The transitional surface extends upward at which slope ratio?

• A. 7:1
• B. 5:1
• C. 10:1
• D. 4:1

Answer: (A)

The transitional surface is designed to provide obstacle clearance for aircraft on approach and departure by rising away from the runway end at a fixed slope. The standard slope used for this surface is seven units of horizontal distance for every one unit of vertical rise. This means as you move outward from the runway end, the surface height increases gradually, creating a protective buffer around the approach and departure paths. A smaller ratio like five to one or four to one would rise more steeply, tightening the protected area, while a larger ratio like ten to one would rise more slowly and could reduce protective effectiveness. Therefore, seven to one is the correct slope.