What must be coordinated regarding arriving and departing aircraft?

The coordination of an altitude with the radar-side controller for arrival aircraft before releasing a departure is crucial for maintaining safe and efficient air traffic management. This process ensures that there is a clear understanding between controllers about the spacing and separation between arriving and departing aircraft.

When an aircraft is departing, it is important to ensure that it will not conflict with an arriving aircraft that may be on a similar path. This negotiation of altitude helps to establish a safe vertical separation, reducing the risk of mid-air collisions and allowing both arrivals and departures to proceed smoothly through controlled airspace.

While considerations such as fuel requirements, readiness of ground services, and selection priorities for departures are important in air traffic control, the negotiation of altitude directly impacts the safety of operations. It is a proactive measure that addresses potential conflicts before they occur, reinforcing the need for coordination in high-traffic environments.