## Contacts

 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 Fusée1130 BrusselsBelgium Contact e-mail address [email protected]

## Statistical presentation

### Data description

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.

ATFM slot adherence monitoring is required by SES legislation. The ATS units are required to provide the information regarding non-compliance to slot adherence for these airports where non-adherence equals or exceeds 20% of the regulated departures, as well as their action plans to mitigate such a non-compliance.

The Network Manager monitors ATFM slot adherence on a monthly basis.

The legislation also requires ATFM slot adherence to be monitored at local level, i.e. at national level with a breakdown at airport level.

### Classification system

ATFM slot adherence is classified per Member State, with a breakdown for each airport subject to the SES performance scheme.

### Sector coverage

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

### Statistical concepts and definitions

ATFM slot adherence is defined as the percentage of departures inside an ATFM slot tolerance window of [-5 minutes, +10 minutes].

### 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 ‘SES airports’ included in the SES performance scheme.

### Reference area

• 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.

### Time coverage

The Network manager has monitored slot adherence to ATFM since 2011, but in the scope of the Performance Scheme, 2015 is the first year for which data is presented.

Not applicable.

## Unit of Measure

The ATC pre-departure delay is measured in minutes per outbound IFR flight [min/departure].

## 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.

## Institutional Mandate

Legal acts and agreements are established in the EU IR691/2010|Performance Regulation (691 / 2010), Commission Implementing Regulation (EU) No 390 / 2013 and Commission Implementing Regulation (EU) 2019/317.

## Confidentiality

The information is disseminated in accordance with the relevant SES legislation.

## Release policy

### Release calendar

ATFM slot adherence is released monthly with yearly aggregates.

Not applicable.

### User access

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

## Frequency of dissemination

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).
Additional definitions of the terms used in the frame of the this KPI are available in the Metadata page.

### Quality documentation

There is no specific documentation on procedures applied for quality management and quality assessment.

## Quality Management

As per SES legislation,

The data providers shall take the necessary measures to ensure the quality, validation and timely transmission of the data, including providing evidence of their quality checks and validation processes, explanations in response to specific requests from the Commission regarding the quality of the data and, where necessary, action plans to improve data quality. The data shall be provided free of charge, in electronic form where applicable, using the format specified by the Commission.

### Quality assurance

Data validation is performed by the Network manager.

### Quality assessment

Quality assessment is under the responsibility of the Network manager.

### Completeness

The data is collected for all airports subject to SES legislation.

## Relevance

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

## Accuracy and reliability

### Overall accuracy

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

### Sampling error

There is no sampling and therefore no sampling error.

## Timeliness and punctuality

### Timeliness

The information is published each month by the Network Manager in their “NM Monthly Adherence to ATFCM Slots” bulletin.

### Punctuality

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

## Comparability

### Comparability — geographical

The data is collected centrally by the Network Manager. The data is transmitted to the EUROCONTROL Performance Review Unit and computed consistently for all airports subject to SES legislation.

### Comparability over time

Comparisons over time are valid.

## Coherence

Not available.

### Coherence — internal

Data is fully coherent from an internal perspective.

Not available.

## Data revision

No data revision foreseen.

## Statistical processing

### Source data

The input variables used for the calculation are detailed in the Statistical concepts and definitions section.

### Frequency of data collection

The data is collected and transmitted for statistical processing on a monthly basis.

### Data collection

The data is collected by the Network Manager.

### Data validation

The data is validation as described in the Quality Management section.

### Data compilation

The departure time of a regulated flight is inside the slot tolerance window when its Actual Take-off time (ATOT) is in a window starting 5 minutes before and ending 10 minutes after its Calculated Take-Off time (CTOT), i.e.

$CTOT – 5 min <= ATOT <= CTOT + 10 min$

It should be acknowledged that the exceptional extension of the standard ATFM slot tolerance window [-5 minutes, +10 minutes], as described in the ATFCM User Manual under 4.6.4 “Adverse Operating Conditions at Aerodromes”, is not taken into account in the calculation of ATFM slot adherence. These exceptions represent in most cases less than 2% of regulated flights.

The adherence to ATFM slots determines the percentage of regulated flights with an ATOT inside the slot tolerance window.

The Actual Take-Off time of a flight can be determined when the NM received an ATC activation message from its departure airport. Therefore, the assessment is made only for those flights for which an activation message at the origin airport (FSA message) or a Departure message (DEP) is available.