definition
strict definition
aircraft warning lights
Small lights at the top or corners of a structure which increase its visibility to pilots.
Aircraft warning lights are small lights placed at the top, setbacks, corners, or other prominent points of a structure in order to make it highly visible from aircraft in the vicinity. They are most often red or white, and are usually set to blink every 1-3 seconds. They are generally turned on at twilight or in foggy weather.
The lights mark prominent parts of the structure for pilots. They can be on setbacks or corners as well as at the highest point.
The defining purpose is visibility to nearby aircraft. The usual colors and operating patterns described above do not impose one universal light arrangement.
