If there is no runway use program in effect, which wind condition indicates the calm wind runway should be used?

• A. less than 3 KT
• B. 3 KT or less
• C. less than 5 KT
• D. 5 KT or less

Answer: (C)

When winds are effectively negligible, you can use a calm wind runway, meaning no single runway is required to be aligned with a wind direction. In this scenario, the threshold for calling a runway “calm wind” is a wind speed under 5 knots. So if the wind is less than 5 knots, you designate the calm wind runway and operate without a wind-direction preference. Winds at 5 knots or more aren’t considered calm, so you’d switch to using the runway that best corresponds to the actual wind. The other thresholds (like 3 knots or 3 knots or less, or 5 knots or less) don’t match this standard definition, which is why less than 5 knots is the best choice.