Definition
The specific runway at an airport from which an aircraft takes off on a given flight. It is identified by its magnetic heading number (and letter if there are parallel runways) and is assigned by ATC at controlled fields or selected by the pilot at non-towered fields based on wind, traffic, and procedure requirements.
Plain English
The runway you actually use to take off. Other runways at the same airport may be in use for landings or unused at the time.
Context Anchor
You may hear this term on an airport information broadcast, from air traffic control, or during takeoff planning.
Why Pilots Care
Determines takeoff performance calculations, noise procedures, and traffic sequencing.
Intuition Check
Do not read departure runway as any runway an aircraft could possibly take off from. In aviation use, it means the specific runway assigned, announced, or selected for that departure.
Example Sentence 1
Tower assigned Runway 27 as the departure runway, so the pilot taxied to its hold-short line and reviewed the obstacle departure procedure for that runway.
Example Sentence 2
With the wind from the south, the tower assigned runway 18 as the departure runway.