Before which action must the runway be free of all vehicles, equipment, and personnel?

• A. An arriving aircraft crosses the runway threshold
• B. The departing aircraft begins takeoff
• C. The runway is declared safe by the supervisor
• D. The tower passes frequency to the other controller

Answer: (A)

The event being tested is runway safety during an arriving operation. Before an arriving aircraft crosses the runway threshold, the runway must be free of all vehicles, equipment, and personnel to prevent any ground traffic from obstructing or colliding with the landing aircraft. This clearance ensures a clear, unobstructed path for the airplane as it touches down and moves onto the runway.

The other actions aren’t the precise moment for this specific clearance: departing aircraft begin takeoff flow with their own clearance needs, but the rule cited here focuses on the risk when an arriving aircraft is about to cross the threshold. A supervisor declaring the runway safe and a frequency handoff are administrative steps, not the moment-by-moment physical clearance of the runway.