Statistical Terms Glossary

Any person, excluding on-duty members of the flight and cabin crews, who makes a journey by air.

All passengers on a particular flight (with one flight number) whose journey begins or terminates at the reporting airport, counted once only and not repeatedly on each stage of that flight.

All passengers on board of the aircraft upon landing at the reporting airport or at taking off from the reporting airport.

A stock whose price has fallen sharply, following an announcement of bad news by the issuing company.

Transport contributes significantly to emissions of air pollutants such as CO, NOX, NMVOCs, PM10, PM2.5 and SOX. Such emissions can be grouped into acidifying substances, particulates and ozone precursors. NOX contributes to acidification, formation of ground level ozone and particulate formation.
- PM2.5: particulate matter with aerodynamic diameter of 2.5 μm or less;
- PM10: particulate matter with aerodynamic diameter of 10 μm or less;
- NMVOCs: non-methane volatile organic compounds;
- SOX: sulphur oxides;
- NOX: nitrogen oxides;
- CO: carbon monoxide.

Air pollutants are substances in air that could, at high enough concentrations, harm human beings, animals, vegetation or material. Air pollutants may thus include forms of matter of almost any natural or artificial composition capable of being airborne. They may consist of solid particles, liquid droplets or gases, or combinations of these forms

Air pollution is the presence of contaminant or pollutant substances in the air that do not disperse properly and that interfere with human health or welfare, or produce other harmful environmental effects

Air pollution control refer to steps taken to maintain a standard of purity of air for good public health; for protection of plant and animal life, and property; for visibility; and for safe ground and air transportation

An air pollution index (API) is a quantitative measure that describes ambient air quality. The index is obtained by combining figures for various air pollutants into a single measurement

Air pollution sources are activities that result in air pollution including agricultural activities, combustion processes, dust producing processes, manufacturing activities, nuclear- energy related activities, spray painting, printing, dry-cleaning and so on

Air quality criteria refer to levels of, and length of exposure to, pollution resulting in adverse effects on human health and well-being

Air quality standards refer to levels of air pollutants prescribed by regulations that may not be exceeded during a specified time in a defined area

Charges to users of wireless networks based on a flat rate or on the actual time used. In cellular/PCS networks, charges are typically on a timed basis.

An air transport undertaking which provides air traffic control services.

An air transport undertaking providing air traffic control services.

The movement of goods and/or passengers on an aircraft flight.

Associated with the environment are caused or worsened by exposure to unhealthy levels of pollutants (such as PM, SO2 or O3), usually found in urban settlements and, in particular, in cities with weaker air quality regulations and/or enforcement capabilities.

A machine that can derive support in the atmosphere from the reactions of the air other than the reactions of air against the earth’s surface.

Years since first registration of an aircraft.

An aircraft landing.

Passenger aircraft: aircraft configured for the transport of passengers and their baggage; any freight, including mail, is generally carried in cargo holds in the belly of the aircraft;
- Cargo aircraft: aircraft configured solely for the carriage of freight and/or mail; persons accompanying certain kinds of cargo, such as livestock, may also be carried;
- Combi aircraft: passenger aircraft with enhanced capabilities for the carriage of freight on the passenger deck;
- Quick change aircraft: aircraft designed to allow a quick change of configuration from passenger to cargo and vice versa;
- Other: aircraft not used for commercial air transport.

- Non-noise certificated aircraft: aircraft not certificated against international noise requirements as set out in Annex 16 of the Chicago Convention on International Civil Aviation (International Civil Aviation Organization-ICAO, 1944);
- Chapter II aircraft: aircraft meeting Annex 16 Chapter II specifications;
- Chapter III aircraft: aircraft meeting Annex 16 Chapter III specifications;
- Chapter IV aircraft: aircraft meeting Annex 16 Chapter IV specifications.

A take-off of an aircraft.

An aircraft hour corresponds to one hour of aircraft operation. Aircraft hours are measured on the basis of block-to-block time.

Aircraft-kilometres performed is the sum of the products obtained by multiplying the number of flight stages flown by the corresponding stage airport-to-airport distance.

An aircraft take-off or landing at an airport.

The total number of incoming and outgoing flights to and from the airport per day and all airlines