When must coordination with the receiving facility occur before an aircraft departs?

Coordination with the receiving facility must occur before an aircraft departs when the departure point is less than 15 minutes flying time from the boundary. This timeframe is critical because it allows air traffic controllers to ensure that there is adequate separation between departing and arriving aircraft, manage air traffic efficiently, and provide timely updates to the receiving facility regarding the aircraft's departure.

This coordination is essential for maintaining safety and preventing potential conflicts in busy airspace, especially with aircraft that are in close proximity to each other. If the departure point is very close to the boundary, clear communication and timely coordination become even more crucial to ensure that all relevant parties are aware of the aircraft’s movements and can adequately prepare for its approach or arrival.

The other options, while relevant to specific aspects of air traffic management, do not address the immediate operational need for coordination based on proximity and timing before departure.