What do red flashing light beacons indicate for pilots?

Red flashing light beacons provide a critical visual warning for pilots, indicating the presence of obstructions or hazardous areas in close proximity. These beacons are often placed at tall structures, such as towers or antennas, as well as in areas where safety risks may be present, like construction zones or other potential obstacles to flight. The red flashing lights serve to alert pilots to exercise caution and avoid these hazards during approach or takeoff.

In contrast, the other options represent situations that are conveyed through different signals or markers. For example, a landing strip does not initiate flashing red lights, and traffic conflicts typically involve air traffic control communications or different visual indicators. Similarly, a closed runway would typically be marked with different signage rather than a flashing beacon, which is more focused on alerting about obstructions rather than operational status.