What does the green flash in a rotating beacon generally indicate?

The green flash in a rotating beacon is primarily used to indicate a helicopter traffic area. It serves as a visual signal for pilots to be aware of the presence of helicopters in that vicinity. This signal is especially important in airports where helicopter operations might intersect with other types of aircraft, ensuring that pilots can maintain situational awareness and avoid potential conflicts.

Other options, while related to airport operations, do not specifically utilize a green flash in the same way. For instance, the location of a control tower is indicated by different types of lights or markings, and an active runway typically uses specific lighting configurations like runway edge lights rather than a rotating beacon. Runway lights also serve to guide pilots but are not linked to the helicopter traffic indication that the green flash represents.