How should obstructions such as buildings be marked?

Obstructions such as buildings should be marked with red lights to ensure visibility, particularly at night or in poor weather conditions. Red lights are commonly used for marking hazards in aviation because they are highly visible and easily distinguishable from other light sources. This color is recognized in aviation safety regulations and guidelines, serving as an important warning signal to pilots and ground personnel.

Using red lights helps minimize the risk of accidents by alerting aircraft to the presence of obstructions during takeoff, landing, or while maneuvering in the vicinity of the airport. The use of proper signage and lighting is a critical aspect of maintaining safety standards in airport environments, helping to guide pilots safely in their operations.

Alternative choices, such as flashing lights only or no special markings, would not provide the consistent visibility needed to alert aircraft to the presence of obstructions. White lights are sometimes used for other applications, but red lights are specifically designated for marking obstructions to enhance safety in aviation operations.