When approaching to land on a runway served by a visual approach slope indicator (VASI) the pilot shall

• A. maintain an altitude at or above the glide slope
• B. descend below the glide slope
• C. ignore glide slope
• D. ascend above glide slope

Answer: (A)

Visual glide slope indicators provide a vertical guide to the runway, so the aim on final is to follow that path for a stabilized descent. You should stay on or above the glide slope as you approach, using it to descend to the proper path and maintain obstacle clearance. Descending below the glide slope too soon can put you lower than intended and risk obstacles or an unstable approach, while ignoring the glide slope or climbing above it won’t give you the correct vertical guidance. Therefore, maintaining an altitude at or above the glide slope ensures you remain on the intended descent path and are prepared to meet the runway safely.