Learn / Airports

How an airport works

Behind the terminal, an airport is a system for moving aircraft safely between the sky and the gate. Its runways decide how many flights it can handle, and where it sits decides how long they must be.

The parts of an airport

The runway is where aircraft take off and land; its numbers come from its compass direction (how runways are numbered). Taxiways link it to the apron, where aircraft park at stands to load. Passengers reach them through the terminal and air bridges, or by bus to a remote stand.

Why some runways are so long

An aircraft needs a certain airspeed to fly. In thin air, at high elevation or on a hot day, wings make less lift and engines less thrust, so it has to run further to reach it. That’s why the highest airports on our list all have long runways.

How many flights can it handle?

A single runway can typically handle a few dozen take-offs and landings an hour; aircraft must be spaced so the turbulence behind one doesn’t upset the next. More runways help only if they can be used at the same time, which is why big airports build parallel runways far enough apart. When demand outgrows the runways, the airport runs on slots: see Airport slots.

Hubs

To connect six cities directly, an airline needs 15 routes. Through one hub, six routes connect every pair, with a change of plane. Network airlines time arrivals and departures in waves, so passengers from many cities can make many connections in an hour or two.

Low-cost airlines mostly fly point to point instead: no connections to protect, simpler operations, and aircraft that keep flying all day.