amount of computed ATFM delay. More information on the adjusted ATFM delay computation as of NM release 20.0 from 4 April can be found here: NM release 20.0 - 4 April 2016 - FB750-Delay Calculation improvements.

Frequency of data collection

Data is collected for each individual flight in real time.

Data collection

Data is collected and compiled by the Network Manager.

Data validation

Data is validated and cross-checked by the Network Manager.

Data compilation

Data is aggregated for different delay groups, airports, and Member States.


Corrections may be made when issues are discovered as described in the Quality Assessment section of this document.

Post-operations performance adjustment

The post-operations performance adjustment process is a means of enhancing operational ATFM delay data used in the Single European Sky performance scheme. It allows operational stakeholders to notify national and European authorities of problems related to air traffic flow management (ATFM) delay measurement, classification and assignment. The main output of this process is a separate performance dataset, which will include the approved changes. Read more about the post-operations performance adjustment process.


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This data is published by the Performance Review Body (PRB) of the Single European Sky. Every effort has been made to ensure that the information and analysis contained on this website are as accurate and complete as possible. Despite these precautions, should you find any errors or inconsistencies we would be grateful if you could please bring them to the Performance Review Unit’s attention.

The information may be copied in whole or in part providing that the copyright notice and disclaimer are included. The information may not be modified without prior written permission from the PRB. The views expressed herein do not necessarily reflect the official views or policy of EUROCONTROL or of the European Commission, which make no warranty, either implied or express, for the information contained on this website, neither do they assume any legal liability or responsibility for the accuracy, completeness or usefulness of this information. The PRB reserves the right to change or amend the information provided at any time and without prior notice.