Definition
A facility located on an airport that uses air/ground radio communications, visual signals, and other devices to provide air traffic control services to aircraft operating in the vicinity of the airport and on the airport movement area (runways and taxiways).
Plain English
The tall building with windows at an airport where controllers watch the runways and taxiways and tell pilots when they can take off, land, or move on the ground.
Context Anchor
You encounter this term in taxi, takeoff, landing, and runway-incursion guidance at towered airports, especially before entering, crossing, or using a runway.
Derivation
“Tower” comes from the idea of a tall structure. At airports, controllers were placed high above the field so they could see the runways and taxiways; today the term can refer to both the tower building and the control service operating from it.
Why Pilots Care
Contact with the airport control tower provides the clearances needed to prevent runway incursions and maintain orderly traffic flow.
Intuition Check
Do not assume every airport has an airport control tower. Also, the tower does not fly the airplane for you; it gives instructions and permissions so everyone moves safely in the same area.
Example Sentence 1
The pilot called the airport control tower for clearance to taxi to the active runway.
Example Sentence 2
The airport control tower cleared the aircraft to cross the runway after confirming no conflicting traffic.