What is the purpose of slats in high-lift devices?

The purpose of slats in high-lift devices is primarily to increase the area and curvature of the wing. When deployed, slats extend from the leading edge of the wing, effectively changing the wing's profile. This alteration allows for a higher maximum lift coefficient, which is particularly useful during low-speed operations such as takeoff and landing. By improving airflow over the wing at higher angles of attack, slats help delay airflow separation, allowing the aircraft to maintain lift even when the wing is at a greater angle relative to the oncoming air. This feature is essential for ensuring safe operation of the aircraft at slower speeds and during critical phases of flight when maximizing lift is crucial.

The other choices, while related to the performance characteristics of an aircraft, do not accurately capture the fundamental role of slats in enhancing wing lift. Slats are not specifically intended to reduce weight or improve maneuverability during descent; their main function is to optimize aerodynamic performance by improving airflow and increasing lift capability.