What is a 'departure clearance'?

A departure clearance is an authorization issued by air traffic control that allows an aircraft to begin taxiing and takeoff procedures. This clearance includes important information such as the assigned departure runway, initial altitude to climb to, and any specific routing instructions. The purpose of the departure clearance is to ensure the safe and orderly movement of aircraft on the ground and during takeoff, as it coordinates their activities with air traffic control to prevent conflicts and maintain safety standards.

The other choices do not accurately describe a departure clearance. While pre-flight checks and passenger boarding are essential steps before a flight, they do not require specific air traffic control authorization. Similarly, entering a holding pattern is a procedure that typically occurs in-flight to manage air traffic but does not relate to the initial clearance for departure. Lastly, notifications of weather conditions affecting departures are important for operational decisions but are separate from the clearance needed to start the taxiing and takeoff process.