The intensity steps chart for HIRL, RCLL, and TDZL applies to which lighting system?

• A. Approach Lighting System
• B. Visual Glideslope Indicator
• C. Taxiway Edge Lights
• D. Runway Centerline Lighting, Touchdown Zone Lighting, and High Intensity Runway Lights

Answer: (D)

The brightness steps chart is used to standardize how runway lighting is adjusted to provide consistent cues during landing. HIRL, RCLL, and TDZL are all part of the runway lighting system, and their brightness levels are controlled together so pilots can reliably interpret the runway environment under different visibility and lighting conditions. The approach lighting system has its own controls and charts, VASI is just an indicator and not part of this brightness scale, and taxiway edge lights use a different lighting scale. So the system described by this chart is Runway Centerline Lighting, Touchdown Zone Lighting, and High Intensity Runway Lights.