Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
The statistics on commercial aviation covers scheduled and non-scheduled air traffic at the five Dutch airports Amsterdam Schiphol, Rotterdam The Hague, Eindhoven, Maastricht Aachen and Groningen Eelde. Based on European legal bases results are transmitted to the statistical office of the European Union (Eurostat) one to four months after the reference month. The data includes all flights with passenger, freight and mail as well as empty leg flights in domestic and international traffic where the take-off or landing airport is located in The Netherlands. The five airports contribute to the statistics by collecting and transmitting data to the national statistical office. The statistics are compiled and transmitted montly to Eurostat by the National Statistical Institute of The Netherlands (Centraal Bureau voor de Statistiek).
EU:
Regulation (EC) N°1358/2003, implementing Regulation N°437/2003 of the European Parliament and of the Council on statistical returns in respect of the carriage of passengers, freight and mail by air.
Three data sets required by the Regulation – A1, B1 and C1 – are provided to Eurostat:
Dataset A1 - Flight Stage dataset : periodic flight stage data registered for airport-to-airport routes, and broken down by arrivals/departures, scheduled/non-scheduled, passenger service/all-freight and mail service, airline information and aircraft type. The values provided concern passengers on board, freight and mail on board, commercial air flights as well as passenger seats available.
Dataset B1 - On Flight Origin/Destination dataset : periodic on flight origin/destination data registered for airport-to-airport routes, and broken down by arrivals/departures, scheduled/non scheduled, passenger service/all-freight and mail service and airline information. The values provided concern passengers carried and freight and mail loaded or unloaded.
Dataset C1 - Airport dataset: periodic airport data registered for declaring airports, and broken down by airline information. The values provided concern total passengers carried, total direct transit passengers, total transfer (indirect transit) passengers (optional variable), total freight and mail loaded or unloaded, total commercial aircraft movements and total aircraft movements.
All data sets are provided on monthly basis.
Airports handling less than 15 000 passenger units annually are not included in the data sets. All data sets have been provided according to the legal act (with no derogations) starting from 2002 reference year. Partial information (passenger transport only, annual aggregates) are available starting from 1993 reference year. When comparing the Dutch air transport statistics data published by Eurostat with the results of the National Statistics Institute, it has to be considered, that the two data sets show small discrepancies by definition. The national published data include empty leg flights and technical stops. The national published data does not include taxi flights. Following Regulation (EC) N°1358/2003, empty leg flights or technical stops are not transmitted to Eurostat. For more information, please refer to Standard-documentation Meta information (Definitions, comments, methods, quality) on Air Transport Statistics, which is prepared for the data collection at national level.
Dataset A1 and B1- data storage: CNA keeps data permanent at individual airport level.
3.2. Classification system
Airports are classified according to ICAO (International Civil Aviation Organization) airport coded as listed in ICAO document 7910.
Aircrafts are classified according to aggregated aircraft categories based on the ICAO aircraft codes as listed in ICAO document 8643.
Airlines are classified according to the ICAO airline codes as listed in the ICAO document 8585. When providing the data to Eurostat, the region where they are licensed is coded accordingly either as European Union (EU) or outside the European Union (non-EU).
3.3. Coverage - sector
Air transport - commercial air services and civil aircraft movements for the airports with traffic in excess of 15 000 passenger units annually.
3.4. Statistical concepts and definitions
The main concepts used in this domain are the following:
Community airport - adefined area on land or water in a Member State subject to the provisions of the treaty, which is intended to be used either wholly or in part for the arrival, departure and surface movement of aircraft and open for commercial air services.
Flight stage - the operation of an aircraft from take-off to its next landing. This is linked to the definition of passengers (or freight and mail) on board.
Passengers on board - all passengers on board of the aircraft upon landing at the reporting airport or at taking off from the reporting airport. All revenue and non-revenue passengers on board an aircraft during a flight stage. Includes direct transit passengers (counted at arrivals and departures).
Direct transit passengers - passengers who, after a short stop, continue their journey on the same aircraft on a flight having the same flight number as the flight on which they arrive.
Transfer of indirect transit passengers - passengers arriving and departing on a different aircraft within 24 hours, or on the same aircraft bearing different flight numbers. They are counted twice: once upon arrival and once on departure.
Freight and mail on board - all freight and mail on board of the aircraft upon landing at the reporting airport or at taking off from the reporting airport. All freight and mail on board an aircraft during a flight stage. Includes direct transit freight and mail (counted at arrivals and departures). Includes express services and diplomatic bags. Excludes passenger baggage.
On flight origin and destination - traffic on a commercial air service identified by a unique flight number subdivided by airport pairs in accordance with point of embarkation and point of disembarkation on that flight. For passengers, freight or mail where the airport of embarkation is not known, the aircraft origin should be deemed to be the point of embarkation; similarly, if the airport of disembarkation is not known, the aircraft destination should be deemed to be the point of disembarkation. This is linked to the definition of passengers carried and freight and mail loaded or unloaded.
Passengers carried - all passengers on a specific flight (with one flight number) counted once only and not repeatedly on each individual stage of that flight. All revenue and non-revenue passengers whose journey begin or terminates at the reporting airport and transfer passengers joining or leaving the flight at the reporting airport. Excludes direct transit passengers.
Freight and mail loaded or unloaded - all freight and mail loaded onto or unloaded from an aircraft. Includes express services and diplomatic bags. Excludes passenger baggage. Excludes direct transit freight and mail.
Passenger unit - one passenger unit is equivalent to either one passenger or 100 kilograms of freight and mail.
3.5. Statistical unit
The data are collected at individual airport level.
3.6. Statistical population
Four categories of Community airports are defined by the Regulation (EC) N°1358/2003:
Category "0": Airports with less than 15 000 passenger units per year are considered as having only "occasional commercial traffic" without obligation to report.
Category "1": Airports with between 15 000 and 150 000 passenger units per year shall transmit only aggregated airport data (Data set C).
Category "2": Airports with more than 150 000 passenger units and less than 1 500 000 passenger units per year shall transmit flight stage data, on flight origin destination data as well as aggregated airport data (Data sets A, B and C).
Category "3": Airports with at least 1 500 000 passenger units per year shall transmit flight stage data, on flight origin destination data as well as aggregated airport data (Data sets A, B and C).
Airports under category ‘0’ are not included in the statistics provided to Eurostat.
3.7. Reference area
Commercial airports located on the territory of The Netherlands.
3.8. Coverage - Time
All data sets have been provided according to the legal act (with no derogations) starting from 2002 reference year. Partial information (annual aggregates on passenger transport only) are available starting from 1993 reference year.
3.9. Base period
Not applicable.
The units used depend on the variables collected within each data set and are: number of passengers, tonnes, flights, aircraft movements and passenger seats available.
The weight of freight and mail is transmitted in tonnes with three decimal places.
Reference period is the calendar year 2023.
6.1. Institutional Mandate - legal acts and other agreements
European level: until 2002, the data were provided to Eurostat on a voluntary basis; since 2002 data provision is based on an EP and Council framework legal act and on several implementing Commission Regulations:
Regulation (EC) No 223/2009 on European statistics (recital 24 and Article 20(4)) of 11 March 2009 (OJ L 87, p. 164), stipulates the need to establish common principles and guidelines ensuring the confidentiality of data used for the production of European statistics and the access to those confidential data with due account for technical developments and the requirements of users in a democratic society.
Only the airline information data is subject to confidentiality. Before providing the data to Eurostat, the region where they are licensed is coded accordingly either as European Union (EU) or outside the European Union (non-EU).
Data confidentiality problems: According to the Dutch Legal base, data on an individual enterprise or data from which this information can be easily obtained cannot be published or otherwise disseminated.
8.1. Release calendar
Air transport statistics is published monthly, within one month after the reference month and are preliminary until publishing the annual results.
8.2. Release calendar access
The release calendar is available at this website (Release calendar).
8.3. Release policy - user access
Main results of commercial aviation statistics are available free of charge to all users. For more detailed results the data user has to pay for accessing the data.
Air transport statistics are published monthly, within one month after the reference month with being preliminary until publishing the annual results.
10.1. Dissemination format - News release
The results are published monthly, one month after the reference month and are preliminary until publishing the annual results.
10.2. Dissemination format - Publications
Publication of air transport statistics (figures) is done through Statline, the database with figures on our website. Articles are published on our main CBS website.
10.3. Dissemination format - online database
The results can be found in the Statline database (Statistics > Verkeer en Vervoer > Vervoer personen en goederen > Vervoer door de lucht). Main results are available free of charge. For more detailed results the data user has to pay for accessing the data.
10.4. Dissemination format - microdata access
Not applicable to air transport statistics.
10.5. Dissemination format - other
Open data access is available for the main results of air transport statistics.
10.6. Documentation on methodology
A Standard-documentation with Meta information (Definitions, comments, methods, quality) on Air Transport Statistics is available at national level.
The system follows as far as possible the European Statistics Code of practice and Quality Assurance Framework of the European Statistical System, more precisely Principle 4: Commitment to Quality: Quality policy is defined and made available to the public. An organisational structure and tools are in place to deal with quality management (please provide more details if relevant). There are procedures in place to plan, monitor and improve the quality of the statistical processes. Procedures based on quality reporting are in place to internally monitor product quality. Results are analysed regularly and improving actions are undertaken, if needed (for example after obtaining annual summary results and mirror checks reports from Eurostat). There is a regular and thorough review of the key statistical outputs using also external experts where appropriate.
11.2. Quality management - assessment
Data quality can be assessed as high. There is a set of validation rules and quality checks put in place, which detect various types of issues. In case of any issues detected, the data providers are contacted to provide explanations or/and revise the data accordingly. Mirror checks (for national transport) and checks for the consistency over times are prepared and revised as well and the results are compared with the data published by the airports at their websites or with overviews they send to Statistics Netherlands.
Annually, Eurostat provides a data quality report with a summary of the main findings affecting quality as well as showing the solution adopted and the materiality of the existing differences. Mirror checks and checks for the consistency over times are prepared as well. Next to the extensive plausibility checks, main strength inlcude the completely automatic data transmission by the airports and the excellent cooperation with the relevant departments of the airports. Timeliness and punctuality are very good. Revisions are rare.
If there are any inconsistencies Statistics Netherlands provides an explanation which is included in the Country Specific Notes (CSNs) available at Eurostat’s metadata page (in Annex part).
12.1. Relevance - User Needs
The key users of air transport statistics collected according to the Regulation 437/2003 are:
Ministery of Infrastructure and Water Management;
Universities and research institutions;
Users involved in the aviation industry.
Data of commercial aircraft movements, the routes, numbers of passengers, amount of transported freight and mail as well as seats available provides an impportant basis for decision-making of politics, society and economy in the context of the development and promotion of transport projects.
12.2. Relevance - User Satisfaction
No surveys on users' satisfaction or data needs.
12.3. Completeness
The data collection on air transport statistics follows the provisions of the Regulation 437/2003. All variables in all three data sets are provided including the voluntary variable – transfer passenger.
Some additional information is provided in the Country Specific Notes (CSNs) available at Eurostat’s metadata page (in Annex part).
Within the current data collection, it is not possible to identify true first origin/final destination, when the journey include multiple flights.
13.1. Accuracy - overall
Overall accuracy of the air transport statistics data is good. The processing with several plausibilty checks as well as checks done before transmitting data to Eurostat provides a high accuracy of the data. Comparisions with published data by the airports are regularly made and show a high level of comparability. The number of transfer passengers in table C1 refers to the number of transfer passengers on outgoing flights.
13.2. Sampling error
Not applicable for air transport data collection.
13.3. Non-sampling error
Not applicable.
14.1. Timeliness
All the statistics required by the provisions of the Regulation 437/2003 are transmitted to Eurostat 4 months after the reference quarter.
Difficulties to respect deadline for data transmission: No difficulty to deliver the three datasets with a shorter delay (T+5).
14.2. Punctuality
All the statistics required by the provisions of the Regulation 437/2003 are available 2 months before the deadline for the data provisions set up in the legal act.
15.1. Comparability - geographical
Not applicable.
15.2. Comparability - over time
As from 2002 the statistics on air transport are comparable over time, as they are collected following fully the provisions of the legal act - the Regulation 437/2003. Time series checks are regularly made to detect inconsistencies in the data.
15.3. Coherence - cross domain
Comparisons with other transport statistics are only partially and to a limited extent possible with regard to freight transport and passenger transport, since data are currently not available or are not collected at the same level of detail and also different methods and underlying objectives.
15.4. Coherence - internal
As from 2002 the 3 data sets (A1, B1 and C1) collected and provided to Eurostat are consistent. Small incoherences between the Dutch air transport statistics data published by Eurostat and the National Statistics Institute might occur. This is partly due to the fact that national data include empty leg flights (A1 and B1 not) and technical stops (all datasets). The national data does not include taxi flights. Following Regulation (EC) N°1358/2003, empty leg flights or technical stops are not transmitted to Eurostat.
The response burden is put on the airports, but is reduced to a minimum. The airports provide the data automatically via a data interface and are only contacted if errors cannot be solved by the NSI.
17.1. Data revision - policy
The results are published montly, maximum one month after the reference month and are preliminary until publishing the annual results. Revision may be required if for example an airport made a mistake with compiling the dataset sended to us. This doesn't happen often.
In case of any data change in the statistics, after the annual data is finalised, an explanation for the change is given in the table publised on the national website.
17.2. Data revision - practice
The policy described in 17.1 is fully implemented.
18.1. Source data
Dataset A1 – Data Suppliers (Passengers on board/Freight and mail on board): Airports (EHAM, EHRD, EHEH, EHBK, EHGG).
Aircraft Information in A1: airports.
Seats information information in A1:
Airport EHAM: Announce the number of seats available. Other airports: Based on ICAO aircraft types classification, technical data.
Dataset B1 –Data Suppliers (Passengers carried/Freight and mail loaded/unloaded): Airports (EHAM, EHRD, EHEH, EHBK, EHGG)
Datasets A1 and B1 - Use of Air Waybill Data as information source of freight data: The airway bill is not used as an information source. Freight transported by truck (trucking-data) is excluded.
Dataset C1 – Bodies that supply the direct transit information to the CNA: The airports supply the direct transit passengers information. Data are collected directly from airlines or their handling agents.
Dataset C1 – Bodies that supply the commercial and total aircraft movement to the CNA:The airports supply the commercial and total aircraft movement information. Data are collected directly from airlines or their handling agents.
18.2. Frequency of data collection
Information needed for the datasets A1, B1 and C1 are collected on a montly basis from all reporting airports.
18.3. Data collection
The data for the purpose of the Regulation 437/2003 is collected montly (txt-formats) from the airports. The transmission is possible via a fttp-port or via email.
18.4. Data validation
Data validation procedure :
Validation of airport codes, airline codes and type of aircraft codes. Comparison of the monthly aggregates by airports with other statistical publications. Consistency over time.
Actions taken when errors are detected:
Investigation and correction of erroneous data.
Request for new data at airport if necessary.
Description of consistency checks :
The total number of seats available is compared with the total number of passengers on board. Verification of sums.
18.5. Data compilation
After various plausibility checks, the data received from the airports are compiled into monthly data following the structure of the data sets which are preset by regulation (EC) 1358/2003.
Data codification practices :
In general the received codes comply with the Regulation. There is one exception: Transcodification is needed for determining the type of aircraft on airport EHRD-data.
Problems on data compilation, validation and delivery :
Problems with SDMX data exchange.
18.6. Adjustment
Not applicable for air transport data collection.
Not applicable.
The statistics on commercial aviation covers scheduled and non-scheduled air traffic at the five Dutch airports Amsterdam Schiphol, Rotterdam The Hague, Eindhoven, Maastricht Aachen and Groningen Eelde. Based on European legal bases results are transmitted to the statistical office of the European Union (Eurostat) one to four months after the reference month. The data includes all flights with passenger, freight and mail as well as empty leg flights in domestic and international traffic where the take-off or landing airport is located in The Netherlands. The five airports contribute to the statistics by collecting and transmitting data to the national statistical office. The statistics are compiled and transmitted montly to Eurostat by the National Statistical Institute of The Netherlands (Centraal Bureau voor de Statistiek).
EU:
Regulation (EC) N°1358/2003, implementing Regulation N°437/2003 of the European Parliament and of the Council on statistical returns in respect of the carriage of passengers, freight and mail by air.
Three data sets required by the Regulation – A1, B1 and C1 – are provided to Eurostat:
Dataset A1 - Flight Stage dataset : periodic flight stage data registered for airport-to-airport routes, and broken down by arrivals/departures, scheduled/non-scheduled, passenger service/all-freight and mail service, airline information and aircraft type. The values provided concern passengers on board, freight and mail on board, commercial air flights as well as passenger seats available.
Dataset B1 - On Flight Origin/Destination dataset : periodic on flight origin/destination data registered for airport-to-airport routes, and broken down by arrivals/departures, scheduled/non scheduled, passenger service/all-freight and mail service and airline information. The values provided concern passengers carried and freight and mail loaded or unloaded.
Dataset C1 - Airport dataset: periodic airport data registered for declaring airports, and broken down by airline information. The values provided concern total passengers carried, total direct transit passengers, total transfer (indirect transit) passengers (optional variable), total freight and mail loaded or unloaded, total commercial aircraft movements and total aircraft movements.
All data sets are provided on monthly basis.
Airports handling less than 15 000 passenger units annually are not included in the data sets. All data sets have been provided according to the legal act (with no derogations) starting from 2002 reference year. Partial information (passenger transport only, annual aggregates) are available starting from 1993 reference year. When comparing the Dutch air transport statistics data published by Eurostat with the results of the National Statistics Institute, it has to be considered, that the two data sets show small discrepancies by definition. The national published data include empty leg flights and technical stops. The national published data does not include taxi flights. Following Regulation (EC) N°1358/2003, empty leg flights or technical stops are not transmitted to Eurostat. For more information, please refer to Standard-documentation Meta information (Definitions, comments, methods, quality) on Air Transport Statistics, which is prepared for the data collection at national level.
Dataset A1 and B1- data storage: CNA keeps data permanent at individual airport level.
21 November 2024
The main concepts used in this domain are the following:
Community airport - adefined area on land or water in a Member State subject to the provisions of the treaty, which is intended to be used either wholly or in part for the arrival, departure and surface movement of aircraft and open for commercial air services.
Flight stage - the operation of an aircraft from take-off to its next landing. This is linked to the definition of passengers (or freight and mail) on board.
Passengers on board - all passengers on board of the aircraft upon landing at the reporting airport or at taking off from the reporting airport. All revenue and non-revenue passengers on board an aircraft during a flight stage. Includes direct transit passengers (counted at arrivals and departures).
Direct transit passengers - passengers who, after a short stop, continue their journey on the same aircraft on a flight having the same flight number as the flight on which they arrive.
Transfer of indirect transit passengers - passengers arriving and departing on a different aircraft within 24 hours, or on the same aircraft bearing different flight numbers. They are counted twice: once upon arrival and once on departure.
Freight and mail on board - all freight and mail on board of the aircraft upon landing at the reporting airport or at taking off from the reporting airport. All freight and mail on board an aircraft during a flight stage. Includes direct transit freight and mail (counted at arrivals and departures). Includes express services and diplomatic bags. Excludes passenger baggage.
On flight origin and destination - traffic on a commercial air service identified by a unique flight number subdivided by airport pairs in accordance with point of embarkation and point of disembarkation on that flight. For passengers, freight or mail where the airport of embarkation is not known, the aircraft origin should be deemed to be the point of embarkation; similarly, if the airport of disembarkation is not known, the aircraft destination should be deemed to be the point of disembarkation. This is linked to the definition of passengers carried and freight and mail loaded or unloaded.
Passengers carried - all passengers on a specific flight (with one flight number) counted once only and not repeatedly on each individual stage of that flight. All revenue and non-revenue passengers whose journey begin or terminates at the reporting airport and transfer passengers joining or leaving the flight at the reporting airport. Excludes direct transit passengers.
Freight and mail loaded or unloaded - all freight and mail loaded onto or unloaded from an aircraft. Includes express services and diplomatic bags. Excludes passenger baggage. Excludes direct transit freight and mail.
Passenger unit - one passenger unit is equivalent to either one passenger or 100 kilograms of freight and mail.
The data are collected at individual airport level.
Four categories of Community airports are defined by the Regulation (EC) N°1358/2003:
Category "0": Airports with less than 15 000 passenger units per year are considered as having only "occasional commercial traffic" without obligation to report.
Category "1": Airports with between 15 000 and 150 000 passenger units per year shall transmit only aggregated airport data (Data set C).
Category "2": Airports with more than 150 000 passenger units and less than 1 500 000 passenger units per year shall transmit flight stage data, on flight origin destination data as well as aggregated airport data (Data sets A, B and C).
Category "3": Airports with at least 1 500 000 passenger units per year shall transmit flight stage data, on flight origin destination data as well as aggregated airport data (Data sets A, B and C).
Airports under category ‘0’ are not included in the statistics provided to Eurostat.
Commercial airports located on the territory of The Netherlands.
Reference period is the calendar year 2023.
Overall accuracy of the air transport statistics data is good. The processing with several plausibilty checks as well as checks done before transmitting data to Eurostat provides a high accuracy of the data. Comparisions with published data by the airports are regularly made and show a high level of comparability. The number of transfer passengers in table C1 refers to the number of transfer passengers on outgoing flights.
The units used depend on the variables collected within each data set and are: number of passengers, tonnes, flights, aircraft movements and passenger seats available.
The weight of freight and mail is transmitted in tonnes with three decimal places.
After various plausibility checks, the data received from the airports are compiled into monthly data following the structure of the data sets which are preset by regulation (EC) 1358/2003.
Data codification practices :
In general the received codes comply with the Regulation. There is one exception: Transcodification is needed for determining the type of aircraft on airport EHRD-data.
Problems on data compilation, validation and delivery :
Problems with SDMX data exchange.
Dataset A1 – Data Suppliers (Passengers on board/Freight and mail on board): Airports (EHAM, EHRD, EHEH, EHBK, EHGG).
Aircraft Information in A1: airports.
Seats information information in A1:
Airport EHAM: Announce the number of seats available. Other airports: Based on ICAO aircraft types classification, technical data.
Dataset B1 –Data Suppliers (Passengers carried/Freight and mail loaded/unloaded): Airports (EHAM, EHRD, EHEH, EHBK, EHGG)
Datasets A1 and B1 - Use of Air Waybill Data as information source of freight data: The airway bill is not used as an information source. Freight transported by truck (trucking-data) is excluded.
Dataset C1 – Bodies that supply the direct transit information to the CNA: The airports supply the direct transit passengers information. Data are collected directly from airlines or their handling agents.
Dataset C1 – Bodies that supply the commercial and total aircraft movement to the CNA:The airports supply the commercial and total aircraft movement information. Data are collected directly from airlines or their handling agents.
Air transport statistics are published monthly, within one month after the reference month with being preliminary until publishing the annual results.
All the statistics required by the provisions of the Regulation 437/2003 are transmitted to Eurostat 4 months after the reference quarter.
Difficulties to respect deadline for data transmission: No difficulty to deliver the three datasets with a shorter delay (T+5).
Not applicable.
As from 2002 the statistics on air transport are comparable over time, as they are collected following fully the provisions of the legal act - the Regulation 437/2003. Time series checks are regularly made to detect inconsistencies in the data.
