How does the holding speed change for different altitudes in airspace?

The holding speed increases with altitude due to the design and operational requirements of airspace management. As altitude increases, the general rule of thumb is that the holding speed needs to accommodate the increased aircraft performance and the need for larger separations in vertical space. Specifically, for aircraft in holding patterns, the maximum holding speeds are defined according to altitude to ensure safe operations.

For instance, the FAA specifies that holding speeds should be set higher at higher altitudes to enhance efficiency and to account for the fact that at lower altitudes, aircraft are often slower due to various constraints such as air traffic and performance limits. Therefore, the regulation specifies a range of speeds that correspond to different altitude bands, which results in an increase in holding speeds as altitude rises.

This pattern is standardized to allow for predictable and safe spacing of aircraft in holding patterns, which is crucial during busy operations in airspace where many aircraft may be maneuvering in a limited area.