What does runway slope indicate?

Runway slope refers to the degree of deviation from a level horizontal plane. This measurement indicates how much the runway tilts either upward or downward along its length. A runway that has a positive slope inclines upward from the threshold to the end, while a negative slope declines. Understanding the slope of a runway is crucial for pilots, as it affects the aircraft's performance during takeoff and landing. A steeper slope can influence the required takeoff distance, landing distance, and overall aircraft handling.

While the other options mention various runway characteristics, none of them accurately define what runway slope specifically refers to. The material used for the runway relates to its construction quality and surface type, rather than its angle. The length of the runway associated with its grade does not address the slope itself as a defining factor. The angle of ascent for takeoff is relevant to aircraft performance but is not equivalent to the measurement of the runway slope. Thus, recognizing that the slope is best described as the deviation from a level horizontal plane is essential for understanding its implications in aviation.