When using the approach light system, descent below 100 feet above the touchdown zone elevation is allowed only if which bars are visible?

• A. Red terminating bars or red side row bars must be distinctly visible
• B. The runway threshold lights alone
• C. No red bars are required
• D. The white runway edge lights only

Answer: (A)

When using the approach lighting system, you’re allowed to descend below 100 feet above the touchdown zone elevation only when you have a definite visual cue that you’re at the final segment of the approach: red terminating bars or red side row bars must be distinctly visible. These red bars mark the end of the lighting sequence and provide the last-needed reference to confirm you’re aligned with the runway and in a position to continue the descent visually. Other lights, like threshold lights or white runway edge lights alone, don’t provide that definitive cue, so they don’t authorize dropping below 100 feet AGL.