An airport rotating beacon operated during daylight hours indicates what?

The operation of an airport rotating beacon during daylight hours is an important visual signal for pilots. It specifically indicates that the airport is in Class D airspace when the weather conditions are below basic Visual Flight Rules (VFR) minimums.

Class D airspace is managed under specific operational rules, and the activation of the beacon during the day alerts pilots that visibility may be limited and that they should exercise caution when flying in the vicinity. This beacon serves as a marker indicating that pilots must be aware of the potential for lower than optimal weather conditions which could affect their ability to navigate safely.

Other options do not accurately convey the primary function of the rotating beacon. For instance, it doesn’t indicate favorable weather, an ongoing emergency, or the arrival of a flight but specifically highlights when the airport is operational under conditions that necessitate additional awareness.