Which of the following items must be checked before entering an active runway?

The necessity to check for runway crossing clearance before entering an active runway is critical for maintaining safety in aviation operations. This requirement ensures that pilots confirm they have received proper authorization to use the runway for takeoff or landing. The purpose of this verification is to prevent collisions with other aircraft that may be operating on or near the runway, as well as to comply with air traffic control instructions.

Ensuring runway crossing clearance is a fundamental part of runway incursion prevention measures. By confirming that they have the appropriate clearance, pilots help maintain situational awareness and adherence to traffic management procedures established by the controlling authority. This is essential for safe operations in the congested environment of an airport.

In contrast, while other factors like weather conditions, fuel levels, and flight time are important aspects to consider during flight preparation and overall safety, they are not specific prerequisites for entering an active runway. Weather might affect flight operations, fuel levels are critical for overall flight safety, and flight time is important for planning, but they do not directly relate to the clearance needed specifically to enter an active runway.