Do not authorize an aircraft to line up and wait at an intersection ___.

• A. between sunrise and sunset
• B. at noon
• C. between sunset and sunrise
• D. at any time when the runway is clear

Answer: (C)

Line up and wait on a runway intersection creates a temporary but real runway occupancy while a pilot awaits takeoff clearance. At night, visibility is reduced, depth perception is poorer, and lighting cues can be harder to interpret. That combination raises the risk of a misread clearance, a runway incursion, or an encounter with other traffic that a pilot or controller might not clearly detect. Because of these safety concerns, authorizing this maneuver after dark is not allowed.

During daylight hours, attitudes and procedures can differ, and line up and wait may be permitted in appropriate situations with clear instructions and adequate runway length for immediate takeoff if needed. The other options imply daylight or blanket permissions, which do not reflect the nighttime restriction.