What must happen when a telephone (landline) call is received by a controller?

When a telephone call is received by a controller, it is essential for the call to be answered by the controller. This procedure is critical for ensuring effective communication, safety, and operational efficiency in air traffic management. Controllers must respond promptly to all incoming calls, as these calls can involve important information regarding flight operations, emergency situations, or coordination with other agencies and stakeholders.

Ignoring the call or allowing it to ring indefinitely would create delays and potentially compromise safety, while redirecting the call is often not an option unless specific protocols are in place. Therefore, answering the call immediately reflects the responsibility of the controller to maintain clear lines of communication in a high-stakes environment.