What does a steady red light on the ground signify?

A steady red light on the ground signifies that pilots must stop their aircraft. This signal is crucial for maintaining safety on the airport surface, particularly near runways and taxiways. The red light alerts pilots to a condition that is not safe to proceed, ensuring they remain vigilant and avoid potential collisions with other aircraft or ground vehicles.

In air traffic control contexts, a steady red indicates that the pilot should halt immediately, as this may signify an impending danger or that the area ahead is not clear for takeoff or landing. Understanding this signal is essential for pilots to navigate safely in busy aerodrome environments, making it a fundamental part of pre-solo knowledge.