What type of lighting does HIRL refer to?

HIRL stands for High Intensity Runway Lighting, which is a specific type of lighting system designed to enhance runway visibility during low visibility conditions. This lighting system utilizes high-intensity lights along the runway to ensure pilots can clearly see the runway's boundaries and centerline, especially during critical phases of approach and landing.

Using high intensity lighting is essential for the safety of operations in adverse weather conditions, as it significantly improves the visual cues necessary for pilots to align and maintain a proper approach path. This kind of lighting is particularly important for airports that may experience frequent fog or heavy precipitation, where visibility can be severely compromised.

The other options describe different types of lighting that may exist but are not recognized as standard definitions in aviation terminology. Hence, understanding the function and purpose of HIRL is crucial for aviation dispatchers and contributes to safe flight operations.