When must coordination by effect with the receiving center occur during non-automated data transfer?

Coordination by effect with the receiving center is an essential part of air traffic control, especially during non-automated data transfer, to ensure safety and effective communication regarding an aircraft's flight plan. The correct answer indicates that this coordination must occur before departure when 15 minutes of flying time is planned. This timeframe allows for timely communication and ensures that the receiving center is prepared to manage the aircraft's arrival or transition into their airspace.

This requirement is particularly crucial for flights with relatively short flight durations, as effective coordination before departure can help preventing potential miscommunications and conflicts that may arise as the aircraft approaches the receiving center. Establishing this connection in advance helps to streamline operations and enhances situational awareness on both ends, providing all involved parties with the necessary information to safely manage the flight.

In this context, the focus is on ensuring that all relevant details are shared and understood ahead of time, which is imperative to maintain an orderly flow of air traffic. By mandating coordination prior to departure within the specified timeframe, controllers can mitigate risks and ensure a smoother transition for the aircraft entering the new sector.