What does a rotating beacon with two quick white flashes and one green flash indicate?

A rotating beacon that emits two quick white flashes followed by one green flash specifically indicates the presence of a military airfield. This signaling is standardized in aviation to help pilots recognize various types of airports and landing facilities from a distance, enhancing situational awareness, especially in locations where standard approaches or navigational aids may not be as prominent.

The unique pattern of two white flashes followed by a green flash is distinctive and is derived from the visual identification procedures established by aviation authorities for military installations. Understanding this sign is crucial for pilots to ensure they are aware of their surroundings and know the type of facilities they may be approaching.

In contrast, other choices refer to different signals as follows: a rotating beacon commonly indicates either a destination or an emergency landing area but has distinct signaling patterns that differ from that of a military airfield. The specific designation for a heliport typically involves a unique visual signature separate from military beacons. Hence, knowing the correct signaling patterns helps pilots navigate effectively and uphold safety standards.