Except where a runway use program is in effect, use the "calm wind" runway when ________.

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

Answer: (C)

The main idea is choosing a runway designated as calm wind when the wind is light enough that its direction doesn’t meaningfully affect takeoffs and landings. In this item, the threshold is less than five knots, so if the observed wind is under five knots, you use the calm wind runway unless a runway use program dictates a specific runway for other reasons. The point is to simplify operations when wind loss of directionality is negligible.

If the wind were 5 knots or more, you’d normally base the runway choice on wind direction (and any applicable program), rather than declaring a calm wind runway. The other options either set a different little threshold or include five knots, which this question treats as not qualifying for calm wind in this context.