Codes
- IATA airport code
- A three-letter code assigned by the International Air Transport Association (IATA) to identify an airport, or certain other transport locations, in reservations, tickets and timetables. Example: LHR is London Heathrow Airport. Our airport data includes only airports that have one.
- ICAO airport code
- A four-letter location indicator assigned under the rules of the International Civil Aviation Organization (ICAO), used mainly in air-traffic control and flight planning. Its first one or two letters identify the region or country. Example: London Heathrow Airport is EGLL. Our airport guides show it where OurAirports records one.
- IATA metropolitan-area code (city code)
- A three-letter IATA code that groups the airports serving one city, so a single search can cover all of them. On AMZBooking these are the “all airports” choices in search boxes. Our list of 18 city codes, and of the airports each one covers, is an editorial list kept by AMZBooking for search convenience, and it is reviewed before we state it as a fact on pages for search engines. When a tool needs a single point for a city code, it uses the first airport in that list and says which one.
Distance and direction
- Great-circle distance
- The shortest distance between two points over the surface of a sphere, measured along the great circle through them — a circle whose centre is the centre of the sphere. We calculate it between airport locations with the haversine formula and a mean Earth radius of 6,371.0088 km. It is not the distance a flight actually flies, and not a flight time (method).
- Haversine formula
- A formula that gives the great-circle distance between two points on a sphere from their latitudes and longitudes. It stays accurate in computer arithmetic even for points close together.
- Mean Earth radius
- The radius of the sphere used to stand in for the Earth in distance calculations. We use 6,371.0088 km, the mean radius defined by the International Union of Geodesy and Geophysics (IUGG). Treating the Earth as a sphere changes distances by less than 0.5% compared with the more exact ellipsoid.
- Initial bearing
- The direction in which the great-circle path leaves its starting point, in degrees clockwise from true north: 0° is north, 90° east, 180° south and 270° west. Also called the forward azimuth. Except along a meridian or the equator, the direction changes along a great circle, so the initial bearing for the return trip is generally not the reverse of the outbound one. Try it in the Flight Distance Calculator.
- True north
- The direction along a meridian toward the geographic North Pole. Our bearings are measured from true north, not from magnetic north, which is where a magnetic compass points and which varies by place and over time.
- 16-point compass
- Direction names that split the circle into 16 sectors of 22.5° each: N, NNE, NE, ENE, E, ESE, SE, SSE, S, SSW, SW, WSW, W, WNW, NW and NNW. We show the point whose sector contains the bearing — for example, 288° is WNW (west-northwest).
- Statute mile (mi)
- The mile used for everyday distances in the United States and the United Kingdom, defined as exactly 1.609344 km (the international mile).
- Nautical mile (nmi)
- The unit of distance used in air and sea navigation, defined as exactly 1,852 metres (1.852 km). It was originally based on one minute of arc of latitude.
- Equal Earth projection
- The map projection behind our world maps (Šavrič, Patterson and Jenny, 2018). It keeps areas in proportion; like every flat map it distorts shapes, which is why a great-circle path looks curved on it.
Airport data
- Airport location (reference point)
- The single latitude and longitude OurAirports records for an airport. All our airport distances are measured between these points; terminals, runways and the city centre can be some distance away from it.
- Scheduled passenger service
- In OurAirports data, a yes/no field recording whether an airport has scheduled airline service. We include only airports marked “yes”. Contributors maintain the field, so it can lag behind real-world changes, and it does not say which airlines fly there or how often.
- Large airport, medium airport
- OurAirports’ classification of an airport by type. It is assigned by OurAirports — not an official status, and not a measure of quality or service. Our data has 1,151 large and 2,093 medium airports with scheduled passenger service and an IATA code (retrieved ).
- Runway length
- The physical length OurAirports records for a runway. Where our pages compare airports by runway, they use the longest open runway.
- City location
- For pages about the airports near a city, the city’s position is Natural Earth’s representative point for that populated place — roughly its centre.
- Nearby airports
- Our term for other airports with scheduled service whose location is within a stated radius of a place, nearest first. It is a starting point for comparing departure options, not a statement about transport links between them (method).
How AMZBooking works
- Provider
- The airline, hotel, rental-car company or travel agency you book and pay with. It owns your reservation and handles changes, refunds and service (who handles what).
- Results page (search.amzbooking.com)
- Our live flight results page, provided through our affiliate partner Travelpayouts. Offers there come from airlines and travel agencies at the moment you search, and can change until you book.
- Affiliate commission
- A payment some partners make to AMZBooking when someone books through our links. AMZBooking adds nothing to the provider’s price (how we make money).
- SubID
- A short, anonymous code on partner links that describes which kind of AMZBooking page and module a click came from, so we can measure which pages are useful. It never contains your name, email or account details.
- Provenance
- The record of where a fact came from: its source, publisher, retrieval or review date, fact type, confidence and status (how we use it).
- Noindex
- An instruction asking search engines not to list a page in their results. Our pages stay noindex until they pass our quality checks and review; only pages that qualify are included in our sitemaps.