Aviation Data Glossary
A reference guide to aviation data terminology used by airlines, airports and operators worldwide.
- Aeronautical charges
- Fees levied by an airport on airlines and aircraft operators for the use of airport infrastructure and services. These are distinct from non-aeronautical revenues such as retail or car parking income.
- See: What are Airport Fees and Charges?
- Airport Carbon Accreditation (ACA)
- An internationally recognised programme that independently assesses and recognises airports' efforts to manage and reduce their carbon emissions.
- See: RDC’s March 2026 Aviation Emissions Report: Ethiopia, RDC’s February 2026 Aviation Emissions Report: Singapore , RDC’s January 2026 Aviation Emissions Report: United Kingdom, RDC Aviation’s Emissions Methodology Independently Verified by Normec Verifavia
- Available Seat Kilometre (ASK)
- A measure of airline capacity: one available passenger seat flown one kilometre. Used as the denominator when calculating emissions or cost efficiency on a comparable basis across airlines and routes.
- See: RDC’s March 2026 Aviation Emissions Report: Ethiopia, RDC’s February 2026 Aviation Emissions Report: Singapore , RDC’s January 2026 Aviation Emissions Report: United Kingdom, RDC’s December 2025 Aviation Emissions Report: Turkey
- Conditions of Use
- A document published by an airport setting out all applicable fees and charges and the terms and conditions governing flights operating to and from that airport. Also referred to as a Schedule of Charges and Terms & Conditions of Use.
- See: What are Airport Fees and Charges?
- Emissions baseline
- A reference point against which current emissions levels are compared. In aviation, January to December 2019 is widely used as a pre-pandemic baseline year.
- See: RDC’s March 2026 Aviation Emissions Report: Ethiopia, RDC’s February 2026 Aviation Emissions Report: Singapore , RDC’s January 2026 Aviation Emissions Report: United Kingdom, RDC’s December 2025 Aviation Emissions Report: Turkey
- Emissions compliance programme
- A regulatory framework requiring airlines or other aviation stakeholders to monitor, report, and offset or reduce their CO2 output.
- See: RDC’s March 2026 Aviation Emissions Report: Ethiopia, RDC’s February 2026 Aviation Emissions Report: Singapore , RDC’s January 2026 Aviation Emissions Report: United Kingdom, RDC’s December 2025 Aviation Emissions Report: Turkey
- Emissions per ASK
- The volume of CO2 produced for every available seat kilometre flown. Used to compare the carbon efficiency of airlines and airports on a like-for-like basis regardless of network size.
- See: RDC’s February 2026 Aviation Emissions Report: Singapore, RDC’s January 2026 Aviation Emissions Report: United Kingdom , RDC’s December 2025 Aviation Emissions Report: Turkey
- Environmental charges
- Fees linked to an aircraft’s environmental impact, particularly noise and emissions. Aircraft are typically grouped into categories, with charges varying by their impact level.
- Government passenger taxes
- Taxes applied on a per passenger basis, often varying by destination or travel class. These are imposed by national governments and may apply to all airports within the country or to specific airports. Example of such a tax is UK Air Passenger Duty (APD).
- ICAO emissions factors
- Standardised values developed by the International Civil Aviation Organization for calculating the CO2 produced by different aircraft types. These form the basis of internationally recognised emissions calculation methodologies.
- See: RDC Aviation’s Emissions Methodology Independently Verified by Normec Verifavia
- Infrastructure charges
- Fees for using airport facilities such as terminals, check-in areas, baggage systems, and airbridges.
- Parking charges
- Costs associated with parking an aircraft at the airport. These are usually based on the length of time parked and aircraft size or weight.
- Passenger charges
- Per passenger fees charged by the airport. These are billed to the airline, which usually incorporates the cost into the passenger’s ticket price.
- RDC CARE Index
- A composite sustainability score developed by RDC Aviation that rates any air route, airline and aircraft combination on a scale of 0 (worst) to 10 (best). The index evaluates fuel burn efficiency, seat capacity and load factor, use of sustainable aviation fuel, participation in emissions compliance programmes such as EU ETS and CORSIA, and whether the carrier offsets its emissions. Published monthly as part of RDC's Aviation Emissions Report, the CARE Index provides a standardised benchmark for comparing airline environmental performance across regions.
- See: RDC’s March 2026 Aviation Emissions Report: Ethiopia, RDC’s February 2026 Aviation Emissions Report: Singapore , RDC’s January 2026 Aviation Emissions Report: United Kingdom
- Runway charges
- Fees imposed by the airport for using runways and taxiways, typically applied when an aircraft lands or arrives.
- Scope 3 emissions
- Indirect greenhouse gas emissions that occur in an airline or airport's value chain but are not directly owned or controlled by that organisation. For airports, Scope 3 covers emissions generated by aircraft taking off and landing at their facilities.
- See: RDC’s February 2026 Aviation Emissions Report: Singapore, RDC’s January 2026 Aviation Emissions Report: United Kingdom , RDC Aviation’s Emissions Methodology Independently Verified by Normec Verifavia
- Security costs
- Charges applied by the airport to cover the security services it provides, including personnel, screening systems, and related equipment.