During which phase of flight must solo pilots ensure they land on a clear runway?

The correct choice emphasizes the importance of ensuring that the runway is clear specifically during the landing phase of flight. This phase is critical for safety, as landing requires precise control and situational awareness. Pilots must confirm that the runway is free of obstacles, other aircraft, and any potential hazards before initiating their landing approach.

While it is also necessary to be aware of the runway conditions during takeoff, taxiing, and pre-flight checks, the landing phase is uniquely susceptible to complications resulting from distractions or unexpected obstacles, making it vital for pilots to thoroughly verify the area before touching down.

This diligent focus during landings significantly enhances safety and reduces the risk of accidents, thereby affirming the priority of a clear runway in this phase of flight.