What is the grade range for a runway shoulder cross section?

The correct grade range for a runway shoulder cross section is 1.5% to 5%. This range is established to ensure proper drainage and stability of the runway shoulder. A shoulder serving as a transition area between the runway and the adjacent terrain must be graded to facilitate the flow of water away from the runway surface, preventing pooling and potential erosion.

Grades within this range strike a balance between effective runoff management and safety, providing a stable area for aircraft in case of an emergency and for maintenance activities. Shoulders that are too flat (below 1.5%) may not facilitate proper drainage, while excessively steep shoulders (above 5%) could pose risks for aircraft operations on the runway edge, including difficulties in maneuvering.