Contaminated Runway criteria example: 25% area with standing water 1/8" qualifies as contaminated.

• A. 25% area with standing water 1/8"
• B. 10% area with standing water 1/8"
• C. 50% area with ice
• D. 25% area with dry pavement

Answer: (A)

Contaminated runway criteria are about how much of the surface is affected and how deep the contamination is. The standard here says that if standing water covers a quarter of the runway and is about 1/8 of an inch deep, that meets the contamination threshold. That level of water across that portion of the surface can significantly reduce braking and increase hydroplaning risk, so it’s treated as contaminated.

That’s why the scenario describing 25% of the runway with standing water at 1/8 inch depth is the best match. A smaller area of standing water, like 10%, doesn’t reach the 25% threshold, so it wouldn’t meet the contamination criterion shown. A surface covered by ice, even at 50% area, would be a contamination condition as well in general, but the example given focuses on standing water at a specific depth, so this wording doesn’t align with the stated criterion. Dry pavement shows no contamination.