Which condition classifies a runway as contaminated?

Which condition classifies a runway as contaminated?

• A. A runway with more than 25% of the surface area covered by frost, ice, snow, slush, or water
• B. A runway with any depth of snow
• C. A runway with frost only
• D. A dry runway

Answer: (A)

Runway contamination is determined by how much of the usable surface is affected by moisture or frozen material, not by depth alone. If more than 25% of the surface area is covered by frost, ice, snow, slush, or standing water, the runway is considered contaminated because this level of coverage degrades friction and makes braking and handling more uncertain during takeoff and landing. This threshold guides performance planning and braking-action assessments. If coverage is less than 25%, it isn’t classified as contaminated, though it can still affect performance (e.g., wet or frosted conditions). A dry runway has no contamination.

Runway contamination is determined by how much of the usable surface is affected by moisture or frozen material, not by depth alone. If more than 25% of the surface area is covered by frost, ice, snow, slush, or standing water, the runway is considered contaminated because this level of coverage degrades friction and makes braking and handling more uncertain during takeoff and landing. This threshold guides performance planning and braking-action assessments. If coverage is less than 25%, it isn’t classified as contaminated, though it can still affect performance (e.g., wet or frosted conditions). A dry runway has no contamination.