What is meant by runway available?

Runway available refers specifically to the usable length of the runway that is cleared and prepared for safe takeoff and landing operations. This measurement is important because it informs the pilots about the maximum distance they can safely operate within, ensuring they have enough runway to achieve the necessary speed for takeoff or to stop after landing safely.

The usability of the runway is critical when pilots calculate takeoff weight, required takeoff distance, and landing distance, taking into account factors such as aircraft performance and environmental conditions. The available length does not include overruns, which are additional sections beyond the designated runway that may not be suitable for regular operations, and thus helps pilots make informed decisions about their performance during critical phases of flight.