What is the primary function of wing fences on an aircraft?

The primary function of wing fences on an aircraft is to prevent airflow from washing out at high angles of attack. Wing fences are vertical surfaces mounted on the wings to improve the airflow characteristics around the wing. At higher angles of attack, airflow can separate from the wing surface, leading to a loss of lift and increased drag, which can result in a stall. Wing fences work by directing the airflow toward the wing and delaying the onset of stall by maintaining attached airflow over the wing surfaces for as long as possible. This design enhances the stall characteristics of the aircraft, allowing for better control and performance when flying at or near critical angles of attack.

While enhancing aerodynamic stability is one benefit of wing fences, their specific role is more focused on airflow management during high angle scenarios. Similarly, while some might consider fuel efficiency or takeoff and landing performance could be impacted by various design features, wing fences do not primarily serve those functions. Their main purpose is clearly aligned with airflow management and stall prevention rather than the broader operational phases such as cruising, takeoff, or landing.