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Flight Completeness Checks: A Verifier’s Perspective
When verification of an aircraft operator’s environmental report begins, one of the first datasets provided to the verifier is generally the flight and fuel data used to prepare the report. Before assessing the accuracy of fuel consumption, emissions calculations or other reported parameters, the verifier needs to establish whether the underlying list of reported flights is complete with respect to the scheme being verified.
The Flight Completeness Check therefore provides an important foundation for the remainder of the verification. The objective is to determine whether all relevant flights have been captured in the operator’s data and whether flights excluded from the reporting population have been appropriately classified and supported by evidence.
The basic approach is common across the different aviation schemes:
Operator flight data → Independent third-party data → Flight-level reconciliation → Investigation of discrepancies → Verification of scope and exemptions
Although the regulatory scope differs between the European Union Emissions Trading Scheme (EU ETS), United Kingdom Emissions Trading Scheme (UK ETS), ReFuelEU Aviation, Non-CO₂ Aviation Effects and Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA), the fundamental verification principle remains the same: the verifier needs to achieve reasonable assurance that the population of relevant flights is complete.
For an operator reporting under EU ETS, UK ETS, ReFuelEU Aviation or Non-CO₂ Aviation Effects, EUROCONTROL is generally the primary third-party data source requested by the verifier, particularly where the operator has relevant EEA operations.
EUROCONTROL data can be available to the operator in several formats. Aircraft operators pay route charges and have access to a dedicated EUROCONTROL portal (CRCO Portal) through which route-charge invoices and associated flight information are made available. As part of the verification, the verifier may request the Route Charges Pro Forma Invoices because they provide a structured list of the flights on which route charges were calculated. Where possible, the verifier extracts the flight data directly from the original PDF Pro Forma invoices. Using the original source provides greater confidence in the integrity and traceability of the information than relying solely on a manually prepared or reformatted dataset.
As an additional source for the completeness assessment, the verifier may use flight information available through the Eurocontrol Environmental Management Information Service (EMIS), formerly known as the EUROCONTROL ETS Support Facility, where applicable. The verifier may also use the operator’s SB (Statement of Billing) and SM (Statement of Movements) files, provided in Excel format, as supporting information for cross-checking the reported flight data.
The SB and SM files are comma separated value (CSV) files, separate from the data obtained through the EUROCONTROL ETS Support Facility. These CSV files also provide a list of flights similar to the one obtained through the Pro Forma files described above and may be used as an additional/alternative source to assess the completeness and consistency of the reported flight data.
The purpose is not necessarily to select one EUROCONTROL dataset over another. Rather the operators can provide any one of the above to the verifiers for the completeness checks.
For CORSIA, the fundamental completeness procedure remains the same, but the principal difference may be the third-party data source used, depending on the geographical distribution of the operator’s operations. Where an operator has a significant proportion of its relevant operations within the EEA, EUROCONTROL data may provide suitable third-party coverage. In such cases where the operator has limited EEA operations, the verifier may request ATC data from the operator’s principal State of operation or another appropriate ATC source providing the maximum practical coverage of the relevant flights.
Where suitable ATC data is not available, FlightRadar24 may be used as an alternative source to identify potential missing flights and support the completeness assessment.
The verifier compares the flights within the relevant regulatory scope in the operator’s submitted data against the corresponding flights in the independent third-party dataset.
The comparison is normally performed at the flight level using information such as:
The verifier looks for differences in both directions:
Third-party source → Operator data
Are there flights in the independent source that are missing from the operator’s reported population?
Operator data → Third-party source
Are there flights in the operator’s data that cannot be identified in the independent source?
Both types of differences require investigation. The absence of a flight from the third-party dataset does not automatically mean that the operator’s data are incorrect, just as the presence of a flight in the third-party dataset does not automatically mean that it should have been reported.
This comparison forms part of the completeness assessment, which is performed for each dataset provided by the aircraft operator. The assessment is an iterative process and may continue throughout the verification activities as additional information, supporting evidence, or discrepancies are identified and addressed.
The objective is to ensure that, by completion of the verification activities, the final dataset used for reporting is complete and appropriately reflects the applicable regulatory scope, with sufficient and appropriate evidence to obtain reasonable assurance that all flights required to be included under the applicable regulatory requirements have been identified and included in the reported flight dataset.
Differences between the two datasets can arise for several reasons.
The most straightforward case is an actual omission or incorrect capture by the operator, where a relevant flight was operated but was not included in the reporting data. However, operational circumstances can also create apparently inconsistent records. For example, a flight may have been diverted, resulting in the third-party source retaining or displaying information associated with the original planned operation while the operator’s records contain the actual operated route.
Similarly, a significant delay may result in a new flight plan being submitted. Depending on how the third-party data is generated, this can result in apparent duplicate records or differences between the planned and operated flight information.
Consequently, the verifier does not treat every data difference as an error. The identified discrepancies are reviewed in the context of the available operational evidence. Where a discrepancy cannot be reasonably explained from the data available to the verifier, it is raised with the aircraft operator for further investigation and supporting evidence.
Some operators also perform this reconciliation internally as part of their Internal Control Activities. Where such a control exists, the operator may already have identified and investigated potential missing, duplicate or incorrectly classified flights before the verification begins. The verifier can then consider the results of the internal control, together with the underlying evidence, when assessing the completeness of the reported data.
Flight completeness can also help assess whether flights excluded from the reporting population have been correctly treated as exempt or outside the applicable scope.
EUROCONTROL data can provide useful information on exemptions through different third-party data sources, including Pro Forma Route Charge invoices, EUROCONTROL ETS Support Facility data, and SB/SM data. These sources may contain exemption codes or indicators, with each code corresponding to a defined exemption category and meaning. The verifier can therefore compare the exemption code identified in the operator’s data against the corresponding code and its defined meaning in the relevant EUROCONTROL source to assess whether the flight has been correctly classified.
Where the operator’s data identifies a flight as exempt, but the available EUROCONTROL source does not support the same classification, the verifier requests the ATC flight plan from the operator to obtain additional evidence supporting the exemption.
The primary supporting evidence shall be the ATC flight plan filed for the flight as required by the various regulations, particularly where the exemption depends on the purpose or operational characteristics of the flight.
The verifier assesses whether the evidence demonstrates that the applicable exemption criteria were actually met. An exemption classification within the operator’s database is therefore not, by itself, sufficient; the classification needs to be supported by appropriate evidence where required.
The Flight Completeness Check is a critical first step in the verification of aviation environmental data. By comparing the operator’s reported flight population with an independent third-party source, the verifier can identify potentially missing, duplicated, incorrectly classified or incorrectly exempted flights before proceeding to the detailed assessment of fuel and emissions data.
Importantly, discrepancies are not automatically treated as errors and the operator is often contacted for clarifications and investigations. The verifier assesses the underlying operational circumstances, including diversions, revised flight plans, duplicate records and other legitimate differences. Where an exemption or discrepancy cannot be supported by the available data, the matter is raised with the operator for further evidence and resolution.
Ultimately, the purpose of the completeness check is to provide confidence that the flights reported by the operator represent the relevant flights actually operated and that any exclusions or exemptions are appropriately justified. A robust, independent and evidence-based completeness assessment therefore provides the foundation for reliable verification across the different aviation environmental schemes.
