To whom should you inform about anticipated delays in departure times?

Informing approach control and/or tower facilities about anticipated delays in departure times is essential for maintaining effective air traffic management and safety. Air traffic controllers rely on accurate and timely information regarding the status of flights to manage air traffic flow, coordinate departures, and ensure that airspace is efficiently utilized. By communicating delays to these facilities, they can adjust their operations and provide updated instructions to other aircraft, thereby minimizing congestion and enhancing safety.

While informing the airlines, passengers, or ground staff can be important for overall customer service or operational efficiency, the most critical entity that needs to be aware of departure delays from a safety and air traffic management perspective is the approach control and tower facilities. These are the entities that directly control the aircraft in the airspace and on the ground, making it imperative for them to receive timely updates on any changes to flight plans.