If holding instructions have been issued to an arriving aircraft, what must the controller do?

When holding instructions have been issued to an arriving aircraft, it is essential for the controller to issue an Expect Further Clearance (EFC) if a delay is expected. The EFC provides the aircraft with important information regarding how long it can expect to remain in the holding pattern before being cleared to continue to its destination. This facilitates proper planning for both the flight crew and air traffic control.

An EFC helps manage the expectations of the pilot and ensures that they can maintain appropriate fuel levels and other operational considerations while in holding patterns. Effective communication about potential delays is crucial in maintaining safety and efficiency within the airspace, allowing the aircraft to be prepared for further instructions.

This action is particularly important because holding patterns are often implemented due to congestion or delays at the destination airport. Without clarity on when the delay might end, pilots could face unnecessary levels of uncertainty, which could impact their decision-making and flight safety.