Definition
An airport at which an operating control tower provides air traffic control services to aircraft taking off, landing, and operating in the airport's surface movement area and surrounding airspace. Pilots must establish two-way radio communication with the tower and receive clearances or instructions before taxiing, taking off, or landing.
Plain English
An airport with a working control tower. You must talk to the tower on the radio and follow their instructions before you taxi, take off, or land.
Context Anchor
Seen in airport operations, radio communication, and flight planning when deciding what procedures apply at the airport.
Derivation
Controlled comes from control, meaning to direct or regulate. Airport combines air and port, meaning a place where aircraft arrive and depart. In aviation, the phrase points to an airport where aircraft traffic is actively directed by an operating tower.
Why Pilots Care
Pilots must use the proper radio frequencies and follow ATC instructions rather than self-announcing on a common frequency.
Intuition Check
Controlled does not mean the airport is closed off, guarded, or free of risk. It means an air traffic control tower is operating and directing aircraft traffic.
Example Sentence 1
Before flying into a controlled airport, the student practiced his radio calls so he could request taxi and takeoff clearances confidently.
Example Sentence 2
VFR aircraft at a controlled airport receive pattern entry clearance from the tower before joining the traffic pattern.