What does a flashing red light signal from ATC indicate while on the ground?

A flashing red light signal from Air Traffic Control (ATC) while on the ground indicates that an aircraft should use extreme caution. This signal typically warns pilots about a situation that could require alertness, such as the presence of another aircraft nearby, potential obstructions, or other safety concerns.

Understanding this signal is crucial because it directs pilots to ensure they are vigilant and prepared to react appropriately to any developments that may affect their safety or the safety of others on the ground. It emphasizes the need for heightened awareness, as conditions may change rapidly, and pilots must be prepared to respond accordingly.