Definition
An explicit authorization issued by air traffic control (ATC) at a controlled airport permitting a specific aircraft to begin its takeoff roll on a specific runway. The clearance is normally given as 'Cleared for takeoff' along with the runway identifier and may include additional instructions such as wind, traffic, or departure heading.
Plain English
Permission from the control tower for one specific aircraft to start its takeoff on a named runway. Until you hear those words, you do not roll.
Context Anchor
You hear or receive takeoff clearance just before beginning the takeoff roll at an airport with an operating control tower.
Derivation
“Takeoff” means the act of leaving the ground. “Clearance” comes from “clear,” meaning free or allowed to proceed. In aviation, a clearance is not just a description that something is clear; it is an official permission from air traffic control.
Why Pilots Care
It ensures the runway and airspace are clear of conflicting traffic, making departure safe and legal.
Intuition Check
Do not read “clearance” as a guarantee that everything is safe. Takeoff clearance means you are authorized to take off, but the pilot must still look, verify, and reject the takeoff if something is unsafe.
Example Sentence 1
After holding short of Runway 27, the pilot received takeoff clearance from the tower and began the takeoff roll.
Example Sentence 2
After receiving takeoff clearance, the aircraft departed without delay.