Definition
An air traffic control tower at an airport that is currently staffed and active, providing ATC services to aircraft operating on the airport surface and in the surrounding airspace. When a control tower is operating, the airport's airspace is Class D (or Class B/C if so designated), and two-way radio communication with the tower is required to enter, depart, or operate within it.
Plain English
A control tower at an airport that is open and working at the time you are flying there. When the tower is open, you must be in radio contact with it to land, take off, or fly nearby.
Context Anchor
Seen in airport traffic pattern and airport operations discussions, especially when deciding whether to use tower procedures or non-tower procedures.
Why Pilots Care
Pilots must use two-way radio communication with the tower for all ground and airborne movements, which prevents conflicts and maintains an orderly flow of traffic.
Intuition Check
Do not assume a control tower is operating just because you can see a tower on the airport. Here, operating means active and providing control service at that time.
Example Sentence 1
Before entering the Class D airspace, the pilot confirmed the control tower was operating and established two-way radio contact on the tower frequency.
Example Sentence 2
When the control tower is operating, arriving aircraft receive a specific pattern entry point and landing clearance from the controller.