The ALS intensity settings are operated at Setting 2 during the day when the visibility is ______.

• A. 5 Up To But Not Including 7 Miles
• B. 3 Up To But Not Including 5 Miles
• C. 1 Up To But Not Including 3 Miles
• D. Less Than 1 Mile

Answer: (A)

Approach lighting brightness in daylight is tuned to current visibility so pilots can see the lights without glare, using enough intensity to be helpful but not excessive. When visibility is in the range of about five miles up to, but not including, seven miles, Setting 2 provides the right balance: it’s bright enough to stand out in daylight and give clear cues, but not so bright as to overwhelm the scene. If visibility were better than seven miles, a lower intensity would usually be sufficient; if visibility dropped below five miles, a higher setting would be needed to keep the lights visible. That’s why the daytime visibility range that uses Setting 2 is five up to but not including seven miles.