What action must be taken to separate a departing helicopter from others?

To ensure safe separation of a departing helicopter from others, it is critical that the preceding helicopter has completely left the takeoff area before the next one departs. This step is vital for safety, as it provides enough space for the departing aircraft to take off without risking collision or wake turbulence from the helicopter that has just left. Clear communication and understanding of this procedure are essential in helicopter operations, as the unique characteristics and flight paths of helicopters necessitate careful consideration of distances and timing during departures.

While other options relate to aspects of helicopter operations, such as time intervals and weather conditions, they do not directly address the immediate need for physical separation in the takeoff area. Ensuring the preceding helicopter has vacated that space before the next one takes off is the most effective way to maintain safety and mitigate risks during helicopter departures.