What is the primary purpose of issuing an EFC time?

The primary purpose of issuing an Estimated Fix Completion (EFC) time is to provide an estimate for the pilot during lengthy delays. This is crucial for flight operations, as it helps pilots manage their expectations and make informed decisions regarding fuel and passenger comfort while waiting for clearance to proceed. An EFC gives pilots a time frame to anticipate when they will be able to continue their flight, alleviating uncertainty during periods of extended waiting.

The other choices represent important elements of air traffic control and pilot situational awareness, but they do not serve as the main function of an EFC. For instance, keeping pilots informed about traffic conditions is essential but is not the specific intent of an EFC. Similarly, confirming altitude or specifying communication frequencies are integral for safety and coordination during flight but are not related to the issuance of EFC times.