The Approach Light System (ALS) Is Operated During Daylight Hours When Which Condition Is Met?

• A. Prevailing Visibility Is 5 Miles Or Less And/Or Ceiling Is Below 1,000 Feet
• B. Prevailing Visibility Is Greater Than 7 Miles
• C. No Condition
• D. Always On

Answer: (A)

Approach lighting is used to give pilots stronger visual cues to locate and align with the runway, especially when visibility is compromised. In daylight hours, this system is activated when the weather reduces visibility to 5 miles or less or when the ceiling drops below 1,000 feet. In such conditions, the extra lighting helps the pilot discern the approach path and runway environment despite the reduced visibility. If visibility is better than that (and ceilings are higher than 1,000 feet), there’s no need to use the ALS, so it isn’t required to be on. The option describing higher visibility or keeping the lights on all the time doesn’t reflect typical operational rules for ALS usage.