Why are outboard ailerons used primarily for slow-flight speeds in some airplanes?

Outboard ailerons are used primarily for slow-flight speeds because they can improve aircraft performance by managing aerodynamic characteristics effectively. When deployed, outboard ailerons can help control roll authority at lower speeds where the effectiveness of control surfaces decreases due to reduced airflow over the wings.

Using outboard ailerons allows for better distribution of aerodynamic loads across the wings, which is crucial during slow-speed operations. At high speeds, however, these ailerons can be subject to significant aerodynamic forces that may cause twisting at the wingtips. This is particularly important for maintaining structural integrity and preventing adverse aerodynamic effects such as aileron reversal or loss of control, which can occur if the wingtips are distorted.

In contrast, while increasing lift at low speeds and managing drag are relevant considerations, they do not directly explain the primary reason for the use of outboard ailerons in those specific flight conditions. Similarly, while turbulence management is an important aspect of flight operation, it is not the main focus of using outboard ailerons at slow speeds. Thus, the primary need for using outboard ailerons revolves around their role in maintaining control and structural integrity at varying flight speeds.