What action must ZAE take if unable to issue a clearance right away for departures?

When ZAE is unable to issue a clearance right away for departures, providing an Expected Further Clearance (EFC) time is the required action. This is important because it informs pilots when they can expect to receive their departure clearance, allowing them to make necessary preparations and maintain situational awareness. An EFC time helps manage the flow of air traffic and minimizes the likelihood of delays and confusion, as pilots can plan their operations around that timeframe.

This action maintains communication and enhances the confidence of the flight crew while ensuring they are adequately informed about their departure sequence. Providing an EFC time rather than issuing a new route or relaying to Approach Control helps establish expectations without altering the departure plan unnecessarily. It also does not involve separating from all arrivals, which would disrupt traffic flow and could lead to inefficiencies.